Age Owner Branch data TLA Line data Source code
1 : : /*-------------------------------------------------------------------------
2 : : *
3 : : * prepjointree.c
4 : : * Planner preprocessing for subqueries and join tree manipulation.
5 : : *
6 : : * NOTE: the intended sequence for invoking these operations is
7 : : * preprocess_relation_rtes
8 : : * replace_empty_jointree
9 : : * pull_up_sublinks
10 : : * preprocess_function_rtes
11 : : * pull_up_subqueries
12 : : * flatten_simple_union_all
13 : : * do expression preprocessing (including flattening JOIN alias vars)
14 : : * reduce_outer_joins
15 : : * remove_useless_result_rtes
16 : : *
17 : : *
18 : : * Portions Copyright (c) 1996-2026, PostgreSQL Global Development Group
19 : : * Portions Copyright (c) 1994, Regents of the University of California
20 : : *
21 : : *
22 : : * IDENTIFICATION
23 : : * src/backend/optimizer/prep/prepjointree.c
24 : : *
25 : : *-------------------------------------------------------------------------
26 : : */
27 : : #include "postgres.h"
28 : :
29 : : #include "access/table.h"
30 : : #include "catalog/pg_type.h"
31 : : #include "funcapi.h"
32 : : #include "miscadmin.h"
33 : : #include "nodes/makefuncs.h"
34 : : #include "nodes/multibitmapset.h"
35 : : #include "nodes/nodeFuncs.h"
36 : : #include "optimizer/clauses.h"
37 : : #include "optimizer/optimizer.h"
38 : : #include "optimizer/placeholder.h"
39 : : #include "optimizer/plancat.h"
40 : : #include "optimizer/prep.h"
41 : : #include "optimizer/subselect.h"
42 : : #include "optimizer/tlist.h"
43 : : #include "parser/parse_relation.h"
44 : : #include "parser/parsetree.h"
45 : : #include "rewrite/rewriteHandler.h"
46 : : #include "rewrite/rewriteManip.h"
47 : : #include "utils/rel.h"
48 : :
49 : :
50 : : typedef struct nullingrel_info
51 : : {
52 : : /*
53 : : * For each leaf RTE, nullingrels[rti] is the set of relids of outer joins
54 : : * that potentially null that RTE.
55 : : */
56 : : Relids *nullingrels;
57 : : /* Length of range table (maximum index in nullingrels[]) */
58 : : int rtlength; /* used only for assertion checks */
59 : : } nullingrel_info;
60 : :
61 : : /* Options for wrapping an expression for identification purposes */
62 : : typedef enum ReplaceWrapOption
63 : : {
64 : : REPLACE_WRAP_NONE, /* no expressions need to be wrapped */
65 : : REPLACE_WRAP_ALL, /* all expressions need to be wrapped */
66 : : REPLACE_WRAP_VARFREE, /* variable-free expressions need to be
67 : : * wrapped */
68 : : } ReplaceWrapOption;
69 : :
70 : : typedef struct pullup_replace_vars_context
71 : : {
72 : : PlannerInfo *root;
73 : : List *targetlist; /* tlist of subquery being pulled up */
74 : : RangeTblEntry *target_rte; /* RTE of subquery */
75 : : int result_relation; /* the index of the result relation in the
76 : : * rewritten query */
77 : : Relids relids; /* relids within subquery, as numbered after
78 : : * pullup (set only if target_rte->lateral) */
79 : : nullingrel_info *nullinfo; /* per-RTE nullingrel info (set only if
80 : : * target_rte->lateral) */
81 : : bool *outer_hasSubLinks; /* -> outer query's hasSubLinks */
82 : : int varno; /* varno of subquery */
83 : : ReplaceWrapOption wrap_option; /* do we need certain outputs to be PHVs? */
84 : : Node **rv_cache; /* cache for results with PHVs */
85 : : } pullup_replace_vars_context;
86 : :
87 : : typedef struct reduce_outer_joins_pass1_state
88 : : {
89 : : Relids relids; /* base relids within this subtree */
90 : : bool contains_outer; /* does subtree contain outer join(s)? */
91 : : Relids nullable_rels; /* base relids that are nullable within this
92 : : * subtree */
93 : : Node *jtnode; /* the jointree node this state describes */
94 : : List *sub_states; /* List of states for subtree components */
95 : : } reduce_outer_joins_pass1_state;
96 : :
97 : : typedef struct reduce_outer_joins_pass2_state
98 : : {
99 : : Relids inner_reduced; /* OJ relids reduced to plain inner joins */
100 : : List *partial_reduced; /* List of partially reduced FULL joins */
101 : : } reduce_outer_joins_pass2_state;
102 : :
103 : : typedef struct reduce_outer_joins_partial_state
104 : : {
105 : : int full_join_rti; /* RT index of a formerly-FULL join */
106 : : Relids unreduced_side; /* relids in its still-nullable side */
107 : : } reduce_outer_joins_partial_state;
108 : :
109 : : static Query *expand_virtual_generated_columns(PlannerInfo *root, Query *parse,
110 : : RangeTblEntry *rte, int rt_index,
111 : : Relation relation);
112 : : static Node *pull_up_sublinks_jointree_recurse(PlannerInfo *root, Node *jtnode,
113 : : Relids *relids);
114 : : static Node *pull_up_sublinks_qual_recurse(PlannerInfo *root, Node *node,
115 : : Node **jtlink1, Relids available_rels1,
116 : : Node **jtlink2, Relids available_rels2);
117 : : static Node *pull_up_subqueries_recurse(PlannerInfo *root, Node *jtnode,
118 : : JoinExpr *lowest_outer_join,
119 : : AppendRelInfo *containing_appendrel);
120 : : static Node *pull_up_simple_subquery(PlannerInfo *root, Node *jtnode,
121 : : RangeTblEntry *rte,
122 : : JoinExpr *lowest_outer_join,
123 : : AppendRelInfo *containing_appendrel);
124 : : static Node *pull_up_simple_union_all(PlannerInfo *root, Node *jtnode,
125 : : RangeTblEntry *rte);
126 : : static void pull_up_union_leaf_queries(Node *setOp, PlannerInfo *root,
127 : : int parentRTindex, Query *setOpQuery,
128 : : int childRToffset);
129 : : static void make_setop_translation_list(Query *query, int newvarno,
130 : : AppendRelInfo *appinfo);
131 : : static bool is_simple_subquery(PlannerInfo *root, Query *subquery,
132 : : RangeTblEntry *rte,
133 : : JoinExpr *lowest_outer_join);
134 : : static Node *pull_up_simple_values(PlannerInfo *root, Node *jtnode,
135 : : RangeTblEntry *rte);
136 : : static bool is_simple_values(PlannerInfo *root, RangeTblEntry *rte);
137 : : static Node *pull_up_constant_function(PlannerInfo *root, Node *jtnode,
138 : : RangeTblEntry *rte,
139 : : AppendRelInfo *containing_appendrel);
140 : : static bool is_simple_union_all(Query *subquery);
141 : : static bool is_simple_union_all_recurse(Node *setOp, Query *setOpQuery,
142 : : List *colTypes);
143 : : static bool is_safe_append_member(Query *subquery);
144 : : static bool jointree_contains_lateral_outer_refs(PlannerInfo *root,
145 : : Node *jtnode, bool restricted,
146 : : Relids safe_upper_varnos);
147 : : static void perform_pullup_replace_vars(PlannerInfo *root,
148 : : pullup_replace_vars_context *rvcontext,
149 : : AppendRelInfo *containing_appendrel);
150 : : static void replace_vars_in_jointree(Node *jtnode,
151 : : pullup_replace_vars_context *context);
152 : : static Node *pullup_replace_vars(Node *expr,
153 : : pullup_replace_vars_context *context);
154 : : static Node *pullup_replace_vars_callback(const Var *var,
155 : : replace_rte_variables_context *context);
156 : : static Query *pullup_replace_vars_subquery(Query *query,
157 : : pullup_replace_vars_context *context);
158 : : static reduce_outer_joins_pass1_state *reduce_outer_joins_pass1(Node *jtnode);
159 : : static void reduce_outer_joins_pass2(Node *jtnode,
160 : : reduce_outer_joins_pass1_state *state1,
161 : : reduce_outer_joins_pass2_state *state2,
162 : : PlannerInfo *root,
163 : : Relids nonnullable_rels,
164 : : List *forced_null_vars);
165 : : static void report_reduced_full_join(reduce_outer_joins_pass2_state *state2,
166 : : int rtindex, Relids relids);
167 : : static bool forced_null_var_is_attnotnull(PlannerInfo *root,
168 : : List *forced_null_vars,
169 : : reduce_outer_joins_pass1_state *state);
170 : : static bool forced_null_var_is_nonnullable(PlannerInfo *root,
171 : : List *forced_null_vars,
172 : : reduce_outer_joins_pass1_state *state,
173 : : List *extra_quals);
174 : : static Node *remove_useless_results_recurse(PlannerInfo *root, Node *jtnode,
175 : : Relids baserels,
176 : : Node **parent_quals,
177 : : Relids *dropped_outer_joins);
178 : : static int get_result_relid(PlannerInfo *root, Node *jtnode);
179 : : static void remove_result_refs(PlannerInfo *root, int varno, Node *newjtloc);
180 : : static bool find_dependent_phvs(PlannerInfo *root, int varno, Relids baserels);
181 : : static bool find_dependent_phvs_in_jointree(PlannerInfo *root,
182 : : Node *node, int varno,
183 : : Relids baserels);
184 : : static void substitute_phv_relids(Node *node,
185 : : int varno, Relids subrelids);
186 : : static void fix_append_rel_relids(PlannerInfo *root, int varno,
187 : : Relids subrelids);
188 : : static Node *find_jointree_node_for_rel(Node *jtnode, int relid);
189 : : static nullingrel_info *get_nullingrels(Query *parse);
190 : : static void get_nullingrels_recurse(Node *jtnode, Relids upper_nullingrels,
191 : : nullingrel_info *info);
192 : :
193 : :
194 : : /*
195 : : * transform_MERGE_to_join
196 : : * Replace a MERGE's jointree to also include the target relation.
197 : : */
198 : : void
1613 alvherre@alvh.no-ip. 199 :CBC 392767 : transform_MERGE_to_join(Query *parse)
200 : : {
201 : : RangeTblEntry *joinrte;
202 : : JoinExpr *joinexpr;
203 : : bool have_action[NUM_MERGE_MATCH_KINDS];
204 : : JoinType jointype;
205 : : int joinrti;
206 : : List *vars;
207 : : RangeTblRef *rtr;
208 : : FromExpr *target;
209 : : Node *source;
210 : : int sourcerti;
211 : :
212 [ + + ]: 392767 : if (parse->commandType != CMD_MERGE)
213 : 391203 : return;
214 : :
215 : : /* XXX probably bogus */
216 : 1564 : vars = NIL;
217 : :
218 : : /*
219 : : * Work out what kind of join is required. If there any WHEN NOT MATCHED
220 : : * BY SOURCE/TARGET actions, an outer join is required so that we process
221 : : * all unmatched tuples from the source and/or target relations.
222 : : * Otherwise, we can use an inner join.
223 : : */
880 dean.a.rasheed@gmail 224 : 1564 : have_action[MERGE_WHEN_MATCHED] = false;
225 : 1564 : have_action[MERGE_WHEN_NOT_MATCHED_BY_SOURCE] = false;
226 : 1564 : have_action[MERGE_WHEN_NOT_MATCHED_BY_TARGET] = false;
227 : :
228 [ + - + + : 5496 : foreach_node(MergeAction, action, parse->mergeActionList)
+ + ]
229 : : {
230 [ + + ]: 2368 : if (action->commandType != CMD_NOTHING)
231 : 2300 : have_action[action->matchKind] = true;
232 : : }
233 : :
234 [ + + ]: 1564 : if (have_action[MERGE_WHEN_NOT_MATCHED_BY_SOURCE] &&
235 [ + + ]: 105 : have_action[MERGE_WHEN_NOT_MATCHED_BY_TARGET])
236 : 80 : jointype = JOIN_FULL;
237 [ + + ]: 1484 : else if (have_action[MERGE_WHEN_NOT_MATCHED_BY_SOURCE])
238 : 25 : jointype = JOIN_LEFT;
239 [ + + ]: 1459 : else if (have_action[MERGE_WHEN_NOT_MATCHED_BY_TARGET])
1613 alvherre@alvh.no-ip. 240 : 674 : jointype = JOIN_RIGHT;
241 : : else
242 : 785 : jointype = JOIN_INNER;
243 : :
244 : : /* Manufacture a join RTE to use. */
245 : 1564 : joinrte = makeNode(RangeTblEntry);
246 : 1564 : joinrte->rtekind = RTE_JOIN;
247 : 1564 : joinrte->jointype = jointype;
248 : 1564 : joinrte->joinmergedcols = 0;
249 : 1564 : joinrte->joinaliasvars = vars;
250 : 1564 : joinrte->joinleftcols = NIL; /* MERGE does not allow JOIN USING */
251 : 1564 : joinrte->joinrightcols = NIL; /* ditto */
252 : 1564 : joinrte->join_using_alias = NULL;
253 : :
254 : 1564 : joinrte->alias = NULL;
255 : 1564 : joinrte->eref = makeAlias("*MERGE*", NIL);
256 : 1564 : joinrte->lateral = false;
257 : 1564 : joinrte->inh = false;
258 : 1564 : joinrte->inFromCl = true;
259 : :
260 : : /*
261 : : * Add completed RTE to pstate's range table list, so that we know its
262 : : * index.
263 : : */
264 : 1564 : parse->rtable = lappend(parse->rtable, joinrte);
265 : 1564 : joinrti = list_length(parse->rtable);
266 : :
267 : : /*
268 : : * Create a JOIN between the target and the source relation.
269 : : *
270 : : * Here the target is identified by parse->mergeTargetRelation. For a
271 : : * regular table, this will equal parse->resultRelation, but for a
272 : : * trigger-updatable view, it will be the expanded view subquery that we
273 : : * need to pull data from.
274 : : *
275 : : * The source relation is in parse->jointree->fromlist, but any quals in
276 : : * parse->jointree->quals are restrictions on the target relation (if the
277 : : * target relation is an auto-updatable view).
278 : : */
279 : : /* target rel, with any quals */
880 dean.a.rasheed@gmail 280 : 1564 : rtr = makeNode(RangeTblRef);
281 : 1564 : rtr->rtindex = parse->mergeTargetRelation;
693 282 : 1564 : target = makeFromExpr(list_make1(rtr), parse->jointree->quals);
283 : :
284 : : /* source rel (expect exactly one -- see transformMergeStmt()) */
285 [ - + ]: 1564 : Assert(list_length(parse->jointree->fromlist) == 1);
286 : 1564 : source = linitial(parse->jointree->fromlist);
287 : :
288 : : /*
289 : : * index of source rel (expect either a RangeTblRef or a JoinExpr -- see
290 : : * transformFromClauseItem()).
291 : : */
292 [ + + ]: 1564 : if (IsA(source, RangeTblRef))
293 : 1494 : sourcerti = ((RangeTblRef *) source)->rtindex;
294 [ + - ]: 70 : else if (IsA(source, JoinExpr))
295 : 70 : sourcerti = ((JoinExpr *) source)->rtindex;
296 : : else
297 : : {
693 dean.a.rasheed@gmail 298 [ # # ]:UBC 0 : elog(ERROR, "unrecognized source node type: %d",
299 : : (int) nodeTag(source));
300 : : sourcerti = 0; /* keep compiler quiet */
301 : : }
302 : :
303 : : /* Join the source and target */
1613 alvherre@alvh.no-ip. 304 :CBC 1564 : joinexpr = makeNode(JoinExpr);
305 : 1564 : joinexpr->jointype = jointype;
306 : 1564 : joinexpr->isNatural = false;
693 dean.a.rasheed@gmail 307 : 1564 : joinexpr->larg = (Node *) target;
308 : 1564 : joinexpr->rarg = source;
1613 alvherre@alvh.no-ip. 309 : 1564 : joinexpr->usingClause = NIL;
310 : 1564 : joinexpr->join_using_alias = NULL;
880 dean.a.rasheed@gmail 311 : 1564 : joinexpr->quals = parse->mergeJoinCondition;
1613 alvherre@alvh.no-ip. 312 : 1564 : joinexpr->alias = NULL;
313 : 1564 : joinexpr->rtindex = joinrti;
314 : :
315 : : /* Make the new join be the sole entry in the query's jointree */
316 : 1564 : parse->jointree->fromlist = list_make1(joinexpr);
317 : 1564 : parse->jointree->quals = NULL;
318 : :
319 : : /*
320 : : * If necessary, mark parse->targetlist entries that refer to the target
321 : : * as nullable by the join. Normally the targetlist will be empty for a
322 : : * MERGE, but if the target is a trigger-updatable view, it will contain a
323 : : * whole-row Var referring to the expanded view query.
324 : : */
910 dean.a.rasheed@gmail 325 [ + + + + ]: 1564 : if (parse->targetList != NIL &&
326 [ + + ]: 35 : (jointype == JOIN_RIGHT || jointype == JOIN_FULL))
327 : 35 : parse->targetList = (List *)
328 : 35 : add_nulling_relids((Node *) parse->targetList,
329 : 35 : bms_make_singleton(parse->mergeTargetRelation),
330 : 35 : bms_make_singleton(joinrti));
331 : :
332 : : /*
333 : : * If the source relation is on the outer side of the join, mark any
334 : : * source relation Vars in the join condition, actions, and RETURNING list
335 : : * as nullable by the join. These Vars will be added to the targetlist by
336 : : * preprocess_targetlist(), so it's important to mark them correctly here.
337 : : *
338 : : * It might seem that this is not necessary for Vars in the join
339 : : * condition, since it is inside the join, but it is also needed above the
340 : : * join (in the ModifyTable node) to distinguish between the MATCHED and
341 : : * NOT MATCHED BY SOURCE cases -- see ExecMergeMatched(). Note that this
342 : : * creates a modified copy of the join condition, for use above the join,
343 : : * without modifying the original join condition, inside the join.
344 : : */
693 345 [ + + + + ]: 1564 : if (jointype == JOIN_LEFT || jointype == JOIN_FULL)
346 : : {
347 : 105 : parse->mergeJoinCondition =
348 : 105 : add_nulling_relids(parse->mergeJoinCondition,
349 : 105 : bms_make_singleton(sourcerti),
350 : 105 : bms_make_singleton(joinrti));
351 : :
352 [ + - + + : 500 : foreach_node(MergeAction, action, parse->mergeActionList)
+ + ]
353 : : {
354 : 290 : action->qual =
355 : 290 : add_nulling_relids(action->qual,
356 : 290 : bms_make_singleton(sourcerti),
357 : 290 : bms_make_singleton(joinrti));
358 : :
359 : 290 : action->targetList = (List *)
360 : 290 : add_nulling_relids((Node *) action->targetList,
361 : 290 : bms_make_singleton(sourcerti),
362 : 290 : bms_make_singleton(joinrti));
363 : : }
364 : :
365 : 105 : parse->returningList = (List *)
366 : 105 : add_nulling_relids((Node *) parse->returningList,
367 : 105 : bms_make_singleton(sourcerti),
368 : 105 : bms_make_singleton(joinrti));
369 : : }
370 : :
371 : : /*
372 : : * If there are any WHEN NOT MATCHED BY SOURCE actions, the executor will
373 : : * use the join condition to distinguish between MATCHED and NOT MATCHED
374 : : * BY SOURCE cases. Otherwise, it's no longer needed, and we set it to
375 : : * NULL, saving cycles during planning and execution.
376 : : *
377 : : * We need to be careful though: the executor evaluates this condition
378 : : * using the output of the join subplan node, which nulls the output from
379 : : * the source relation when the join condition doesn't match. That risks
380 : : * producing incorrect results when rechecking using a "non-strict" join
381 : : * condition, such as "src.col IS NOT DISTINCT FROM tgt.col". To guard
382 : : * against that, we add an additional "src IS NOT NULL" check to the join
383 : : * condition, so that it does the right thing when performing a recheck
384 : : * based on the output of the join subplan.
385 : : */
386 [ + + ]: 1564 : if (have_action[MERGE_WHEN_NOT_MATCHED_BY_SOURCE])
387 : : {
388 : : Var *var;
389 : : NullTest *ntest;
390 : :
391 : : /* source wholerow Var (nullable by the new join) */
392 : 105 : var = makeWholeRowVar(rt_fetch(sourcerti, parse->rtable),
393 : : sourcerti, 0, false);
394 : 105 : var->varnullingrels = bms_make_singleton(joinrti);
395 : :
396 : : /* "src IS NOT NULL" check */
397 : 105 : ntest = makeNode(NullTest);
398 : 105 : ntest->arg = (Expr *) var;
399 : 105 : ntest->nulltesttype = IS_NOT_NULL;
400 : 105 : ntest->argisrow = false;
401 : 105 : ntest->location = -1;
402 : :
403 : : /* combine it with the original join condition */
404 : 105 : parse->mergeJoinCondition =
405 : 105 : (Node *) make_and_qual((Node *) ntest, parse->mergeJoinCondition);
406 : : }
407 : : else
408 : 1459 : parse->mergeJoinCondition = NULL; /* join condition not needed */
409 : : }
410 : :
411 : : /*
412 : : * preprocess_relation_rtes
413 : : * Do the preprocessing work for any relation RTEs in the FROM clause.
414 : : *
415 : : * This scans the rangetable for relation RTEs and retrieves the necessary
416 : : * catalog information for each relation. Using this information, it clears
417 : : * the inh flag for any relation that has no children, collects not-null
418 : : * attribute numbers for any relation that has column not-null constraints, and
419 : : * expands virtual generated columns for any relation that contains them.
420 : : *
421 : : * Note that expanding virtual generated columns may cause the query tree to
422 : : * have new copies of rangetable entries. Therefore, we have to use list_nth
423 : : * instead of foreach when iterating over the query's rangetable.
424 : : *
425 : : * Returns a modified copy of the query tree, if any relations with virtual
426 : : * generated columns are present.
427 : : */
428 : : Query *
401 rguo@postgresql.org 429 : 430368 : preprocess_relation_rtes(PlannerInfo *root)
430 : : {
431 : 430368 : Query *parse = root->parse;
432 : : int rtable_size;
433 : : int rt_index;
434 : :
435 : 430368 : rtable_size = list_length(parse->rtable);
436 : :
437 [ + + ]: 967948 : for (rt_index = 0; rt_index < rtable_size; rt_index++)
438 : : {
439 : 537580 : RangeTblEntry *rte = rt_fetch(rt_index + 1, parse->rtable);
440 : : Relation relation;
441 : :
442 : : /* We only care about relation RTEs. */
443 [ + + ]: 537580 : if (rte->rtekind != RTE_RELATION)
444 : 176421 : continue;
445 : :
446 : : /*
447 : : * We need not lock the relation since it was already locked by the
448 : : * rewriter.
449 : : */
450 : 361159 : relation = table_open(rte->relid, NoLock);
451 : :
452 : : /*
453 : : * Check to see if the relation actually has any children; if not,
454 : : * clear the inh flag so we can treat it as a plain base relation.
455 : : *
456 : : * Note: this could give a false-positive result, if the rel once had
457 : : * children but no longer does. We used to be able to clear rte->inh
458 : : * later on when we discovered that, but no more; we have to handle
459 : : * such cases as full-fledged inheritance.
460 : : */
461 [ + + ]: 361159 : if (rte->inh)
462 : 304915 : rte->inh = relation->rd_rel->relhassubclass;
463 : :
464 : : /*
465 : : * Check to see if the relation has any column not-null constraints;
466 : : * if so, retrieve the constraint information and store it in a
467 : : * relation OID based hash table.
468 : : */
469 : 361159 : get_relation_notnullatts(root, relation);
470 : :
471 : : /*
472 : : * Check to see if the relation has any virtual generated columns; if
473 : : * so, replace all Var nodes in the query that reference these columns
474 : : * with the generation expressions.
475 : : */
476 : 361159 : parse = expand_virtual_generated_columns(root, parse,
477 : : rte, rt_index + 1,
478 : : relation);
479 : :
480 : 361159 : table_close(relation, NoLock);
481 : : }
482 : :
483 : 430368 : return parse;
484 : : }
485 : :
486 : : /*
487 : : * expand_virtual_generated_columns
488 : : * Expand virtual generated columns for the given relation.
489 : : *
490 : : * This checks whether the given relation has any virtual generated columns,
491 : : * and if so, replaces all Var nodes in the query that reference those columns
492 : : * with their generation expressions.
493 : : *
494 : : * Returns a modified copy of the query tree if the relation contains virtual
495 : : * generated columns.
496 : : */
497 : : static Query *
498 : 361159 : expand_virtual_generated_columns(PlannerInfo *root, Query *parse,
499 : : RangeTblEntry *rte, int rt_index,
500 : : Relation relation)
501 : : {
502 : : TupleDesc tupdesc;
503 : :
504 : : /* Only normal relations can have virtual generated columns */
505 [ - + ]: 361159 : Assert(rte->rtekind == RTE_RELATION);
506 : :
507 : 361159 : tupdesc = RelationGetDescr(relation);
508 [ + + + + ]: 361159 : if (tupdesc->constr && tupdesc->constr->has_generated_virtual)
509 : : {
510 : 1156 : List *tlist = NIL;
511 : : pullup_replace_vars_context rvcontext;
127 dean.a.rasheed@gmail 512 : 1156 : List *save_exclRelTlist = NIL;
513 : :
401 rguo@postgresql.org 514 [ + + ]: 4632 : for (int i = 0; i < tupdesc->natts; i++)
515 : : {
516 : 3476 : Form_pg_attribute attr = TupleDescAttr(tupdesc, i);
517 : : TargetEntry *tle;
518 : :
519 [ + + ]: 3476 : if (attr->attgenerated == ATTRIBUTE_GENERATED_VIRTUAL)
520 : : {
521 : : Node *defexpr;
522 : :
523 : 1531 : defexpr = build_generation_expression(relation, i + 1);
524 : 1531 : ChangeVarNodes(defexpr, 1, rt_index, 0);
525 : :
526 : 1531 : tle = makeTargetEntry((Expr *) defexpr, i + 1, 0, false);
527 : 1531 : tlist = lappend(tlist, tle);
528 : : }
529 : : else
530 : : {
531 : : Var *var;
532 : :
533 : 1945 : var = makeVar(rt_index,
534 : 1945 : i + 1,
535 : : attr->atttypid,
536 : : attr->atttypmod,
537 : : attr->attcollation,
538 : : 0);
539 : :
540 : 1945 : tle = makeTargetEntry((Expr *) var, i + 1, 0, false);
541 : 1945 : tlist = lappend(tlist, tle);
542 : : }
543 : : }
544 : :
545 [ - + ]: 1156 : Assert(list_length(tlist) > 0);
546 [ - + ]: 1156 : Assert(!rte->lateral);
547 : :
548 : : /*
549 : : * The relation's targetlist items are now in the appropriate form to
550 : : * insert into the query, except that we may need to wrap them in
551 : : * PlaceHolderVars. Set up required context data for
552 : : * pullup_replace_vars.
553 : : */
554 : 1156 : rvcontext.root = root;
555 : 1156 : rvcontext.targetlist = tlist;
556 : 1156 : rvcontext.target_rte = rte;
557 : 1156 : rvcontext.result_relation = parse->resultRelation;
558 : : /* won't need these values */
559 : 1156 : rvcontext.relids = NULL;
560 : 1156 : rvcontext.nullinfo = NULL;
561 : : /* pass NULL for outer_hasSubLinks */
562 : 1156 : rvcontext.outer_hasSubLinks = NULL;
563 : 1156 : rvcontext.varno = rt_index;
564 : : /* this flag will be set below, if needed */
565 : 1156 : rvcontext.wrap_option = REPLACE_WRAP_NONE;
566 : : /* initialize cache array with indexes 0 .. length(tlist) */
10 michael@paquier.xyz 567 :GNC 1156 : rvcontext.rv_cache = palloc0_array(Node *, list_length(tlist) + 1);
568 : :
569 : : /*
570 : : * If the query uses grouping sets, we need a PlaceHolderVar for each
571 : : * expression of the relation's targetlist items. (See comments in
572 : : * pull_up_simple_subquery().)
573 : : */
401 rguo@postgresql.org 574 [ + + ]:CBC 1156 : if (parse->groupingSets)
575 : 10 : rvcontext.wrap_option = REPLACE_WRAP_ALL;
576 : :
577 : : /*
578 : : * Apply pullup variable replacement throughout the query tree.
579 : : *
580 : : * We intentionally do not touch the EXCLUDED pseudo-relation's
581 : : * targetlist here. Various places in the planner assume that it
582 : : * contains only Vars, and we want that to remain the case. More
583 : : * importantly, we don't want setrefs.c to turn any expanded
584 : : * EXCLUDED.virtual_column expressions in other parts of the query
585 : : * back into Vars referencing the original virtual column, which
586 : : * set_plan_refs() would do if exclRelTlist contained matching
587 : : * expressions.
588 : : */
127 dean.a.rasheed@gmail 589 [ + + ]: 1156 : if (parse->onConflict)
590 : : {
591 : 50 : save_exclRelTlist = parse->onConflict->exclRelTlist;
592 : 50 : parse->onConflict->exclRelTlist = NIL;
593 : : }
594 : :
401 rguo@postgresql.org 595 : 1156 : parse = (Query *) pullup_replace_vars((Node *) parse, &rvcontext);
596 : :
127 dean.a.rasheed@gmail 597 [ + + ]: 1156 : if (parse->onConflict)
598 : 50 : parse->onConflict->exclRelTlist = save_exclRelTlist;
599 : : }
600 : :
401 rguo@postgresql.org 601 : 361159 : return parse;
602 : : }
603 : :
604 : : /*
605 : : * replace_empty_jointree
606 : : * If the Query's jointree is empty, replace it with a dummy RTE_RESULT
607 : : * relation.
608 : : *
609 : : * By doing this, we can avoid a bunch of corner cases that formerly existed
610 : : * for SELECTs with omitted FROM clauses. An example is that a subquery
611 : : * with empty jointree previously could not be pulled up, because that would
612 : : * have resulted in an empty relid set, making the subquery not uniquely
613 : : * identifiable for join or PlaceHolderVar processing.
614 : : *
615 : : * Unlike most other functions in this file, this function doesn't recurse;
616 : : * we rely on other processing to invoke it on sub-queries at suitable times.
617 : : */
618 : : void
2768 tgl@sss.pgh.pa.us 619 : 430368 : replace_empty_jointree(Query *parse)
620 : : {
621 : : RangeTblEntry *rte;
622 : : Index rti;
623 : : RangeTblRef *rtr;
624 : :
625 : : /* Nothing to do if jointree is already nonempty */
626 [ + + ]: 430368 : if (parse->jointree->fromlist != NIL)
627 : 283597 : return;
628 : :
629 : : /* We mustn't change it in the top level of a setop tree, either */
630 [ + + ]: 146771 : if (parse->setOperations)
631 : 5468 : return;
632 : :
633 : : /* Create suitable RTE */
634 : 141303 : rte = makeNode(RangeTblEntry);
635 : 141303 : rte->rtekind = RTE_RESULT;
636 : 141303 : rte->eref = makeAlias("*RESULT*", NIL);
637 : :
638 : : /* Add it to rangetable */
639 : 141303 : parse->rtable = lappend(parse->rtable, rte);
640 : 141303 : rti = list_length(parse->rtable);
641 : :
642 : : /* And jam a reference into the jointree */
643 : 141303 : rtr = makeNode(RangeTblRef);
644 : 141303 : rtr->rtindex = rti;
645 : 141303 : parse->jointree->fromlist = list_make1(rtr);
646 : : }
647 : :
648 : : /*
649 : : * pull_up_sublinks
650 : : * Attempt to pull up ANY and EXISTS SubLinks to be treated as
651 : : * semijoins or anti-semijoins.
652 : : *
653 : : * A clause "foo op ANY (sub-SELECT)" can be processed by pulling the
654 : : * sub-SELECT up to become a rangetable entry and treating the implied
655 : : * comparisons as quals of a semijoin. However, this optimization *only*
656 : : * works at the top level of WHERE or a JOIN/ON clause, because we cannot
657 : : * distinguish whether the ANY ought to return FALSE or NULL in cases
658 : : * involving NULL inputs. Also, in an outer join's ON clause we can only
659 : : * do this if the sublink is degenerate (ie, references only the nullable
660 : : * side of the join). In that case it is legal to push the semijoin
661 : : * down into the nullable side of the join. If the sublink references any
662 : : * nonnullable-side variables then it would have to be evaluated as part
663 : : * of the outer join, which makes things way too complicated.
664 : : *
665 : : * Under similar conditions, EXISTS and NOT EXISTS clauses can be handled
666 : : * by pulling up the sub-SELECT and creating a semijoin or anti-semijoin.
667 : : *
668 : : * This routine searches for such clauses and does the necessary parsetree
669 : : * transformations if any are found.
670 : : *
671 : : * This routine has to run before preprocess_expression(), so the quals
672 : : * clauses are not yet reduced to implicit-AND format, and are not guaranteed
673 : : * to be AND/OR-flat either. That means we need to recursively search through
674 : : * explicit AND clauses. We stop as soon as we hit a non-AND item.
675 : : */
676 : : void
6584 677 : 31674 : pull_up_sublinks(PlannerInfo *root)
678 : : {
679 : : Node *jtnode;
680 : : Relids relids;
681 : :
682 : : /* Begin recursion through the jointree */
6392 683 : 31674 : jtnode = pull_up_sublinks_jointree_recurse(root,
684 : 31674 : (Node *) root->parse->jointree,
685 : : &relids);
686 : :
687 : : /*
688 : : * root->parse->jointree must always be a FromExpr, so insert a dummy one
689 : : * if we got a bare RangeTblRef or JoinExpr out of the recursion.
690 : : */
691 [ + + ]: 31674 : if (IsA(jtnode, FromExpr))
692 : 20073 : root->parse->jointree = (FromExpr *) jtnode;
693 : : else
694 : 11601 : root->parse->jointree = makeFromExpr(list_make1(jtnode), NULL);
6584 695 : 31674 : }
696 : :
697 : : /*
698 : : * Recurse through jointree nodes for pull_up_sublinks()
699 : : *
700 : : * In addition to returning the possibly-modified jointree node, we return
701 : : * a relids set of the contained rels into *relids.
702 : : */
703 : : static Node *
704 : 109034 : pull_up_sublinks_jointree_recurse(PlannerInfo *root, Node *jtnode,
705 : : Relids *relids)
706 : : {
707 : : /* Since this function recurses, it could be driven to stack overflow. */
1344 708 : 109034 : check_stack_depth();
709 : :
6584 710 [ - + ]: 109034 : if (jtnode == NULL)
711 : : {
6584 tgl@sss.pgh.pa.us 712 :UBC 0 : *relids = NULL;
713 : : }
6584 tgl@sss.pgh.pa.us 714 [ + + ]:CBC 109034 : else if (IsA(jtnode, RangeTblRef))
715 : : {
716 : 61687 : int varno = ((RangeTblRef *) jtnode)->rtindex;
717 : :
718 : 61687 : *relids = bms_make_singleton(varno);
719 : : /* jtnode is returned unmodified */
720 : : }
721 [ + + ]: 47347 : else if (IsA(jtnode, FromExpr))
722 : : {
723 : 31865 : FromExpr *f = (FromExpr *) jtnode;
724 : 31865 : List *newfromlist = NIL;
725 : 31865 : Relids frelids = NULL;
726 : : FromExpr *newf;
727 : : Node *jtlink;
728 : : ListCell *l;
729 : :
730 : : /* First, recurse to process children and collect their relids */
731 [ + - + + : 66517 : foreach(l, f->fromlist)
+ + ]
732 : : {
733 : : Node *newchild;
734 : : Relids childrelids;
735 : :
736 : 34652 : newchild = pull_up_sublinks_jointree_recurse(root,
737 : 34652 : lfirst(l),
738 : : &childrelids);
739 : 34652 : newfromlist = lappend(newfromlist, newchild);
740 : 34652 : frelids = bms_join(frelids, childrelids);
741 : : }
742 : : /* Build the replacement FromExpr; no quals yet */
6392 743 : 31865 : newf = makeFromExpr(newfromlist, NULL);
744 : : /* Set up a link representing the rebuilt jointree */
745 : 31865 : jtlink = (Node *) newf;
746 : : /* Now process qual --- all children are available for use */
5326 747 : 31865 : newf->quals = pull_up_sublinks_qual_recurse(root, f->quals,
748 : : &jtlink, frelids,
749 : : NULL, NULL);
750 : :
751 : : /*
752 : : * Note that the result will be either newf, or a stack of JoinExprs
753 : : * with newf at the base. We rely on subsequent optimization steps to
754 : : * flatten this and rearrange the joins as needed.
755 : : *
756 : : * Although we could include the pulled-up subqueries in the returned
757 : : * relids, there's no need since upper quals couldn't refer to their
758 : : * outputs anyway.
759 : : */
6584 760 : 31865 : *relids = frelids;
6392 761 : 31865 : jtnode = jtlink;
762 : : }
6584 763 [ + - ]: 15482 : else if (IsA(jtnode, JoinExpr))
764 : : {
765 : : JoinExpr *j;
766 : : Relids leftrelids;
767 : : Relids rightrelids;
768 : : Node *jtlink;
769 : :
770 : : /*
771 : : * Make a modifiable copy of join node, but don't bother copying its
772 : : * subnodes (yet).
773 : : */
260 michael@paquier.xyz 774 : 15482 : j = palloc_object(JoinExpr);
6584 tgl@sss.pgh.pa.us 775 : 15482 : memcpy(j, jtnode, sizeof(JoinExpr));
6392 776 : 15482 : jtlink = (Node *) j;
777 : :
778 : : /* Recurse to process children and collect their relids */
6584 779 : 15482 : j->larg = pull_up_sublinks_jointree_recurse(root, j->larg,
780 : : &leftrelids);
781 : 15482 : j->rarg = pull_up_sublinks_jointree_recurse(root, j->rarg,
782 : : &rightrelids);
783 : :
784 : : /*
785 : : * Now process qual, showing appropriate child relids as available,
786 : : * and attach any pulled-up jointree items at the right place. In the
787 : : * inner-join case we put new JoinExprs above the existing one (much
788 : : * as for a FromExpr-style join). In outer-join cases the new
789 : : * JoinExprs must go into the nullable side of the outer join. The
790 : : * point of the available_rels machinations is to ensure that we only
791 : : * pull up quals for which that's okay.
792 : : *
793 : : * We don't expect to see any pre-existing JOIN_SEMI, JOIN_ANTI,
794 : : * JOIN_RIGHT_SEMI, or JOIN_RIGHT_ANTI jointypes here.
795 : : */
796 [ + + + + : 15482 : switch (j->jointype)
- ]
797 : : {
798 : 7416 : case JOIN_INNER:
799 : 7416 : j->quals = pull_up_sublinks_qual_recurse(root, j->quals,
800 : : &jtlink,
801 : : bms_union(leftrelids,
802 : : rightrelids),
803 : : NULL, NULL);
804 : 7416 : break;
805 : 7966 : case JOIN_LEFT:
806 : 7966 : j->quals = pull_up_sublinks_qual_recurse(root, j->quals,
807 : : &j->rarg,
808 : : rightrelids,
809 : : NULL, NULL);
810 : 7966 : break;
811 : 20 : case JOIN_FULL:
812 : : /* can't do anything with full-join quals */
813 : 20 : break;
814 : 80 : case JOIN_RIGHT:
815 : 80 : j->quals = pull_up_sublinks_qual_recurse(root, j->quals,
816 : : &j->larg,
817 : : leftrelids,
818 : : NULL, NULL);
819 : 80 : break;
6584 tgl@sss.pgh.pa.us 820 :UBC 0 : default:
821 [ # # ]: 0 : elog(ERROR, "unrecognized join type: %d",
822 : : (int) j->jointype);
823 : : break;
824 : : }
825 : :
826 : : /*
827 : : * Although we could include the pulled-up subqueries in the returned
828 : : * relids, there's no need since upper quals couldn't refer to their
829 : : * outputs anyway. But we *do* need to include the join's own rtindex
830 : : * because we haven't yet collapsed join alias variables, so upper
831 : : * levels would mistakenly think they couldn't use references to this
832 : : * join.
833 : : */
6392 tgl@sss.pgh.pa.us 834 :CBC 15482 : *relids = bms_join(leftrelids, rightrelids);
835 [ + - ]: 15482 : if (j->rtindex)
836 : 15482 : *relids = bms_add_member(*relids, j->rtindex);
837 : 15482 : jtnode = jtlink;
838 : : }
839 : : else
6584 tgl@sss.pgh.pa.us 840 [ # # ]:UBC 0 : elog(ERROR, "unrecognized node type: %d",
841 : : (int) nodeTag(jtnode));
6584 tgl@sss.pgh.pa.us 842 :CBC 109034 : return jtnode;
843 : : }
844 : :
845 : : /*
846 : : * Recurse through top-level qual nodes for pull_up_sublinks()
847 : : *
848 : : * jtlink1 points to the link in the jointree where any new JoinExprs should
849 : : * be inserted if they reference available_rels1 (i.e., available_rels1
850 : : * denotes the relations present underneath jtlink1). Optionally, jtlink2 can
851 : : * point to a second link where new JoinExprs should be inserted if they
852 : : * reference available_rels2 (pass NULL for both those arguments if not used).
853 : : * Note that SubLinks referencing both sets of variables cannot be optimized.
854 : : * If we find multiple pull-up-able SubLinks, they'll get stacked onto jtlink1
855 : : * and/or jtlink2 in the order we encounter them. We rely on subsequent
856 : : * optimization to rearrange the stack if appropriate.
857 : : *
858 : : * Returns the replacement qual node, or NULL if the qual should be removed.
859 : : */
860 : : static Node *
861 : 127708 : pull_up_sublinks_qual_recurse(PlannerInfo *root, Node *node,
862 : : Node **jtlink1, Relids available_rels1,
863 : : Node **jtlink2, Relids available_rels2)
864 : : {
8620 865 [ + + ]: 127708 : if (node == NULL)
866 : 4784 : return NULL;
867 [ + + ]: 122924 : if (IsA(node, SubLink))
868 : : {
8424 bruce@momjian.us 869 : 4474 : SubLink *sublink = (SubLink *) node;
870 : : JoinExpr *j;
871 : : Relids child_rels;
872 : :
873 : : /* Is it a convertible ANY or EXISTS clause? */
6587 tgl@sss.pgh.pa.us 874 [ + + ]: 4474 : if (sublink->subLinkType == ANY_SUBLINK)
875 : : {
876 : : ScalarArrayOpExpr *saop;
877 : :
510 akorotkov@postgresql 878 [ + + ]: 3766 : if ((saop = convert_VALUES_to_ANY(root,
879 : : sublink->testexpr,
880 : 3766 : (Query *) sublink->subselect)) != NULL)
881 : : {
882 : : /*
883 : : * The VALUES sequence was simplified. Nothing more to do
884 : : * here.
885 : : */
886 : 70 : return (Node *) saop;
887 : : }
888 : :
168 rguo@postgresql.org 889 [ + + ]: 3696 : if ((j = convert_ANY_sublink_to_join(root, sublink, false,
890 : : available_rels1)) != NULL)
891 : : {
892 : : /* Yes; insert the new join node into the join tree */
5326 tgl@sss.pgh.pa.us 893 : 3609 : j->larg = *jtlink1;
894 : 3609 : *jtlink1 = (Node *) j;
895 : : /* Recursively process pulled-up jointree nodes */
896 : 3609 : j->rarg = pull_up_sublinks_jointree_recurse(root,
897 : : j->rarg,
898 : : &child_rels);
899 : :
900 : : /*
901 : : * Now recursively process the pulled-up quals. Any inserted
902 : : * joins can get stacked onto either j->larg or j->rarg,
903 : : * depending on which rels they reference.
904 : : */
905 : 3609 : j->quals = pull_up_sublinks_qual_recurse(root,
906 : : j->quals,
907 : : &j->larg,
908 : : available_rels1,
909 : : &j->rarg,
910 : : child_rels);
911 : : /* Return NULL representing constant TRUE */
912 : 3609 : return NULL;
913 : : }
914 [ + + - + ]: 92 : if (available_rels2 != NULL &&
168 rguo@postgresql.org 915 : 5 : (j = convert_ANY_sublink_to_join(root, sublink, false,
916 : : available_rels2)) != NULL)
917 : : {
918 : : /* Yes; insert the new join node into the join tree */
5326 tgl@sss.pgh.pa.us 919 :UBC 0 : j->larg = *jtlink2;
920 : 0 : *jtlink2 = (Node *) j;
921 : : /* Recursively process pulled-up jointree nodes */
5596 922 : 0 : j->rarg = pull_up_sublinks_jointree_recurse(root,
923 : : j->rarg,
924 : : &child_rels);
925 : :
926 : : /*
927 : : * Now recursively process the pulled-up quals. Any inserted
928 : : * joins can get stacked onto either j->larg or j->rarg,
929 : : * depending on which rels they reference.
930 : : */
931 : 0 : j->quals = pull_up_sublinks_qual_recurse(root,
932 : : j->quals,
933 : : &j->larg,
934 : : available_rels2,
935 : : &j->rarg,
936 : : child_rels);
937 : : /* Return NULL representing constant TRUE */
6392 938 : 0 : return NULL;
939 : : }
940 : : }
6587 tgl@sss.pgh.pa.us 941 [ + + ]:CBC 708 : else if (sublink->subLinkType == EXISTS_SUBLINK)
942 : : {
5326 943 [ + + ]: 658 : if ((j = convert_EXISTS_sublink_to_join(root, sublink, false,
944 : : available_rels1)) != NULL)
945 : : {
946 : : /* Yes; insert the new join node into the join tree */
947 : 546 : j->larg = *jtlink1;
948 : 546 : *jtlink1 = (Node *) j;
949 : : /* Recursively process pulled-up jointree nodes */
5596 950 : 546 : j->rarg = pull_up_sublinks_jointree_recurse(root,
951 : : j->rarg,
952 : : &child_rels);
953 : :
954 : : /*
955 : : * Now recursively process the pulled-up quals. Any inserted
956 : : * joins can get stacked onto either j->larg or j->rarg,
957 : : * depending on which rels they reference.
958 : : */
959 : 546 : j->quals = pull_up_sublinks_qual_recurse(root,
960 : : j->quals,
961 : : &j->larg,
962 : : available_rels1,
963 : : &j->rarg,
964 : : child_rels);
965 : : /* Return NULL representing constant TRUE */
5326 966 : 546 : return NULL;
967 : : }
968 [ + + + - ]: 128 : if (available_rels2 != NULL &&
969 : 16 : (j = convert_EXISTS_sublink_to_join(root, sublink, false,
970 : : available_rels2)) != NULL)
971 : : {
972 : : /* Yes; insert the new join node into the join tree */
973 : 16 : j->larg = *jtlink2;
974 : 16 : *jtlink2 = (Node *) j;
975 : : /* Recursively process pulled-up jointree nodes */
976 : 16 : j->rarg = pull_up_sublinks_jointree_recurse(root,
977 : : j->rarg,
978 : : &child_rels);
979 : :
980 : : /*
981 : : * Now recursively process the pulled-up quals. Any inserted
982 : : * joins can get stacked onto either j->larg or j->rarg,
983 : : * depending on which rels they reference.
984 : : */
985 : 16 : j->quals = pull_up_sublinks_qual_recurse(root,
986 : : j->quals,
987 : : &j->larg,
988 : : available_rels2,
989 : : &j->rarg,
990 : : child_rels);
991 : : /* Return NULL representing constant TRUE */
6392 992 : 16 : return NULL;
993 : : }
994 : : }
995 : : /* Else return it unmodified */
6587 996 : 233 : return node;
997 : : }
2767 998 [ + + ]: 118450 : if (is_notclause(node))
999 : : {
1000 : : /* If the immediate argument of NOT is ANY or EXISTS, try to convert */
6587 1001 : 14619 : SubLink *sublink = (SubLink *) get_notclausearg((Expr *) node);
1002 : : JoinExpr *j;
1003 : : Relids child_rels;
1004 : :
1005 [ + - + + ]: 14619 : if (sublink && IsA(sublink, SubLink))
1006 : : {
168 rguo@postgresql.org 1007 [ + + ]: 7727 : if (sublink->subLinkType == ANY_SUBLINK)
1008 : : {
1009 [ + + ]: 220 : if ((j = convert_ANY_sublink_to_join(root, sublink, true,
1010 : : available_rels1)) != NULL)
1011 : : {
1012 : : /* Yes; insert the new join node into the join tree */
1013 : 75 : j->larg = *jtlink1;
1014 : 75 : *jtlink1 = (Node *) j;
1015 : : /* Recursively process pulled-up jointree nodes */
1016 : 75 : j->rarg = pull_up_sublinks_jointree_recurse(root,
1017 : : j->rarg,
1018 : : &child_rels);
1019 : :
1020 : : /*
1021 : : * Now recursively process the pulled-up quals. Because
1022 : : * we are underneath a NOT, we can't pull up sublinks that
1023 : : * reference the left-hand stuff, but it's still okay to
1024 : : * pull up sublinks referencing j->rarg.
1025 : : */
1026 : 75 : j->quals = pull_up_sublinks_qual_recurse(root,
1027 : : j->quals,
1028 : : &j->rarg,
1029 : : child_rels,
1030 : : NULL, NULL);
1031 : : /* Return NULL representing constant TRUE */
1032 : 75 : return NULL;
1033 : : }
1034 [ - + - - ]: 145 : if (available_rels2 != NULL &&
168 rguo@postgresql.org 1035 :UBC 0 : (j = convert_ANY_sublink_to_join(root, sublink, true,
1036 : : available_rels2)) != NULL)
1037 : : {
1038 : : /* Yes; insert the new join node into the join tree */
1039 : 0 : j->larg = *jtlink2;
1040 : 0 : *jtlink2 = (Node *) j;
1041 : : /* Recursively process pulled-up jointree nodes */
1042 : 0 : j->rarg = pull_up_sublinks_jointree_recurse(root,
1043 : : j->rarg,
1044 : : &child_rels);
1045 : :
1046 : : /*
1047 : : * Now recursively process the pulled-up quals. Because
1048 : : * we are underneath a NOT, we can't pull up sublinks that
1049 : : * reference the left-hand stuff, but it's still okay to
1050 : : * pull up sublinks referencing j->rarg.
1051 : : */
1052 : 0 : j->quals = pull_up_sublinks_qual_recurse(root,
1053 : : j->quals,
1054 : : &j->rarg,
1055 : : child_rels,
1056 : : NULL, NULL);
1057 : : /* Return NULL representing constant TRUE */
1058 : 0 : return NULL;
1059 : : }
1060 : : }
168 rguo@postgresql.org 1061 [ + - ]:CBC 7507 : else if (sublink->subLinkType == EXISTS_SUBLINK)
1062 : : {
5326 tgl@sss.pgh.pa.us 1063 [ + + ]: 7507 : if ((j = convert_EXISTS_sublink_to_join(root, sublink, true,
1064 : : available_rels1)) != NULL)
1065 : : {
1066 : : /* Yes; insert the new join node into the join tree */
1067 : 7498 : j->larg = *jtlink1;
1068 : 7498 : *jtlink1 = (Node *) j;
1069 : : /* Recursively process pulled-up jointree nodes */
1070 : 7498 : j->rarg = pull_up_sublinks_jointree_recurse(root,
1071 : : j->rarg,
1072 : : &child_rels);
1073 : :
1074 : : /*
1075 : : * Now recursively process the pulled-up quals. Because
1076 : : * we are underneath a NOT, we can't pull up sublinks that
1077 : : * reference the left-hand stuff, but it's still okay to
1078 : : * pull up sublinks referencing j->rarg.
1079 : : */
1080 : 7498 : j->quals = pull_up_sublinks_qual_recurse(root,
1081 : : j->quals,
1082 : : &j->rarg,
1083 : : child_rels,
1084 : : NULL, NULL);
1085 : : /* Return NULL representing constant TRUE */
1086 : 7498 : return NULL;
1087 : : }
1088 [ - + - - ]: 9 : if (available_rels2 != NULL &&
5326 tgl@sss.pgh.pa.us 1089 :UBC 0 : (j = convert_EXISTS_sublink_to_join(root, sublink, true,
1090 : : available_rels2)) != NULL)
1091 : : {
1092 : : /* Yes; insert the new join node into the join tree */
1093 : 0 : j->larg = *jtlink2;
1094 : 0 : *jtlink2 = (Node *) j;
1095 : : /* Recursively process pulled-up jointree nodes */
5596 1096 : 0 : j->rarg = pull_up_sublinks_jointree_recurse(root,
1097 : : j->rarg,
1098 : : &child_rels);
1099 : :
1100 : : /*
1101 : : * Now recursively process the pulled-up quals. Because
1102 : : * we are underneath a NOT, we can't pull up sublinks that
1103 : : * reference the left-hand stuff, but it's still okay to
1104 : : * pull up sublinks referencing j->rarg.
1105 : : */
1106 : 0 : j->quals = pull_up_sublinks_qual_recurse(root,
1107 : : j->quals,
1108 : : &j->rarg,
1109 : : child_rels,
1110 : : NULL, NULL);
1111 : : /* Return NULL representing constant TRUE */
6392 1112 : 0 : return NULL;
1113 : : }
1114 : : }
1115 : : }
1116 : : /* Else return it unmodified */
6587 tgl@sss.pgh.pa.us 1117 :CBC 7046 : return node;
1118 : : }
2767 1119 [ + + ]: 103831 : if (is_andclause(node))
1120 : : {
1121 : : /* Recurse into AND clause */
8424 bruce@momjian.us 1122 : 25391 : List *newclauses = NIL;
1123 : : ListCell *l;
1124 : :
8128 neilc@samurai.com 1125 [ + - + + : 94028 : foreach(l, ((BoolExpr *) node)->args)
+ + ]
1126 : : {
1127 : 68637 : Node *oldclause = (Node *) lfirst(l);
1128 : : Node *newclause;
1129 : :
6392 tgl@sss.pgh.pa.us 1130 : 68637 : newclause = pull_up_sublinks_qual_recurse(root,
1131 : : oldclause,
1132 : : jtlink1,
1133 : : available_rels1,
1134 : : jtlink2,
1135 : : available_rels2);
1136 [ + + ]: 68637 : if (newclause)
1137 : 58875 : newclauses = lappend(newclauses, newclause);
1138 : : }
1139 : : /* We might have got back fewer clauses than we started with */
1140 [ + + ]: 25391 : if (newclauses == NIL)
1141 : 67 : return NULL;
1142 [ + + ]: 25324 : else if (list_length(newclauses) == 1)
1143 : 917 : return (Node *) linitial(newclauses);
1144 : : else
1145 : 24407 : return (Node *) make_andclause(newclauses);
1146 : : }
1147 : : /* Stop if not an AND */
8620 1148 : 78440 : return node;
1149 : : }
1150 : :
1151 : : /*
1152 : : * preprocess_function_rtes
1153 : : * Constant-simplify any FUNCTION RTEs in the FROM clause, and then
1154 : : * attempt to "inline" any that can be converted to simple subqueries.
1155 : : *
1156 : : * If an RTE_FUNCTION rtable entry invokes a set-returning SQL function that
1157 : : * contains just a simple SELECT, we can convert the rtable entry to an
1158 : : * RTE_SUBQUERY entry exposing the SELECT directly. Other sorts of functions
1159 : : * are also inline-able if they have a support function that can generate
1160 : : * the replacement sub-Query. This is especially useful if the subquery can
1161 : : * then be "pulled up" for further optimization, but we do it even if not,
1162 : : * to reduce executor overhead.
1163 : : *
1164 : : * This has to be done before we have started to do any optimization of
1165 : : * subqueries, else any such steps wouldn't get applied to subqueries
1166 : : * obtained via inlining. However, we do it after pull_up_sublinks
1167 : : * so that we can inline any functions used in SubLink subselects.
1168 : : *
1169 : : * The reason for applying const-simplification at this stage is that
1170 : : * (a) we'd need to do it anyway to inline a SRF, and (b) by doing it now,
1171 : : * we can be sure that pull_up_constant_function() will see constants
1172 : : * if there are constants to be seen. This approach also guarantees
1173 : : * that every FUNCTION RTE has been const-simplified, allowing planner.c's
1174 : : * preprocess_expression() to skip doing it again.
1175 : : *
1176 : : * Like most of the planner, this feels free to scribble on its input data
1177 : : * structure.
1178 : : */
1179 : : void
2583 1180 : 422282 : preprocess_function_rtes(PlannerInfo *root)
1181 : : {
1182 : : ListCell *rt;
1183 : :
6736 1184 [ + - + + : 1104789 : foreach(rt, root->parse->rtable)
+ + ]
1185 : : {
1186 : 682511 : RangeTblEntry *rte = (RangeTblEntry *) lfirst(rt);
1187 : :
1188 [ + + ]: 682511 : if (rte->rtekind == RTE_FUNCTION)
1189 : : {
1190 : : Query *funcquery;
1191 : :
1192 : : /* Apply const-simplification */
2583 1193 : 35774 : rte->functions = (List *)
1194 : 35774 : eval_const_expressions(root, (Node *) rte->functions);
1195 : :
1196 : : /* Check safety of expansion, and expand if possible */
278 1197 : 35774 : funcquery = inline_function_in_from(root, rte);
6736 1198 [ + + ]: 35770 : if (funcquery)
1199 : : {
1200 : : /* Successful expansion, convert the RTE to a subquery */
1201 : 205 : rte->rtekind = RTE_SUBQUERY;
1202 : 205 : rte->subquery = funcquery;
2900 1203 : 205 : rte->security_barrier = false;
1204 : :
1205 : : /*
1206 : : * Clear fields that should not be set in a subquery RTE.
1207 : : * However, we leave rte->functions filled in for the moment,
1208 : : * in case makeWholeRowVar needs to consult it. We'll clear
1209 : : * it in setrefs.c (see add_rte_to_flat_rtable) so that this
1210 : : * abuse of the data structure doesn't escape the planner.
1211 : : */
1212 : 205 : rte->funcordinality = false;
1213 : : }
1214 : : }
1215 : : }
6736 1216 : 422278 : }
1217 : :
1218 : : /*
1219 : : * pull_up_subqueries
1220 : : * Look for subqueries in the rangetable that can be pulled up into
1221 : : * the parent query. If the subquery has no special features like
1222 : : * grouping/aggregation then we can merge it into the parent's jointree.
1223 : : * Also, subqueries that are simple UNION ALL structures can be
1224 : : * converted into "append relations".
1225 : : */
1226 : : void
4187 1227 : 422278 : pull_up_subqueries(PlannerInfo *root)
1228 : : {
1229 : : /* Top level of jointree must always be a FromExpr */
1230 [ - + ]: 422278 : Assert(IsA(root->parse->jointree, FromExpr));
1231 : : /* Recursion starts with no containing join nor appendrel */
1232 : 844556 : root->parse->jointree = (FromExpr *)
1233 : 422278 : pull_up_subqueries_recurse(root, (Node *) root->parse->jointree,
1234 : : NULL, NULL);
1235 : : /* We should still have a FromExpr */
1236 [ - + ]: 422278 : Assert(IsA(root->parse->jointree, FromExpr));
5128 1237 : 422278 : }
1238 : :
1239 : : /*
1240 : : * pull_up_subqueries_recurse
1241 : : * Recursive guts of pull_up_subqueries.
1242 : : *
1243 : : * This recursively processes the jointree and returns a modified jointree.
1244 : : *
1245 : : * If this jointree node is within either side of an outer join, then
1246 : : * lowest_outer_join references the lowest such JoinExpr node; otherwise
1247 : : * it is NULL. We use this to constrain the effects of LATERAL subqueries.
1248 : : *
1249 : : * If we are looking at a member subquery of an append relation,
1250 : : * containing_appendrel describes that relation; else it is NULL.
1251 : : * This forces use of the PlaceHolderVar mechanism for all non-Var targetlist
1252 : : * items, and puts some additional restrictions on what can be pulled up.
1253 : : *
1254 : : * A tricky aspect of this code is that if we pull up a subquery we have
1255 : : * to replace Vars that reference the subquery's outputs throughout the
1256 : : * parent query, including quals attached to jointree nodes above the one
1257 : : * we are currently processing! We handle this by being careful to maintain
1258 : : * validity of the jointree structure while recursing, in the following sense:
1259 : : * whenever we recurse, all qual expressions in the tree must be reachable
1260 : : * from the top level, in case the recursive call needs to modify them.
1261 : : *
1262 : : * Notice also that we can't turn pullup_replace_vars loose on the whole
1263 : : * jointree, because it'd return a mutated copy of the tree; we have to
1264 : : * invoke it just on the quals, instead. This behavior is what makes it
1265 : : * reasonable to pass lowest_outer_join as a pointer rather than some
1266 : : * more-indirect way of identifying the lowest OJ. Likewise, we don't
1267 : : * replace append_rel_list members but only their substructure, so the
1268 : : * containing_appendrel reference is safe to use.
1269 : : */
1270 : : static Node *
1271 : 1068952 : pull_up_subqueries_recurse(PlannerInfo *root, Node *jtnode,
1272 : : JoinExpr *lowest_outer_join,
1273 : : AppendRelInfo *containing_appendrel)
1274 : : {
1275 : : /* Since this function recurses, it could be driven to stack overflow. */
1344 1276 : 1068952 : check_stack_depth();
1277 : : /* Also, since it's a bit expensive, let's check for query cancel. */
1278 [ + + ]: 1068952 : CHECK_FOR_INTERRUPTS();
1279 : :
4187 1280 [ - + ]: 1068952 : Assert(jtnode != NULL);
8620 1281 [ + + ]: 1068952 : if (IsA(jtnode, RangeTblRef))
1282 : : {
1283 : 550045 : int varno = ((RangeTblRef *) jtnode)->rtindex;
7510 1284 : 550045 : RangeTblEntry *rte = rt_fetch(varno, root->parse->rtable);
1285 : :
1286 : : /*
1287 : : * Is this a subquery RTE, and if so, is the subquery simple enough to
1288 : : * pull up?
1289 : : *
1290 : : * If we are looking at an append-relation member, we can't pull it up
1291 : : * unless is_safe_append_member says so.
1292 : : */
8144 1293 [ + + + + ]: 600643 : if (rte->rtekind == RTE_SUBQUERY &&
2044 1294 [ + + ]: 84005 : is_simple_subquery(root, rte->subquery, rte, lowest_outer_join) &&
6330 1295 [ + + ]: 9169 : (containing_appendrel == NULL ||
1296 : 9169 : is_safe_append_member(rte->subquery)))
7510 1297 : 29531 : return pull_up_simple_subquery(root, jtnode, rte,
1298 : : lowest_outer_join,
1299 : : containing_appendrel);
1300 : :
1301 : : /*
1302 : : * Alternatively, is it a simple UNION ALL subquery? If so, flatten
1303 : : * into an "append relation".
1304 : : *
1305 : : * It's safe to do this regardless of whether this query is itself an
1306 : : * appendrel member. (If you're thinking we should try to flatten the
1307 : : * two levels of appendrel together, you're right; but we handle that
1308 : : * in set_append_rel_pathlist, not here.)
1309 : : */
1310 [ + + + + ]: 541581 : if (rte->rtekind == RTE_SUBQUERY &&
1311 : 21067 : is_simple_union_all(rte->subquery))
1312 : 4005 : return pull_up_simple_union_all(root, jtnode, rte);
1313 : :
1314 : : /*
1315 : : * Or perhaps it's a simple VALUES RTE?
1316 : : *
1317 : : * We don't allow VALUES pullup below an outer join nor into an
1318 : : * appendrel (such cases are impossible anyway at the moment).
1319 : : */
4187 1320 [ + + + - ]: 516509 : if (rte->rtekind == RTE_VALUES &&
1321 [ + - ]: 10695 : lowest_outer_join == NULL &&
1322 [ + + ]: 10695 : containing_appendrel == NULL &&
2768 1323 : 10695 : is_simple_values(root, rte))
4187 1324 : 3768 : return pull_up_simple_values(root, jtnode, rte);
1325 : :
1326 : : /*
1327 : : * Or perhaps it's a FUNCTION RTE that we could inline?
1328 : : */
2583 1329 [ + + ]: 512741 : if (rte->rtekind == RTE_FUNCTION)
1330 : 35565 : return pull_up_constant_function(root, jtnode, rte,
1331 : : containing_appendrel);
1332 : :
1333 : : /* Otherwise, do nothing at this node. */
1334 : : }
8620 1335 [ + + ]: 518907 : else if (IsA(jtnode, FromExpr))
1336 : : {
1337 : 435459 : FromExpr *f = (FromExpr *) jtnode;
1338 : : ListCell *l;
1339 : :
6330 1340 [ - + ]: 435459 : Assert(containing_appendrel == NULL);
1341 : : /* Recursively transform all the child nodes */
8620 1342 [ + + + + : 903046 : foreach(l, f->fromlist)
+ + ]
1343 : : {
5128 1344 : 467587 : lfirst(l) = pull_up_subqueries_recurse(root, lfirst(l),
1345 : : lowest_outer_join,
1346 : : NULL);
1347 : : }
1348 : : }
8620 1349 [ + - ]: 83448 : else if (IsA(jtnode, JoinExpr))
1350 : : {
1351 : 83448 : JoinExpr *j = (JoinExpr *) jtnode;
1352 : :
6330 1353 [ - + ]: 83448 : Assert(containing_appendrel == NULL);
1354 : : /* Recurse, being careful to tell myself when inside outer join */
8620 1355 [ + + + + : 83448 : switch (j->jointype)
- ]
1356 : : {
1357 : 35051 : case JOIN_INNER:
5128 1358 : 35051 : j->larg = pull_up_subqueries_recurse(root, j->larg,
1359 : : lowest_outer_join,
1360 : : NULL);
1361 : 35051 : j->rarg = pull_up_subqueries_recurse(root, j->rarg,
1362 : : lowest_outer_join,
1363 : : NULL);
8620 1364 : 35051 : break;
1365 : 46464 : case JOIN_LEFT:
1366 : : case JOIN_SEMI:
1367 : : case JOIN_ANTI:
5128 1368 : 46464 : j->larg = pull_up_subqueries_recurse(root, j->larg,
1369 : : j,
1370 : : NULL);
1371 : 46464 : j->rarg = pull_up_subqueries_recurse(root, j->rarg,
1372 : : j,
1373 : : NULL);
8620 1374 : 46464 : break;
1375 : 960 : case JOIN_FULL:
5128 1376 : 960 : j->larg = pull_up_subqueries_recurse(root, j->larg,
1377 : : j,
1378 : : NULL);
1379 : 960 : j->rarg = pull_up_subqueries_recurse(root, j->rarg,
1380 : : j,
1381 : : NULL);
8620 1382 : 960 : break;
1383 : 973 : case JOIN_RIGHT:
5128 1384 : 973 : j->larg = pull_up_subqueries_recurse(root, j->larg,
1385 : : j,
1386 : : NULL);
1387 : 973 : j->rarg = pull_up_subqueries_recurse(root, j->rarg,
1388 : : j,
1389 : : NULL);
8620 1390 : 973 : break;
8620 tgl@sss.pgh.pa.us 1391 :UBC 0 : default:
8434 1392 [ # # ]: 0 : elog(ERROR, "unrecognized join type: %d",
1393 : : (int) j->jointype);
1394 : : break;
1395 : : }
1396 : : }
1397 : : else
1398 [ # # ]: 0 : elog(ERROR, "unrecognized node type: %d",
1399 : : (int) nodeTag(jtnode));
8620 tgl@sss.pgh.pa.us 1400 :CBC 996083 : return jtnode;
1401 : : }
1402 : :
1403 : : /*
1404 : : * pull_up_simple_subquery
1405 : : * Attempt to pull up a single simple subquery.
1406 : : *
1407 : : * jtnode is a RangeTblRef that has been tentatively identified as a simple
1408 : : * subquery by pull_up_subqueries. We return the replacement jointree node,
1409 : : * or jtnode itself if we determine that the subquery can't be pulled up
1410 : : * after all.
1411 : : *
1412 : : * rte is the RangeTblEntry referenced by jtnode. Remaining parameters are
1413 : : * as for pull_up_subqueries_recurse.
1414 : : */
1415 : : static Node *
7510 1416 : 29531 : pull_up_simple_subquery(PlannerInfo *root, Node *jtnode, RangeTblEntry *rte,
1417 : : JoinExpr *lowest_outer_join,
1418 : : AppendRelInfo *containing_appendrel)
1419 : : {
1420 : 29531 : Query *parse = root->parse;
1421 : 29531 : int varno = ((RangeTblRef *) jtnode)->rtindex;
1422 : : Query *subquery;
1423 : : PlannerInfo *subroot;
1424 : : int rtoffset;
1425 : : pullup_replace_vars_context rvcontext;
1426 : : ListCell *lc;
1427 : :
1428 : : /*
1429 : : * Make a modifiable copy of the subquery to hack on, so that the RTE will
1430 : : * be left unchanged in case we decide below that we can't pull it up
1431 : : * after all.
1432 : : */
1433 : 29531 : subquery = copyObject(rte->subquery);
1434 : :
1435 : : /*
1436 : : * Create a PlannerInfo data structure for this subquery.
1437 : : *
1438 : : * NOTE: the next few steps should match the first processing in
1439 : : * subquery_planner(). Can we refactor to avoid code duplication, or
1440 : : * would that just make things uglier?
1441 : : */
1442 : 29531 : subroot = makeNode(PlannerInfo);
1443 : 29531 : subroot->parse = subquery;
7129 1444 : 29531 : subroot->glob = root->glob;
1445 : 29531 : subroot->query_level = root->query_level;
324 rhaas@postgresql.org 1446 : 29531 : subroot->plan_name = root->plan_name;
154 1447 : 29531 : subroot->alternative_plan_name = root->alternative_plan_name;
6536 tgl@sss.pgh.pa.us 1448 : 29531 : subroot->parent_root = root->parent_root;
5104 1449 : 29531 : subroot->plan_params = NIL;
4034 1450 : 29531 : subroot->outer_params = NULL;
7159 1451 : 29531 : subroot->planner_cxt = CurrentMemoryContext;
7129 1452 : 29531 : subroot->init_plans = NIL;
6536 1453 : 29531 : subroot->cte_plan_ids = NIL;
4453 1454 : 29531 : subroot->multiexpr_params = NIL;
1305 1455 : 29531 : subroot->join_domains = NIL;
6736 1456 : 29531 : subroot->eq_classes = NIL;
2594 drowley@postgresql.o 1457 : 29531 : subroot->ec_merging_done = false;
1305 tgl@sss.pgh.pa.us 1458 : 29531 : subroot->last_rinfo_serial = 0;
1975 1459 : 29531 : subroot->all_result_relids = NULL;
1460 : 29531 : subroot->leaf_result_relids = NULL;
7510 1461 : 29531 : subroot->append_rel_list = NIL;
1975 1462 : 29531 : subroot->row_identity_vars = NIL;
6149 1463 : 29531 : subroot->rowMarks = NIL;
3825 1464 : 29531 : memset(subroot->upper_rels, 0, sizeof(subroot->upper_rels));
3818 1465 : 29531 : memset(subroot->upper_targets, 0, sizeof(subroot->upper_targets));
1317 1466 : 29531 : subroot->processed_groupClause = NIL;
1467 : 29531 : subroot->processed_distinctClause = NIL;
3825 1468 : 29531 : subroot->processed_tlist = NIL;
1975 1469 : 29531 : subroot->update_colnos = NIL;
3825 1470 : 29531 : subroot->grouping_map = NULL;
1471 : 29531 : subroot->minmax_aggs = NIL;
3508 1472 : 29531 : subroot->qual_security_level = 0;
1471 1473 : 29531 : subroot->placeholdersFrozen = false;
6536 1474 : 29531 : subroot->hasRecursion = false;
372 rhaas@postgresql.org 1475 : 29531 : subroot->assumeReplanning = false;
6536 tgl@sss.pgh.pa.us 1476 : 29531 : subroot->wt_param_id = -1;
3825 1477 : 29531 : subroot->non_recursive_path = NULL;
1478 : : /* We don't currently need a top JoinDomain for the subroot */
1479 : :
1480 : : /* No CTEs to worry about */
6536 1481 [ - + ]: 29531 : Assert(subquery->cteList == NIL);
1482 : :
1483 : : /*
1484 : : * Scan the rangetable for relation RTEs and retrieve the necessary
1485 : : * catalog information for each relation. Using this information, clear
1486 : : * the inh flag for any relation that has no children, collect not-null
1487 : : * attribute numbers for any relation that has column not-null
1488 : : * constraints, and expand virtual generated columns for any relation that
1489 : : * contains them.
1490 : : */
401 rguo@postgresql.org 1491 : 29531 : subquery = subroot->parse = preprocess_relation_rtes(subroot);
1492 : :
1493 : : /*
1494 : : * If the FROM clause is empty, replace it with a dummy RTE_RESULT RTE, so
1495 : : * that we don't need so many special cases to deal with that situation.
1496 : : */
2768 tgl@sss.pgh.pa.us 1497 : 29531 : replace_empty_jointree(subquery);
1498 : :
1499 : : /*
1500 : : * Pull up any SubLinks within the subquery's quals, so that we don't
1501 : : * leave unoptimized SubLinks behind.
1502 : : */
7510 1503 [ + + ]: 29531 : if (subquery->hasSubLinks)
6584 1504 : 1607 : pull_up_sublinks(subroot);
1505 : :
1506 : : /*
1507 : : * Similarly, preprocess its function RTEs to inline any set-returning
1508 : : * functions in its rangetable.
1509 : : */
2583 1510 : 29531 : preprocess_function_rtes(subroot);
1511 : :
1512 : : /*
1513 : : * Recursively pull up the subquery's subqueries, so that
1514 : : * pull_up_subqueries' processing is complete for its jointree and
1515 : : * rangetable.
1516 : : *
1517 : : * Note: it's okay that the subquery's recursion starts with NULL for
1518 : : * containing-join info, even if we are within an outer join in the upper
1519 : : * query; the lower query starts with a clean slate for outer-join
1520 : : * semantics. Likewise, we needn't pass down appendrel state.
1521 : : */
4187 1522 : 29531 : pull_up_subqueries(subroot);
1523 : :
1524 : : /*
1525 : : * Now we must recheck whether the subquery is still simple enough to pull
1526 : : * up. If not, abandon processing it.
1527 : : *
1528 : : * We don't really need to recheck all the conditions involved, but it's
1529 : : * easier just to keep this "if" looking the same as the one in
1530 : : * pull_up_subqueries_recurse.
1531 : : */
2044 1532 [ + + + + ]: 34696 : if (is_simple_subquery(root, subquery, rte, lowest_outer_join) &&
6330 1533 [ + + ]: 5293 : (containing_appendrel == NULL || is_safe_append_member(subquery)))
1534 : : {
1535 : : /* good to go */
1536 : : }
1537 : : else
1538 : : {
1539 : : /*
1540 : : * Give up, return unmodified RangeTblRef.
1541 : : *
1542 : : * Note: The work we just did will be redone when the subquery gets
1543 : : * planned on its own. Perhaps we could avoid that by storing the
1544 : : * modified subquery back into the rangetable, but I'm not gonna risk
1545 : : * it now.
1546 : : */
7510 1547 : 138 : return jtnode;
1548 : : }
1549 : :
1550 : : /*
1551 : : * We must flatten any join alias Vars in the subquery's targetlist,
1552 : : * because pulling up the subquery's subqueries might have changed their
1553 : : * expansions into arbitrary expressions, which could affect
1554 : : * pullup_replace_vars' decisions about whether PlaceHolderVar wrappers
1555 : : * are needed for tlist entries. (Likely it'd be better to do
1556 : : * flatten_join_alias_vars on the whole query tree at some earlier stage,
1557 : : * maybe even in the rewriter; but for now let's just fix this case here.)
1558 : : */
4661 1559 : 29393 : subquery->targetList = (List *)
1305 1560 : 29393 : flatten_join_alias_vars(subroot, subroot->parse,
1561 : 29393 : (Node *) subquery->targetList);
1562 : :
1563 : : /*
1564 : : * Adjust level-0 varnos in subquery so that we can append its rangetable
1565 : : * to upper query's. We have to fix the subquery's append_rel_list as
1566 : : * well.
1567 : : */
7510 1568 : 29393 : rtoffset = list_length(parse->rtable);
1569 : 29393 : OffsetVarNodes((Node *) subquery, rtoffset, 0);
1570 : 29393 : OffsetVarNodes((Node *) subroot->append_rel_list, rtoffset, 0);
1571 : :
1572 : : /*
1573 : : * Upper-level vars in subquery are now one level closer to their parent
1574 : : * than before.
1575 : : */
1576 : 29393 : IncrementVarSublevelsUp((Node *) subquery, -1, 1);
1577 : 29393 : IncrementVarSublevelsUp((Node *) subroot->append_rel_list, -1, 1);
1578 : :
1579 : : /*
1580 : : * The subquery's targetlist items are now in the appropriate form to
1581 : : * insert into the top query, except that we may need to wrap them in
1582 : : * PlaceHolderVars. Set up required context data for pullup_replace_vars.
1583 : : * (Note that we should include the subquery's inner joins in relids,
1584 : : * since it may include join alias vars referencing them.)
1585 : : */
6203 1586 : 29393 : rvcontext.root = root;
1587 : 29393 : rvcontext.targetlist = subquery->targetList;
1588 : 29393 : rvcontext.target_rte = rte;
548 rguo@postgresql.org 1589 : 29393 : rvcontext.result_relation = 0;
4758 tgl@sss.pgh.pa.us 1590 [ + + ]: 29393 : if (rte->lateral)
1591 : : {
1592 : 1381 : rvcontext.relids = get_relids_in_jointree((Node *) subquery->jointree,
1593 : : true, true);
635 1594 : 1381 : rvcontext.nullinfo = get_nullingrels(parse);
1595 : : }
1596 : : else /* won't need these values */
1597 : : {
4758 1598 : 28012 : rvcontext.relids = NULL;
635 1599 : 28012 : rvcontext.nullinfo = NULL;
1600 : : }
6203 1601 : 29393 : rvcontext.outer_hasSubLinks = &parse->hasSubLinks;
1602 : 29393 : rvcontext.varno = varno;
1603 : : /* this flag will be set below, if needed */
532 rguo@postgresql.org 1604 : 29393 : rvcontext.wrap_option = REPLACE_WRAP_NONE;
1605 : : /* initialize cache array with indexes 0 .. length(tlist) */
10 michael@paquier.xyz 1606 :GNC 29393 : rvcontext.rv_cache = palloc0_array(Node *, list_length(subquery->targetList) + 1);
1607 : :
1608 : : /*
1609 : : * If the parent query uses grouping sets, we need a PlaceHolderVar for
1610 : : * each expression of the subquery's targetlist items. This ensures that
1611 : : * expressions retain their separate identity so that they will match
1612 : : * grouping set columns when appropriate. (It'd be sufficient to wrap
1613 : : * values used in grouping set columns, and do so only in non-aggregated
1614 : : * portions of the tlist and havingQual, but that would require a lot of
1615 : : * infrastructure that pullup_replace_vars hasn't currently got.)
1616 : : */
3149 tgl@sss.pgh.pa.us 1617 [ + + ]:CBC 29393 : if (parse->groupingSets)
532 rguo@postgresql.org 1618 : 401 : rvcontext.wrap_option = REPLACE_WRAP_ALL;
1619 : :
1620 : : /*
1621 : : * Replace all of the top query's references to the subquery's outputs
1622 : : * with copies of the adjusted subtlist items, being careful not to
1623 : : * replace any of the jointree structure.
1624 : : */
2583 tgl@sss.pgh.pa.us 1625 : 29393 : perform_pullup_replace_vars(root, &rvcontext,
1626 : : containing_appendrel);
1627 : :
1628 : : /*
1629 : : * If the subquery had a LATERAL marker, propagate that to any of its
1630 : : * child RTEs that could possibly now contain lateral cross-references.
1631 : : * The children might or might not contain any actual lateral
1632 : : * cross-references, but we have to mark the pulled-up child RTEs so that
1633 : : * later planner stages will check for such.
1634 : : */
5128 1635 [ + + ]: 29393 : if (rte->lateral)
1636 : : {
1637 [ + - + + : 3656 : foreach(lc, subquery->rtable)
+ + ]
1638 : : {
1639 : 2275 : RangeTblEntry *child_rte = (RangeTblEntry *) lfirst(lc);
1640 : :
1641 [ + + + - : 2275 : switch (child_rte->rtekind)
- ]
1642 : : {
4051 1643 : 1580 : case RTE_RELATION:
1644 [ + + ]: 1580 : if (child_rte->tablesample)
1645 : 31 : child_rte->lateral = true;
1646 : 1580 : break;
5128 1647 : 247 : case RTE_SUBQUERY:
1648 : : case RTE_FUNCTION:
1649 : : case RTE_VALUES:
1650 : : case RTE_TABLEFUNC:
1651 : 247 : child_rte->lateral = true;
1652 : 247 : break;
1653 : 448 : case RTE_JOIN:
1654 : : case RTE_CTE:
1655 : : case RTE_NAMEDTUPLESTORE:
1656 : : case RTE_RESULT:
1657 : : case RTE_GROUP:
1658 : : /* these can't contain any lateral references */
1659 : 448 : break;
164 peter@eisentraut.org 1660 :UBC 0 : case RTE_GRAPH_TABLE:
1661 : : /* shouldn't happen here */
1662 : 0 : Assert(false);
1663 : : break;
1664 : : }
1665 : : }
1666 : : }
1667 : :
1668 : : /*
1669 : : * Now append the adjusted rtable entries and their perminfos to upper
1670 : : * query. (We hold off until after fixing the upper rtable entries; no
1671 : : * point in running that code on the subquery ones too.)
1672 : : */
1360 alvherre@alvh.no-ip. 1673 :CBC 29393 : CombineRangeTables(&parse->rtable, &parse->rteperminfos,
1674 : : subquery->rtable, subquery->rteperminfos);
1675 : :
1676 : : /*
1677 : : * Pull up any FOR UPDATE/SHARE markers, too. (OffsetVarNodes already
1678 : : * adjusted the marker rtindexes, so just concat the lists.)
1679 : : */
7510 tgl@sss.pgh.pa.us 1680 : 29393 : parse->rowMarks = list_concat(parse->rowMarks, subquery->rowMarks);
1681 : :
1682 : : /*
1683 : : * We also have to fix the relid sets of any PlaceHolderVar nodes in the
1684 : : * parent query. (This could perhaps be done by pullup_replace_vars(),
1685 : : * but it seems cleaner to use two passes.) Note in particular that any
1686 : : * PlaceHolderVar nodes just created by pullup_replace_vars() will be
1687 : : * adjusted, so having created them with the subquery's varno is correct.
1688 : : *
1689 : : * Likewise, relids appearing in AppendRelInfo nodes have to be fixed. We
1690 : : * already checked that this won't require introducing multiple subrelids
1691 : : * into the single-slot AppendRelInfo structs.
1692 : : */
1344 1693 [ + + + + ]: 29393 : if (root->glob->lastPHId != 0 || root->append_rel_list)
1694 : : {
1695 : : Relids subrelids;
1696 : :
1305 1697 : 6948 : subrelids = get_relids_in_jointree((Node *) subquery->jointree,
1698 : : true, false);
1344 1699 [ + + ]: 6948 : if (root->glob->lastPHId != 0)
1700 : 1813 : substitute_phv_relids((Node *) parse, varno, subrelids);
1701 : 6948 : fix_append_rel_relids(root, varno, subrelids);
1702 : : }
1703 : :
1704 : : /*
1705 : : * And now add subquery's AppendRelInfos to our list.
1706 : : */
7510 1707 : 58786 : root->append_rel_list = list_concat(root->append_rel_list,
1708 : 29393 : subroot->append_rel_list);
1709 : :
1710 : : /*
1711 : : * We don't have to do the equivalent bookkeeping for outer-join info,
1712 : : * because that hasn't been set up yet. placeholder_list likewise.
1713 : : */
6587 1714 [ - + ]: 29393 : Assert(root->join_info_list == NIL);
1715 [ - + ]: 29393 : Assert(subroot->join_info_list == NIL);
6518 1716 [ - + ]: 29393 : Assert(root->placeholder_list == NIL);
1717 [ - + ]: 29393 : Assert(subroot->placeholder_list == NIL);
1718 : :
1719 : : /*
1720 : : * We no longer need the RTE's copy of the subquery's query tree. Getting
1721 : : * rid of it saves nothing in particular so far as this level of query is
1722 : : * concerned; but if this query level is in turn pulled up into a parent,
1723 : : * we'd waste cycles copying the now-unused query tree.
1724 : : */
1878 1725 : 29393 : rte->subquery = NULL;
1726 : :
1727 : : /*
1728 : : * Miscellaneous housekeeping.
1729 : : *
1730 : : * Although replace_rte_variables() faithfully updated parse->hasSubLinks
1731 : : * if it copied any SubLinks out of the subquery's targetlist, we still
1732 : : * could have SubLinks added to the query in the expressions of FUNCTION
1733 : : * and VALUES RTEs copied up from the subquery. So it's necessary to copy
1734 : : * subquery->hasSubLinks anyway. Perhaps this can be improved someday.
1735 : : */
7510 1736 : 29393 : parse->hasSubLinks |= subquery->hasSubLinks;
1737 : :
1738 : : /* If subquery had any RLS conditions, now main query does too */
3577 1739 : 29393 : parse->hasRowSecurity |= subquery->hasRowSecurity;
1740 : :
1741 : : /*
1742 : : * subquery won't be pulled up if it hasAggs, hasWindowFuncs, or
1743 : : * hasTargetSRFs, so no work needed on those flags
1744 : : */
1745 : :
1746 : : /*
1747 : : * Return the adjusted subquery jointree to replace the RangeTblRef entry
1748 : : * in parent's jointree; or, if the FromExpr is degenerate, just return
1749 : : * its single member.
1750 : : */
2768 1751 [ - + ]: 29393 : Assert(IsA(subquery->jointree, FromExpr));
1752 [ - + ]: 29393 : Assert(subquery->jointree->fromlist != NIL);
1753 [ + + + + ]: 54369 : if (subquery->jointree->quals == NULL &&
1754 : 24976 : list_length(subquery->jointree->fromlist) == 1)
1755 : 24708 : return (Node *) linitial(subquery->jointree->fromlist);
1756 : :
7510 1757 : 4685 : return (Node *) subquery->jointree;
1758 : : }
1759 : :
1760 : : /*
1761 : : * pull_up_simple_union_all
1762 : : * Pull up a single simple UNION ALL subquery.
1763 : : *
1764 : : * jtnode is a RangeTblRef that has been identified as a simple UNION ALL
1765 : : * subquery by pull_up_subqueries. We pull up the leaf subqueries and
1766 : : * build an "append relation" for the union set. The result value is just
1767 : : * jtnode, since we don't actually need to change the query jointree.
1768 : : */
1769 : : static Node *
1770 : 4005 : pull_up_simple_union_all(PlannerInfo *root, Node *jtnode, RangeTblEntry *rte)
1771 : : {
1772 : 4005 : int varno = ((RangeTblRef *) jtnode)->rtindex;
1773 : 4005 : Query *subquery = rte->subquery;
5129 1774 : 4005 : int rtoffset = list_length(root->parse->rtable);
1775 : : List *rtable;
1776 : :
1777 : : /*
1778 : : * Make a modifiable copy of the subquery's rtable, so we can adjust
1779 : : * upper-level Vars in it. There are no such Vars in the setOperations
1780 : : * tree proper, so fixing the rtable should be sufficient.
1781 : : */
1782 : 4005 : rtable = copyObject(subquery->rtable);
1783 : :
1784 : : /*
1785 : : * Upper-level vars in subquery are now one level closer to their parent
1786 : : * than before. We don't have to worry about offsetting varnos, though,
1787 : : * because the UNION leaf queries can't cross-reference each other.
1788 : : */
6587 heikki.linnakangas@i 1789 : 4005 : IncrementVarSublevelsUp_rtable(rtable, -1, 1);
1790 : :
1791 : : /*
1792 : : * If the UNION ALL subquery had a LATERAL marker, propagate that to all
1793 : : * its children. The individual children might or might not contain any
1794 : : * actual lateral cross-references, but we have to mark the pulled-up
1795 : : * child RTEs so that later planner stages will check for such.
1796 : : */
5129 tgl@sss.pgh.pa.us 1797 [ + + ]: 4005 : if (rte->lateral)
1798 : : {
1799 : : ListCell *rt;
1800 : :
1801 [ + - + + : 1078 : foreach(rt, rtable)
+ + ]
1802 : : {
1803 : 837 : RangeTblEntry *child_rte = (RangeTblEntry *) lfirst(rt);
1804 : :
1805 [ - + ]: 837 : Assert(child_rte->rtekind == RTE_SUBQUERY);
1806 : 837 : child_rte->lateral = true;
1807 : : }
1808 : : }
1809 : :
1810 : : /*
1811 : : * Append child RTEs (and their perminfos) to parent rtable.
1812 : : */
1360 alvherre@alvh.no-ip. 1813 : 4005 : CombineRangeTables(&root->parse->rtable, &root->parse->rteperminfos,
1814 : : rtable, subquery->rteperminfos);
1815 : :
1816 : : /*
1817 : : * Recursively scan the subquery's setOperations tree and add
1818 : : * AppendRelInfo nodes for leaf subqueries to the parent's
1819 : : * append_rel_list. Also apply pull_up_subqueries to the leaf subqueries.
1820 : : */
7510 tgl@sss.pgh.pa.us 1821 [ - + ]: 4005 : Assert(subquery->setOperations);
6587 heikki.linnakangas@i 1822 : 4005 : pull_up_union_leaf_queries(subquery->setOperations, root, varno, subquery,
1823 : : rtoffset);
1824 : :
1825 : : /*
1826 : : * Mark the parent as an append relation.
1827 : : */
7510 tgl@sss.pgh.pa.us 1828 : 4005 : rte->inh = true;
1829 : :
1830 : 4005 : return jtnode;
1831 : : }
1832 : :
1833 : : /*
1834 : : * pull_up_union_leaf_queries -- recursive guts of pull_up_simple_union_all
1835 : : *
1836 : : * Build an AppendRelInfo for each leaf query in the setop tree, and then
1837 : : * apply pull_up_subqueries to the leaf query.
1838 : : *
1839 : : * Note that setOpQuery is the Query containing the setOp node, whose tlist
1840 : : * contains references to all the setop output columns. When called from
1841 : : * pull_up_simple_union_all, this is *not* the same as root->parse, which is
1842 : : * the parent Query we are pulling up into.
1843 : : *
1844 : : * parentRTindex is the appendrel parent's index in root->parse->rtable.
1845 : : *
1846 : : * The child RTEs have already been copied to the parent. childRToffset
1847 : : * tells us where in the parent's range table they were copied. When called
1848 : : * from flatten_simple_union_all, childRToffset is 0 since the child RTEs
1849 : : * were already in root->parse->rtable and no RT index adjustment is needed.
1850 : : */
1851 : : static void
1852 : 19826 : pull_up_union_leaf_queries(Node *setOp, PlannerInfo *root, int parentRTindex,
1853 : : Query *setOpQuery, int childRToffset)
1854 : : {
1855 [ + + ]: 19826 : if (IsA(setOp, RangeTblRef))
1856 : : {
1857 : 12191 : RangeTblRef *rtr = (RangeTblRef *) setOp;
1858 : : int childRTindex;
1859 : : AppendRelInfo *appinfo;
1860 : :
1861 : : /*
1862 : : * Calculate the index in the parent's range table
1863 : : */
6587 heikki.linnakangas@i 1864 : 12191 : childRTindex = childRToffset + rtr->rtindex;
1865 : :
1866 : : /*
1867 : : * Build a suitable AppendRelInfo, and attach to parent's list.
1868 : : */
7510 tgl@sss.pgh.pa.us 1869 : 12191 : appinfo = makeNode(AppendRelInfo);
1870 : 12191 : appinfo->parent_relid = parentRTindex;
1871 : 12191 : appinfo->child_relid = childRTindex;
1872 : 12191 : appinfo->parent_reltype = InvalidOid;
1873 : 12191 : appinfo->child_reltype = InvalidOid;
2460 1874 : 12191 : make_setop_translation_list(setOpQuery, childRTindex, appinfo);
7510 1875 : 12191 : appinfo->parent_reloid = InvalidOid;
1876 : 12191 : root->append_rel_list = lappend(root->append_rel_list, appinfo);
1877 : :
1878 : : /*
1879 : : * Recursively apply pull_up_subqueries to the new child RTE. (We
1880 : : * must build the AppendRelInfo first, because this will modify it;
1881 : : * indeed, that's the only part of the upper query where Vars
1882 : : * referencing childRTindex can exist at this point.)
1883 : : *
1884 : : * Note that we can pass NULL for containing-join info even if we're
1885 : : * actually under an outer join, because the child's expressions
1886 : : * aren't going to propagate up to the join. Also, we ignore the
1887 : : * possibility that pull_up_subqueries_recurse() returns a different
1888 : : * jointree node than what we pass it; if it does, the important thing
1889 : : * is that it replaced the child relid in the AppendRelInfo node.
1890 : : */
1891 : 12191 : rtr = makeNode(RangeTblRef);
1892 : 12191 : rtr->rtindex = childRTindex;
5128 1893 : 12191 : (void) pull_up_subqueries_recurse(root, (Node *) rtr,
1894 : : NULL, appinfo);
1895 : : }
7510 1896 [ + - ]: 7635 : else if (IsA(setOp, SetOperationStmt))
1897 : : {
1898 : 7635 : SetOperationStmt *op = (SetOperationStmt *) setOp;
1899 : :
1900 : : /* Recurse to reach leaf queries */
6587 heikki.linnakangas@i 1901 : 7635 : pull_up_union_leaf_queries(op->larg, root, parentRTindex, setOpQuery,
1902 : : childRToffset);
1903 : 7635 : pull_up_union_leaf_queries(op->rarg, root, parentRTindex, setOpQuery,
1904 : : childRToffset);
1905 : : }
1906 : : else
1907 : : {
7510 tgl@sss.pgh.pa.us 1908 [ # # ]:UBC 0 : elog(ERROR, "unrecognized node type: %d",
1909 : : (int) nodeTag(setOp));
1910 : : }
7510 tgl@sss.pgh.pa.us 1911 :CBC 19826 : }
1912 : :
1913 : : /*
1914 : : * make_setop_translation_list
1915 : : * Build the list of translations from parent Vars to child Vars for
1916 : : * a UNION ALL member. (At this point it's just a simple list of
1917 : : * referencing Vars, but if we succeed in pulling up the member
1918 : : * subquery, the Vars will get replaced by pulled-up expressions.)
1919 : : * Also create the rather trivial reverse-translation array.
1920 : : */
1921 : : static void
1807 1922 : 12191 : make_setop_translation_list(Query *query, int newvarno,
1923 : : AppendRelInfo *appinfo)
1924 : : {
7510 1925 : 12191 : List *vars = NIL;
1926 : : AttrNumber *pcolnos;
1927 : : ListCell *l;
1928 : :
1929 : : /* Initialize reverse-translation array with all entries zero */
1930 : : /* (entries for resjunk columns will stay that way) */
2460 1931 : 12191 : appinfo->num_child_cols = list_length(query->targetList);
10 michael@paquier.xyz 1932 :GNC 12191 : appinfo->parent_colnos = pcolnos = palloc0_array(AttrNumber, appinfo->num_child_cols);
1933 : :
7510 tgl@sss.pgh.pa.us 1934 [ + + + + :CBC 48600 : foreach(l, query->targetList)
+ + ]
1935 : : {
1936 : 36409 : TargetEntry *tle = (TargetEntry *) lfirst(l);
1937 : :
1938 [ - + ]: 36409 : if (tle->resjunk)
7510 tgl@sss.pgh.pa.us 1939 :UBC 0 : continue;
1940 : :
5844 peter_e@gmx.net 1941 :CBC 36409 : vars = lappend(vars, makeVarFromTargetEntry(newvarno, tle));
2460 tgl@sss.pgh.pa.us 1942 : 36409 : pcolnos[tle->resno - 1] = tle->resno;
1943 : : }
1944 : :
1945 : 12191 : appinfo->translated_vars = vars;
7510 1946 : 12191 : }
1947 : :
1948 : : /*
1949 : : * is_simple_subquery
1950 : : * Check a subquery in the range table to see if it's simple enough
1951 : : * to pull up into the parent query.
1952 : : *
1953 : : * rte is the RTE_SUBQUERY RangeTblEntry that contained the subquery.
1954 : : * (Note subquery is not necessarily equal to rte->subquery; it could be a
1955 : : * processed copy of that.)
1956 : : * lowest_outer_join is the lowest outer join above the subquery, or NULL.
1957 : : */
1958 : : static bool
2044 1959 : 80129 : is_simple_subquery(PlannerInfo *root, Query *subquery, RangeTblEntry *rte,
1960 : : JoinExpr *lowest_outer_join)
1961 : : {
1962 : : /*
1963 : : * Let's just make sure it's a valid subselect ...
1964 : : */
8620 1965 [ + - ]: 80129 : if (!IsA(subquery, Query) ||
3512 1966 [ - + ]: 80129 : subquery->commandType != CMD_SELECT)
8434 tgl@sss.pgh.pa.us 1967 [ # # ]:UBC 0 : elog(ERROR, "subquery is bogus");
1968 : :
1969 : : /*
1970 : : * Can't currently pull up a query with setops (unless it's simple UNION
1971 : : * ALL, which is handled by a different code path). Maybe after querytree
1972 : : * redesign...
1973 : : */
8620 tgl@sss.pgh.pa.us 1974 [ + + ]:CBC 80129 : if (subquery->setOperations)
1975 : 4712 : return false;
1976 : :
1977 : : /*
1978 : : * Can't pull up a subquery involving grouping, aggregation, SRFs,
1979 : : * sorting, limiting, or WITH. (XXX WITH could possibly be allowed later)
1980 : : *
1981 : : * We also don't pull up a subquery that has explicit FOR UPDATE/SHARE
1982 : : * clauses, because pullup would cause the locking to occur semantically
1983 : : * higher than it should. Implicit FOR UPDATE/SHARE is okay because in
1984 : : * that case the locking was originally declared in the upper query
1985 : : * anyway.
1986 : : */
1987 [ + + ]: 75417 : if (subquery->hasAggs ||
6451 1988 [ + + ]: 73888 : subquery->hasWindowFuncs ||
3635 1989 [ + + ]: 73478 : subquery->hasTargetSRFs ||
8620 1990 [ + + ]: 69816 : subquery->groupClause ||
4121 andres@anarazel.de 1991 [ + + ]: 69732 : subquery->groupingSets ||
8620 tgl@sss.pgh.pa.us 1992 [ + - ]: 69702 : subquery->havingQual ||
1993 [ + + ]: 69702 : subquery->sortClause ||
1994 [ + + ]: 68926 : subquery->distinctClause ||
1995 [ + + ]: 68278 : subquery->limitOffset ||
6536 1996 [ + + ]: 67893 : subquery->limitCount ||
6147 1997 [ + + ]: 67609 : subquery->hasForUpdate ||
6536 1998 [ + + ]: 64340 : subquery->cteList)
8620 1999 : 11222 : return false;
2000 : :
2001 : : /*
2002 : : * Don't pull up if the RTE represents a security-barrier view; we
2003 : : * couldn't prevent information leakage once the RTE's Vars are scattered
2004 : : * about in the upper query.
2005 : : */
5128 2006 [ + + ]: 64195 : if (rte->security_barrier)
5133 2007 : 1019 : return false;
2008 : :
2009 : : /*
2010 : : * If the subquery is LATERAL, check for pullup restrictions from that.
2011 : : */
4756 2012 [ + + ]: 63176 : if (rte->lateral)
2013 : : {
2014 : : bool restricted;
2015 : : Relids safe_upper_varnos;
2016 : :
2017 : : /*
2018 : : * The subquery's WHERE and JOIN/ON quals mustn't contain any lateral
2019 : : * references to rels outside a higher outer join (including the case
2020 : : * where the outer join is within the subquery itself). In such a
2021 : : * case, pulling up would result in a situation where we need to
2022 : : * postpone quals from below an outer join to above it, which is
2023 : : * probably completely wrong and in any case is a complication that
2024 : : * doesn't seem worth addressing at the moment.
2025 : : */
2026 [ + + ]: 3484 : if (lowest_outer_join != NULL)
2027 : : {
2028 : 1030 : restricted = true;
2029 : 1030 : safe_upper_varnos = get_relids_in_jointree((Node *) lowest_outer_join,
2030 : : true, true);
2031 : : }
2032 : : else
2033 : : {
2034 : 2454 : restricted = false;
2035 : 2454 : safe_upper_varnos = NULL; /* doesn't matter */
2036 : : }
2037 : :
2044 2038 [ + + ]: 3484 : if (jointree_contains_lateral_outer_refs(root,
2039 : 3484 : (Node *) subquery->jointree,
2040 : : restricted, safe_upper_varnos))
5128 2041 : 20 : return false;
2042 : :
2043 : : /*
2044 : : * If there's an outer join above the LATERAL subquery, also disallow
2045 : : * pullup if the subquery's targetlist has any references to rels
2046 : : * outside the outer join, since these might get pulled into quals
2047 : : * above the subquery (but in or below the outer join) and then lead
2048 : : * to qual-postponement issues similar to the case checked for above.
2049 : : * (We wouldn't need to prevent pullup if no such references appear in
2050 : : * outer-query quals, but we don't have enough info here to check
2051 : : * that. Also, maybe this restriction could be removed if we forced
2052 : : * such refs to be wrapped in PlaceHolderVars, even when they're below
2053 : : * the nearest outer join? But it's a pretty hokey usage, so not
2054 : : * clear this is worth sweating over.)
2055 : : *
2056 : : * If you change this, see also the comments about lateral references
2057 : : * in pullup_replace_vars_callback().
2058 : : */
4756 2059 [ + + ]: 3464 : if (lowest_outer_join != NULL)
2060 : : {
2044 2061 : 1030 : Relids lvarnos = pull_varnos_of_level(root,
2062 : 1030 : (Node *) subquery->targetList,
2063 : : 1);
2064 : :
4756 2065 [ + + ]: 1030 : if (!bms_is_subset(lvarnos, safe_upper_varnos))
2066 : 10 : return false;
2067 : : }
2068 : : }
2069 : :
2070 : : /*
2071 : : * Don't pull up a subquery that has any volatile functions in its
2072 : : * targetlist. Otherwise we might introduce multiple evaluations of these
2073 : : * functions, if they get copied to multiple places in the upper query,
2074 : : * leading to surprising results. (Note: the PlaceHolderVar mechanism
2075 : : * doesn't quite guarantee single evaluation; else we could pull up anyway
2076 : : * and just wrap such items in PlaceHolderVars ...)
2077 : : */
7313 2078 [ + + ]: 63146 : if (contain_volatile_functions((Node *) subquery->targetList))
8620 2079 : 218 : return false;
2080 : :
4187 2081 : 62928 : return true;
2082 : : }
2083 : :
2084 : : /*
2085 : : * pull_up_simple_values
2086 : : * Pull up a single simple VALUES RTE.
2087 : : *
2088 : : * jtnode is a RangeTblRef that has been identified as a simple VALUES RTE
2089 : : * by pull_up_subqueries. We always return a RangeTblRef representing a
2090 : : * RESULT RTE to replace it (all failure cases should have been detected by
2091 : : * is_simple_values()). Actually, what we return is just jtnode, because
2092 : : * we replace the VALUES RTE in the rangetable with the RESULT RTE.
2093 : : *
2094 : : * rte is the RangeTblEntry referenced by jtnode. Because of the limited
2095 : : * possible usage of VALUES RTEs, we do not need the remaining parameters
2096 : : * of pull_up_subqueries_recurse.
2097 : : */
2098 : : static Node *
2099 : 3768 : pull_up_simple_values(PlannerInfo *root, Node *jtnode, RangeTblEntry *rte)
2100 : : {
2101 : 3768 : Query *parse = root->parse;
2102 : 3768 : int varno = ((RangeTblRef *) jtnode)->rtindex;
2103 : : List *values_list;
2104 : : List *tlist;
2105 : : AttrNumber attrno;
2106 : : pullup_replace_vars_context rvcontext;
2107 : : ListCell *lc;
2108 : :
2109 [ - + ]: 3768 : Assert(rte->rtekind == RTE_VALUES);
2110 [ - + ]: 3768 : Assert(list_length(rte->values_lists) == 1);
2111 : :
2112 : : /*
2113 : : * Need a modifiable copy of the VALUES list to hack on, just in case it's
2114 : : * multiply referenced.
2115 : : */
3458 peter_e@gmx.net 2116 : 3768 : values_list = copyObject(linitial(rte->values_lists));
2117 : :
2118 : : /*
2119 : : * The VALUES RTE can't contain any Vars of level zero, let alone any that
2120 : : * are join aliases, so no need to flatten join alias Vars.
2121 : : */
4187 tgl@sss.pgh.pa.us 2122 [ - + ]: 3768 : Assert(!contain_vars_of_level((Node *) values_list, 0));
2123 : :
2124 : : /*
2125 : : * Set up required context data for pullup_replace_vars. In particular,
2126 : : * we have to make the VALUES list look like a subquery targetlist.
2127 : : */
2128 : 3768 : tlist = NIL;
2129 : 3768 : attrno = 1;
2130 [ + + + + : 8062 : foreach(lc, values_list)
+ + ]
2131 : : {
2132 : 4294 : tlist = lappend(tlist,
2133 : 4294 : makeTargetEntry((Expr *) lfirst(lc),
2134 : : attrno,
2135 : : NULL,
2136 : : false));
2137 : 4294 : attrno++;
2138 : : }
2139 : 3768 : rvcontext.root = root;
2140 : 3768 : rvcontext.targetlist = tlist;
2141 : 3768 : rvcontext.target_rte = rte;
548 rguo@postgresql.org 2142 : 3768 : rvcontext.result_relation = 0;
635 tgl@sss.pgh.pa.us 2143 : 3768 : rvcontext.relids = NULL; /* can't be any lateral references here */
2144 : 3768 : rvcontext.nullinfo = NULL;
4187 2145 : 3768 : rvcontext.outer_hasSubLinks = &parse->hasSubLinks;
2146 : 3768 : rvcontext.varno = varno;
532 rguo@postgresql.org 2147 : 3768 : rvcontext.wrap_option = REPLACE_WRAP_NONE;
2148 : : /* initialize cache array with indexes 0 .. length(tlist) */
10 michael@paquier.xyz 2149 :GNC 3768 : rvcontext.rv_cache = palloc0_array(Node *, list_length(tlist) + 1);
2150 : :
2151 : : /*
2152 : : * Replace all of the top query's references to the RTE's outputs with
2153 : : * copies of the adjusted VALUES expressions, being careful not to replace
2154 : : * any of the jointree structure. We can assume there's no outer joins or
2155 : : * appendrels in the dummy Query that surrounds a VALUES RTE.
2156 : : */
1305 tgl@sss.pgh.pa.us 2157 :CBC 3768 : perform_pullup_replace_vars(root, &rvcontext, NULL);
2158 : :
2159 : : /*
2160 : : * There should be no appendrels to fix, nor any outer joins and hence no
2161 : : * PlaceHolderVars.
2162 : : */
4187 2163 [ - + ]: 3768 : Assert(root->append_rel_list == NIL);
2164 [ - + ]: 3768 : Assert(root->join_info_list == NIL);
2165 [ - + ]: 3768 : Assert(root->placeholder_list == NIL);
2166 : :
2167 : : /*
2168 : : * Replace the VALUES RTE with a RESULT RTE. The VALUES RTE is the only
2169 : : * rtable entry in the current query level, so this is easy.
2170 : : */
2768 2171 [ - + ]: 3768 : Assert(list_length(parse->rtable) == 1);
2172 : :
2173 : : /* Create suitable RTE */
2174 : 3768 : rte = makeNode(RangeTblEntry);
2175 : 3768 : rte->rtekind = RTE_RESULT;
2176 : 3768 : rte->eref = makeAlias("*RESULT*", NIL);
2177 : :
2178 : : /* Replace rangetable */
2179 : 3768 : parse->rtable = list_make1(rte);
2180 : :
2181 : : /* We could manufacture a new RangeTblRef, but the one we have is fine */
2182 [ - + ]: 3768 : Assert(varno == 1);
2183 : :
2184 : 3768 : return jtnode;
2185 : : }
2186 : :
2187 : : /*
2188 : : * is_simple_values
2189 : : * Check a VALUES RTE in the range table to see if it's simple enough
2190 : : * to pull up into the parent query.
2191 : : *
2192 : : * rte is the RTE_VALUES RangeTblEntry to check.
2193 : : */
2194 : : static bool
2195 : 10695 : is_simple_values(PlannerInfo *root, RangeTblEntry *rte)
2196 : : {
4187 2197 [ - + ]: 10695 : Assert(rte->rtekind == RTE_VALUES);
2198 : :
2199 : : /*
2200 : : * There must be exactly one VALUES list, else it's not semantically
2201 : : * correct to replace the VALUES RTE with a RESULT RTE, nor would we have
2202 : : * a unique set of expressions to substitute into the parent query.
2203 : : */
2204 [ + + ]: 10695 : if (list_length(rte->values_lists) != 1)
2205 : 6927 : return false;
2206 : :
2207 : : /*
2208 : : * Because VALUES can't appear under an outer join (or at least, we won't
2209 : : * try to pull it up if it does), we need not worry about LATERAL, nor
2210 : : * about validity of PHVs for the VALUES' outputs.
2211 : : */
2212 : :
2213 : : /*
2214 : : * Don't pull up a VALUES that contains any set-returning or volatile
2215 : : * functions. The considerations here are basically identical to the
2216 : : * restrictions on a pull-able subquery's targetlist.
2217 : : */
2218 [ + - - + ]: 7536 : if (expression_returns_set((Node *) rte->values_lists) ||
2219 : 3768 : contain_volatile_functions((Node *) rte->values_lists))
4187 tgl@sss.pgh.pa.us 2220 :UBC 0 : return false;
2221 : :
2222 : : /*
2223 : : * Do not pull up a VALUES that's not the only RTE in its parent query.
2224 : : * This is actually the only case that the parser will generate at the
2225 : : * moment, and assuming this is true greatly simplifies
2226 : : * pull_up_simple_values().
2227 : : */
4187 tgl@sss.pgh.pa.us 2228 [ + - ]:CBC 3768 : if (list_length(root->parse->rtable) != 1 ||
2229 [ - + ]: 3768 : rte != (RangeTblEntry *) linitial(root->parse->rtable))
8620 tgl@sss.pgh.pa.us 2230 :UBC 0 : return false;
2231 : :
8620 tgl@sss.pgh.pa.us 2232 :CBC 3768 : return true;
2233 : : }
2234 : :
2235 : : /*
2236 : : * pull_up_constant_function
2237 : : * Pull up an RTE_FUNCTION expression that was simplified to a constant.
2238 : : *
2239 : : * jtnode is a RangeTblRef that has been identified as a FUNCTION RTE by
2240 : : * pull_up_subqueries. If its expression is just a Const, hoist that value
2241 : : * up into the parent query, and replace the RTE_FUNCTION with RTE_RESULT.
2242 : : *
2243 : : * In principle we could pull up any immutable expression, but we don't.
2244 : : * That might result in multiple evaluations of the expression, which could
2245 : : * be costly if it's not just a Const. Also, the main value of this is
2246 : : * to let the constant participate in further const-folding, and of course
2247 : : * that won't happen for a non-Const.
2248 : : *
2249 : : * The pulled-up value might need to be wrapped in a PlaceHolderVar if the
2250 : : * RTE is below an outer join or is part of an appendrel; the extra
2251 : : * parameters show whether that's needed.
2252 : : */
2253 : : static Node *
2583 2254 : 35565 : pull_up_constant_function(PlannerInfo *root, Node *jtnode,
2255 : : RangeTblEntry *rte,
2256 : : AppendRelInfo *containing_appendrel)
2257 : : {
2258 : 35565 : Query *parse = root->parse;
2259 : : RangeTblFunction *rtf;
2260 : : TypeFuncClass functypclass;
2261 : : Oid funcrettype;
2262 : : TupleDesc tupdesc;
2263 : : pullup_replace_vars_context rvcontext;
2264 : :
2265 : : /* Fail if the RTE has ORDINALITY - we don't implement that here. */
2266 [ + + ]: 35565 : if (rte->funcordinality)
2267 : 759 : return jtnode;
2268 : :
2269 : : /* Fail if RTE isn't a single, simple Const expr */
2270 [ + + ]: 34806 : if (list_length(rte->functions) != 1)
2271 : 72 : return jtnode;
2272 : 34734 : rtf = linitial_node(RangeTblFunction, rte->functions);
2273 [ + + ]: 34734 : if (!IsA(rtf->funcexpr, Const))
2274 : 34424 : return jtnode;
2275 : :
2276 : : /*
2277 : : * If the function's result is not a scalar, we punt. In principle we
2278 : : * could break the composite constant value apart into per-column
2279 : : * constants, but for now it seems not worth the work.
2280 : : */
2529 2281 [ + + ]: 310 : if (rtf->funccolcount != 1)
2282 : 25 : return jtnode; /* definitely composite */
2283 : :
2284 : : /* If it has a coldeflist, it certainly returns RECORD */
864 2285 [ - + ]: 285 : if (rtf->funccolnames != NIL)
864 tgl@sss.pgh.pa.us 2286 :UBC 0 : return jtnode; /* must be a one-column RECORD type */
2287 : :
2529 tgl@sss.pgh.pa.us 2288 :CBC 285 : functypclass = get_expr_result_type(rtf->funcexpr,
2289 : : &funcrettype,
2290 : : &tupdesc);
2291 [ + + ]: 285 : if (functypclass != TYPEFUNC_SCALAR)
2292 : 10 : return jtnode; /* must be a one-column composite type */
2293 : :
2294 : : /* Create context for applying pullup_replace_vars */
2583 2295 : 275 : rvcontext.root = root;
2296 : 275 : rvcontext.targetlist = list_make1(makeTargetEntry((Expr *) rtf->funcexpr,
2297 : : 1, /* resno */
2298 : : NULL, /* resname */
2299 : : false)); /* resjunk */
2300 : 275 : rvcontext.target_rte = rte;
548 rguo@postgresql.org 2301 : 275 : rvcontext.result_relation = 0;
2302 : :
2303 : : /*
2304 : : * Since this function was reduced to a Const, it doesn't contain any
2305 : : * lateral references, even if it's marked as LATERAL. This means we
2306 : : * don't need to fill relids or nullinfo.
2307 : : */
2583 tgl@sss.pgh.pa.us 2308 : 275 : rvcontext.relids = NULL;
635 2309 : 275 : rvcontext.nullinfo = NULL;
2310 : :
2583 2311 : 275 : rvcontext.outer_hasSubLinks = &parse->hasSubLinks;
2312 : 275 : rvcontext.varno = ((RangeTblRef *) jtnode)->rtindex;
2313 : : /* this flag will be set below, if needed */
532 rguo@postgresql.org 2314 : 275 : rvcontext.wrap_option = REPLACE_WRAP_NONE;
2315 : : /* initialize cache array with indexes 0 .. length(tlist) */
10 michael@paquier.xyz 2316 :GNC 275 : rvcontext.rv_cache = palloc0_array(Node *, list_length(rvcontext.targetlist) + 1);
2317 : :
2318 : : /*
2319 : : * If the parent query uses grouping sets, we need a PlaceHolderVar for
2320 : : * each expression of the subquery's targetlist items. (See comments in
2321 : : * pull_up_simple_subquery().)
2322 : : */
2583 tgl@sss.pgh.pa.us 2323 [ - + ]:CBC 275 : if (parse->groupingSets)
532 rguo@postgresql.org 2324 :UBC 0 : rvcontext.wrap_option = REPLACE_WRAP_ALL;
2325 : :
2326 : : /*
2327 : : * Replace all of the top query's references to the RTE's output with
2328 : : * copies of the funcexpr, being careful not to replace any of the
2329 : : * jointree structure.
2330 : : */
2583 tgl@sss.pgh.pa.us 2331 :CBC 275 : perform_pullup_replace_vars(root, &rvcontext,
2332 : : containing_appendrel);
2333 : :
2334 : : /*
2335 : : * We don't need to bother with changing PlaceHolderVars in the parent
2336 : : * query. Their references to the RT index are still good for now, and
2337 : : * will get removed later if we're able to drop the RTE_RESULT.
2338 : : */
2339 : :
2340 : : /*
2341 : : * Convert the RTE to be RTE_RESULT type, signifying that we don't need to
2342 : : * scan it anymore, and zero out RTE_FUNCTION-specific fields. Also make
2343 : : * sure the RTE is not marked LATERAL, since elsewhere we don't expect
2344 : : * RTE_RESULTs to be LATERAL.
2345 : : */
2346 : 275 : rte->rtekind = RTE_RESULT;
2347 : 275 : rte->functions = NIL;
1875 2348 : 275 : rte->lateral = false;
2349 : :
2350 : : /*
2351 : : * We can reuse the RangeTblRef node.
2352 : : */
2583 2353 : 275 : return jtnode;
2354 : : }
2355 : :
2356 : : /*
2357 : : * is_simple_union_all
2358 : : * Check a subquery to see if it's a simple UNION ALL.
2359 : : *
2360 : : * We require all the setops to be UNION ALL (no mixing) and there can't be
2361 : : * any datatype coercions involved, ie, all the leaf queries must emit the
2362 : : * same datatypes.
2363 : : */
2364 : : static bool
7510 2365 : 21067 : is_simple_union_all(Query *subquery)
2366 : : {
2367 : : SetOperationStmt *topop;
2368 : :
2369 : : /* Let's just make sure it's a valid subselect ... */
2370 [ + - ]: 21067 : if (!IsA(subquery, Query) ||
3512 2371 [ - + ]: 21067 : subquery->commandType != CMD_SELECT)
7510 tgl@sss.pgh.pa.us 2372 [ # # ]:UBC 0 : elog(ERROR, "subquery is bogus");
2373 : :
2374 : : /* Is it a set-operation query at all? */
3474 peter_e@gmx.net 2375 :CBC 21067 : topop = castNode(SetOperationStmt, subquery->setOperations);
7510 tgl@sss.pgh.pa.us 2376 [ + + ]: 21067 : if (!topop)
2377 : 16355 : return false;
2378 : :
2379 : : /* Can't handle ORDER BY, LIMIT/OFFSET, locking, or WITH */
2380 [ + + ]: 4712 : if (subquery->sortClause ||
2381 [ + - ]: 4660 : subquery->limitOffset ||
2382 [ + - ]: 4660 : subquery->limitCount ||
6536 2383 [ + - ]: 4660 : subquery->rowMarks ||
2384 [ + + ]: 4660 : subquery->cteList)
7510 2385 : 162 : return false;
2386 : :
2387 : : /* Recursively check the tree of set operations */
2388 : 4550 : return is_simple_union_all_recurse((Node *) topop, subquery,
2389 : : topop->colTypes);
2390 : : }
2391 : :
2392 : : static bool
2393 : 25891 : is_simple_union_all_recurse(Node *setOp, Query *setOpQuery, List *colTypes)
2394 : : {
2395 : : /* Since this function recurses, it could be driven to stack overflow. */
1344 2396 : 25891 : check_stack_depth();
2397 : :
7510 2398 [ + + ]: 25891 : if (IsA(setOp, RangeTblRef))
2399 : : {
2400 : 12946 : RangeTblRef *rtr = (RangeTblRef *) setOp;
2401 : 12946 : RangeTblEntry *rte = rt_fetch(rtr->rtindex, setOpQuery->rtable);
2402 : 12946 : Query *subquery = rte->subquery;
2403 : :
2404 [ - + ]: 12946 : Assert(subquery != NULL);
2405 : :
2406 : : /* Leaf nodes are OK if they match the toplevel column types */
2407 : : /* We don't have to compare typmods or collations here */
2408 : 12946 : return tlist_same_datatypes(subquery->targetList, colTypes, true);
2409 : : }
2410 [ + - ]: 12945 : else if (IsA(setOp, SetOperationStmt))
2411 : : {
2412 : 12945 : SetOperationStmt *op = (SetOperationStmt *) setOp;
2413 : :
2414 : : /* Must be UNION ALL */
2415 [ + + + + ]: 12945 : if (op->op != SETOP_UNION || !op->all)
2416 : 4360 : return false;
2417 : :
2418 : : /* Recurse to check inputs */
2419 [ + + + + ]: 16514 : return is_simple_union_all_recurse(op->larg, setOpQuery, colTypes) &&
2420 : 7929 : is_simple_union_all_recurse(op->rarg, setOpQuery, colTypes);
2421 : : }
2422 : : else
2423 : : {
7510 tgl@sss.pgh.pa.us 2424 [ # # ]:UBC 0 : elog(ERROR, "unrecognized node type: %d",
2425 : : (int) nodeTag(setOp));
2426 : : return false; /* keep compiler quiet */
2427 : : }
2428 : : }
2429 : :
2430 : : /*
2431 : : * is_safe_append_member
2432 : : * Check a subquery that is a leaf of a UNION ALL appendrel to see if it's
2433 : : * safe to pull up.
2434 : : */
2435 : : static bool
7510 tgl@sss.pgh.pa.us 2436 :CBC 14462 : is_safe_append_member(Query *subquery)
2437 : : {
2438 : : FromExpr *jtnode;
2439 : :
2440 : : /*
2441 : : * It's only safe to pull up the child if its jointree contains exactly
2442 : : * one RTE, else the AppendRelInfo data structure breaks. The one base RTE
2443 : : * could be buried in several levels of FromExpr, however. Also, if the
2444 : : * child's jointree is completely empty, we can pull up because
2445 : : * pull_up_simple_subquery will insert a single RTE_RESULT RTE instead.
2446 : : *
2447 : : * Also, the child can't have any WHERE quals because there's no place to
2448 : : * put them in an appendrel. (This is a bit annoying...) If we didn't
2449 : : * need to check this, we'd just test whether get_relids_in_jointree()
2450 : : * yields a singleton set, to be more consistent with the coding of
2451 : : * fix_append_rel_relids().
2452 : : */
2453 : 14462 : jtnode = subquery->jointree;
2768 2454 [ - + ]: 14462 : Assert(IsA(jtnode, FromExpr));
2455 : : /* Check the completely-empty case */
2456 [ + + + + ]: 14462 : if (jtnode->fromlist == NIL && jtnode->quals == NULL)
2457 : 569 : return true;
2458 : : /* Check the more general case */
7510 2459 [ + + ]: 24717 : while (IsA(jtnode, FromExpr))
2460 : : {
2461 [ + + ]: 13903 : if (jtnode->quals != NULL)
2462 : 3079 : return false;
2463 [ - + ]: 10824 : if (list_length(jtnode->fromlist) != 1)
7510 tgl@sss.pgh.pa.us 2464 :UBC 0 : return false;
7510 tgl@sss.pgh.pa.us 2465 :CBC 10824 : jtnode = linitial(jtnode->fromlist);
2466 : : }
2467 [ + + ]: 10814 : if (!IsA(jtnode, RangeTblRef))
2468 : 925 : return false;
2469 : :
2470 : 9889 : return true;
2471 : : }
2472 : :
2473 : : /*
2474 : : * jointree_contains_lateral_outer_refs
2475 : : * Check for disallowed lateral references in a jointree's quals
2476 : : *
2477 : : * If restricted is false, all level-1 Vars are allowed (but we still must
2478 : : * search the jointree, since it might contain outer joins below which there
2479 : : * will be restrictions). If restricted is true, return true when any qual
2480 : : * in the jointree contains level-1 Vars coming from outside the rels listed
2481 : : * in safe_upper_varnos.
2482 : : */
2483 : : static bool
2044 2484 : 10241 : jointree_contains_lateral_outer_refs(PlannerInfo *root, Node *jtnode,
2485 : : bool restricted,
2486 : : Relids safe_upper_varnos)
2487 : : {
4756 2488 [ - + ]: 10241 : if (jtnode == NULL)
4756 tgl@sss.pgh.pa.us 2489 :UBC 0 : return false;
4756 tgl@sss.pgh.pa.us 2490 [ + + ]:CBC 10241 : if (IsA(jtnode, RangeTblRef))
2491 : 6458 : return false;
2492 [ + + ]: 3783 : else if (IsA(jtnode, FromExpr))
2493 : : {
2494 : 3524 : FromExpr *f = (FromExpr *) jtnode;
2495 : : ListCell *l;
2496 : :
2497 : : /* First, recurse to check child joins */
2498 [ + + + + : 9743 : foreach(l, f->fromlist)
+ + ]
2499 : : {
2044 2500 [ + + ]: 6239 : if (jointree_contains_lateral_outer_refs(root,
2501 : 6239 : lfirst(l),
2502 : : restricted,
2503 : : safe_upper_varnos))
4756 2504 : 20 : return true;
2505 : : }
2506 : :
2507 : : /* Then check the top-level quals */
2508 [ + + ]: 3504 : if (restricted &&
2044 2509 [ - + ]: 1070 : !bms_is_subset(pull_varnos_of_level(root, f->quals, 1),
2510 : : safe_upper_varnos))
4756 tgl@sss.pgh.pa.us 2511 :UBC 0 : return true;
2512 : : }
4756 tgl@sss.pgh.pa.us 2513 [ + - ]:CBC 259 : else if (IsA(jtnode, JoinExpr))
2514 : : {
2515 : 259 : JoinExpr *j = (JoinExpr *) jtnode;
2516 : :
2517 : : /*
2518 : : * If this is an outer join, we mustn't allow any upper lateral
2519 : : * references in or below it.
2520 : : */
2521 [ + + ]: 259 : if (j->jointype != JOIN_INNER)
2522 : : {
2523 : 129 : restricted = true;
2524 : 129 : safe_upper_varnos = NULL;
2525 : : }
2526 : :
2527 : : /* Check the child joins */
2044 2528 [ - + ]: 259 : if (jointree_contains_lateral_outer_refs(root,
2529 : : j->larg,
2530 : : restricted,
2531 : : safe_upper_varnos))
4756 tgl@sss.pgh.pa.us 2532 :UBC 0 : return true;
2044 tgl@sss.pgh.pa.us 2533 [ - + ]:CBC 259 : if (jointree_contains_lateral_outer_refs(root,
2534 : : j->rarg,
2535 : : restricted,
2536 : : safe_upper_varnos))
4756 tgl@sss.pgh.pa.us 2537 :UBC 0 : return true;
2538 : :
2539 : : /* Check the JOIN's qual clauses */
4756 tgl@sss.pgh.pa.us 2540 [ + + ]:CBC 259 : if (restricted &&
2044 2541 [ + + ]: 239 : !bms_is_subset(pull_varnos_of_level(root, j->quals, 1),
2542 : : safe_upper_varnos))
4756 2543 : 20 : return true;
2544 : : }
2545 : : else
4756 tgl@sss.pgh.pa.us 2546 [ # # ]:UBC 0 : elog(ERROR, "unrecognized node type: %d",
2547 : : (int) nodeTag(jtnode));
4756 tgl@sss.pgh.pa.us 2548 :CBC 3743 : return false;
2549 : : }
2550 : :
2551 : : /*
2552 : : * Perform pullup_replace_vars everyplace it's needed in the query tree.
2553 : : *
2554 : : * Caller has already filled *rvcontext with data describing what to
2555 : : * substitute for Vars referencing the target subquery. In addition
2556 : : * we need the identity of the containing appendrel if any.
2557 : : */
2558 : : static void
2583 2559 : 33436 : perform_pullup_replace_vars(PlannerInfo *root,
2560 : : pullup_replace_vars_context *rvcontext,
2561 : : AppendRelInfo *containing_appendrel)
2562 : : {
2563 : 33436 : Query *parse = root->parse;
2564 : : ListCell *lc;
2565 : :
2566 : : /*
2567 : : * If we are considering an appendrel child subquery (that is, a UNION ALL
2568 : : * member query that we're pulling up), then the only part of the upper
2569 : : * query that could reference the child yet is the translated_vars list of
2570 : : * the associated AppendRelInfo. Furthermore, we do not want to force use
2571 : : * of PHVs in the AppendRelInfo --- there isn't any outer join between.
2572 : : */
1344 2573 [ + + ]: 33436 : if (containing_appendrel)
2574 : : {
532 rguo@postgresql.org 2575 : 5165 : ReplaceWrapOption save_wrap_option = rvcontext->wrap_option;
2576 : :
2577 : 5165 : rvcontext->wrap_option = REPLACE_WRAP_NONE;
1344 tgl@sss.pgh.pa.us 2578 : 5165 : containing_appendrel->translated_vars = (List *)
2579 : 5165 : pullup_replace_vars((Node *) containing_appendrel->translated_vars,
2580 : : rvcontext);
532 rguo@postgresql.org 2581 : 5165 : rvcontext->wrap_option = save_wrap_option;
1344 tgl@sss.pgh.pa.us 2582 : 5165 : return;
2583 : : }
2584 : :
2585 : : /*
2586 : : * Replace all of the top query's references to the subquery's outputs
2587 : : * with copies of the adjusted subtlist items, being careful not to
2588 : : * replace any of the jointree structure. (This'd be a lot cleaner if we
2589 : : * could use query_tree_mutator.) We have to use PHVs in the targetList,
2590 : : * returningList, and havingQual, since those are certainly above any
2591 : : * outer join. replace_vars_in_jointree tracks its location in the
2592 : : * jointree and uses PHVs or not appropriately.
2593 : : */
2583 2594 : 28271 : parse->targetList = (List *)
2595 : 28271 : pullup_replace_vars((Node *) parse->targetList, rvcontext);
2596 : 28271 : parse->returningList = (List *)
2597 : 28271 : pullup_replace_vars((Node *) parse->returningList, rvcontext);
2598 : :
2599 [ + + ]: 28271 : if (parse->onConflict)
2600 : : {
2601 : 34 : parse->onConflict->onConflictSet = (List *)
2602 : 17 : pullup_replace_vars((Node *) parse->onConflict->onConflictSet,
2603 : : rvcontext);
2604 : 17 : parse->onConflict->onConflictWhere =
2605 : 17 : pullup_replace_vars(parse->onConflict->onConflictWhere,
2606 : : rvcontext);
2607 : :
2608 : : /*
2609 : : * We assume ON CONFLICT's arbiterElems, arbiterWhere, exclRelTlist
2610 : : * can't contain any references to a subquery.
2611 : : */
2612 : : }
1613 alvherre@alvh.no-ip. 2613 [ + + ]: 28271 : if (parse->mergeActionList)
2614 : : {
2615 [ + - + + : 2374 : foreach(lc, parse->mergeActionList)
+ + ]
2616 : : {
2617 : 1411 : MergeAction *action = lfirst(lc);
2618 : :
2619 : 1411 : action->qual = pullup_replace_vars(action->qual, rvcontext);
2620 : 1411 : action->targetList = (List *)
2621 : 1411 : pullup_replace_vars((Node *) action->targetList, rvcontext);
2622 : : }
2623 : : }
880 dean.a.rasheed@gmail 2624 : 28271 : parse->mergeJoinCondition = pullup_replace_vars(parse->mergeJoinCondition,
2625 : : rvcontext);
1305 tgl@sss.pgh.pa.us 2626 : 28271 : replace_vars_in_jointree((Node *) parse->jointree, rvcontext);
2583 2627 [ - + ]: 28271 : Assert(parse->setOperations == NULL);
2628 : 28271 : parse->havingQual = pullup_replace_vars(parse->havingQual, rvcontext);
2629 : :
2630 : : /*
2631 : : * Replace references in the translated_vars lists of appendrels.
2632 : : */
2633 [ + + + + : 28341 : foreach(lc, root->append_rel_list)
+ + ]
2634 : : {
2635 : 70 : AppendRelInfo *appinfo = (AppendRelInfo *) lfirst(lc);
2636 : :
2637 : 70 : appinfo->translated_vars = (List *)
2638 : 70 : pullup_replace_vars((Node *) appinfo->translated_vars, rvcontext);
2639 : : }
2640 : :
2641 : : /*
2642 : : * Replace references in the joinaliasvars lists of join RTEs and the
2643 : : * groupexprs list of group RTE.
2644 : : */
2645 [ + - + + : 79368 : foreach(lc, parse->rtable)
+ + ]
2646 : : {
2647 : 51097 : RangeTblEntry *otherrte = (RangeTblEntry *) lfirst(lc);
2648 : :
2649 [ + + ]: 51097 : if (otherrte->rtekind == RTE_JOIN)
2650 : 5576 : otherrte->joinaliasvars = (List *)
2651 : 5576 : pullup_replace_vars((Node *) otherrte->joinaliasvars,
2652 : : rvcontext);
716 rguo@postgresql.org 2653 [ + + ]: 45521 : else if (otherrte->rtekind == RTE_GROUP)
2654 : 723 : otherrte->groupexprs = (List *)
2655 : 723 : pullup_replace_vars((Node *) otherrte->groupexprs,
2656 : : rvcontext);
2657 : : }
2658 : : }
2659 : :
2660 : : /*
2661 : : * Helper routine for perform_pullup_replace_vars: do pullup_replace_vars on
2662 : : * every expression in the jointree, without changing the jointree structure
2663 : : * itself. Ugly, but there's no other way...
2664 : : */
2665 : : static void
6203 tgl@sss.pgh.pa.us 2666 : 74286 : replace_vars_in_jointree(Node *jtnode,
2667 : : pullup_replace_vars_context *context)
2668 : : {
8620 2669 [ - + ]: 74286 : if (jtnode == NULL)
8620 tgl@sss.pgh.pa.us 2670 :UBC 0 : return;
8620 tgl@sss.pgh.pa.us 2671 [ + + ]:CBC 74286 : if (IsA(jtnode, RangeTblRef))
2672 : : {
2673 : : /*
2674 : : * If the RangeTblRef refers to a LATERAL subquery (that isn't the
2675 : : * same subquery we're pulling up), it might contain references to the
2676 : : * target subquery, which we must replace. We drive this from the
2677 : : * jointree scan, rather than a scan of the rtable, so that we can
2678 : : * avoid processing no-longer-referenced RTEs.
2679 : : */
5122 2680 : 37264 : int varno = ((RangeTblRef *) jtnode)->rtindex;
2681 : :
2682 [ + + ]: 37264 : if (varno != context->varno) /* ignore target subquery itself */
2683 : : {
2684 : 8993 : RangeTblEntry *rte = rt_fetch(varno, context->root->parse->rtable);
2685 : :
2686 [ - + ]: 8993 : Assert(rte != context->target_rte);
2687 [ + + ]: 8993 : if (rte->lateral)
2688 : : {
2689 [ - + + + : 761 : switch (rte->rtekind)
- - - - ]
2690 : : {
4051 tgl@sss.pgh.pa.us 2691 :UBC 0 : case RTE_RELATION:
2692 : : /* shouldn't be marked LATERAL unless tablesample */
2693 [ # # ]: 0 : Assert(rte->tablesample);
2694 : 0 : rte->tablesample = (TableSampleClause *)
2695 : 0 : pullup_replace_vars((Node *) rte->tablesample,
2696 : : context);
2697 : 0 : break;
5122 tgl@sss.pgh.pa.us 2698 :CBC 376 : case RTE_SUBQUERY:
2699 : 376 : rte->subquery =
2700 : 376 : pullup_replace_vars_subquery(rte->subquery,
2701 : : context);
2702 : 376 : break;
2703 : 295 : case RTE_FUNCTION:
4662 2704 : 295 : rte->functions = (List *)
2705 : 295 : pullup_replace_vars((Node *) rte->functions,
2706 : : context);
5122 2707 : 295 : break;
3459 alvherre@alvh.no-ip. 2708 : 90 : case RTE_TABLEFUNC:
2709 : 90 : rte->tablefunc = (TableFunc *)
2710 : 90 : pullup_replace_vars((Node *) rte->tablefunc,
2711 : : context);
2712 : 90 : break;
5122 tgl@sss.pgh.pa.us 2713 :UBC 0 : case RTE_VALUES:
2714 : 0 : rte->values_lists = (List *)
2715 : 0 : pullup_replace_vars((Node *) rte->values_lists,
2716 : : context);
2717 : 0 : break;
2718 : 0 : case RTE_JOIN:
2719 : : case RTE_CTE:
2720 : : case RTE_NAMEDTUPLESTORE:
2721 : : case RTE_RESULT:
2722 : : case RTE_GROUP:
2723 : : /* these shouldn't be marked LATERAL */
2724 : 0 : Assert(false);
2725 : : break;
164 peter@eisentraut.org 2726 : 0 : case RTE_GRAPH_TABLE:
2727 : : /* shouldn't happen here */
2728 : 0 : Assert(false);
2729 : : break;
2730 : : }
2731 : : }
2732 : : }
2733 : : }
8620 tgl@sss.pgh.pa.us 2734 [ + + ]:CBC 37022 : else if (IsA(jtnode, FromExpr))
2735 : : {
2736 : 30479 : FromExpr *f = (FromExpr *) jtnode;
2737 : : ListCell *l;
2738 : :
2739 [ + - + + : 63408 : foreach(l, f->fromlist)
+ + ]
1305 2740 : 32929 : replace_vars_in_jointree(lfirst(l), context);
6203 2741 : 30479 : f->quals = pullup_replace_vars(f->quals, context);
2742 : : }
8620 2743 [ + - ]: 6543 : else if (IsA(jtnode, JoinExpr))
2744 : : {
2745 : 6543 : JoinExpr *j = (JoinExpr *) jtnode;
532 rguo@postgresql.org 2746 : 6543 : ReplaceWrapOption save_wrap_option = context->wrap_option;
2747 : :
1305 tgl@sss.pgh.pa.us 2748 : 6543 : replace_vars_in_jointree(j->larg, context);
2749 : 6543 : replace_vars_in_jointree(j->rarg, context);
2750 : :
2751 : : /*
2752 : : * Use PHVs within the join quals of a full join for variable-free
2753 : : * expressions. Otherwise, we cannot identify which side of the join
2754 : : * a pulled-up variable-free expression came from, which can lead to
2755 : : * failure to make a plan at all because none of the quals appear to
2756 : : * be mergeable or hashable conditions.
2757 : : */
2874 2758 [ + + ]: 6543 : if (j->jointype == JOIN_FULL)
532 rguo@postgresql.org 2759 : 525 : context->wrap_option = REPLACE_WRAP_VARFREE;
2760 : :
6203 tgl@sss.pgh.pa.us 2761 : 6543 : j->quals = pullup_replace_vars(j->quals, context);
2762 : :
532 rguo@postgresql.org 2763 : 6543 : context->wrap_option = save_wrap_option;
2764 : : }
2765 : : else
8434 tgl@sss.pgh.pa.us 2766 [ # # ]:UBC 0 : elog(ERROR, "unrecognized node type: %d",
2767 : : (int) nodeTag(jtnode));
2768 : : }
2769 : :
2770 : : /*
2771 : : * Apply pullup variable replacement throughout an expression tree
2772 : : *
2773 : : * Returns a modified copy of the tree, so this can't be used where we
2774 : : * need to do in-place replacement.
2775 : : */
2776 : : static Node *
6203 tgl@sss.pgh.pa.us 2777 :CBC 166037 : pullup_replace_vars(Node *expr, pullup_replace_vars_context *context)
2778 : : {
2779 : 166037 : return replace_rte_variables(expr,
2780 : : context->varno, 0,
2781 : : pullup_replace_vars_callback,
2782 : : context,
2783 : : context->outer_hasSubLinks);
2784 : : }
2785 : :
2786 : : static Node *
161 peter@eisentraut.org 2787 : 97522 : pullup_replace_vars_callback(const Var *var,
2788 : : replace_rte_variables_context *context)
2789 : : {
6203 tgl@sss.pgh.pa.us 2790 : 97522 : pullup_replace_vars_context *rcon = (pullup_replace_vars_context *) context->callback_arg;
2791 : 97522 : int varattno = var->varattno;
2792 : : bool need_phv;
2793 : : Node *newnode;
2794 : :
2795 : : /* System columns are not replaced. */
548 rguo@postgresql.org 2796 [ + + ]: 97522 : if (varattno < InvalidAttrNumber)
2797 : 35 : return (Node *) copyObject(var);
2798 : :
2799 : : /*
2800 : : * We need a PlaceHolderVar if the Var-to-be-replaced has nonempty
2801 : : * varnullingrels (unless we find below that the replacement expression is
2802 : : * a Var or PlaceHolderVar that we can just add the nullingrels to). We
2803 : : * also need one if the caller has instructed us that certain expression
2804 : : * replacements need to be wrapped for identification purposes.
2805 : : */
532 2806 [ + + ]: 185237 : need_phv = (var->varnullingrels != NULL) ||
2807 [ + + ]: 87750 : (rcon->wrap_option != REPLACE_WRAP_NONE);
2808 : :
2809 : : /*
2810 : : * If PlaceHolderVars are needed, we cache the modified expressions in
2811 : : * rcon->rv_cache[]. This is not in hopes of any material speed gain
2812 : : * within this function, but to avoid generating identical PHVs with
2813 : : * different IDs. That would result in duplicate evaluations at runtime,
2814 : : * and possibly prevent optimizations that rely on recognizing different
2815 : : * references to the same subquery output as being equal(). So it's worth
2816 : : * a bit of extra effort to avoid it.
2817 : : *
2818 : : * The cached items have phlevelsup = 0 and phnullingrels = NULL; we'll
2819 : : * copy them and adjust those values for this reference site below.
2820 : : */
1305 tgl@sss.pgh.pa.us 2821 [ + + + - ]: 97487 : if (need_phv &&
6203 2822 [ + - ]: 11695 : varattno >= InvalidAttrNumber &&
2823 : 11695 : varattno <= list_length(rcon->targetlist) &&
2824 [ + + ]: 11695 : rcon->rv_cache[varattno] != NULL)
2825 : : {
2826 : : /* Just copy the entry and fall through to adjust phlevelsup etc */
2827 : 2510 : newnode = copyObject(rcon->rv_cache[varattno]);
2828 : : }
2829 : : else
2830 : : {
2831 : : /*
2832 : : * Generate the replacement expression. This takes care of expanding
2833 : : * wholerow references and dealing with non-default varreturningtype.
2834 : : */
548 rguo@postgresql.org 2835 : 94977 : newnode = ReplaceVarFromTargetList(var,
2836 : : rcon->target_rte,
2837 : : rcon->targetlist,
2838 : : rcon->result_relation,
2839 : : REPLACEVARS_REPORT_ERROR,
2840 : : 0);
2841 : :
2842 : : /* Insert PlaceHolderVar if needed */
1305 tgl@sss.pgh.pa.us 2843 [ + + ]: 94977 : if (need_phv)
2844 : : {
2845 : : bool wrap;
2846 : :
532 rguo@postgresql.org 2847 [ + + ]: 9185 : if (rcon->wrap_option == REPLACE_WRAP_ALL)
2848 : : {
2849 : : /* Caller told us to wrap all expressions in a PlaceHolderVar */
2850 : 907 : wrap = true;
2851 : : }
2852 [ + + ]: 8278 : else if (varattno == InvalidAttrNumber)
2853 : : {
2854 : : /*
2855 : : * Insert PlaceHolderVar for whole-tuple reference. Notice
2856 : : * that we are wrapping one PlaceHolderVar around the whole
2857 : : * RowExpr, rather than putting one around each element of the
2858 : : * row. This is because we need the expression to yield NULL,
2859 : : * not ROW(NULL,NULL,...) when it is forced to null by an
2860 : : * outer join.
2861 : : */
548 2862 : 55 : wrap = true;
2863 : : }
2864 [ + - + + ]: 8223 : else if (newnode && IsA(newnode, Var) &&
2865 [ + + ]: 6568 : ((Var *) newnode)->varlevelsup == 0)
2866 : : {
2867 : : /*
2868 : : * Simple Vars always escape being wrapped, unless they are
2869 : : * lateral references to something outside the subquery being
2870 : : * pulled up and the referenced rel is not under the same
2871 : : * lowest nulling outer join.
2872 : : */
626 2873 : 6556 : wrap = false;
4758 tgl@sss.pgh.pa.us 2874 [ + + ]: 6556 : if (rcon->target_rte->lateral &&
2875 [ + + ]: 1185 : !bms_is_member(((Var *) newnode)->varno, rcon->relids))
2876 : : {
626 rguo@postgresql.org 2877 : 110 : nullingrel_info *nullinfo = rcon->nullinfo;
2878 : 110 : int lvarno = ((Var *) newnode)->varno;
2879 : :
2880 [ + - - + ]: 110 : Assert(lvarno > 0 && lvarno <= nullinfo->rtlength);
2881 [ + + ]: 110 : if (!bms_is_subset(nullinfo->nullingrels[rcon->varno],
2882 : 110 : nullinfo->nullingrels[lvarno]))
2883 : 90 : wrap = true;
2884 : : }
2885 : : }
5497 tgl@sss.pgh.pa.us 2886 [ + - + + ]: 1667 : else if (newnode && IsA(newnode, PlaceHolderVar) &&
2887 [ + - ]: 150 : ((PlaceHolderVar *) newnode)->phlevelsup == 0)
2888 : : {
2889 : : /* The same rules apply for a PlaceHolderVar */
626 rguo@postgresql.org 2890 : 150 : wrap = false;
959 tgl@sss.pgh.pa.us 2891 [ + + ]: 150 : if (rcon->target_rte->lateral &&
2892 [ + - ]: 40 : !bms_is_subset(((PlaceHolderVar *) newnode)->phrels,
2893 : 40 : rcon->relids))
2894 : : {
626 rguo@postgresql.org 2895 : 40 : nullingrel_info *nullinfo = rcon->nullinfo;
2896 : 40 : Relids lvarnos = ((PlaceHolderVar *) newnode)->phrels;
2897 : : int lvarno;
2898 : :
2899 : 40 : lvarno = -1;
2900 [ + + ]: 60 : while ((lvarno = bms_next_member(lvarnos, lvarno)) >= 0)
2901 : : {
2902 [ + - - + ]: 40 : Assert(lvarno > 0 && lvarno <= nullinfo->rtlength);
2903 [ + + ]: 40 : if (!bms_is_subset(nullinfo->nullingrels[rcon->varno],
2904 : 40 : nullinfo->nullingrels[lvarno]))
2905 : : {
2906 : 20 : wrap = true;
2907 : 20 : break;
2908 : : }
2909 : : }
2910 : : }
2911 : : }
2912 : : else
2913 : : {
2914 : : /*
2915 : : * If the node contains Var(s) or PlaceHolderVar(s) of the
2916 : : * subquery being pulled up, or of rels that are under the
2917 : : * same lowest nulling outer join as the subquery, and does
2918 : : * not contain any non-strict constructs, then instead of
2919 : : * adding a PHV on top we can add the required nullingrels to
2920 : : * those Vars/PHVs. (This is fundamentally a generalization
2921 : : * of the above cases for bare Vars and PHVs.)
2922 : : *
2923 : : * This test is somewhat expensive, but it avoids pessimizing
2924 : : * the plan in cases where the nullingrels get removed again
2925 : : * later by outer join reduction.
2926 : : *
2927 : : * Note that we don't force wrapping of expressions containing
2928 : : * lateral references, so long as they also contain Vars/PHVs
2929 : : * of the subquery, or of rels that are under the same lowest
2930 : : * nulling outer join as the subquery. This is okay because
2931 : : * of the restriction to strict constructs: if those Vars/PHVs
2932 : : * have been forced to NULL by an outer join then the end
2933 : : * result of the expression will be NULL too, regardless of
2934 : : * the lateral references. So it's not necessary to force the
2935 : : * expression to be evaluated below the outer join. This can
2936 : : * be a very valuable optimization, because it may allow us to
2937 : : * avoid using a nested loop to pass the lateral reference
2938 : : * down.
2939 : : *
2940 : : * This analysis could be tighter: in particular, a non-strict
2941 : : * construct hidden within a lower-level PlaceHolderVar is not
2942 : : * reason to add another PHV. But for now it doesn't seem
2943 : : * worth the code to be more exact. This is also why it's
2944 : : * preferable to handle bare PHVs in the above branch, rather
2945 : : * than this branch. We also prefer to handle bare Vars in a
2946 : : * separate branch, as it's cheaper this way and parallels the
2947 : : * handling of PHVs.
2948 : : *
2949 : : * For a LATERAL subquery, we have to check the actual var
2950 : : * membership of the node, but if it's non-lateral then any
2951 : : * level-zero var must belong to the subquery.
2952 : : */
618 2953 : 1517 : bool contain_nullable_vars = false;
2954 : :
2955 [ + + ]: 1517 : if (!rcon->target_rte->lateral)
2956 : : {
2957 [ + + ]: 1327 : if (contain_vars_of_level(newnode, 0))
2958 : 443 : contain_nullable_vars = true;
2959 : : }
2960 : : else
2961 : : {
2962 : : Relids all_varnos;
2963 : :
2964 : 190 : all_varnos = pull_varnos(rcon->root, newnode);
2965 [ + + ]: 190 : if (bms_overlap(all_varnos, rcon->relids))
2966 : 110 : contain_nullable_vars = true;
2967 : : else
2968 : : {
2969 : 80 : nullingrel_info *nullinfo = rcon->nullinfo;
2970 : : int varno;
2971 : :
2972 : 80 : varno = -1;
2973 [ + + ]: 150 : while ((varno = bms_next_member(all_varnos, varno)) >= 0)
2974 : : {
2975 [ + - - + ]: 90 : Assert(varno > 0 && varno <= nullinfo->rtlength);
2976 [ + + ]: 90 : if (bms_is_subset(nullinfo->nullingrels[rcon->varno],
2977 : 90 : nullinfo->nullingrels[varno]))
2978 : : {
2979 : 20 : contain_nullable_vars = true;
2980 : 20 : break;
2981 : : }
2982 : : }
2983 : : }
2984 : : }
2985 : :
2986 [ + + ]: 1517 : if (contain_nullable_vars &&
727 tgl@sss.pgh.pa.us 2987 [ + + ]: 573 : !contain_nonstrict_functions(newnode))
2988 : : {
2989 : : /* No wrap needed */
2990 : 240 : wrap = false;
2991 : : }
2992 : : else
2993 : : {
2994 : : /* Else wrap it in a PlaceHolderVar */
2995 : 1277 : wrap = true;
2996 : : }
2997 : : }
2998 : :
6203 2999 [ + + ]: 9185 : if (wrap)
3000 : : {
3001 : : newnode = (Node *)
3002 : 2349 : make_placeholder_expr(rcon->root,
3003 : : (Expr *) newnode,
3004 : : bms_make_singleton(rcon->varno));
3005 : :
3006 : : /*
3007 : : * Cache it if possible (ie, if the attno is in range, which
3008 : : * it probably always should be).
3009 : : */
548 rguo@postgresql.org 3010 [ + - + - ]: 4698 : if (varattno >= InvalidAttrNumber &&
1305 tgl@sss.pgh.pa.us 3011 : 2349 : varattno <= list_length(rcon->targetlist))
3012 : 2349 : rcon->rv_cache[varattno] = copyObject(newnode);
3013 : : }
3014 : : }
3015 : : }
3016 : :
3017 : : /* Propagate any varnullingrels into the replacement expression */
3018 [ + + ]: 97487 : if (var->varnullingrels != NULL)
3019 : : {
3020 [ + + ]: 9737 : if (IsA(newnode, Var))
3021 : : {
3022 : 6087 : Var *newvar = (Var *) newnode;
3023 : :
727 3024 [ - + ]: 6087 : Assert(newvar->varlevelsup == 0);
1305 3025 : 6087 : newvar->varnullingrels = bms_add_members(newvar->varnullingrels,
3026 : 6087 : var->varnullingrels);
3027 : : }
3028 [ + + ]: 3650 : else if (IsA(newnode, PlaceHolderVar))
3029 : : {
3030 : 3410 : PlaceHolderVar *newphv = (PlaceHolderVar *) newnode;
3031 : :
727 3032 [ - + ]: 3410 : Assert(newphv->phlevelsup == 0);
1305 3033 : 3410 : newphv->phnullingrels = bms_add_members(newphv->phnullingrels,
3034 : 3410 : var->varnullingrels);
3035 : : }
3036 : : else
3037 : : {
3038 : : /*
3039 : : * There should be Vars/PHVs within the expression that we can
3040 : : * modify. Vars/PHVs of the subquery should have the full
3041 : : * var->varnullingrels added to them, but if there are lateral
3042 : : * references within the expression, those must be marked with
3043 : : * only the nullingrels that potentially apply to them. (This
3044 : : * corresponds to the fact that the expression will now be
3045 : : * evaluated at the join level of the Var that we are replacing:
3046 : : * the lateral references may have bubbled up through fewer outer
3047 : : * joins than the subquery's Vars have. Per the discussion above,
3048 : : * we'll still get the right answers.) That relid set could be
3049 : : * different for different lateral relations, so we have to do
3050 : : * this work for each one.
3051 : : *
3052 : : * (Currently, the restrictions in is_simple_subquery() mean that
3053 : : * at most we have to remove the lowest outer join's relid from
3054 : : * the nullingrels of a lateral reference. However, we might
3055 : : * relax those restrictions someday, so let's do this right.)
3056 : : */
635 3057 [ + + ]: 240 : if (rcon->target_rte->lateral)
3058 : : {
3059 : 70 : nullingrel_info *nullinfo = rcon->nullinfo;
3060 : : Relids lvarnos;
3061 : : int lvarno;
3062 : :
3063 : : /*
3064 : : * Identify lateral varnos used within newnode. We must do
3065 : : * this before injecting var->varnullingrels into the tree.
3066 : : */
3067 : 70 : lvarnos = pull_varnos(rcon->root, newnode);
3068 : 70 : lvarnos = bms_del_members(lvarnos, rcon->relids);
3069 : : /* For each one, add relevant nullingrels if any */
3070 : 70 : lvarno = -1;
3071 [ + + ]: 140 : while ((lvarno = bms_next_member(lvarnos, lvarno)) >= 0)
3072 : : {
3073 : : Relids lnullingrels;
3074 : :
3075 [ + - - + ]: 70 : Assert(lvarno > 0 && lvarno <= nullinfo->rtlength);
3076 : 70 : lnullingrels = bms_intersect(var->varnullingrels,
3077 : 70 : nullinfo->nullingrels[lvarno]);
3078 [ + + ]: 70 : if (!bms_is_empty(lnullingrels))
3079 : 40 : newnode = add_nulling_relids(newnode,
3080 : 40 : bms_make_singleton(lvarno),
3081 : : lnullingrels);
3082 : : }
3083 : : }
3084 : :
3085 : : /* Finally, deal with Vars/PHVs of the subquery itself */
727 3086 : 240 : newnode = add_nulling_relids(newnode,
637 3087 : 240 : rcon->relids,
727 3088 : 240 : var->varnullingrels);
3089 : : /* Assert we did put the varnullingrels into the expression */
3090 [ - + ]: 240 : Assert(bms_is_subset(var->varnullingrels,
3091 : : pull_varnos(rcon->root, newnode)));
3092 : : }
3093 : : }
3094 : :
3095 : : /* Must adjust varlevelsup if replaced Var is within a subquery */
3096 [ + + ]: 97487 : if (var->varlevelsup > 0)
3097 : 899 : IncrementVarSublevelsUp(newnode, var->varlevelsup, 0);
3098 : :
6203 3099 : 97487 : return newnode;
3100 : : }
3101 : :
3102 : : /*
3103 : : * Apply pullup variable replacement to a subquery
3104 : : *
3105 : : * This needs to be different from pullup_replace_vars() because
3106 : : * replace_rte_variables will think that it shouldn't increment sublevels_up
3107 : : * before entering the Query; so we need to call it with sublevels_up == 1.
3108 : : */
3109 : : static Query *
5122 3110 : 376 : pullup_replace_vars_subquery(Query *query,
3111 : : pullup_replace_vars_context *context)
3112 : : {
3113 [ - + ]: 376 : Assert(IsA(query, Query));
3114 : 376 : return (Query *) replace_rte_variables((Node *) query,
3115 : : context->varno, 1,
3116 : : pullup_replace_vars_callback,
3117 : : context,
3118 : : NULL);
3119 : : }
3120 : :
3121 : :
3122 : : /*
3123 : : * flatten_simple_union_all
3124 : : * Try to optimize top-level UNION ALL structure into an appendrel
3125 : : *
3126 : : * If a query's setOperations tree consists entirely of simple UNION ALL
3127 : : * operations, flatten it into an append relation, which we can process more
3128 : : * intelligently than the general setops case. Otherwise, do nothing.
3129 : : *
3130 : : * In most cases, this can succeed only for a top-level query, because for a
3131 : : * subquery in FROM, the parent query's invocation of pull_up_subqueries would
3132 : : * already have flattened the UNION via pull_up_simple_union_all. But there
3133 : : * are a few cases we can support here but not in that code path, for example
3134 : : * when the subquery also contains ORDER BY.
3135 : : */
3136 : : void
5771 3137 : 5468 : flatten_simple_union_all(PlannerInfo *root)
3138 : : {
3139 : 5468 : Query *parse = root->parse;
3140 : : SetOperationStmt *topop;
3141 : : Node *leftmostjtnode;
3142 : : int leftmostRTI;
3143 : : RangeTblEntry *leftmostRTE;
3144 : : int childRTI;
3145 : : RangeTblEntry *childRTE;
3146 : : RangeTblRef *rtr;
3147 : :
3148 : : /* Shouldn't be called unless query has setops */
3474 peter_e@gmx.net 3149 : 5468 : topop = castNode(SetOperationStmt, parse->setOperations);
3150 [ - + ]: 5468 : Assert(topop);
3151 : :
3152 : : /* Can't optimize away a recursive UNION */
5771 tgl@sss.pgh.pa.us 3153 [ + + ]: 5468 : if (root->hasRecursion)
3154 : 641 : return;
3155 : :
3156 : : /*
3157 : : * Recursively check the tree of set operations. If not all UNION ALL
3158 : : * with identical column types, punt.
3159 : : */
3160 [ + + ]: 4827 : if (!is_simple_union_all_recurse((Node *) topop, parse, topop->colTypes))
3161 : 4276 : return;
3162 : :
3163 : : /*
3164 : : * Locate the leftmost leaf query in the setops tree. The upper query's
3165 : : * Vars all refer to this RTE (see transformSetOperationStmt).
3166 : : */
3167 : 551 : leftmostjtnode = topop->larg;
3168 [ + - + + ]: 789 : while (leftmostjtnode && IsA(leftmostjtnode, SetOperationStmt))
3169 : 238 : leftmostjtnode = ((SetOperationStmt *) leftmostjtnode)->larg;
3170 [ + - - + ]: 551 : Assert(leftmostjtnode && IsA(leftmostjtnode, RangeTblRef));
3171 : 551 : leftmostRTI = ((RangeTblRef *) leftmostjtnode)->rtindex;
3172 : 551 : leftmostRTE = rt_fetch(leftmostRTI, parse->rtable);
3173 [ - + ]: 551 : Assert(leftmostRTE->rtekind == RTE_SUBQUERY);
3174 : :
3175 : : /*
3176 : : * Make a copy of the leftmost RTE and add it to the rtable. This copy
3177 : : * will represent the leftmost leaf query in its capacity as a member of
3178 : : * the appendrel. The original will represent the appendrel as a whole.
3179 : : * (We must do things this way because the upper query's Vars have to be
3180 : : * seen as referring to the whole appendrel.)
3181 : : */
3182 : 551 : childRTE = copyObject(leftmostRTE);
3183 : 551 : parse->rtable = lappend(parse->rtable, childRTE);
3184 : 551 : childRTI = list_length(parse->rtable);
3185 : :
3186 : : /* Modify the setops tree to reference the child copy */
3187 : 551 : ((RangeTblRef *) leftmostjtnode)->rtindex = childRTI;
3188 : :
3189 : : /* Modify the formerly-leftmost RTE to mark it as an appendrel parent */
3190 : 551 : leftmostRTE->inh = true;
3191 : :
3192 : : /*
3193 : : * Form a RangeTblRef for the appendrel, and insert it into FROM. The top
3194 : : * Query of a setops tree should have had an empty FromClause initially.
3195 : : */
3196 : 551 : rtr = makeNode(RangeTblRef);
3197 : 551 : rtr->rtindex = leftmostRTI;
3198 [ - + ]: 551 : Assert(parse->jointree->fromlist == NIL);
3199 : 551 : parse->jointree->fromlist = list_make1(rtr);
3200 : :
3201 : : /*
3202 : : * Now pretend the query has no setops. We must do this before trying to
3203 : : * do subquery pullup, because of Assert in pull_up_simple_subquery.
3204 : : */
3205 : 551 : parse->setOperations = NULL;
3206 : :
3207 : : /*
3208 : : * Build AppendRelInfo information, and apply pull_up_subqueries to the
3209 : : * leaf queries of the UNION ALL. (We must do that now because they
3210 : : * weren't previously referenced by the jointree, and so were missed by
3211 : : * the main invocation of pull_up_subqueries.)
3212 : : */
3213 : 551 : pull_up_union_leaf_queries((Node *) topop, root, leftmostRTI, parse, 0);
3214 : : }
3215 : :
3216 : :
3217 : : /*
3218 : : * reduce_outer_joins
3219 : : * Attempt to reduce outer joins to plain inner joins.
3220 : : *
3221 : : * The idea here is that given a query like
3222 : : * SELECT ... FROM a LEFT JOIN b ON (...) WHERE b.y = 42;
3223 : : * we can reduce the LEFT JOIN to a plain JOIN if the "=" operator in WHERE
3224 : : * is strict. The strict operator will always return NULL, causing the outer
3225 : : * WHERE to fail, on any row where the LEFT JOIN filled in NULLs for b's
3226 : : * columns. Therefore, there's no need for the join to produce null-extended
3227 : : * rows in the first place --- which makes it a plain join not an outer join.
3228 : : * (This scenario may not be very likely in a query written out by hand, but
3229 : : * it's reasonably likely when pushing quals down into complex views.)
3230 : : *
3231 : : * More generally, an outer join can be reduced in strength if there is a
3232 : : * strict qual above it in the qual tree that constrains a Var from the
3233 : : * nullable side of the join to be non-null. (For FULL joins this applies
3234 : : * to each side separately.)
3235 : : *
3236 : : * Another transformation we apply here is to recognize cases like
3237 : : * SELECT ... FROM a LEFT JOIN b ON (a.x = b.y) WHERE b.z IS NULL;
3238 : : * If we can prove that b.z must be non-null for any matching row, because
3239 : : * the join clause is strict for b.z and b.z happens to be the join key b.y,
3240 : : * because a strict qual within b's own subtree forces b.z non-null, or
3241 : : * because b.z is defined NOT NULL by table constraints and is not nullable
3242 : : * due to lower-level outer joins, then only null-extended rows could pass
3243 : : * the upper WHERE, and we can conclude that what the query is really
3244 : : * specifying is an anti-semijoin. We change the join type from JOIN_LEFT
3245 : : * to JOIN_ANTI. The IS NULL clause then becomes redundant, and must be
3246 : : * removed to prevent bogus selectivity calculations, but we leave it to
3247 : : * distribute_qual_to_rels to get rid of such clauses.
3248 : : *
3249 : : * A whole-row Var works too. "WHERE b IS NULL" in row-format semantics is
3250 : : * true when b's whole-row value is NULL or when every column of b is NULL;
3251 : : * for a matching row only the latter is possible, so proving any one column
3252 : : * of b non-null in matching rows justifies the same reduction.
3253 : : *
3254 : : * The same recognition reduces a FULL join to an anti-semijoin when a
3255 : : * forced-null Var on either side is proven non-null: only the other side's
3256 : : * unmatched rows can survive. If that surviving side is the right-hand
3257 : : * input, we switch the inputs (as we do for JOIN_RIGHT below) so that it
3258 : : * ends up on the left, where JOIN_ANTI requires the surviving side to be.
3259 : : *
3260 : : * Also, we get rid of JOIN_RIGHT cases by flipping them around to become
3261 : : * JOIN_LEFT. This saves some code here and in some later planner routines;
3262 : : * the main benefit is to reduce the number of jointypes that can appear in
3263 : : * SpecialJoinInfo nodes. Note that we can still generate Paths and Plans
3264 : : * that use JOIN_RIGHT (or JOIN_RIGHT_ANTI) by switching the inputs again.
3265 : : *
3266 : : * To ease recognition of strict qual clauses, we require this routine to be
3267 : : * run after expression preprocessing (i.e., qual canonicalization and JOIN
3268 : : * alias-var expansion).
3269 : : */
3270 : : void
7753 3271 : 25489 : reduce_outer_joins(PlannerInfo *root)
3272 : : {
3273 : : reduce_outer_joins_pass1_state *state1;
3274 : : reduce_outer_joins_pass2_state state2;
3275 : : ListCell *lc;
3276 : :
3277 : : /*
3278 : : * To avoid doing strictness checks on more quals than necessary, we want
3279 : : * to stop descending the jointree as soon as there are no outer joins
3280 : : * below our current point. This consideration forces a two-pass process.
3281 : : * The first pass gathers information about which base rels appear below
3282 : : * each side of each join clause, about whether there are outer join(s)
3283 : : * below each side of each join clause, and about which base rels are from
3284 : : * the nullable side of those outer join(s). The second pass examines
3285 : : * qual clauses and changes join types as it descends the tree.
3286 : : */
1305 3287 : 25489 : state1 = reduce_outer_joins_pass1((Node *) root->parse->jointree);
3288 : :
3289 : : /* planner.c shouldn't have called me if no outer joins */
3290 [ + - - + ]: 25489 : if (state1 == NULL || !state1->contains_outer)
8434 tgl@sss.pgh.pa.us 3291 [ # # ]:UBC 0 : elog(ERROR, "so where are the outer joins?");
3292 : :
1305 tgl@sss.pgh.pa.us 3293 :CBC 25489 : state2.inner_reduced = NULL;
3294 : 25489 : state2.partial_reduced = NIL;
3295 : :
7753 3296 : 25489 : reduce_outer_joins_pass2((Node *) root->parse->jointree,
3297 : : state1, &state2,
3298 : : root, NULL, NIL);
3299 : :
3300 : : /*
3301 : : * If we successfully reduced the strength of any outer joins, we must
3302 : : * remove references to those joins as nulling rels. This is handled as
3303 : : * an additional pass, for simplicity and because we can handle all
3304 : : * fully-reduced joins in a single pass over the parse tree.
3305 : : */
1305 3306 [ + + ]: 25489 : if (!bms_is_empty(state2.inner_reduced))
3307 : : {
3308 : 2151 : root->parse = (Query *)
3309 : 2151 : remove_nulling_relids((Node *) root->parse,
3310 : 2151 : state2.inner_reduced,
3311 : : NULL);
3312 : : /* There could be references in the append_rel_list, too */
3313 : 2151 : root->append_rel_list = (List *)
3314 : 2151 : remove_nulling_relids((Node *) root->append_rel_list,
3315 : 2151 : state2.inner_reduced,
3316 : : NULL);
3317 : : }
3318 : :
3319 : : /*
3320 : : * Partially-reduced full joins have to be done one at a time, since
3321 : : * they'll each need a different setting of except_relids.
3322 : : */
3323 [ + + + + : 25598 : foreach(lc, state2.partial_reduced)
+ + ]
3324 : : {
3325 : 109 : reduce_outer_joins_partial_state *statep = lfirst(lc);
3326 : 109 : Relids full_join_relids = bms_make_singleton(statep->full_join_rti);
3327 : :
3328 : 109 : root->parse = (Query *)
3329 : 109 : remove_nulling_relids((Node *) root->parse,
3330 : : full_join_relids,
3331 : 109 : statep->unreduced_side);
3332 : 109 : root->append_rel_list = (List *)
3333 : 109 : remove_nulling_relids((Node *) root->append_rel_list,
3334 : : full_join_relids,
3335 : 109 : statep->unreduced_side);
3336 : : }
8600 3337 : 25489 : }
3338 : :
3339 : : /*
3340 : : * reduce_outer_joins_pass1 - phase 1 data collection
3341 : : *
3342 : : * Returns a state node describing the given jointree node.
3343 : : */
3344 : : static reduce_outer_joins_pass1_state *
3345 : 144496 : reduce_outer_joins_pass1(Node *jtnode)
3346 : : {
3347 : : reduce_outer_joins_pass1_state *result;
3348 : :
260 michael@paquier.xyz 3349 : 144496 : result = palloc_object(reduce_outer_joins_pass1_state);
8600 tgl@sss.pgh.pa.us 3350 : 144496 : result->relids = NULL;
3351 : 144496 : result->contains_outer = false;
196 rguo@postgresql.org 3352 : 144496 : result->nullable_rels = NULL;
6 rguo@postgresql.org 3353 :GNC 144496 : result->jtnode = jtnode;
8600 tgl@sss.pgh.pa.us 3354 :CBC 144496 : result->sub_states = NIL;
3355 : :
3356 [ - + ]: 144496 : if (jtnode == NULL)
8600 tgl@sss.pgh.pa.us 3357 :UBC 0 : return result;
8600 tgl@sss.pgh.pa.us 3358 [ + + ]:CBC 144496 : if (IsA(jtnode, RangeTblRef))
3359 : : {
3360 : 72125 : int varno = ((RangeTblRef *) jtnode)->rtindex;
3361 : :
3362 : 72125 : result->relids = bms_make_singleton(varno);
3363 : : }
3364 [ + + ]: 72371 : else if (IsA(jtnode, FromExpr))
3365 : : {
3366 : 28046 : FromExpr *f = (FromExpr *) jtnode;
3367 : : ListCell *l;
3368 : :
3369 [ + - + + : 58403 : foreach(l, f->fromlist)
+ + ]
3370 : : {
3371 : : reduce_outer_joins_pass1_state *sub_state;
3372 : :
3373 : 30357 : sub_state = reduce_outer_joins_pass1(lfirst(l));
3374 : 60714 : result->relids = bms_add_members(result->relids,
3375 : 30357 : sub_state->relids);
3376 : 30357 : result->contains_outer |= sub_state->contains_outer;
196 rguo@postgresql.org 3377 : 60714 : result->nullable_rels = bms_add_members(result->nullable_rels,
3378 : 30357 : sub_state->nullable_rels);
8600 tgl@sss.pgh.pa.us 3379 : 30357 : result->sub_states = lappend(result->sub_states, sub_state);
3380 : : }
3381 : : }
3382 [ + - ]: 44325 : else if (IsA(jtnode, JoinExpr))
3383 : : {
3384 : 44325 : JoinExpr *j = (JoinExpr *) jtnode;
3385 : : reduce_outer_joins_pass1_state *left_state;
3386 : : reduce_outer_joins_pass1_state *right_state;
3387 : :
3388 : : /* Recurse to children */
196 rguo@postgresql.org 3389 : 44325 : left_state = reduce_outer_joins_pass1(j->larg);
3390 : 44325 : right_state = reduce_outer_joins_pass1(j->rarg);
3391 : :
3392 : : /* join's own RT index is not wanted in result->relids */
3393 : 44325 : result->relids = bms_union(left_state->relids, right_state->relids);
3394 : :
3395 : : /* Store children's states for pass 2 */
3396 : 44325 : result->sub_states = list_make2(left_state, right_state);
3397 : :
3398 : : /* Collect outer join information */
3399 [ + + + + : 44325 : switch (j->jointype)
- ]
3400 : : {
3401 : 7411 : case JOIN_INNER:
3402 : : case JOIN_SEMI:
3403 : : /* No new nullability; propagate state from children */
3404 [ + + ]: 14195 : result->contains_outer = left_state->contains_outer ||
3405 [ + + ]: 6784 : right_state->contains_outer;
3406 : 14822 : result->nullable_rels = bms_union(left_state->nullable_rels,
3407 : 7411 : right_state->nullable_rels);
3408 : 7411 : break;
3409 : 34989 : case JOIN_LEFT:
3410 : : case JOIN_ANTI:
3411 : : /* RHS is nullable; LHS keeps existing status */
3412 : 34989 : result->contains_outer = true;
3413 : 69978 : result->nullable_rels = bms_union(left_state->nullable_rels,
3414 : 34989 : right_state->relids);
3415 : 34989 : break;
3416 : 965 : case JOIN_RIGHT:
3417 : : /* LHS is nullable; RHS keeps existing status */
3418 : 965 : result->contains_outer = true;
3419 : 1930 : result->nullable_rels = bms_union(left_state->relids,
3420 : 965 : right_state->nullable_rels);
3421 : 965 : break;
3422 : 960 : case JOIN_FULL:
3423 : : /* Both sides are nullable */
3424 : 960 : result->contains_outer = true;
3425 : 1920 : result->nullable_rels = bms_union(left_state->relids,
3426 : 960 : right_state->relids);
3427 : 960 : break;
196 rguo@postgresql.org 3428 :UBC 0 : default:
3429 [ # # ]: 0 : elog(ERROR, "unrecognized join type: %d",
3430 : : (int) j->jointype);
3431 : : break;
3432 : : }
3433 : : }
3434 : : else
8434 tgl@sss.pgh.pa.us 3435 [ # # ]: 0 : elog(ERROR, "unrecognized node type: %d",
3436 : : (int) nodeTag(jtnode));
8600 tgl@sss.pgh.pa.us 3437 :CBC 144496 : return result;
3438 : : }
3439 : :
3440 : : /*
3441 : : * reduce_outer_joins_pass2 - phase 2 processing
3442 : : *
3443 : : * jtnode: current jointree node
3444 : : * state1: state data collected by phase 1 for this node
3445 : : * state2: where to accumulate info about successfully-reduced joins
3446 : : * root: toplevel planner state
3447 : : * nonnullable_rels: set of base relids forced non-null by upper quals
3448 : : * forced_null_vars: multibitmapset of Vars forced null by upper quals
3449 : : *
3450 : : * Returns info in state2 about outer joins that were successfully simplified.
3451 : : * Joins that were fully reduced to inner joins are all added to
3452 : : * state2->inner_reduced. If a full join is reduced to a left join,
3453 : : * it needs its own entry in state2->partial_reduced, since that will
3454 : : * require custom processing to remove only the correct nullingrel markers.
3455 : : */
3456 : : static void
3457 : 64209 : reduce_outer_joins_pass2(Node *jtnode,
3458 : : reduce_outer_joins_pass1_state *state1,
3459 : : reduce_outer_joins_pass2_state *state2,
3460 : : PlannerInfo *root,
3461 : : Relids nonnullable_rels,
3462 : : List *forced_null_vars)
3463 : : {
3464 : : /*
3465 : : * pass 2 should never descend as far as an empty subnode or base rel,
3466 : : * because it's only called on subtrees marked as contains_outer.
3467 : : */
3468 [ - + ]: 64209 : if (jtnode == NULL)
8434 tgl@sss.pgh.pa.us 3469 [ # # ]:UBC 0 : elog(ERROR, "reached empty jointree");
8600 tgl@sss.pgh.pa.us 3470 [ - + ]:CBC 64209 : if (IsA(jtnode, RangeTblRef))
8434 tgl@sss.pgh.pa.us 3471 [ # # ]:UBC 0 : elog(ERROR, "reached base rel");
8600 tgl@sss.pgh.pa.us 3472 [ + + ]:CBC 64209 : else if (IsA(jtnode, FromExpr))
3473 : : {
3474 : 26543 : FromExpr *f = (FromExpr *) jtnode;
3475 : : ListCell *l;
3476 : : ListCell *s;
3477 : : Relids pass_nonnullable_rels;
3478 : : List *pass_forced_null_vars;
3479 : :
3480 : : /* Scan quals to see if we can add any constraints */
6587 3481 : 26543 : pass_nonnullable_rels = find_nonnullable_rels(f->quals);
3482 : 26543 : pass_nonnullable_rels = bms_add_members(pass_nonnullable_rels,
3483 : : nonnullable_rels);
3484 : 26543 : pass_forced_null_vars = find_forced_null_vars(f->quals);
1380 3485 : 26543 : pass_forced_null_vars = mbms_add_members(pass_forced_null_vars,
3486 : : forced_null_vars);
3487 : : /* And recurse --- but only into interesting subtrees */
1305 3488 [ - + ]: 26543 : Assert(list_length(f->fromlist) == list_length(state1->sub_states));
3489 [ + - + + : 55252 : forboth(l, f->fromlist, s, state1->sub_states)
+ - + + +
+ + - +
+ ]
3490 : : {
3491 : 28709 : reduce_outer_joins_pass1_state *sub_state = lfirst(s);
3492 : :
8600 3493 [ + + ]: 28709 : if (sub_state->contains_outer)
1305 3494 : 26568 : reduce_outer_joins_pass2(lfirst(l), sub_state,
3495 : : state2, root,
3496 : : pass_nonnullable_rels,
3497 : : pass_forced_null_vars);
3498 : : }
6587 3499 : 26543 : bms_free(pass_nonnullable_rels);
3500 : : /* can't so easily clean up var lists, unfortunately */
3501 : : }
8600 3502 [ + - ]: 37666 : else if (IsA(jtnode, JoinExpr))
3503 : : {
3504 : 37666 : JoinExpr *j = (JoinExpr *) jtnode;
3505 : 37666 : int rtindex = j->rtindex;
3506 : 37666 : JoinType jointype = j->jointype;
1305 3507 : 37666 : reduce_outer_joins_pass1_state *left_state = linitial(state1->sub_states);
3508 : 37666 : reduce_outer_joins_pass1_state *right_state = lsecond(state1->sub_states);
3509 : :
3510 : : /* Can we simplify this join? */
8600 3511 [ + + + + : 37666 : switch (jointype)
+ - ]
3512 : : {
6587 3513 : 704 : case JOIN_INNER:
3514 : 704 : break;
8600 3515 : 34720 : case JOIN_LEFT:
3516 [ + + ]: 34720 : if (bms_overlap(nonnullable_rels, right_state->relids))
3517 : 2403 : jointype = JOIN_INNER;
3518 : 34720 : break;
3519 : 965 : case JOIN_RIGHT:
3520 [ + + ]: 965 : if (bms_overlap(nonnullable_rels, left_state->relids))
3521 : 69 : jointype = JOIN_INNER;
3522 : 965 : break;
3523 : 960 : case JOIN_FULL:
3524 [ + + ]: 960 : if (bms_overlap(nonnullable_rels, left_state->relids))
3525 : : {
3526 [ + + ]: 35 : if (bms_overlap(nonnullable_rels, right_state->relids))
3527 : 10 : jointype = JOIN_INNER;
3528 : : else
3529 : : {
3530 : 25 : jointype = JOIN_LEFT;
3531 : : /* Also report partial reduction in state2 */
1305 3532 : 25 : report_reduced_full_join(state2, rtindex,
3533 : : right_state->relids);
3534 : : }
3535 : : }
8 rguo@postgresql.org 3536 [ + + ]:GNC 925 : else if (bms_overlap(nonnullable_rels, right_state->relids))
3537 : : {
3538 : 29 : jointype = JOIN_RIGHT;
3539 : : /* Also report partial reduction in state2 */
3540 : 29 : report_reduced_full_join(state2, rtindex,
3541 : : left_state->relids);
3542 : : }
3543 [ + + ]: 896 : else if (forced_null_vars != NIL)
3544 : : {
3545 : : /*
3546 : : * Neither side is forced non-null by a strict upper qual,
3547 : : * but an upper qual may force a Var on one side to be
3548 : : * NULL while that Var is non-null in every row that side
3549 : : * emits (proven by quals within the side's own subtree,
3550 : : * or a NOT NULL constraint). Then only rows where that
3551 : : * side was null-extended can satisfy the upper qual: the
3552 : : * matched rows and that side's unmatched rows all drop
3553 : : * out, leaving an anti-join.
3554 : : *
3555 : : * Unlike the JOIN_LEFT case below, we must not consult
3556 : : * the join's own ON quals here: they do not hold for the
3557 : : * unmatched rows that this proof has to cover.
3558 : : *
3559 : : * If the constrained Var is on the RHS the result is a
3560 : : * plain anti-join; if it is on the LHS it is a right
3561 : : * anti-join, which the input-switching step below
3562 : : * normalizes to a plain anti-join (just as it does for
3563 : : * JOIN_RIGHT).
3564 : : */
3565 [ + + ]: 75 : if (forced_null_var_is_nonnullable(root,
3566 : : forced_null_vars,
3567 : : right_state, NIL))
3568 : : {
3569 : 35 : jointype = JOIN_ANTI;
3570 : 35 : report_reduced_full_join(state2, rtindex,
3571 : : right_state->relids);
3572 : : }
3573 [ + + ]: 40 : else if (forced_null_var_is_nonnullable(root,
3574 : : forced_null_vars,
3575 : : left_state, NIL))
3576 : : {
3577 : 20 : jointype = JOIN_RIGHT_ANTI;
1305 tgl@sss.pgh.pa.us 3578 :CBC 20 : report_reduced_full_join(state2, rtindex,
3579 : : left_state->relids);
3580 : : }
3581 : : }
8600 3582 : 960 : break;
6392 3583 : 317 : case JOIN_SEMI:
3584 : : case JOIN_ANTI:
3585 : :
3586 : : /*
3587 : : * These could only have been introduced by pull_up_sublinks,
3588 : : * so there's no way that upper quals could refer to their
3589 : : * righthand sides, and no point in checking. We don't expect
3590 : : * a JOIN_RIGHT_SEMI or JOIN_RIGHT_ANTI input here; the
3591 : : * JOIN_FULL case above produces JOIN_RIGHT_ANTI only as a
3592 : : * transient, which is converted to JOIN_ANTI below.
3593 : : */
3594 : 317 : break;
8600 tgl@sss.pgh.pa.us 3595 :UBC 0 : default:
6587 3596 [ # # ]: 0 : elog(ERROR, "unrecognized join type: %d",
3597 : : (int) jointype);
3598 : : break;
3599 : : }
3600 : :
3601 : : /*
3602 : : * Convert JOIN_RIGHT to JOIN_LEFT, and likewise the JOIN_RIGHT_ANTI
3603 : : * that the JOIN_FULL arm may have produced just above to JOIN_ANTI,
3604 : : * by switching the inputs. Note that in the case where we reduced
3605 : : * JOIN_FULL this way, this will mean the JoinExpr no longer matches
3606 : : * the internal ordering of any CoalesceExpr's built to represent
3607 : : * merged join variables. We don't care about that at present, but be
3608 : : * wary of it ...
3609 : : */
8 rguo@postgresql.org 3610 [ + + + + ]:GNC 37666 : if (jointype == JOIN_RIGHT || jointype == JOIN_RIGHT_ANTI)
3611 : : {
3612 : : Node *tmparg;
3613 : :
6587 tgl@sss.pgh.pa.us 3614 :CBC 945 : tmparg = j->larg;
3615 : 945 : j->larg = j->rarg;
3616 : 945 : j->rarg = tmparg;
8 rguo@postgresql.org 3617 [ + + ]:GNC 945 : jointype = (jointype == JOIN_RIGHT) ? JOIN_LEFT : JOIN_ANTI;
1305 tgl@sss.pgh.pa.us 3618 :CBC 945 : right_state = linitial(state1->sub_states);
3619 : 945 : left_state = lsecond(state1->sub_states);
3620 : : }
3621 : :
3622 : : /*
3623 : : * See if we can reduce JOIN_LEFT to JOIN_ANTI. This is the case if
3624 : : * any var from the RHS was forced null by higher qual levels, but is
3625 : : * known to be non-nullable in any matching row. We can prove that in
3626 : : * any of these ways: the join's own quals are strict for the var;
3627 : : * strict quals applied within the RHS subtree prove it; or the var is
3628 : : * defined NOT NULL by table constraints (being careful to exclude
3629 : : * vars that are nullable due to lower-level outer joins). In each
3630 : : * such case, the only way the higher qual clause's requirement for
3631 : : * NULL can be met is if the join fails to match, producing a
3632 : : * null-extended row. Thus, we can treat this as an anti-join.
3633 : : */
196 rguo@postgresql.org 3634 [ + + + + ]: 37666 : if (jointype == JOIN_LEFT && forced_null_vars != NIL)
3635 : : {
3636 : : /*
3637 : : * A forced-null RHS Var that is proven non-null can be NULL here
3638 : : * only by null-extension. That makes this an anti-join.
3639 : : */
8 rguo@postgresql.org 3640 [ + + ]:GNC 1206 : if (forced_null_var_is_nonnullable(root, forced_null_vars,
3641 : 1206 : right_state, (List *) j->quals))
6587 tgl@sss.pgh.pa.us 3642 :CBC 1022 : jointype = JOIN_ANTI;
3643 : : }
3644 : :
3645 : : /*
3646 : : * Apply the jointype change, if any, to both jointree node and RTE.
3647 : : * Also, if we changed an RTE to INNER, add its RTI to inner_reduced.
3648 : : */
6392 3649 [ + + + + ]: 37666 : if (rtindex && jointype != j->jointype)
3650 : : {
7753 3651 : 4509 : RangeTblEntry *rte = rt_fetch(rtindex, root->parse->rtable);
3652 : :
8600 3653 [ - + ]: 4509 : Assert(rte->rtekind == RTE_JOIN);
3654 [ - + ]: 4509 : Assert(rte->jointype == j->jointype);
6392 3655 : 4509 : rte->jointype = jointype;
1305 3656 [ + + ]: 4509 : if (jointype == JOIN_INNER)
3657 : 2482 : state2->inner_reduced = bms_add_member(state2->inner_reduced,
3658 : : rtindex);
3659 : : }
6392 3660 : 37666 : j->jointype = jointype;
3661 : :
3662 : : /* Only recurse if there's more to do below here */
8600 3663 [ + + + + ]: 37666 : if (left_state->contains_outer || right_state->contains_outer)
3664 : : {
3665 : : Relids local_nonnullable_rels;
3666 : : List *local_forced_null_vars;
3667 : : Relids pass_nonnullable_rels;
3668 : : List *pass_forced_null_vars;
3669 : :
3670 : : /*
3671 : : * If this join is (now) inner, we can add any constraints its
3672 : : * quals provide to those we got from above. But if it is outer,
3673 : : * we can pass down the local constraints only into the nullable
3674 : : * side, because an outer join never eliminates any rows from its
3675 : : * non-nullable side. Also, there is no point in passing upper
3676 : : * constraints into the nullable side, since if there were any
3677 : : * we'd have been able to reduce the join. (In the case of upper
3678 : : * forced-null constraints, we *must not* pass them into the
3679 : : * nullable side --- they either applied here, or not.) The upshot
3680 : : * is that we pass either the local or the upper constraints,
3681 : : * never both, to the children of an outer join.
3682 : : *
3683 : : * Note that a SEMI join works like an inner join here: it's okay
3684 : : * to pass down both local and upper constraints. (There can't be
3685 : : * any upper constraints affecting its inner side, but it's not
3686 : : * worth having a separate code path to avoid passing them.)
3687 : : *
3688 : : * At a FULL join we just punt and pass nothing down --- is it
3689 : : * possible to be smarter?
3690 : : */
8599 3691 [ + + ]: 12098 : if (jointype != JOIN_FULL)
3692 : : {
6587 3693 : 11985 : local_nonnullable_rels = find_nonnullable_rels(j->quals);
3694 : 11985 : local_forced_null_vars = find_forced_null_vars(j->quals);
5688 3695 [ + + + + ]: 11985 : if (jointype == JOIN_INNER || jointype == JOIN_SEMI)
3696 : : {
3697 : : /* OK to merge upper and local constraints */
6587 3698 : 1542 : local_nonnullable_rels = bms_add_members(local_nonnullable_rels,
3699 : : nonnullable_rels);
1380 3700 : 1542 : local_forced_null_vars = mbms_add_members(local_forced_null_vars,
3701 : : forced_null_vars);
3702 : : }
3703 : : }
3704 : : else
3705 : : {
3706 : : /* no use in calculating these */
6587 3707 : 113 : local_nonnullable_rels = NULL;
3708 : 113 : local_forced_null_vars = NIL;
3709 : : }
3710 : :
8600 3711 [ + + ]: 12098 : if (left_state->contains_outer)
3712 : : {
5688 3713 [ + + + + ]: 11393 : if (jointype == JOIN_INNER || jointype == JOIN_SEMI)
3714 : : {
3715 : : /* pass union of local and upper constraints */
6587 3716 : 1361 : pass_nonnullable_rels = local_nonnullable_rels;
3717 : 1361 : pass_forced_null_vars = local_forced_null_vars;
3718 : : }
5618 bruce@momjian.us 3719 [ + + ]: 10032 : else if (jointype != JOIN_FULL) /* ie, LEFT or ANTI */
3720 : : {
3721 : : /* can't pass local constraints to non-nullable side */
6587 tgl@sss.pgh.pa.us 3722 : 9952 : pass_nonnullable_rels = nonnullable_rels;
3723 : 9952 : pass_forced_null_vars = forced_null_vars;
3724 : : }
3725 : : else
3726 : : {
3727 : : /* no constraints pass through JOIN_FULL */
3728 : 80 : pass_nonnullable_rels = NULL;
3729 : 80 : pass_forced_null_vars = NIL;
3730 : : }
1305 3731 : 11393 : reduce_outer_joins_pass2(j->larg, left_state,
3732 : : state2, root,
3733 : : pass_nonnullable_rels,
3734 : : pass_forced_null_vars);
3735 : : }
3736 : :
8600 3737 [ + + ]: 12098 : if (right_state->contains_outer)
3738 : : {
3354 3739 [ + + ]: 759 : if (jointype != JOIN_FULL) /* ie, INNER/LEFT/SEMI/ANTI */
3740 : : {
3741 : : /* pass appropriate constraints, per comment above */
6587 3742 : 726 : pass_nonnullable_rels = local_nonnullable_rels;
3743 : 726 : pass_forced_null_vars = local_forced_null_vars;
3744 : : }
3745 : : else
3746 : : {
3747 : : /* no constraints pass through JOIN_FULL */
3748 : 33 : pass_nonnullable_rels = NULL;
3749 : 33 : pass_forced_null_vars = NIL;
3750 : : }
1305 3751 : 759 : reduce_outer_joins_pass2(j->rarg, right_state,
3752 : : state2, root,
3753 : : pass_nonnullable_rels,
3754 : : pass_forced_null_vars);
3755 : : }
6587 3756 : 12098 : bms_free(local_nonnullable_rels);
3757 : : }
3758 : : }
3759 : : else
8434 tgl@sss.pgh.pa.us 3760 [ # # ]:UBC 0 : elog(ERROR, "unrecognized node type: %d",
3761 : : (int) nodeTag(jtnode));
8600 tgl@sss.pgh.pa.us 3762 :CBC 64209 : }
3763 : :
3764 : : /* Helper for reduce_outer_joins_pass2 */
3765 : : static void
1305 3766 : 109 : report_reduced_full_join(reduce_outer_joins_pass2_state *state2,
3767 : : int rtindex, Relids relids)
3768 : : {
3769 : : reduce_outer_joins_partial_state *statep;
3770 : :
260 michael@paquier.xyz 3771 : 109 : statep = palloc_object(reduce_outer_joins_partial_state);
1305 tgl@sss.pgh.pa.us 3772 : 109 : statep->full_join_rti = rtindex;
3773 : 109 : statep->unreduced_side = relids;
3774 : 109 : state2->partial_reduced = lappend(state2->partial_reduced, statep);
3775 : 109 : }
3776 : :
3777 : : /*
3778 : : * forced_null_var_is_attnotnull
3779 : : * Check if "forced_null_vars" contains any Vars belonging to the subtree
3780 : : * indicated by "state" that are known to be non-nullable due to table
3781 : : * constraints.
3782 : : *
3783 : : * A whole-row Var, in any matching row, requires every column of its relation
3784 : : * to be NULL, so any NOT NULL column of the relation refutes it.
3785 : : *
3786 : : * Note that we must also consider the situation where a NOT NULL Var can be
3787 : : * nulled by lower-level outer joins.
3788 : : *
3789 : : * Helper for reduce_outer_joins_pass2.
3790 : : */
3791 : : static bool
8 rguo@postgresql.org 3792 :GNC 314 : forced_null_var_is_attnotnull(PlannerInfo *root, List *forced_null_vars,
3793 : : reduce_outer_joins_pass1_state *state)
3794 : : {
196 rguo@postgresql.org 3795 :CBC 314 : int varno = -1;
3796 : :
3797 [ + - + + : 1916 : foreach_node(Bitmapset, attrs, forced_null_vars)
+ + ]
3798 : : {
3799 : : RangeTblEntry *rte;
3800 : : Bitmapset *notnullattnums;
3801 : : Bitmapset *forcednullattnums;
8 rguo@postgresql.org 3802 :GNC 1428 : bool wholerow = false;
3803 : : int lowest_attno;
3804 : :
196 rguo@postgresql.org 3805 :CBC 1428 : varno++;
3806 : :
3807 : : /* Skip empty bitmaps */
3808 [ + + ]: 1428 : if (bms_is_empty(attrs))
3809 : 1114 : continue;
3810 : :
3811 : : /* Skip Vars that do not belong to the target relations */
8 rguo@postgresql.org 3812 [ + + ]:GNC 314 : if (!bms_is_member(varno, state->relids))
196 rguo@postgresql.org 3813 :CBC 110 : continue;
3814 : :
3815 : : /*
3816 : : * Skip Vars that can be nulled by lower-level outer joins within the
3817 : : * given subtree. These Vars might be NULL even if the schema defines
3818 : : * them as NOT NULL.
3819 : : */
8 rguo@postgresql.org 3820 [ + + ]:GNC 204 : if (bms_is_member(varno, state->nullable_rels))
196 rguo@postgresql.org 3821 :CBC 25 : continue;
3822 : :
3823 : : /* find the lowest member to check if system columns are present */
49 drowley@postgresql.o 3824 :GNC 179 : lowest_attno = bms_next_member(attrs, -1);
3825 : :
3826 : : /* we checked for an empty set above */
3827 [ - + ]: 179 : Assert(lowest_attno >= 0);
3828 : :
3829 : : /* system columns cannot be NULL */
3830 [ - + ]: 179 : if (lowest_attno + FirstLowInvalidHeapAttributeNumber < 0)
3831 : 70 : return true;
3832 : :
3833 : : /* attno 0 is a whole-row Var, which forces every column null */
8 rguo@postgresql.org 3834 [ + + ]: 179 : if (lowest_attno + FirstLowInvalidHeapAttributeNumber == 0)
3835 : 40 : wholerow = true;
3836 : :
196 rguo@postgresql.org 3837 :CBC 179 : rte = rt_fetch(varno, root->parse->rtable);
3838 : :
3839 : : /* We can only reason about ordinary relations */
168 3840 [ + + ]: 179 : if (rte->rtekind != RTE_RELATION)
3841 : 34 : continue;
3842 : :
3843 : : /*
3844 : : * We must skip inheritance parent tables, as some child tables may
3845 : : * have a NOT NULL constraint for a column while others may not. This
3846 : : * cannot happen with partitioned tables, though.
3847 : : */
196 3848 [ - + - - ]: 145 : if (rte->inh && rte->relkind != RELKIND_PARTITIONED_TABLE)
196 rguo@postgresql.org 3849 :UBC 0 : continue;
3850 : :
3851 : : /* Get the column not-null constraint information for this relation */
196 rguo@postgresql.org 3852 :CBC 145 : notnullattnums = find_relation_notnullatts(root, rte->relid);
3853 : :
3854 : : /*
3855 : : * A forced-null whole-row Var, in any matching row, requires every
3856 : : * column of the relation to be NULL, so any NOT NULL column refutes
3857 : : * it.
3858 : : */
8 rguo@postgresql.org 3859 [ + + + + ]:GNC 145 : if (wholerow && !bms_is_empty(notnullattnums))
3860 : 10 : return true;
3861 : :
3862 : : /*
3863 : : * Offset the bitmap members by FirstLowInvalidHeapAttributeNumber to
3864 : : * get the actual attribute numbers.
3865 : : */
3866 : 135 : forcednullattnums = bms_offset_members(attrs,
3867 : : FirstLowInvalidHeapAttributeNumber);
3868 : :
3869 : : /*
3870 : : * Check if any forced-null attributes are defined as NOT NULL by
3871 : : * table constraints.
3872 : : */
196 rguo@postgresql.org 3873 [ + + ]:CBC 135 : if (bms_overlap(notnullattnums, forcednullattnums))
3874 : : {
3875 : 60 : bms_free(forcednullattnums);
3876 : 60 : return true;
3877 : : }
3878 : :
3879 : 75 : bms_free(forcednullattnums);
3880 : : }
3881 : :
3882 : 244 : return false;
3883 : : }
3884 : :
3885 : : /*
3886 : : * forced_null_var_is_nonnullable
3887 : : * Detect whether some Var that "forced_null_vars" requires to be NULL is
3888 : : * actually non-nullable in every row that the given subtree emits.
3889 : : *
3890 : : * We prove non-nullness from quals that hold for every such row: the subtree's
3891 : : * safe quals, plus any "extra_quals" the caller knows also constrain the Var,
3892 : : * or a NOT NULL table constraint (excluding Vars nullable due to lower-level
3893 : : * outer joins).
3894 : : *
3895 : : * A whole-row Var in "forced_null_vars" requires, in any matching row, every
3896 : : * column of its relation to be NULL, so it is refuted by proving any one of
3897 : : * those columns non-null.
3898 : : *
3899 : : * Helper for reduce_outer_joins_pass2.
3900 : : */
3901 : : static bool
8 rguo@postgresql.org 3902 :GNC 1321 : forced_null_var_is_nonnullable(PlannerInfo *root, List *forced_null_vars,
3903 : : reduce_outer_joins_pass1_state *state,
3904 : : List *extra_quals)
3905 : : {
6 3906 : 1321 : List *all_quals = NIL;
3907 : : List *nonnullable_vars;
8 3908 : 1321 : int wholerow_attno = 0 - FirstLowInvalidHeapAttributeNumber;
3909 : 1321 : int varno = -1;
3910 : :
6 3911 : 1321 : find_safe_quals(state->jtnode, &all_quals);
3912 : 1321 : all_quals = list_concat(all_quals, extra_quals);
8 3913 : 1321 : nonnullable_vars = find_nonnullable_vars((Node *) all_quals);
3914 : :
3915 : : /*
3916 : : * It's not sufficient to consider all matches between nonnullable_vars
3917 : : * and forced_null_vars: a match counts only for a Var belonging to this
3918 : : * subtree, and the whole-row attribute needs special treatment.
3919 : : */
3920 [ + - + + : 4580 : foreach_node(Bitmapset, attrs, forced_null_vars)
+ + ]
3921 : : {
3922 : : Bitmapset *nonnull_attrs;
3923 : :
3924 : 4148 : varno++;
3925 : :
3926 : : /* Beyond the end of nonnullable_vars there is nothing left to prove */
3927 [ + + ]: 4148 : if (varno >= list_length(nonnullable_vars))
3928 : 196 : break;
3929 : :
3930 : : /* Skip empty bitmaps */
3931 [ + + ]: 3952 : if (bms_is_empty(attrs))
3932 : 2827 : continue;
3933 : :
3934 : : /* Skip Vars that do not belong to the target relations */
3935 [ + + ]: 1125 : if (!bms_is_member(varno, state->relids))
3936 : 44 : continue;
3937 : :
3938 : : /* Get what the quals prove non-null for this relation, if anything */
3939 : 1081 : nonnull_attrs = list_nth_node(Bitmapset, nonnullable_vars, varno);
3940 : :
3941 : : /*
3942 : : * A proof for the whole-row attribute refutes nothing: it shows only
3943 : : * that the composite datum is non-null, and such a datum can still
3944 : : * have all columns NULL. Discard it up front.
3945 : : */
3946 : 1081 : nonnull_attrs = bms_del_member(nonnull_attrs, wholerow_attno);
3947 : :
3948 : : /* A forced-null attribute that is proven non-null settles it. */
3949 [ + + ]: 1081 : if (bms_overlap(attrs, nonnull_attrs))
3950 : 1007 : return true;
3951 : :
3952 : : /*
3953 : : * So does any real column proven non-null, if the whole-row Var is
3954 : : * forced null: in a matching row (whose whole-row datum is non-null)
3955 : : * the row-format IS NULL test is true only when every column is NULL.
3956 : : * System attributes don't count, since they are not part of the row
3957 : : * value; conveniently they sort below the whole-row attribute in the
3958 : : * bitmap.
3959 : : */
3960 [ + + + + ]: 124 : if (bms_is_member(wholerow_attno, attrs) &&
3961 : 35 : bms_next_member(nonnull_attrs, wholerow_attno) >= 0)
3962 : 15 : return true;
3963 : : }
3964 : :
3965 : : /*
3966 : : * Otherwise, check if any forced-null var is defined NOT NULL by table
3967 : : * constraints.
3968 : : */
3969 : 314 : return forced_null_var_is_attnotnull(root, forced_null_vars, state);
3970 : : }
3971 : :
3972 : :
3973 : : /*
3974 : : * remove_useless_result_rtes
3975 : : * Attempt to remove RTE_RESULT RTEs from the join tree.
3976 : : * Also, elide single-child FromExprs where possible.
3977 : : *
3978 : : * We can remove RTE_RESULT entries from the join tree using the knowledge
3979 : : * that RTE_RESULT returns exactly one row and has no output columns. Hence,
3980 : : * if one is inner-joined to anything else, we can delete it. Optimizations
3981 : : * are also possible for some outer-join cases, as detailed below.
3982 : : *
3983 : : * This pass also replaces single-child FromExprs with their child node
3984 : : * where possible. It's appropriate to do that here and not earlier because
3985 : : * RTE_RESULT removal might reduce a multiple-child FromExpr to have only one
3986 : : * child. We can remove such a FromExpr if its quals are empty, or if it's
3987 : : * semantically valid to merge the quals into those of the parent node.
3988 : : * While removing unnecessary join tree nodes has some micro-efficiency value,
3989 : : * the real reason to do this is to eliminate cases where the nullable side of
3990 : : * an outer join node is a FromExpr whose single child is another outer join.
3991 : : * To correctly determine whether the two outer joins can commute,
3992 : : * deconstruct_jointree() must treat any quals of such a FromExpr as being
3993 : : * degenerate quals of the upper outer join. The best way to do that is to
3994 : : * make them actually *be* quals of the upper join, by dropping the FromExpr
3995 : : * and hoisting the quals up into the upper join's quals. (Note that there is
3996 : : * no hazard when the intermediate FromExpr has multiple children, since then
3997 : : * it represents an inner join that cannot commute with the upper outer join.)
3998 : : * As long as we have to do that, we might as well elide such FromExprs
3999 : : * everywhere.
4000 : : *
4001 : : * Some of these optimizations depend on recognizing empty (constant-true)
4002 : : * quals for FromExprs and JoinExprs. That makes it useful to apply this
4003 : : * optimization pass after expression preprocessing, since that will have
4004 : : * eliminated constant-true quals, allowing more cases to be recognized as
4005 : : * optimizable. What's more, the usual reason for an RTE_RESULT to be present
4006 : : * is that we pulled up a subquery or VALUES clause, thus very possibly
4007 : : * replacing Vars with constants, making it more likely that a qual can be
4008 : : * reduced to constant true. Also, because some optimizations depend on
4009 : : * the outer-join type, it's best to have done reduce_outer_joins() first.
4010 : : *
4011 : : * A PlaceHolderVar referencing an RTE_RESULT RTE poses an obstacle to this
4012 : : * process: we must remove the RTE_RESULT's relid from the PHV's phrels, but
4013 : : * we must not reduce the phrels set to empty. If that would happen, and
4014 : : * the RTE_RESULT is an immediate child of an outer join, we have to give up
4015 : : * and not remove the RTE_RESULT: there is noplace else to evaluate the
4016 : : * PlaceHolderVar. (That is, in such cases the RTE_RESULT *does* have output
4017 : : * columns.) But if the RTE_RESULT is an immediate child of an inner join,
4018 : : * we can usually change the PlaceHolderVar's phrels so as to evaluate it at
4019 : : * the inner join instead. This is OK because we really only care that PHVs
4020 : : * are evaluated above or below the correct outer joins. We can't, however,
4021 : : * postpone the evaluation of a PHV to above where it is used; so there are
4022 : : * some checks below on whether output PHVs are laterally referenced in the
4023 : : * other join input rel(s).
4024 : : *
4025 : : * We used to try to do this work as part of pull_up_subqueries() where the
4026 : : * potentially-optimizable cases get introduced; but it's way simpler, and
4027 : : * more effective, to do it separately.
4028 : : */
4029 : : void
2768 tgl@sss.pgh.pa.us 4030 :CBC 166921 : remove_useless_result_rtes(PlannerInfo *root)
4031 : : {
38 rguo@postgresql.org 4032 : 166921 : Relids baserels = NULL;
1305 tgl@sss.pgh.pa.us 4033 : 166921 : Relids dropped_outer_joins = NULL;
4034 : : ListCell *cell;
4035 : :
4036 : : /*
4037 : : * We'll need the set of baserels in the jointree to perform
4038 : : * find_dependent_phvs() checks. But if there are no PHVs anywhere in the
4039 : : * query, those checks are no-ops, so we can skip the work.
4040 : : */
38 rguo@postgresql.org 4041 [ + + ]: 166921 : if (root->glob->lastPHId != 0)
4042 : 1311 : baserels = get_relids_in_jointree((Node *) root->parse->jointree,
4043 : : false, false);
4044 : :
4045 : : /* Top level of jointree must always be a FromExpr */
2768 tgl@sss.pgh.pa.us 4046 [ - + ]: 166921 : Assert(IsA(root->parse->jointree, FromExpr));
4047 : : /* Recurse ... */
4048 : 333842 : root->parse->jointree = (FromExpr *)
1305 4049 : 166921 : remove_useless_results_recurse(root,
4050 : 166921 : (Node *) root->parse->jointree,
4051 : : baserels,
4052 : : NULL,
4053 : : &dropped_outer_joins);
4054 : : /* We should still have a FromExpr */
2768 4055 [ - + ]: 166921 : Assert(IsA(root->parse->jointree, FromExpr));
4056 : :
4057 : : /*
4058 : : * If we removed any outer-join nodes from the jointree, run around and
4059 : : * remove references to those joins as nulling rels. (There could be such
4060 : : * references in PHVs that we pulled up out of the original subquery that
4061 : : * the RESULT rel replaced. This is kosher on the grounds that we now
4062 : : * know that such an outer join wouldn't really have nulled anything.) We
4063 : : * don't do this during the main recursion, for simplicity and because we
4064 : : * can handle all such joins in a single pass over the parse tree.
4065 : : */
1305 4066 [ + + ]: 166921 : if (!bms_is_empty(dropped_outer_joins))
4067 : : {
4068 : 65 : root->parse = (Query *)
4069 : 65 : remove_nulling_relids((Node *) root->parse,
4070 : : dropped_outer_joins,
4071 : : NULL);
4072 : : /* There could be references in the append_rel_list, too */
4073 : 65 : root->append_rel_list = (List *)
4074 : 65 : remove_nulling_relids((Node *) root->append_rel_list,
4075 : : dropped_outer_joins,
4076 : : NULL);
4077 : : }
4078 : :
4079 : : /*
4080 : : * Remove any PlanRowMark referencing an RTE_RESULT RTE. We obviously
4081 : : * must do that for any RTE_RESULT that we just removed. But one for a
4082 : : * RTE that we did not remove can be dropped anyway: since the RTE has
4083 : : * only one possible output row, there is no need for EPQ to mark and
4084 : : * restore that row.
4085 : : *
4086 : : * It's necessary, not optional, to remove the PlanRowMark for a surviving
4087 : : * RTE_RESULT RTE; otherwise we'll generate a whole-row Var for the
4088 : : * RTE_RESULT, which the executor has no support for.
4089 : : */
2600 4090 [ + + + + : 168502 : foreach(cell, root->rowMarks)
+ + ]
4091 : : {
2768 4092 : 1581 : PlanRowMark *rc = (PlanRowMark *) lfirst(cell);
4093 : :
4094 [ + + ]: 1581 : if (rt_fetch(rc->rti, root->parse->rtable)->rtekind == RTE_RESULT)
2600 4095 : 660 : root->rowMarks = foreach_delete_current(root->rowMarks, cell);
4096 : : }
2768 4097 : 166921 : }
4098 : :
4099 : : /*
4100 : : * remove_useless_results_recurse
4101 : : * Recursive guts of remove_useless_result_rtes.
4102 : : *
4103 : : * This recursively processes the jointree and returns a modified jointree.
4104 : : * In addition, the RT indexes of any removed outer-join nodes are added to
4105 : : * *dropped_outer_joins.
4106 : : *
4107 : : * jtnode is the current jointree node. If it could be valid to merge
4108 : : * its quals into those of the parent node, parent_quals should point to
4109 : : * the parent's quals list; otherwise, pass NULL for parent_quals.
4110 : : * (Note that in some cases, parent_quals points to the quals of a parent
4111 : : * more than one level up in the tree.)
4112 : : *
4113 : : * baserels is the set of base (non-join) RT indexes in the whole jointree;
4114 : : * it can be NULL if the query contains no PHVs.
4115 : : */
4116 : : static Node *
1305 4117 : 437225 : remove_useless_results_recurse(PlannerInfo *root, Node *jtnode,
4118 : : Relids baserels,
4119 : : Node **parent_quals,
4120 : : Relids *dropped_outer_joins)
4121 : : {
2768 4122 [ - + ]: 437225 : Assert(jtnode != NULL);
4123 [ + + ]: 437225 : if (IsA(jtnode, RangeTblRef))
4124 : : {
4125 : : /* Can't immediately do anything with a RangeTblRef */
4126 : : }
4127 [ + + ]: 219950 : else if (IsA(jtnode, FromExpr))
4128 : : {
4129 : 172507 : FromExpr *f = (FromExpr *) jtnode;
4130 : 172507 : Relids result_relids = NULL;
4131 : : ListCell *cell;
4132 : :
4133 : : /*
4134 : : * We can drop RTE_RESULT rels from the fromlist so long as at least
4135 : : * one child remains, since joining to a one-row table changes
4136 : : * nothing. (But we can't drop a RTE_RESULT that computes PHV(s) that
4137 : : * are needed by some sibling. The cleanup transformation below would
4138 : : * reassign the PHVs to be computed at the join, which is too late for
4139 : : * the sibling's use.) The easiest way to mechanize this rule is to
4140 : : * modify the list in-place.
4141 : : */
2600 4142 [ + - + + : 347925 : foreach(cell, f->fromlist)
+ + ]
4143 : : {
2768 4144 : 175418 : Node *child = (Node *) lfirst(cell);
4145 : : int varno;
4146 : :
4147 : : /* Recursively transform child, allowing it to push up quals ... */
1305 4148 : 175418 : child = remove_useless_results_recurse(root, child,
4149 : : baserels,
4150 : : &f->quals,
4151 : : dropped_outer_joins);
4152 : : /* ... and stick it back into the tree */
2768 4153 : 175418 : lfirst(cell) = child;
4154 : :
4155 : : /*
4156 : : * If it's an RTE_RESULT with at least one sibling, and no sibling
4157 : : * references dependent PHVs, we can drop it. We don't yet know
4158 : : * what the inner join's final relid set will be, so postpone
4159 : : * cleanup of PHVs etc till after this loop.
4160 : : */
4161 [ + + + + ]: 180071 : if (list_length(f->fromlist) > 1 &&
2448 4162 : 4653 : (varno = get_result_relid(root, child)) != 0 &&
40 4163 [ + + ]: 290 : !find_dependent_phvs_in_jointree(root, (Node *) f, varno,
4164 : : baserels))
4165 : : {
2600 4166 : 270 : f->fromlist = foreach_delete_current(f->fromlist, cell);
2768 4167 : 270 : result_relids = bms_add_member(result_relids, varno);
4168 : : }
4169 : : }
4170 : :
4171 : : /*
4172 : : * Clean up if we dropped any RTE_RESULT RTEs. This is a bit
4173 : : * inefficient if there's more than one, but it seems better to
4174 : : * optimize the support code for the single-relid case.
4175 : : */
4176 [ + + ]: 172507 : if (result_relids)
4177 : : {
4178 : 260 : int varno = -1;
4179 : :
4180 [ + + ]: 530 : while ((varno = bms_next_member(result_relids, varno)) >= 0)
4181 : 270 : remove_result_refs(root, varno, (Node *) f);
4182 : : }
4183 : :
4184 : : /*
4185 : : * If the FromExpr now has only one child, see if we can elide it.
4186 : : * This is always valid if there are no quals, except at the top of
4187 : : * the jointree (since Query.jointree is required to point to a
4188 : : * FromExpr). Otherwise, we can do it if we can push the quals up to
4189 : : * the parent node.
4190 : : *
4191 : : * Note: while it would not be terribly hard to generalize this
4192 : : * transformation to merge multi-child FromExprs into their parent
4193 : : * FromExpr, that risks making the parent join too expensive to plan.
4194 : : * We leave it to later processing to decide heuristically whether
4195 : : * that's a good idea. Pulling up a single child is always OK,
4196 : : * however.
4197 : : */
1305 4198 [ + + ]: 172507 : if (list_length(f->fromlist) == 1 &&
4199 [ + + ]: 170939 : f != root->parse->jointree &&
4200 [ + + + + ]: 5375 : (f->quals == NULL || parent_quals != NULL))
4201 : : {
4202 : : /*
4203 : : * Merge any quals up to parent. They should be in implicit-AND
4204 : : * format by now, so we just need to concatenate lists. Put the
4205 : : * child quals at the front, on the grounds that they should
4206 : : * nominally be evaluated earlier.
4207 : : */
4208 [ + + ]: 2279 : if (f->quals != NULL)
4209 : 1160 : *parent_quals = (Node *)
4210 : 1160 : list_concat(castNode(List, f->quals),
4211 : 1160 : castNode(List, *parent_quals));
2768 4212 : 2279 : return (Node *) linitial(f->fromlist);
4213 : : }
4214 : : }
4215 [ + - ]: 47443 : else if (IsA(jtnode, JoinExpr))
4216 : : {
4217 : 47443 : JoinExpr *j = (JoinExpr *) jtnode;
4218 : : int varno;
4219 : :
4220 : : /*
4221 : : * First, recurse. We can absorb pushed-up FromExpr quals from either
4222 : : * child into this node if the jointype is INNER, since then this is
4223 : : * equivalent to a FromExpr. When the jointype is LEFT, we can absorb
4224 : : * quals from the RHS child into the current node, as they're
4225 : : * essentially degenerate quals of the outer join. Moreover, if we've
4226 : : * been passed down a parent_quals pointer then we can allow quals of
4227 : : * the LHS child to be absorbed into the parent. (This is important
4228 : : * to ensure we remove single-child FromExprs immediately below
4229 : : * commutable left joins.) For other jointypes, we can't move child
4230 : : * quals up, or at least there's no particular reason to.
4231 : : */
1305 4232 : 47443 : j->larg = remove_useless_results_recurse(root, j->larg,
4233 : : baserels,
4234 [ + + ]: 47443 : (j->jointype == JOIN_INNER) ?
4235 : : &j->quals :
1164 4236 : 37138 : (j->jointype == JOIN_LEFT) ?
4237 [ + + ]: 37138 : parent_quals : NULL,
4238 : : dropped_outer_joins);
1305 4239 : 47443 : j->rarg = remove_useless_results_recurse(root, j->rarg,
4240 : : baserels,
4241 [ + + ]: 47443 : (j->jointype == JOIN_INNER ||
4242 [ + + ]: 37138 : j->jointype == JOIN_LEFT) ?
4243 : : &j->quals : NULL,
4244 : : dropped_outer_joins);
4245 : :
4246 : : /* Apply join-type-specific optimization rules */
2768 4247 [ + + + + : 47443 : switch (j->jointype)
- ]
4248 : : {
4249 : 10305 : case JOIN_INNER:
4250 : :
4251 : : /*
4252 : : * An inner join is equivalent to a FromExpr, so if either
4253 : : * side was simplified to an RTE_RESULT rel, we can replace
4254 : : * the join with a FromExpr with just the other side.
4255 : : * Furthermore, we can elide that FromExpr according to the
4256 : : * same rules as above.
4257 : : *
4258 : : * Just as in the FromExpr case, we can't simplify if the
4259 : : * other input rel references any PHVs that are marked as to
4260 : : * be evaluated at the RTE_RESULT rel, because we can't
4261 : : * postpone their evaluation in that case. But we only have
4262 : : * to check this in cases where it's syntactically legal for
4263 : : * the other input to have a LATERAL reference to the
4264 : : * RTE_RESULT rel. Only RHSes of inner and left joins are
4265 : : * allowed to have such refs.
4266 : : */
2448 4267 [ + + ]: 10305 : if ((varno = get_result_relid(root, j->larg)) != 0 &&
40 4268 [ + - ]: 86 : !find_dependent_phvs_in_jointree(root, j->rarg, varno,
4269 : : baserels))
4270 : : {
2768 4271 : 86 : remove_result_refs(root, varno, j->rarg);
1305 4272 [ + + + + ]: 86 : if (j->quals != NULL && parent_quals == NULL)
2768 4273 : 10 : jtnode = (Node *)
4274 : 10 : makeFromExpr(list_make1(j->rarg), j->quals);
4275 : : else
4276 : : {
4277 : : /* Merge any quals up to parent */
1305 4278 [ + + ]: 76 : if (j->quals != NULL)
4279 : 58 : *parent_quals = (Node *)
4280 : 58 : list_concat(castNode(List, j->quals),
4281 : 58 : castNode(List, *parent_quals));
2768 4282 : 76 : jtnode = j->rarg;
4283 : : }
4284 : : }
4285 [ + + ]: 10219 : else if ((varno = get_result_relid(root, j->rarg)) != 0)
4286 : : {
4287 : 570 : remove_result_refs(root, varno, j->larg);
1305 4288 [ + + + + ]: 570 : if (j->quals != NULL && parent_quals == NULL)
2768 4289 : 10 : jtnode = (Node *)
4290 : 10 : makeFromExpr(list_make1(j->larg), j->quals);
4291 : : else
4292 : : {
4293 : : /* Merge any quals up to parent */
1305 4294 [ + + ]: 560 : if (j->quals != NULL)
4295 : 399 : *parent_quals = (Node *)
4296 : 399 : list_concat(castNode(List, j->quals),
4297 : 399 : castNode(List, *parent_quals));
2768 4298 : 560 : jtnode = j->larg;
4299 : : }
4300 : : }
4301 : 10305 : break;
4302 : 32245 : case JOIN_LEFT:
4303 : :
4304 : : /*
4305 : : * We can simplify this case if the RHS is an RTE_RESULT, with
4306 : : * two different possibilities:
4307 : : *
4308 : : * If the qual is empty (JOIN ON TRUE), then the join can be
4309 : : * strength-reduced to a plain inner join, since each LHS row
4310 : : * necessarily has exactly one join partner. So we can always
4311 : : * discard the RHS, much as in the JOIN_INNER case above.
4312 : : * (Again, the LHS could not contain a lateral reference to
4313 : : * the RHS.)
4314 : : *
4315 : : * Otherwise, it's still true that each LHS row should be
4316 : : * returned exactly once, and since the RHS returns no columns
4317 : : * (unless there are PHVs that have to be evaluated there), we
4318 : : * don't much care if it's null-extended or not. So in this
4319 : : * case also, we can just ignore the qual and discard the left
4320 : : * join.
4321 : : */
4322 [ + + ]: 32245 : if ((varno = get_result_relid(root, j->rarg)) != 0 &&
4323 [ + + ]: 134 : (j->quals == NULL ||
40 4324 [ - + ]: 69 : !find_dependent_phvs(root, varno, baserels)))
4325 : : {
2768 4326 : 65 : remove_result_refs(root, varno, j->larg);
1305 4327 : 65 : *dropped_outer_joins = bms_add_member(*dropped_outer_joins,
4328 : : j->rtindex);
2768 4329 : 65 : jtnode = j->larg;
4330 : : }
4331 : 32245 : break;
4332 : 2706 : case JOIN_SEMI:
4333 : :
4334 : : /*
4335 : : * We may simplify this case if the RHS is an RTE_RESULT; the
4336 : : * join qual becomes effectively just a filter qual for the
4337 : : * LHS, since we should either return the LHS row or not. The
4338 : : * filter clause must go into a new FromExpr if we can't push
4339 : : * it up to the parent.
4340 : : *
4341 : : * There is a fine point about PHVs that are supposed to be
4342 : : * evaluated at the RHS. Such PHVs could only appear in the
4343 : : * semijoin's qual, since the rest of the query cannot
4344 : : * reference any outputs of the semijoin's RHS. Therefore,
4345 : : * they can't actually go to null before being examined, and
4346 : : * it'd be OK to just remove the PHV wrapping. We don't have
4347 : : * infrastructure for that, but remove_result_refs() will
4348 : : * relabel them as to be evaluated at the LHS, which is fine.
4349 : : *
4350 : : * Also, we don't need to worry about removing traces of the
4351 : : * join's rtindex, since it hasn't got one.
4352 : : */
4353 [ + + ]: 2706 : if ((varno = get_result_relid(root, j->rarg)) != 0)
4354 : : {
1305 4355 [ - + ]: 30 : Assert(j->rtindex == 0);
2768 4356 : 30 : remove_result_refs(root, varno, j->larg);
1305 4357 [ + - - + ]: 30 : if (j->quals != NULL && parent_quals == NULL)
2768 tgl@sss.pgh.pa.us 4358 :UBC 0 : jtnode = (Node *)
4359 : 0 : makeFromExpr(list_make1(j->larg), j->quals);
4360 : : else
4361 : : {
4362 : : /* Merge any quals up to parent */
1305 tgl@sss.pgh.pa.us 4363 [ + - ]:CBC 30 : if (j->quals != NULL)
4364 : 30 : *parent_quals = (Node *)
4365 : 30 : list_concat(castNode(List, j->quals),
4366 : 30 : castNode(List, *parent_quals));
2768 4367 : 30 : jtnode = j->larg;
4368 : : }
4369 : : }
4370 : 2706 : break;
4371 : 2187 : case JOIN_FULL:
4372 : : case JOIN_ANTI:
4373 : : /* We have no special smarts for these cases */
4374 : 2187 : break;
2768 tgl@sss.pgh.pa.us 4375 :UBC 0 : default:
4376 : : /* Note: JOIN_RIGHT should be gone at this point */
4377 [ # # ]: 0 : elog(ERROR, "unrecognized join type: %d",
4378 : : (int) j->jointype);
4379 : : break;
4380 : : }
4381 : : }
4382 : : else
4383 [ # # ]: 0 : elog(ERROR, "unrecognized node type: %d",
4384 : : (int) nodeTag(jtnode));
2768 tgl@sss.pgh.pa.us 4385 :CBC 434946 : return jtnode;
4386 : : }
4387 : :
4388 : : /*
4389 : : * get_result_relid
4390 : : * If jtnode is a RangeTblRef for an RTE_RESULT RTE, return its relid;
4391 : : * otherwise return 0.
4392 : : */
4393 : : static int
4394 : 60128 : get_result_relid(PlannerInfo *root, Node *jtnode)
4395 : : {
4396 : : int varno;
4397 : :
4398 [ + + ]: 60128 : if (!IsA(jtnode, RangeTblRef))
4399 : 6244 : return 0;
4400 : 53884 : varno = ((RangeTblRef *) jtnode)->rtindex;
4401 [ + + ]: 53884 : if (rt_fetch(varno, root->parse->rtable)->rtekind != RTE_RESULT)
4402 : 52774 : return 0;
4403 : 1110 : return varno;
4404 : : }
4405 : :
4406 : : /*
4407 : : * remove_result_refs
4408 : : * Helper routine for dropping an unneeded RTE_RESULT RTE.
4409 : : *
4410 : : * This doesn't physically remove the RTE from the jointree, because that's
4411 : : * more easily handled in remove_useless_results_recurse. What it does do
4412 : : * is the necessary cleanup in the rest of the tree: we must adjust any PHVs
4413 : : * that may reference the RTE. Be sure to call this at a point where the
4414 : : * jointree is valid (no disconnected nodes).
4415 : : *
4416 : : * Note that we don't need to process the append_rel_list, since RTEs
4417 : : * referenced directly in the jointree won't be appendrel members.
4418 : : *
4419 : : * varno is the RTE_RESULT's relid.
4420 : : * newjtloc is the jointree location at which any PHVs referencing the
4421 : : * RTE_RESULT should be evaluated instead.
4422 : : */
4423 : : static void
4424 : 1021 : remove_result_refs(PlannerInfo *root, int varno, Node *newjtloc)
4425 : : {
4426 : : /* Fix up PlaceHolderVars as needed */
4427 : : /* If there are no PHVs anywhere, we can skip this bit */
4428 [ + + ]: 1021 : if (root->glob->lastPHId != 0)
4429 : : {
4430 : : Relids subrelids;
4431 : :
1305 4432 : 215 : subrelids = get_relids_in_jointree(newjtloc, true, false);
2768 4433 [ - + ]: 215 : Assert(!bms_is_empty(subrelids));
4434 : 215 : substitute_phv_relids((Node *) root->parse, varno, subrelids);
1344 4435 : 215 : fix_append_rel_relids(root, varno, subrelids);
4436 : : }
4437 : :
4438 : : /*
4439 : : * We also need to remove any PlanRowMark referencing the RTE, but we
4440 : : * postpone that work until we return to remove_useless_result_rtes.
4441 : : */
2768 4442 : 1021 : }
4443 : :
4444 : :
4445 : : /*
4446 : : * find_dependent_phvs - are there any PlaceHolderVars whose base relids are
4447 : : * exactly the given varno?
4448 : : *
4449 : : * We ignore outer-join relids present in a PHV's phrels, by intersecting
4450 : : * with the caller-supplied "baserels" set. This is necessary in part
4451 : : * because some of the OJ relids may be stale, that is we may have
4452 : : * already decided to remove those joins in remove_useless_result_rtes
4453 : : * and not yet have cleaned their relid bits out of upper PHVs.
4454 : : * But in general, it's the set of baserels that identify possible places
4455 : : * to evaluate a PHV, and we mustn't let that go to empty. (The caller is
4456 : : * allowed to pass baserels as NULL if the query contains no PHVs at all,
4457 : : * since then there is no work to do anyway.)
4458 : : *
4459 : : * find_dependent_phvs should be used when we want to see if there are
4460 : : * any such PHVs anywhere in the Query. Another use-case is to see if
4461 : : * a subtree of the join tree contains such PHVs; but for that, we have
4462 : : * to look not only at the join tree nodes themselves but at the
4463 : : * referenced RTEs. For that, use find_dependent_phvs_in_jointree.
4464 : : */
4465 : :
4466 : : typedef struct
4467 : : {
4468 : : Relids relids; /* target relid, represented as a relid set */
4469 : : Relids baserels; /* base RT indexes in query, NULL if no PHVs */
4470 : : int sublevels_up; /* current nesting level */
4471 : : } find_dependent_phvs_context;
4472 : :
4473 : : static bool
4474 : 1785 : find_dependent_phvs_walker(Node *node,
4475 : : find_dependent_phvs_context *context)
4476 : : {
4477 [ + + ]: 1785 : if (node == NULL)
4478 : 451 : return false;
4479 [ + + ]: 1334 : if (IsA(node, PlaceHolderVar))
4480 : : {
4481 : 124 : PlaceHolderVar *phv = (PlaceHolderVar *) node;
4482 : :
40 4483 [ + - ]: 124 : if (phv->phlevelsup == context->sublevels_up)
4484 : : {
4485 : 124 : Relids phbaserels = bms_intersect(phv->phrels,
4486 : 124 : context->baserels);
4487 : 124 : bool match = bms_equal(context->relids, phbaserels);
4488 : :
4489 : 124 : bms_free(phbaserels);
4490 [ + + ]: 124 : if (match)
4491 : 89 : return true;
4492 : : }
4493 : : /* fall through to examine children */
4494 : : }
2768 4495 [ + + ]: 1245 : if (IsA(node, Query))
4496 : : {
4497 : : /* Recurse into subselects */
4498 : : bool result;
4499 : :
4500 : 40 : context->sublevels_up++;
4501 : 40 : result = query_tree_walker((Query *) node,
4502 : : find_dependent_phvs_walker,
4503 : : context, 0);
4504 : 40 : context->sublevels_up--;
4505 : 40 : return result;
4506 : : }
4507 : : /* Shouldn't need to handle most planner auxiliary nodes here */
4508 [ - + ]: 1205 : Assert(!IsA(node, SpecialJoinInfo));
4509 [ - + ]: 1205 : Assert(!IsA(node, PlaceHolderInfo));
4510 [ - + ]: 1205 : Assert(!IsA(node, MinMaxAggInfo));
4511 : :
637 peter@eisentraut.org 4512 : 1205 : return expression_tree_walker(node, find_dependent_phvs_walker, context);
4513 : : }
4514 : :
4515 : : static bool
40 tgl@sss.pgh.pa.us 4516 : 69 : find_dependent_phvs(PlannerInfo *root, int varno, Relids baserels)
4517 : : {
4518 : : find_dependent_phvs_context context;
4519 : :
4520 : : /* If there are no PHVs anywhere, we needn't work hard */
2448 4521 [ - + ]: 69 : if (root->glob->lastPHId == 0)
2448 tgl@sss.pgh.pa.us 4522 :UBC 0 : return false;
4523 : :
2768 tgl@sss.pgh.pa.us 4524 :CBC 69 : context.relids = bms_make_singleton(varno);
40 4525 : 69 : context.baserels = baserels;
2768 4526 : 69 : context.sublevels_up = 0;
4527 : :
637 peter@eisentraut.org 4528 [ + - ]: 69 : if (query_tree_walker(root->parse, find_dependent_phvs_walker, &context, 0))
1305 tgl@sss.pgh.pa.us 4529 : 69 : return true;
4530 : : /* The append_rel_list could be populated already, so check it too */
1305 tgl@sss.pgh.pa.us 4531 [ # # ]:UBC 0 : if (expression_tree_walker((Node *) root->append_rel_list,
4532 : : find_dependent_phvs_walker,
4533 : : &context))
4534 : 0 : return true;
4535 : 0 : return false;
4536 : : }
4537 : :
4538 : : static bool
40 tgl@sss.pgh.pa.us 4539 :CBC 376 : find_dependent_phvs_in_jointree(PlannerInfo *root, Node *node, int varno,
4540 : : Relids baserels)
4541 : : {
4542 : : find_dependent_phvs_context context;
4543 : : Relids subrelids;
4544 : : int relid;
4545 : :
4546 : : /* If there are no PHVs anywhere, we needn't work hard */
2448 4547 [ + + ]: 376 : if (root->glob->lastPHId == 0)
4548 : 321 : return false;
4549 : :
4550 : 55 : context.relids = bms_make_singleton(varno);
40 4551 : 55 : context.baserels = baserels;
2448 4552 : 55 : context.sublevels_up = 0;
4553 : :
4554 : : /*
4555 : : * See if the jointree fragment itself contains references (in join quals)
4556 : : */
4557 [ - + ]: 55 : if (find_dependent_phvs_walker(node, &context))
2448 tgl@sss.pgh.pa.us 4558 :UBC 0 : return true;
4559 : :
4560 : : /*
4561 : : * Otherwise, identify the set of referenced RTEs (we can ignore joins,
4562 : : * since they should be flattened already, so their join alias lists no
4563 : : * longer matter), and tediously check each RTE. We can ignore RTEs that
4564 : : * are not marked LATERAL, though, since they couldn't possibly contain
4565 : : * any cross-references to other RTEs.
4566 : : */
1305 tgl@sss.pgh.pa.us 4567 :CBC 55 : subrelids = get_relids_in_jointree(node, false, false);
2448 4568 : 55 : relid = -1;
4569 [ + + ]: 120 : while ((relid = bms_next_member(subrelids, relid)) >= 0)
4570 : : {
4571 : 85 : RangeTblEntry *rte = rt_fetch(relid, root->parse->rtable);
4572 : :
4573 [ + + + - ]: 105 : if (rte->lateral &&
637 peter@eisentraut.org 4574 : 20 : range_table_entry_walker(rte, find_dependent_phvs_walker, &context, 0))
2448 tgl@sss.pgh.pa.us 4575 : 20 : return true;
4576 : : }
4577 : :
4578 : 35 : return false;
4579 : : }
4580 : :
4581 : : /*
4582 : : * substitute_phv_relids - adjust PlaceHolderVar relid sets after pulling up
4583 : : * a subquery or removing an RTE_RESULT jointree item
4584 : : *
4585 : : * Find any PlaceHolderVar nodes in the given tree that reference the
4586 : : * pulled-up relid, and change them to reference the replacement relid(s).
4587 : : *
4588 : : * NOTE: although this has the form of a walker, we cheat and modify the
4589 : : * nodes in-place. This should be OK since the tree was copied by
4590 : : * pullup_replace_vars earlier. Avoid scribbling on the original values of
4591 : : * the bitmapsets, though, because expression_tree_mutator doesn't copy those.
4592 : : */
4593 : :
4594 : : typedef struct
4595 : : {
4596 : : int varno;
4597 : : int sublevels_up;
4598 : : Relids subrelids;
4599 : : } substitute_phv_relids_context;
4600 : :
4601 : : static bool
2768 4602 : 234542 : substitute_phv_relids_walker(Node *node,
4603 : : substitute_phv_relids_context *context)
4604 : : {
6587 4605 [ + + ]: 234542 : if (node == NULL)
4606 : 96450 : return false;
6519 4607 [ + + ]: 138092 : if (IsA(node, PlaceHolderVar))
4608 : : {
4609 : 6752 : PlaceHolderVar *phv = (PlaceHolderVar *) node;
4610 : :
5269 4611 [ + + + + ]: 13480 : if (phv->phlevelsup == context->sublevels_up &&
4612 : 6728 : bms_is_member(context->varno, phv->phrels))
4613 : : {
6519 4614 : 9772 : phv->phrels = bms_union(phv->phrels,
4615 : 4886 : context->subrelids);
4616 : 4886 : phv->phrels = bms_del_member(phv->phrels,
4617 : : context->varno);
4618 : : /* Assert we haven't broken the PHV */
2768 4619 [ - + ]: 4886 : Assert(!bms_is_empty(phv->phrels));
4620 : : }
4621 : : /* fall through to examine children */
4622 : : }
5269 4623 [ + + ]: 138092 : if (IsA(node, Query))
4624 : : {
4625 : : /* Recurse into subselects */
4626 : : bool result;
4627 : :
4628 : 3937 : context->sublevels_up++;
4629 : 3937 : result = query_tree_walker((Query *) node,
4630 : : substitute_phv_relids_walker,
4631 : : context, 0);
4632 : 3937 : context->sublevels_up--;
4633 : 3937 : return result;
4634 : : }
4635 : : /* Shouldn't need to handle planner auxiliary nodes here */
6518 4636 [ - + ]: 134155 : Assert(!IsA(node, SpecialJoinInfo));
4637 [ - + ]: 134155 : Assert(!IsA(node, AppendRelInfo));
4638 [ - + ]: 134155 : Assert(!IsA(node, PlaceHolderInfo));
5775 4639 [ - + ]: 134155 : Assert(!IsA(node, MinMaxAggInfo));
4640 : :
637 peter@eisentraut.org 4641 : 134155 : return expression_tree_walker(node, substitute_phv_relids_walker, context);
4642 : : }
4643 : :
4644 : : static void
2768 tgl@sss.pgh.pa.us 4645 : 2183 : substitute_phv_relids(Node *node, int varno, Relids subrelids)
4646 : : {
4647 : : substitute_phv_relids_context context;
4648 : :
6587 4649 : 2183 : context.varno = varno;
5269 4650 : 2183 : context.sublevels_up = 0;
6587 4651 : 2183 : context.subrelids = subrelids;
4652 : :
4653 : : /*
4654 : : * Must be prepared to start with a Query or a bare expression tree.
4655 : : */
4656 : 2183 : query_or_expression_tree_walker(node,
4657 : : substitute_phv_relids_walker,
4658 : : &context,
4659 : : 0);
8620 4660 : 2183 : }
4661 : :
4662 : : /*
4663 : : * fix_append_rel_relids: update RT-index fields of AppendRelInfo nodes
4664 : : *
4665 : : * When we pull up a subquery, any AppendRelInfo references to the subquery's
4666 : : * RT index have to be replaced by the substituted relid (and there had better
4667 : : * be only one). We also need to apply substitute_phv_relids to their
4668 : : * translated_vars lists, since those might contain PlaceHolderVars.
4669 : : *
4670 : : * We assume we may modify the AppendRelInfo nodes in-place.
4671 : : */
4672 : : static void
1344 4673 : 7163 : fix_append_rel_relids(PlannerInfo *root, int varno, Relids subrelids)
4674 : : {
4675 : : ListCell *l;
7510 4676 : 7163 : int subvarno = -1;
4677 : :
4678 : : /*
4679 : : * We only want to extract the member relid once, but we mustn't fail
4680 : : * immediately if there are multiple members; it could be that none of the
4681 : : * AppendRelInfo nodes refer to it. So compute it on first use. Note that
4682 : : * bms_singleton_member will complain if set is not singleton.
4683 : : */
1344 4684 [ + + + + : 16807 : foreach(l, root->append_rel_list)
+ + ]
4685 : : {
7510 4686 : 9644 : AppendRelInfo *appinfo = (AppendRelInfo *) lfirst(l);
4687 : :
4688 : : /* The parent_relid shouldn't ever be a pullup target */
4689 [ - + ]: 9644 : Assert(appinfo->parent_relid != varno);
4690 : :
4691 [ + + ]: 9644 : if (appinfo->child_relid == varno)
4692 : : {
4693 [ + - ]: 5165 : if (subvarno < 0)
4694 : 5165 : subvarno = bms_singleton_member(subrelids);
4695 : 5165 : appinfo->child_relid = subvarno;
4696 : : }
4697 : :
4698 : : /* Also fix up any PHVs in its translated vars */
1344 4699 [ + + ]: 9644 : if (root->glob->lastPHId != 0)
4700 : 155 : substitute_phv_relids((Node *) appinfo->translated_vars,
4701 : : varno, subrelids);
4702 : : }
7510 4703 : 7163 : }
4704 : :
4705 : : /*
4706 : : * get_relids_in_jointree: get set of RT indexes present in a jointree
4707 : : *
4708 : : * Base-relation relids are always included in the result.
4709 : : * If include_outer_joins is true, outer-join RT indexes are included.
4710 : : * If include_inner_joins is true, inner-join RT indexes are included.
4711 : : *
4712 : : * Note that for most purposes in the planner, outer joins are included
4713 : : * in standard relid sets. Setting include_inner_joins true is only
4714 : : * appropriate for special purposes during subquery flattening.
4715 : : */
4716 : : Relids
1305 4717 : 83347 : get_relids_in_jointree(Node *jtnode, bool include_outer_joins,
4718 : : bool include_inner_joins)
4719 : : {
8601 4720 : 83347 : Relids result = NULL;
4721 : :
8620 4722 [ - + ]: 83347 : if (jtnode == NULL)
8620 tgl@sss.pgh.pa.us 4723 :UBC 0 : return result;
8620 tgl@sss.pgh.pa.us 4724 [ + + ]:CBC 83347 : if (IsA(jtnode, RangeTblRef))
4725 : : {
4726 : 42168 : int varno = ((RangeTblRef *) jtnode)->rtindex;
4727 : :
8601 4728 : 42168 : result = bms_make_singleton(varno);
4729 : : }
8620 4730 [ + + ]: 41179 : else if (IsA(jtnode, FromExpr))
4731 : : {
4732 : 34437 : FromExpr *f = (FromExpr *) jtnode;
4733 : : ListCell *l;
4734 : :
4735 [ + - + + : 70657 : foreach(l, f->fromlist)
+ + ]
4736 : : {
8601 4737 : 36220 : result = bms_join(result,
6584 4738 : 36220 : get_relids_in_jointree(lfirst(l),
4739 : : include_outer_joins,
4740 : : include_inner_joins));
4741 : : }
4742 : : }
8620 4743 [ + - ]: 6742 : else if (IsA(jtnode, JoinExpr))
4744 : : {
4745 : 6742 : JoinExpr *j = (JoinExpr *) jtnode;
4746 : :
1305 4747 : 6742 : result = get_relids_in_jointree(j->larg,
4748 : : include_outer_joins,
4749 : : include_inner_joins);
6584 4750 : 6742 : result = bms_join(result,
4751 : : get_relids_in_jointree(j->rarg,
4752 : : include_outer_joins,
4753 : : include_inner_joins));
1305 4754 [ + + ]: 6742 : if (j->rtindex)
4755 : : {
4756 [ + + ]: 6472 : if (j->jointype == JOIN_INNER)
4757 : : {
4758 [ + + ]: 2494 : if (include_inner_joins)
4759 : 635 : result = bms_add_member(result, j->rtindex);
4760 : : }
4761 : : else
4762 : : {
4763 [ + + ]: 3978 : if (include_outer_joins)
4764 : 1762 : result = bms_add_member(result, j->rtindex);
4765 : : }
4766 : : }
4767 : : }
4768 : : else
8434 tgl@sss.pgh.pa.us 4769 [ # # ]:UBC 0 : elog(ERROR, "unrecognized node type: %d",
4770 : : (int) nodeTag(jtnode));
8620 tgl@sss.pgh.pa.us 4771 :CBC 83347 : return result;
4772 : : }
4773 : :
4774 : : /*
4775 : : * get_relids_for_join: get set of base+OJ RT indexes making up a join
4776 : : */
4777 : : Relids
2767 4778 : 347 : get_relids_for_join(Query *query, int joinrelid)
4779 : : {
4780 : : Node *jtnode;
4781 : :
4782 : 347 : jtnode = find_jointree_node_for_rel((Node *) query->jointree,
4783 : : joinrelid);
8620 4784 [ - + ]: 347 : if (!jtnode)
8434 tgl@sss.pgh.pa.us 4785 [ # # ]:UBC 0 : elog(ERROR, "could not find join node %d", joinrelid);
1305 tgl@sss.pgh.pa.us 4786 :CBC 347 : return get_relids_in_jointree(jtnode, true, false);
4787 : : }
4788 : :
4789 : : /*
4790 : : * find_jointree_node_for_rel: locate jointree node for a base or join RT index
4791 : : *
4792 : : * Returns NULL if not found
4793 : : */
4794 : : static Node *
8620 4795 : 1625 : find_jointree_node_for_rel(Node *jtnode, int relid)
4796 : : {
4797 [ - + ]: 1625 : if (jtnode == NULL)
8620 tgl@sss.pgh.pa.us 4798 :UBC 0 : return NULL;
8620 tgl@sss.pgh.pa.us 4799 [ + + ]:CBC 1625 : if (IsA(jtnode, RangeTblRef))
4800 : : {
4801 : 422 : int varno = ((RangeTblRef *) jtnode)->rtindex;
4802 : :
4803 [ - + ]: 422 : if (relid == varno)
8620 tgl@sss.pgh.pa.us 4804 :UBC 0 : return jtnode;
4805 : : }
8620 tgl@sss.pgh.pa.us 4806 [ + + ]:CBC 1203 : else if (IsA(jtnode, FromExpr))
4807 : : {
4808 : 354 : FromExpr *f = (FromExpr *) jtnode;
4809 : : ListCell *l;
4810 : :
4811 [ + - + - : 369 : foreach(l, f->fromlist)
+ - ]
4812 : : {
4813 : 369 : jtnode = find_jointree_node_for_rel(lfirst(l), relid);
4814 [ + + ]: 369 : if (jtnode)
4815 : 354 : return jtnode;
4816 : : }
4817 : : }
4818 [ + - ]: 849 : else if (IsA(jtnode, JoinExpr))
4819 : : {
4820 : 849 : JoinExpr *j = (JoinExpr *) jtnode;
4821 : :
4822 [ + + ]: 849 : if (relid == j->rtindex)
4823 : 347 : return jtnode;
4824 : 502 : jtnode = find_jointree_node_for_rel(j->larg, relid);
4825 [ + + ]: 502 : if (jtnode)
4826 : 95 : return jtnode;
4827 : 407 : jtnode = find_jointree_node_for_rel(j->rarg, relid);
4828 [ + - ]: 407 : if (jtnode)
4829 : 407 : return jtnode;
4830 : : }
4831 : : else
8434 tgl@sss.pgh.pa.us 4832 [ # # ]:UBC 0 : elog(ERROR, "unrecognized node type: %d",
4833 : : (int) nodeTag(jtnode));
8620 tgl@sss.pgh.pa.us 4834 :CBC 422 : return NULL;
4835 : : }
4836 : :
4837 : : /*
4838 : : * get_nullingrels: collect info about which outer joins null which relations
4839 : : *
4840 : : * The result struct contains, for each leaf relation used in the query,
4841 : : * the set of relids of outer joins that potentially null that rel.
4842 : : */
4843 : : static nullingrel_info *
635 4844 : 1381 : get_nullingrels(Query *parse)
4845 : : {
4846 : 1381 : nullingrel_info *result = palloc_object(nullingrel_info);
4847 : :
4848 : 1381 : result->rtlength = list_length(parse->rtable);
4849 : 1381 : result->nullingrels = palloc0_array(Relids, result->rtlength + 1);
4850 : 1381 : get_nullingrels_recurse((Node *) parse->jointree, NULL, result);
4851 : 1381 : return result;
4852 : : }
4853 : :
4854 : : /*
4855 : : * Recursive guts of get_nullingrels().
4856 : : *
4857 : : * Note: at any recursion level, the passed-down upper_nullingrels must be
4858 : : * treated as a constant, but it can be stored directly into *info
4859 : : * if we're at leaf level. Upper recursion levels do not free their mutated
4860 : : * copies of the nullingrels, because those are probably referenced by
4861 : : * at least one leaf rel.
4862 : : */
4863 : : static void
4864 : 5657 : get_nullingrels_recurse(Node *jtnode, Relids upper_nullingrels,
4865 : : nullingrel_info *info)
4866 : : {
4867 [ - + ]: 5657 : if (jtnode == NULL)
635 tgl@sss.pgh.pa.us 4868 :UBC 0 : return;
635 tgl@sss.pgh.pa.us 4869 [ + + ]:CBC 5657 : if (IsA(jtnode, RangeTblRef))
4870 : : {
4871 : 2989 : int varno = ((RangeTblRef *) jtnode)->rtindex;
4872 : :
4873 [ + - - + ]: 2989 : Assert(varno > 0 && varno <= info->rtlength);
4874 : 2989 : info->nullingrels[varno] = upper_nullingrels;
4875 : : }
4876 [ + + ]: 2668 : else if (IsA(jtnode, FromExpr))
4877 : : {
4878 : 1451 : FromExpr *f = (FromExpr *) jtnode;
4879 : : ListCell *l;
4880 : :
4881 [ + - + + : 3293 : foreach(l, f->fromlist)
+ + ]
4882 : : {
4883 : 1842 : get_nullingrels_recurse(lfirst(l), upper_nullingrels, info);
4884 : : }
4885 : : }
4886 [ + - ]: 1217 : else if (IsA(jtnode, JoinExpr))
4887 : : {
4888 : 1217 : JoinExpr *j = (JoinExpr *) jtnode;
4889 : : Relids local_nullingrels;
4890 : :
4891 [ + + + - : 1217 : switch (j->jointype)
- ]
4892 : : {
4893 : 395 : case JOIN_INNER:
4894 : 395 : get_nullingrels_recurse(j->larg, upper_nullingrels, info);
4895 : 395 : get_nullingrels_recurse(j->rarg, upper_nullingrels, info);
4896 : 395 : break;
4897 : 817 : case JOIN_LEFT:
4898 : : case JOIN_SEMI:
4899 : : case JOIN_ANTI:
4900 : 817 : local_nullingrels = bms_add_member(bms_copy(upper_nullingrels),
4901 : : j->rtindex);
4902 : 817 : get_nullingrels_recurse(j->larg, upper_nullingrels, info);
4903 : 817 : get_nullingrels_recurse(j->rarg, local_nullingrels, info);
4904 : 817 : break;
4905 : 5 : case JOIN_FULL:
4906 : 5 : local_nullingrels = bms_add_member(bms_copy(upper_nullingrels),
4907 : : j->rtindex);
4908 : 5 : get_nullingrels_recurse(j->larg, local_nullingrels, info);
4909 : 5 : get_nullingrels_recurse(j->rarg, local_nullingrels, info);
4910 : 5 : break;
635 tgl@sss.pgh.pa.us 4911 :UBC 0 : case JOIN_RIGHT:
4912 : 0 : local_nullingrels = bms_add_member(bms_copy(upper_nullingrels),
4913 : : j->rtindex);
4914 : 0 : get_nullingrels_recurse(j->larg, local_nullingrels, info);
4915 : 0 : get_nullingrels_recurse(j->rarg, upper_nullingrels, info);
4916 : 0 : break;
4917 : 0 : default:
4918 [ # # ]: 0 : elog(ERROR, "unrecognized join type: %d",
4919 : : (int) j->jointype);
4920 : : break;
4921 : : }
4922 : : }
4923 : : else
4924 [ # # ]: 0 : elog(ERROR, "unrecognized node type: %d",
4925 : : (int) nodeTag(jtnode));
4926 : : }
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