Branch data 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 : : Relids anti_reduced; /* OJ relids reduced to antijoins */
102 : : } reduce_outer_joins_pass2_state;
103 : :
104 : : typedef struct reduce_outer_joins_partial_state
105 : : {
106 : : int full_join_rti; /* RT index of a formerly-FULL join */
107 : : Relids unreduced_side; /* relids in its still-nullable side */
108 : : } reduce_outer_joins_partial_state;
109 : :
110 : : static Query *expand_virtual_generated_columns(PlannerInfo *root, Query *parse,
111 : : RangeTblEntry *rte, int rt_index,
112 : : Relation relation);
113 : : static Node *pull_up_sublinks_jointree_recurse(PlannerInfo *root, Node *jtnode,
114 : : Relids *relids);
115 : : static Node *pull_up_sublinks_qual_recurse(PlannerInfo *root, Node *node,
116 : : Node **jtlink1, Relids available_rels1,
117 : : Node **jtlink2, Relids available_rels2);
118 : : static Node *pull_up_subqueries_recurse(PlannerInfo *root, Node *jtnode,
119 : : JoinExpr *lowest_outer_join,
120 : : AppendRelInfo *containing_appendrel);
121 : : static Node *pull_up_simple_subquery(PlannerInfo *root, Node *jtnode,
122 : : RangeTblEntry *rte,
123 : : JoinExpr *lowest_outer_join,
124 : : AppendRelInfo *containing_appendrel);
125 : : static Node *pull_up_simple_union_all(PlannerInfo *root, Node *jtnode,
126 : : RangeTblEntry *rte);
127 : : static void pull_up_union_leaf_queries(Node *setOp, PlannerInfo *root,
128 : : int parentRTindex, Query *setOpQuery,
129 : : int childRToffset);
130 : : static void make_setop_translation_list(Query *query, int newvarno,
131 : : AppendRelInfo *appinfo);
132 : : static bool is_simple_subquery(PlannerInfo *root, Query *subquery,
133 : : RangeTblEntry *rte,
134 : : JoinExpr *lowest_outer_join);
135 : : static Node *pull_up_simple_values(PlannerInfo *root, Node *jtnode,
136 : : RangeTblEntry *rte);
137 : : static bool is_simple_values(PlannerInfo *root, RangeTblEntry *rte);
138 : : static Node *pull_up_constant_function(PlannerInfo *root, Node *jtnode,
139 : : RangeTblEntry *rte,
140 : : AppendRelInfo *containing_appendrel);
141 : : static bool is_simple_union_all(Query *subquery);
142 : : static bool is_simple_union_all_recurse(Node *setOp, Query *setOpQuery,
143 : : List *colTypes);
144 : : static bool is_safe_append_member(Query *subquery);
145 : : static bool jointree_contains_lateral_outer_refs(PlannerInfo *root,
146 : : Node *jtnode, bool restricted,
147 : : Relids safe_upper_varnos);
148 : : static void flatten_join_alias_vars_in_jointree(PlannerInfo *root,
149 : : Node *jtnode);
150 : : static void perform_pullup_replace_vars(PlannerInfo *root,
151 : : pullup_replace_vars_context *rvcontext,
152 : : AppendRelInfo *containing_appendrel);
153 : : static void replace_vars_in_jointree(Node *jtnode,
154 : : pullup_replace_vars_context *context);
155 : : static Node *pullup_replace_vars(Node *expr,
156 : : pullup_replace_vars_context *context);
157 : : static Node *pullup_replace_vars_callback(const Var *var,
158 : : replace_rte_variables_context *context);
159 : : static Query *pullup_replace_vars_subquery(Query *query,
160 : : pullup_replace_vars_context *context);
161 : : static reduce_outer_joins_pass1_state *reduce_outer_joins_pass1(Node *jtnode);
162 : : static void reduce_outer_joins_pass2(Node *jtnode,
163 : : reduce_outer_joins_pass1_state *state1,
164 : : reduce_outer_joins_pass2_state *state2,
165 : : PlannerInfo *root,
166 : : Relids nonnullable_rels,
167 : : List *forced_null_vars);
168 : : static void report_reduced_full_join(reduce_outer_joins_pass2_state *state2,
169 : : int rtindex, Relids relids);
170 : : static void remove_redundant_nullability_quals(Node *jtnode,
171 : : Relids antijoins);
172 : : static Node *strip_redundant_nullability_quals(Node *quals, Relids antijoins);
173 : : static bool forced_null_var_is_attnotnull(PlannerInfo *root,
174 : : List *forced_null_vars,
175 : : reduce_outer_joins_pass1_state *state);
176 : : static bool forced_null_var_is_nonnullable(PlannerInfo *root,
177 : : List *forced_null_vars,
178 : : reduce_outer_joins_pass1_state *state,
179 : : List *extra_quals);
180 : : static Node *remove_useless_results_recurse(PlannerInfo *root, Node *jtnode,
181 : : Relids baserels,
182 : : Node **parent_quals,
183 : : Relids *dropped_outer_joins);
184 : : static int get_result_relid(PlannerInfo *root, Node *jtnode);
185 : : static void remove_result_refs(PlannerInfo *root, int varno, Node *newjtloc);
186 : : static bool find_dependent_phvs(PlannerInfo *root, int varno, Relids baserels);
187 : : static bool find_dependent_phvs_in_jointree(PlannerInfo *root,
188 : : Node *node, int varno,
189 : : Relids baserels);
190 : : static void substitute_phv_relids(Node *node,
191 : : int varno, Relids subrelids);
192 : : static void fix_append_rel_relids(PlannerInfo *root, int varno,
193 : : Relids subrelids);
194 : : static Node *find_jointree_node_for_rel(Node *jtnode, int relid);
195 : : static nullingrel_info *get_nullingrels(Query *parse);
196 : : static void get_nullingrels_recurse(Node *jtnode, Relids upper_nullingrels,
197 : : nullingrel_info *info);
198 : :
199 : :
200 : : /*
201 : : * transform_MERGE_to_join
202 : : * Replace a MERGE's jointree to also include the target relation.
203 : : */
204 : : void
205 : 393864 : transform_MERGE_to_join(Query *parse)
206 : : {
207 : : RangeTblEntry *joinrte;
208 : : JoinExpr *joinexpr;
209 : : bool have_action[NUM_MERGE_MATCH_KINDS];
210 : : JoinType jointype;
211 : : int joinrti;
212 : : List *vars;
213 : : RangeTblRef *rtr;
214 : : FromExpr *target;
215 : : Node *source;
216 : : int sourcerti;
217 : :
218 [ + + ]: 393864 : if (parse->commandType != CMD_MERGE)
219 : 392294 : return;
220 : :
221 : : /* XXX probably bogus */
222 : 1570 : vars = NIL;
223 : :
224 : : /*
225 : : * Work out what kind of join is required. If there any WHEN NOT MATCHED
226 : : * BY SOURCE/TARGET actions, an outer join is required so that we process
227 : : * all unmatched tuples from the source and/or target relations.
228 : : * Otherwise, we can use an inner join.
229 : : */
230 : 1570 : have_action[MERGE_WHEN_MATCHED] = false;
231 : 1570 : have_action[MERGE_WHEN_NOT_MATCHED_BY_SOURCE] = false;
232 : 1570 : have_action[MERGE_WHEN_NOT_MATCHED_BY_TARGET] = false;
233 : :
234 [ + - + + : 5526 : foreach_node(MergeAction, action, parse->mergeActionList)
+ + ]
235 : : {
236 [ + + ]: 2386 : if (action->commandType != CMD_NOTHING)
237 : 2318 : have_action[action->matchKind] = true;
238 : : }
239 : :
240 [ + + ]: 1570 : if (have_action[MERGE_WHEN_NOT_MATCHED_BY_SOURCE] &&
241 [ + + ]: 111 : have_action[MERGE_WHEN_NOT_MATCHED_BY_TARGET])
242 : 86 : jointype = JOIN_FULL;
243 [ + + ]: 1484 : else if (have_action[MERGE_WHEN_NOT_MATCHED_BY_SOURCE])
244 : 25 : jointype = JOIN_LEFT;
245 [ + + ]: 1459 : else if (have_action[MERGE_WHEN_NOT_MATCHED_BY_TARGET])
246 : 674 : jointype = JOIN_RIGHT;
247 : : else
248 : 785 : jointype = JOIN_INNER;
249 : :
250 : : /* Manufacture a join RTE to use. */
251 : 1570 : joinrte = makeNode(RangeTblEntry);
252 : 1570 : joinrte->rtekind = RTE_JOIN;
253 : 1570 : joinrte->jointype = jointype;
254 : 1570 : joinrte->joinmergedcols = 0;
255 : 1570 : joinrte->joinaliasvars = vars;
256 : 1570 : joinrte->joinleftcols = NIL; /* MERGE does not allow JOIN USING */
257 : 1570 : joinrte->joinrightcols = NIL; /* ditto */
258 : 1570 : joinrte->join_using_alias = NULL;
259 : :
260 : 1570 : joinrte->alias = NULL;
261 : 1570 : joinrte->eref = makeAlias("*MERGE*", NIL);
262 : 1570 : joinrte->lateral = false;
263 : 1570 : joinrte->inh = false;
264 : 1570 : joinrte->inFromCl = true;
265 : :
266 : : /*
267 : : * Add completed RTE to pstate's range table list, so that we know its
268 : : * index.
269 : : */
270 : 1570 : parse->rtable = lappend(parse->rtable, joinrte);
271 : 1570 : joinrti = list_length(parse->rtable);
272 : :
273 : : /*
274 : : * Create a JOIN between the target and the source relation.
275 : : *
276 : : * Here the target is identified by parse->mergeTargetRelation. For a
277 : : * regular table, this will equal parse->resultRelation, but for a
278 : : * trigger-updatable view, it will be the expanded view subquery that we
279 : : * need to pull data from.
280 : : *
281 : : * The source relation is in parse->jointree->fromlist, but any quals in
282 : : * parse->jointree->quals are restrictions on the target relation (if the
283 : : * target relation is an auto-updatable view).
284 : : */
285 : : /* target rel, with any quals */
286 : 1570 : rtr = makeNode(RangeTblRef);
287 : 1570 : rtr->rtindex = parse->mergeTargetRelation;
288 : 1570 : target = makeFromExpr(list_make1(rtr), parse->jointree->quals);
289 : :
290 : : /* source rel (expect exactly one -- see transformMergeStmt()) */
291 : : Assert(list_length(parse->jointree->fromlist) == 1);
292 : 1570 : source = linitial(parse->jointree->fromlist);
293 : :
294 : : /*
295 : : * index of source rel (expect either a RangeTblRef or a JoinExpr -- see
296 : : * transformFromClauseItem()).
297 : : */
298 [ + + ]: 1570 : if (IsA(source, RangeTblRef))
299 : 1500 : sourcerti = ((RangeTblRef *) source)->rtindex;
300 [ + - ]: 70 : else if (IsA(source, JoinExpr))
301 : 70 : sourcerti = ((JoinExpr *) source)->rtindex;
302 : : else
303 : : {
304 [ # # ]: 0 : elog(ERROR, "unrecognized source node type: %d",
305 : : (int) nodeTag(source));
306 : : sourcerti = 0; /* keep compiler quiet */
307 : : }
308 : :
309 : : /* Join the source and target */
310 : 1570 : joinexpr = makeNode(JoinExpr);
311 : 1570 : joinexpr->jointype = jointype;
312 : 1570 : joinexpr->isNatural = false;
313 : 1570 : joinexpr->larg = (Node *) target;
314 : 1570 : joinexpr->rarg = source;
315 : 1570 : joinexpr->usingClause = NIL;
316 : 1570 : joinexpr->join_using_alias = NULL;
317 : 1570 : joinexpr->quals = parse->mergeJoinCondition;
318 : 1570 : joinexpr->alias = NULL;
319 : 1570 : joinexpr->rtindex = joinrti;
320 : :
321 : : /* Make the new join be the sole entry in the query's jointree */
322 : 1570 : parse->jointree->fromlist = list_make1(joinexpr);
323 : 1570 : parse->jointree->quals = NULL;
324 : :
325 : : /*
326 : : * If necessary, mark parse->targetlist entries that refer to the target
327 : : * as nullable by the join. Normally the targetlist will be empty for a
328 : : * MERGE, but if the target is a trigger-updatable view, it will contain a
329 : : * whole-row Var referring to the expanded view query.
330 : : */
331 [ + + + + ]: 1570 : if (parse->targetList != NIL &&
332 [ + + ]: 35 : (jointype == JOIN_RIGHT || jointype == JOIN_FULL))
333 : 35 : parse->targetList = (List *)
334 : 35 : add_nulling_relids((Node *) parse->targetList,
335 : 35 : bms_make_singleton(parse->mergeTargetRelation),
336 : 35 : bms_make_singleton(joinrti));
337 : :
338 : : /*
339 : : * If the source relation is on the outer side of the join, mark any
340 : : * source relation Vars in the join condition, actions, and RETURNING list
341 : : * as nullable by the join. These Vars will be added to the targetlist by
342 : : * preprocess_targetlist(), so it's important to mark them correctly here.
343 : : *
344 : : * It might seem that this is not necessary for Vars in the join
345 : : * condition, since it is inside the join, but it is also needed above the
346 : : * join (in the ModifyTable node) to distinguish between the MATCHED and
347 : : * NOT MATCHED BY SOURCE cases -- see ExecMergeMatched(). Note that this
348 : : * creates a modified copy of the join condition, for use above the join,
349 : : * without modifying the original join condition, inside the join.
350 : : */
351 [ + + + + ]: 1570 : if (jointype == JOIN_LEFT || jointype == JOIN_FULL)
352 : : {
353 : 111 : parse->mergeJoinCondition =
354 : 111 : add_nulling_relids(parse->mergeJoinCondition,
355 : 111 : bms_make_singleton(sourcerti),
356 : 111 : bms_make_singleton(joinrti));
357 : :
358 [ + - + + : 530 : foreach_node(MergeAction, action, parse->mergeActionList)
+ + ]
359 : : {
360 : 308 : action->qual =
361 : 308 : add_nulling_relids(action->qual,
362 : 308 : bms_make_singleton(sourcerti),
363 : 308 : bms_make_singleton(joinrti));
364 : :
365 : 308 : action->targetList = (List *)
366 : 308 : add_nulling_relids((Node *) action->targetList,
367 : 308 : bms_make_singleton(sourcerti),
368 : 308 : bms_make_singleton(joinrti));
369 : : }
370 : :
371 : 111 : parse->returningList = (List *)
372 : 111 : add_nulling_relids((Node *) parse->returningList,
373 : 111 : bms_make_singleton(sourcerti),
374 : 111 : bms_make_singleton(joinrti));
375 : : }
376 : :
377 : : /*
378 : : * If there are any WHEN NOT MATCHED BY SOURCE actions, the executor will
379 : : * use the join condition to distinguish between MATCHED and NOT MATCHED
380 : : * BY SOURCE cases. Otherwise, it's no longer needed, and we set it to
381 : : * NULL, saving cycles during planning and execution.
382 : : *
383 : : * We need to be careful though: the executor evaluates this condition
384 : : * using the output of the join subplan node, which nulls the output from
385 : : * the source relation when the join condition doesn't match. That risks
386 : : * producing incorrect results when rechecking using a "non-strict" join
387 : : * condition, such as "src.col IS NOT DISTINCT FROM tgt.col". To guard
388 : : * against that, we add an additional "src IS NOT NULL" check to the join
389 : : * condition, so that it does the right thing when performing a recheck
390 : : * based on the output of the join subplan.
391 : : */
392 [ + + ]: 1570 : if (have_action[MERGE_WHEN_NOT_MATCHED_BY_SOURCE])
393 : : {
394 : : Var *var;
395 : : NullTest *ntest;
396 : :
397 : : /* source wholerow Var (nullable by the new join) */
398 : 111 : var = makeWholeRowVar(rt_fetch(sourcerti, parse->rtable),
399 : : sourcerti, 0, false);
400 : 111 : var->varnullingrels = bms_make_singleton(joinrti);
401 : :
402 : : /* "src IS NOT NULL" check */
403 : 111 : ntest = makeNode(NullTest);
404 : 111 : ntest->arg = (Expr *) var;
405 : 111 : ntest->nulltesttype = IS_NOT_NULL;
406 : 111 : ntest->argisrow = false;
407 : 111 : ntest->location = -1;
408 : :
409 : : /* combine it with the original join condition */
410 : 111 : parse->mergeJoinCondition =
411 : 111 : (Node *) make_and_qual((Node *) ntest, parse->mergeJoinCondition);
412 : : }
413 : : else
414 : 1459 : parse->mergeJoinCondition = NULL; /* join condition not needed */
415 : : }
416 : :
417 : : /*
418 : : * preprocess_relation_rtes
419 : : * Do the preprocessing work for any relation RTEs in the FROM clause.
420 : : *
421 : : * This scans the rangetable for relation RTEs and retrieves the necessary
422 : : * catalog information for each relation. Using this information, it clears
423 : : * the inh flag for any relation that has no children, collects not-null
424 : : * attribute numbers for any relation that has column not-null constraints, and
425 : : * expands virtual generated columns for any relation that contains them.
426 : : *
427 : : * Note that expanding virtual generated columns may cause the query tree to
428 : : * have new copies of rangetable entries. Therefore, we have to use list_nth
429 : : * instead of foreach when iterating over the query's rangetable.
430 : : *
431 : : * Returns a modified copy of the query tree, if any relations with virtual
432 : : * generated columns are present.
433 : : */
434 : : Query *
435 : 431498 : preprocess_relation_rtes(PlannerInfo *root)
436 : : {
437 : 431498 : Query *parse = root->parse;
438 : : int rtable_size;
439 : : int rt_index;
440 : :
441 : 431498 : rtable_size = list_length(parse->rtable);
442 : :
443 [ + + ]: 969610 : for (rt_index = 0; rt_index < rtable_size; rt_index++)
444 : : {
445 : 538112 : RangeTblEntry *rte = rt_fetch(rt_index + 1, parse->rtable);
446 : : Relation relation;
447 : :
448 : : /* We only care about relation RTEs. */
449 [ + + ]: 538112 : if (rte->rtekind != RTE_RELATION)
450 : 177345 : continue;
451 : :
452 : : /*
453 : : * We need not lock the relation since it was already locked by the
454 : : * rewriter.
455 : : */
456 : 360767 : relation = table_open(rte->relid, NoLock);
457 : :
458 : : /*
459 : : * Check to see if the relation actually has any children; if not,
460 : : * clear the inh flag so we can treat it as a plain base relation.
461 : : *
462 : : * Note: this could give a false-positive result, if the rel once had
463 : : * children but no longer does. We used to be able to clear rte->inh
464 : : * later on when we discovered that, but no more; we have to handle
465 : : * such cases as full-fledged inheritance.
466 : : */
467 [ + + ]: 360767 : if (rte->inh)
468 : 301044 : rte->inh = relation->rd_rel->relhassubclass;
469 : :
470 : : /*
471 : : * Check to see if the relation has any column not-null constraints;
472 : : * if so, retrieve the constraint information and store it in a
473 : : * relation OID based hash table.
474 : : */
475 : 360767 : get_relation_notnullatts(root, relation);
476 : :
477 : : /*
478 : : * Check to see if the relation has any virtual generated columns; if
479 : : * so, replace all Var nodes in the query that reference these columns
480 : : * with the generation expressions.
481 : : */
482 : 360767 : parse = expand_virtual_generated_columns(root, parse,
483 : : rte, rt_index + 1,
484 : : relation);
485 : :
486 : 360767 : table_close(relation, NoLock);
487 : : }
488 : :
489 : 431498 : return parse;
490 : : }
491 : :
492 : : /*
493 : : * expand_virtual_generated_columns
494 : : * Expand virtual generated columns for the given relation.
495 : : *
496 : : * This checks whether the given relation has any virtual generated columns,
497 : : * and if so, replaces all Var nodes in the query that reference those columns
498 : : * with their generation expressions.
499 : : *
500 : : * Returns a modified copy of the query tree if the relation contains virtual
501 : : * generated columns.
502 : : */
503 : : static Query *
504 : 360767 : expand_virtual_generated_columns(PlannerInfo *root, Query *parse,
505 : : RangeTblEntry *rte, int rt_index,
506 : : Relation relation)
507 : : {
508 : : TupleDesc tupdesc;
509 : :
510 : : /* Only normal relations can have virtual generated columns */
511 : : Assert(rte->rtekind == RTE_RELATION);
512 : :
513 : 360767 : tupdesc = RelationGetDescr(relation);
514 [ + + + + ]: 360767 : if (tupdesc->constr && tupdesc->constr->has_generated_virtual)
515 : : {
516 : 1111 : List *tlist = NIL;
517 : : pullup_replace_vars_context rvcontext;
518 : 1111 : List *save_exclRelTlist = NIL;
519 : :
520 [ + + ]: 4417 : for (int i = 0; i < tupdesc->natts; i++)
521 : : {
522 : 3306 : Form_pg_attribute attr = TupleDescAttr(tupdesc, i);
523 : : TargetEntry *tle;
524 : :
525 [ + + ]: 3306 : if (attr->attgenerated == ATTRIBUTE_GENERATED_VIRTUAL)
526 : : {
527 : : Node *defexpr;
528 : :
529 : 1486 : defexpr = build_generation_expression(relation, i + 1);
530 : 1486 : ChangeVarNodes(defexpr, 1, rt_index, 0);
531 : :
532 : 1486 : tle = makeTargetEntry((Expr *) defexpr, i + 1, 0, false);
533 : 1486 : tlist = lappend(tlist, tle);
534 : : }
535 : : else
536 : : {
537 : : Var *var;
538 : :
539 : 1820 : var = makeVar(rt_index,
540 : 1820 : i + 1,
541 : : attr->atttypid,
542 : : attr->atttypmod,
543 : : attr->attcollation,
544 : : 0);
545 : :
546 : 1820 : tle = makeTargetEntry((Expr *) var, i + 1, 0, false);
547 : 1820 : tlist = lappend(tlist, tle);
548 : : }
549 : : }
550 : :
551 : : Assert(list_length(tlist) > 0);
552 : : Assert(!rte->lateral);
553 : :
554 : : /*
555 : : * The relation's targetlist items are now in the appropriate form to
556 : : * insert into the query, except that we may need to wrap them in
557 : : * PlaceHolderVars. Set up required context data for
558 : : * pullup_replace_vars.
559 : : */
560 : 1111 : rvcontext.root = root;
561 : 1111 : rvcontext.targetlist = tlist;
562 : 1111 : rvcontext.target_rte = rte;
563 : 1111 : rvcontext.result_relation = parse->resultRelation;
564 : : /* won't need these values */
565 : 1111 : rvcontext.relids = NULL;
566 : 1111 : rvcontext.nullinfo = NULL;
567 : : /* pass NULL for outer_hasSubLinks */
568 : 1111 : rvcontext.outer_hasSubLinks = NULL;
569 : 1111 : rvcontext.varno = rt_index;
570 : : /* this flag will be set below, if needed */
571 : 1111 : rvcontext.wrap_option = REPLACE_WRAP_NONE;
572 : : /* initialize cache array with indexes 0 .. length(tlist) */
573 : 1111 : rvcontext.rv_cache = palloc0_array(Node *, list_length(tlist) + 1);
574 : :
575 : : /*
576 : : * If the query uses grouping sets, we need a PlaceHolderVar for each
577 : : * expression of the relation's targetlist items. (See comments in
578 : : * pull_up_simple_subquery().)
579 : : */
580 [ + + ]: 1111 : if (parse->groupingSets)
581 : 10 : rvcontext.wrap_option = REPLACE_WRAP_ALL;
582 : :
583 : : /*
584 : : * Apply pullup variable replacement throughout the query tree.
585 : : *
586 : : * We intentionally do not touch the EXCLUDED pseudo-relation's
587 : : * targetlist here. Various places in the planner assume that it
588 : : * contains only Vars, and we want that to remain the case. More
589 : : * importantly, we don't want setrefs.c to turn any expanded
590 : : * EXCLUDED.virtual_column expressions in other parts of the query
591 : : * back into Vars referencing the original virtual column, which
592 : : * set_plan_refs() would do if exclRelTlist contained matching
593 : : * expressions.
594 : : */
595 [ + + ]: 1111 : if (parse->onConflict)
596 : : {
597 : 50 : save_exclRelTlist = parse->onConflict->exclRelTlist;
598 : 50 : parse->onConflict->exclRelTlist = NIL;
599 : : }
600 : :
601 : 1111 : parse = (Query *) pullup_replace_vars((Node *) parse, &rvcontext);
602 : :
603 [ + + ]: 1111 : if (parse->onConflict)
604 : 50 : parse->onConflict->exclRelTlist = save_exclRelTlist;
605 : : }
606 : :
607 : 360767 : return parse;
608 : : }
609 : :
610 : : /*
611 : : * replace_empty_jointree
612 : : * If the Query's jointree is empty, replace it with a dummy RTE_RESULT
613 : : * relation.
614 : : *
615 : : * By doing this, we can avoid a bunch of corner cases that formerly existed
616 : : * for SELECTs with omitted FROM clauses. An example is that a subquery
617 : : * with empty jointree previously could not be pulled up, because that would
618 : : * have resulted in an empty relid set, making the subquery not uniquely
619 : : * identifiable for join or PlaceHolderVar processing.
620 : : *
621 : : * Unlike most other functions in this file, this function doesn't recurse;
622 : : * we rely on other processing to invoke it on sub-queries at suitable times.
623 : : */
624 : : void
625 : 431498 : replace_empty_jointree(Query *parse)
626 : : {
627 : : RangeTblEntry *rte;
628 : : Index rti;
629 : : RangeTblRef *rtr;
630 : :
631 : : /* Nothing to do if jointree is already nonempty */
632 [ + + ]: 431498 : if (parse->jointree->fromlist != NIL)
633 : 281489 : return;
634 : :
635 : : /* We mustn't change it in the top level of a setop tree, either */
636 [ + + ]: 150009 : if (parse->setOperations)
637 : 5637 : return;
638 : :
639 : : /* Create suitable RTE */
640 : 144372 : rte = makeNode(RangeTblEntry);
641 : 144372 : rte->rtekind = RTE_RESULT;
642 : 144372 : rte->eref = makeAlias("*RESULT*", NIL);
643 : :
644 : : /* Add it to rangetable */
645 : 144372 : parse->rtable = lappend(parse->rtable, rte);
646 : 144372 : rti = list_length(parse->rtable);
647 : :
648 : : /* And jam a reference into the jointree */
649 : 144372 : rtr = makeNode(RangeTblRef);
650 : 144372 : rtr->rtindex = rti;
651 : 144372 : parse->jointree->fromlist = list_make1(rtr);
652 : : }
653 : :
654 : : /*
655 : : * pull_up_sublinks
656 : : * Attempt to pull up ANY and EXISTS SubLinks to be treated as
657 : : * semijoins or anti-semijoins.
658 : : *
659 : : * A clause "foo op ANY (sub-SELECT)" can be processed by pulling the
660 : : * sub-SELECT up to become a rangetable entry and treating the implied
661 : : * comparisons as quals of a semijoin. However, this optimization *only*
662 : : * works at the top level of WHERE or a JOIN/ON clause, because we cannot
663 : : * distinguish whether the ANY ought to return FALSE or NULL in cases
664 : : * involving NULL inputs. Also, in an outer join's ON clause we can only
665 : : * do this if the sublink is degenerate (ie, references only the nullable
666 : : * side of the join). In that case it is legal to push the semijoin
667 : : * down into the nullable side of the join. If the sublink references any
668 : : * nonnullable-side variables then it would have to be evaluated as part
669 : : * of the outer join, which makes things way too complicated.
670 : : *
671 : : * Under similar conditions, EXISTS and NOT EXISTS clauses can be handled
672 : : * by pulling up the sub-SELECT and creating a semijoin or anti-semijoin.
673 : : *
674 : : * This routine searches for such clauses and does the necessary parsetree
675 : : * transformations if any are found.
676 : : *
677 : : * This routine has to run before preprocess_expression(), so the quals
678 : : * clauses are not yet reduced to implicit-AND format, and are not guaranteed
679 : : * to be AND/OR-flat either. That means we need to recursively search through
680 : : * explicit AND clauses. We stop as soon as we hit a non-AND item.
681 : : */
682 : : void
683 : 31847 : pull_up_sublinks(PlannerInfo *root)
684 : : {
685 : : Node *jtnode;
686 : : Relids relids;
687 : :
688 : : /* Begin recursion through the jointree */
689 : 31847 : jtnode = pull_up_sublinks_jointree_recurse(root,
690 : 31847 : (Node *) root->parse->jointree,
691 : : &relids);
692 : :
693 : : /*
694 : : * root->parse->jointree must always be a FromExpr, so insert a dummy one
695 : : * if we got a bare RangeTblRef or JoinExpr out of the recursion.
696 : : */
697 [ + + ]: 31847 : if (IsA(jtnode, FromExpr))
698 : 20228 : root->parse->jointree = (FromExpr *) jtnode;
699 : : else
700 : 11619 : root->parse->jointree = makeFromExpr(list_make1(jtnode), NULL);
701 : 31847 : }
702 : :
703 : : /*
704 : : * Recurse through jointree nodes for pull_up_sublinks()
705 : : *
706 : : * In addition to returning the possibly-modified jointree node, we return
707 : : * a relids set of the contained rels into *relids.
708 : : */
709 : : static Node *
710 : 109835 : pull_up_sublinks_jointree_recurse(PlannerInfo *root, Node *jtnode,
711 : : Relids *relids)
712 : : {
713 : : /* Since this function recurses, it could be driven to stack overflow. */
714 : 109835 : check_stack_depth();
715 : :
716 [ - + ]: 109835 : if (jtnode == NULL)
717 : : {
718 : 0 : *relids = NULL;
719 : : }
720 [ + + ]: 109835 : else if (IsA(jtnode, RangeTblRef))
721 : : {
722 : 62126 : int varno = ((RangeTblRef *) jtnode)->rtindex;
723 : :
724 : 62126 : *relids = bms_make_singleton(varno);
725 : : /* jtnode is returned unmodified */
726 : : }
727 [ + + ]: 47709 : else if (IsA(jtnode, FromExpr))
728 : : {
729 : 32038 : FromExpr *f = (FromExpr *) jtnode;
730 : 32038 : List *newfromlist = NIL;
731 : 32038 : Relids frelids = NULL;
732 : : FromExpr *newf;
733 : : Node *jtlink;
734 : : ListCell *l;
735 : :
736 : : /* First, recurse to process children and collect their relids */
737 [ + - + + : 66918 : foreach(l, f->fromlist)
+ + ]
738 : : {
739 : : Node *newchild;
740 : : Relids childrelids;
741 : :
742 : 34880 : newchild = pull_up_sublinks_jointree_recurse(root,
743 : 34880 : lfirst(l),
744 : : &childrelids);
745 : 34880 : newfromlist = lappend(newfromlist, newchild);
746 : 34880 : frelids = bms_join(frelids, childrelids);
747 : : }
748 : : /* Build the replacement FromExpr; no quals yet */
749 : 32038 : newf = makeFromExpr(newfromlist, NULL);
750 : : /* Set up a link representing the rebuilt jointree */
751 : 32038 : jtlink = (Node *) newf;
752 : : /* Now process qual --- all children are available for use */
753 : 32038 : newf->quals = pull_up_sublinks_qual_recurse(root, f->quals,
754 : : &jtlink, frelids,
755 : : NULL, NULL);
756 : :
757 : : /*
758 : : * Note that the result will be either newf, or a stack of JoinExprs
759 : : * with newf at the base. We rely on subsequent optimization steps to
760 : : * flatten this and rearrange the joins as needed.
761 : : *
762 : : * Although we could include the pulled-up subqueries in the returned
763 : : * relids, there's no need since upper quals couldn't refer to their
764 : : * outputs anyway.
765 : : */
766 : 32038 : *relids = frelids;
767 : 32038 : jtnode = jtlink;
768 : : }
769 [ + - ]: 15671 : else if (IsA(jtnode, JoinExpr))
770 : : {
771 : : JoinExpr *j;
772 : : Relids leftrelids;
773 : : Relids rightrelids;
774 : : Node *jtlink;
775 : :
776 : : /*
777 : : * Make a modifiable copy of join node, but don't bother copying its
778 : : * subnodes (yet).
779 : : */
780 : 15671 : j = palloc_object(JoinExpr);
781 : 15671 : memcpy(j, jtnode, sizeof(JoinExpr));
782 : 15671 : jtlink = (Node *) j;
783 : :
784 : : /* Recurse to process children and collect their relids */
785 : 15671 : j->larg = pull_up_sublinks_jointree_recurse(root, j->larg,
786 : : &leftrelids);
787 : 15671 : j->rarg = pull_up_sublinks_jointree_recurse(root, j->rarg,
788 : : &rightrelids);
789 : :
790 : : /*
791 : : * Now process qual, showing appropriate child relids as available,
792 : : * and attach any pulled-up jointree items at the right place. In the
793 : : * inner-join case we put new JoinExprs above the existing one (much
794 : : * as for a FromExpr-style join). In outer-join cases the new
795 : : * JoinExprs must go into the nullable side of the outer join. The
796 : : * point of the available_rels machinations is to ensure that we only
797 : : * pull up quals for which that's okay.
798 : : *
799 : : * We don't expect to see any pre-existing JOIN_SEMI, JOIN_ANTI,
800 : : * JOIN_RIGHT_SEMI, or JOIN_RIGHT_ANTI jointypes here.
801 : : */
802 [ + + + + : 15671 : switch (j->jointype)
- ]
803 : : {
804 : 7449 : case JOIN_INNER:
805 : 7449 : j->quals = pull_up_sublinks_qual_recurse(root, j->quals,
806 : : &jtlink,
807 : : bms_union(leftrelids,
808 : : rightrelids),
809 : : NULL, NULL);
810 : 7449 : break;
811 : 8082 : case JOIN_LEFT:
812 : 8082 : j->quals = pull_up_sublinks_qual_recurse(root, j->quals,
813 : : &j->rarg,
814 : : rightrelids,
815 : : NULL, NULL);
816 : 8082 : break;
817 : 35 : case JOIN_FULL:
818 : : /* can't do anything with full-join quals */
819 : 35 : break;
820 : 105 : case JOIN_RIGHT:
821 : 105 : j->quals = pull_up_sublinks_qual_recurse(root, j->quals,
822 : : &j->larg,
823 : : leftrelids,
824 : : NULL, NULL);
825 : 105 : break;
826 : 0 : default:
827 [ # # ]: 0 : elog(ERROR, "unrecognized join type: %d",
828 : : (int) j->jointype);
829 : : break;
830 : : }
831 : :
832 : : /*
833 : : * Although we could include the pulled-up subqueries in the returned
834 : : * relids, there's no need since upper quals couldn't refer to their
835 : : * outputs anyway. But we *do* need to include the join's own rtindex
836 : : * because we haven't yet collapsed join alias variables, so upper
837 : : * levels would mistakenly think they couldn't use references to this
838 : : * join.
839 : : */
840 : 15671 : *relids = bms_join(leftrelids, rightrelids);
841 [ + - ]: 15671 : if (j->rtindex)
842 : 15671 : *relids = bms_add_member(*relids, j->rtindex);
843 : 15671 : jtnode = jtlink;
844 : : }
845 : : else
846 [ # # ]: 0 : elog(ERROR, "unrecognized node type: %d",
847 : : (int) nodeTag(jtnode));
848 : 109835 : return jtnode;
849 : : }
850 : :
851 : : /*
852 : : * Recurse through top-level qual nodes for pull_up_sublinks()
853 : : *
854 : : * jtlink1 points to the link in the jointree where any new JoinExprs should
855 : : * be inserted if they reference available_rels1 (i.e., available_rels1
856 : : * denotes the relations present underneath jtlink1). Optionally, jtlink2 can
857 : : * point to a second link where new JoinExprs should be inserted if they
858 : : * reference available_rels2 (pass NULL for both those arguments if not used).
859 : : * Note that SubLinks referencing both sets of variables cannot be optimized.
860 : : * If we find multiple pull-up-able SubLinks, they'll get stacked onto jtlink1
861 : : * and/or jtlink2 in the order we encounter them. We rely on subsequent
862 : : * optimization to rearrange the stack if appropriate.
863 : : *
864 : : * Returns the replacement qual node, or NULL if the qual should be removed.
865 : : */
866 : : static Node *
867 : 128227 : pull_up_sublinks_qual_recurse(PlannerInfo *root, Node *node,
868 : : Node **jtlink1, Relids available_rels1,
869 : : Node **jtlink2, Relids available_rels2)
870 : : {
871 [ + + ]: 128227 : if (node == NULL)
872 : 5050 : return NULL;
873 [ + + ]: 123177 : if (IsA(node, SubLink))
874 : : {
875 : 4583 : SubLink *sublink = (SubLink *) node;
876 : : JoinExpr *j;
877 : : Relids child_rels;
878 : :
879 : : /* Is it a convertible ANY or EXISTS clause? */
880 [ + + ]: 4583 : if (sublink->subLinkType == ANY_SUBLINK)
881 : : {
882 : : ScalarArrayOpExpr *saop;
883 : :
884 [ + + ]: 3865 : if ((saop = convert_VALUES_to_ANY(root,
885 : : sublink->testexpr,
886 : 3865 : (Query *) sublink->subselect)) != NULL)
887 : : {
888 : : /*
889 : : * The VALUES sequence was simplified. Nothing more to do
890 : : * here.
891 : : */
892 : 70 : return (Node *) saop;
893 : : }
894 : :
895 [ + + ]: 3795 : if ((j = convert_ANY_sublink_to_join(root, sublink, false,
896 : : available_rels1)) != NULL)
897 : : {
898 : : /* Yes; insert the new join node into the join tree */
899 : 3703 : j->larg = *jtlink1;
900 : 3703 : *jtlink1 = (Node *) j;
901 : : /* Recursively process pulled-up jointree nodes */
902 : 3703 : j->rarg = pull_up_sublinks_jointree_recurse(root,
903 : : j->rarg,
904 : : &child_rels);
905 : :
906 : : /*
907 : : * Now recursively process the pulled-up quals. Any inserted
908 : : * joins can get stacked onto either j->larg or j->rarg,
909 : : * depending on which rels they reference.
910 : : */
911 : 3703 : j->quals = pull_up_sublinks_qual_recurse(root,
912 : : j->quals,
913 : : &j->larg,
914 : : available_rels1,
915 : : &j->rarg,
916 : : child_rels);
917 : : /* Return NULL representing constant TRUE */
918 : 3703 : return NULL;
919 : : }
920 [ + + - + ]: 97 : if (available_rels2 != NULL &&
921 : 5 : (j = convert_ANY_sublink_to_join(root, sublink, false,
922 : : available_rels2)) != NULL)
923 : : {
924 : : /* Yes; insert the new join node into the join tree */
925 : 0 : j->larg = *jtlink2;
926 : 0 : *jtlink2 = (Node *) j;
927 : : /* Recursively process pulled-up jointree nodes */
928 : 0 : j->rarg = pull_up_sublinks_jointree_recurse(root,
929 : : j->rarg,
930 : : &child_rels);
931 : :
932 : : /*
933 : : * Now recursively process the pulled-up quals. Any inserted
934 : : * joins can get stacked onto either j->larg or j->rarg,
935 : : * depending on which rels they reference.
936 : : */
937 : 0 : j->quals = pull_up_sublinks_qual_recurse(root,
938 : : j->quals,
939 : : &j->larg,
940 : : available_rels2,
941 : : &j->rarg,
942 : : child_rels);
943 : : /* Return NULL representing constant TRUE */
944 : 0 : return NULL;
945 : : }
946 : : }
947 [ + + ]: 718 : else if (sublink->subLinkType == EXISTS_SUBLINK)
948 : : {
949 [ + + ]: 668 : if ((j = convert_EXISTS_sublink_to_join(root, sublink, false,
950 : : available_rels1)) != NULL)
951 : : {
952 : : /* Yes; insert the new join node into the join tree */
953 : 551 : j->larg = *jtlink1;
954 : 551 : *jtlink1 = (Node *) j;
955 : : /* Recursively process pulled-up jointree nodes */
956 : 551 : j->rarg = pull_up_sublinks_jointree_recurse(root,
957 : : j->rarg,
958 : : &child_rels);
959 : :
960 : : /*
961 : : * Now recursively process the pulled-up quals. Any inserted
962 : : * joins can get stacked onto either j->larg or j->rarg,
963 : : * depending on which rels they reference.
964 : : */
965 : 551 : j->quals = pull_up_sublinks_qual_recurse(root,
966 : : j->quals,
967 : : &j->larg,
968 : : available_rels1,
969 : : &j->rarg,
970 : : child_rels);
971 : : /* Return NULL representing constant TRUE */
972 : 551 : return NULL;
973 : : }
974 [ + + + - ]: 133 : if (available_rels2 != NULL &&
975 : 16 : (j = convert_EXISTS_sublink_to_join(root, sublink, false,
976 : : available_rels2)) != NULL)
977 : : {
978 : : /* Yes; insert the new join node into the join tree */
979 : 16 : j->larg = *jtlink2;
980 : 16 : *jtlink2 = (Node *) j;
981 : : /* Recursively process pulled-up jointree nodes */
982 : 16 : j->rarg = pull_up_sublinks_jointree_recurse(root,
983 : : j->rarg,
984 : : &child_rels);
985 : :
986 : : /*
987 : : * Now recursively process the pulled-up quals. Any inserted
988 : : * joins can get stacked onto either j->larg or j->rarg,
989 : : * depending on which rels they reference.
990 : : */
991 : 16 : j->quals = pull_up_sublinks_qual_recurse(root,
992 : : j->quals,
993 : : &j->larg,
994 : : available_rels2,
995 : : &j->rarg,
996 : : child_rels);
997 : : /* Return NULL representing constant TRUE */
998 : 16 : return NULL;
999 : : }
1000 : : }
1001 : : /* Else return it unmodified */
1002 : 243 : return node;
1003 : : }
1004 [ + + ]: 118594 : if (is_notclause(node))
1005 : : {
1006 : : /* If the immediate argument of NOT is ANY or EXISTS, try to convert */
1007 : 14562 : SubLink *sublink = (SubLink *) get_notclausearg((Expr *) node);
1008 : : JoinExpr *j;
1009 : : Relids child_rels;
1010 : :
1011 [ + - + + ]: 14562 : if (sublink && IsA(sublink, SubLink))
1012 : : {
1013 [ + + ]: 7650 : if (sublink->subLinkType == ANY_SUBLINK)
1014 : : {
1015 [ + + ]: 220 : if ((j = convert_ANY_sublink_to_join(root, sublink, true,
1016 : : available_rels1)) != NULL)
1017 : : {
1018 : : /* Yes; insert the new join node into the join tree */
1019 : 75 : j->larg = *jtlink1;
1020 : 75 : *jtlink1 = (Node *) j;
1021 : : /* Recursively process pulled-up jointree nodes */
1022 : 75 : j->rarg = pull_up_sublinks_jointree_recurse(root,
1023 : : j->rarg,
1024 : : &child_rels);
1025 : :
1026 : : /*
1027 : : * Now recursively process the pulled-up quals. Because
1028 : : * we are underneath a NOT, we can't pull up sublinks that
1029 : : * reference the left-hand stuff, but it's still okay to
1030 : : * pull up sublinks referencing j->rarg.
1031 : : */
1032 : 75 : j->quals = pull_up_sublinks_qual_recurse(root,
1033 : : j->quals,
1034 : : &j->rarg,
1035 : : child_rels,
1036 : : NULL, NULL);
1037 : : /* Return NULL representing constant TRUE */
1038 : 75 : return NULL;
1039 : : }
1040 [ - + - - ]: 145 : if (available_rels2 != NULL &&
1041 : 0 : (j = convert_ANY_sublink_to_join(root, sublink, true,
1042 : : available_rels2)) != NULL)
1043 : : {
1044 : : /* Yes; insert the new join node into the join tree */
1045 : 0 : j->larg = *jtlink2;
1046 : 0 : *jtlink2 = (Node *) j;
1047 : : /* Recursively process pulled-up jointree nodes */
1048 : 0 : j->rarg = pull_up_sublinks_jointree_recurse(root,
1049 : : j->rarg,
1050 : : &child_rels);
1051 : :
1052 : : /*
1053 : : * Now recursively process the pulled-up quals. Because
1054 : : * we are underneath a NOT, we can't pull up sublinks that
1055 : : * reference the left-hand stuff, but it's still okay to
1056 : : * pull up sublinks referencing j->rarg.
1057 : : */
1058 : 0 : j->quals = pull_up_sublinks_qual_recurse(root,
1059 : : j->quals,
1060 : : &j->rarg,
1061 : : child_rels,
1062 : : NULL, NULL);
1063 : : /* Return NULL representing constant TRUE */
1064 : 0 : return NULL;
1065 : : }
1066 : : }
1067 [ + - ]: 7430 : else if (sublink->subLinkType == EXISTS_SUBLINK)
1068 : : {
1069 [ + + ]: 7430 : if ((j = convert_EXISTS_sublink_to_join(root, sublink, true,
1070 : : available_rels1)) != NULL)
1071 : : {
1072 : : /* Yes; insert the new join node into the join tree */
1073 : 7421 : j->larg = *jtlink1;
1074 : 7421 : *jtlink1 = (Node *) j;
1075 : : /* Recursively process pulled-up jointree nodes */
1076 : 7421 : j->rarg = pull_up_sublinks_jointree_recurse(root,
1077 : : j->rarg,
1078 : : &child_rels);
1079 : :
1080 : : /*
1081 : : * Now recursively process the pulled-up quals. Because
1082 : : * we are underneath a NOT, we can't pull up sublinks that
1083 : : * reference the left-hand stuff, but it's still okay to
1084 : : * pull up sublinks referencing j->rarg.
1085 : : */
1086 : 7421 : j->quals = pull_up_sublinks_qual_recurse(root,
1087 : : j->quals,
1088 : : &j->rarg,
1089 : : child_rels,
1090 : : NULL, NULL);
1091 : : /* Return NULL representing constant TRUE */
1092 : 7421 : return NULL;
1093 : : }
1094 [ - + - - ]: 9 : if (available_rels2 != NULL &&
1095 : 0 : (j = convert_EXISTS_sublink_to_join(root, sublink, true,
1096 : : available_rels2)) != NULL)
1097 : : {
1098 : : /* Yes; insert the new join node into the join tree */
1099 : 0 : j->larg = *jtlink2;
1100 : 0 : *jtlink2 = (Node *) j;
1101 : : /* Recursively process pulled-up jointree nodes */
1102 : 0 : j->rarg = pull_up_sublinks_jointree_recurse(root,
1103 : : j->rarg,
1104 : : &child_rels);
1105 : :
1106 : : /*
1107 : : * Now recursively process the pulled-up quals. Because
1108 : : * we are underneath a NOT, we can't pull up sublinks that
1109 : : * reference the left-hand stuff, but it's still okay to
1110 : : * pull up sublinks referencing j->rarg.
1111 : : */
1112 : 0 : j->quals = pull_up_sublinks_qual_recurse(root,
1113 : : j->quals,
1114 : : &j->rarg,
1115 : : child_rels,
1116 : : NULL, NULL);
1117 : : /* Return NULL representing constant TRUE */
1118 : 0 : return NULL;
1119 : : }
1120 : : }
1121 : : }
1122 : : /* Else return it unmodified */
1123 : 7066 : return node;
1124 : : }
1125 [ + + ]: 104032 : if (is_andclause(node))
1126 : : {
1127 : : /* Recurse into AND clause */
1128 : 25302 : List *newclauses = NIL;
1129 : : ListCell *l;
1130 : :
1131 [ + - + + : 94089 : foreach(l, ((BoolExpr *) node)->args)
+ + ]
1132 : : {
1133 : 68787 : Node *oldclause = (Node *) lfirst(l);
1134 : : Node *newclause;
1135 : :
1136 : 68787 : newclause = pull_up_sublinks_qual_recurse(root,
1137 : : oldclause,
1138 : : jtlink1,
1139 : : available_rels1,
1140 : : jtlink2,
1141 : : available_rels2);
1142 [ + + ]: 68787 : if (newclause)
1143 : 58988 : newclauses = lappend(newclauses, newclause);
1144 : : }
1145 : : /* We might have got back fewer clauses than we started with */
1146 [ + + ]: 25302 : if (newclauses == NIL)
1147 : 71 : return NULL;
1148 [ + + ]: 25231 : else if (list_length(newclauses) == 1)
1149 : 897 : return (Node *) linitial(newclauses);
1150 : : else
1151 : 24334 : return (Node *) make_andclause(newclauses);
1152 : : }
1153 : : /* Stop if not an AND */
1154 : 78730 : return node;
1155 : : }
1156 : :
1157 : : /*
1158 : : * preprocess_function_rtes
1159 : : * Constant-simplify any FUNCTION RTEs in the FROM clause, and then
1160 : : * attempt to "inline" any that can be converted to simple subqueries.
1161 : : *
1162 : : * If an RTE_FUNCTION rtable entry invokes a set-returning SQL function that
1163 : : * contains just a simple SELECT, we can convert the rtable entry to an
1164 : : * RTE_SUBQUERY entry exposing the SELECT directly. Other sorts of functions
1165 : : * are also inline-able if they have a support function that can generate
1166 : : * the replacement sub-Query. This is especially useful if the subquery can
1167 : : * then be "pulled up" for further optimization, but we do it even if not,
1168 : : * to reduce executor overhead.
1169 : : *
1170 : : * This has to be done before we have started to do any optimization of
1171 : : * subqueries, else any such steps wouldn't get applied to subqueries
1172 : : * obtained via inlining. However, we do it after pull_up_sublinks
1173 : : * so that we can inline any functions used in SubLink subselects.
1174 : : *
1175 : : * The reason for applying const-simplification at this stage is that
1176 : : * (a) we'd need to do it anyway to inline a SRF, and (b) by doing it now,
1177 : : * we can be sure that pull_up_constant_function() will see constants
1178 : : * if there are constants to be seen. This approach also guarantees
1179 : : * that every FUNCTION RTE has been const-simplified, allowing planner.c's
1180 : : * preprocess_expression() to skip doing it again.
1181 : : *
1182 : : * Like most of the planner, this feels free to scribble on its input data
1183 : : * structure.
1184 : : */
1185 : : void
1186 : 423484 : preprocess_function_rtes(PlannerInfo *root)
1187 : : {
1188 : : ListCell *rt;
1189 : :
1190 [ + - + + : 1109686 : foreach(rt, root->parse->rtable)
+ + ]
1191 : : {
1192 : 686206 : RangeTblEntry *rte = (RangeTblEntry *) lfirst(rt);
1193 : :
1194 [ + + ]: 686206 : if (rte->rtekind == RTE_FUNCTION)
1195 : : {
1196 : : Query *funcquery;
1197 : :
1198 : : /* Apply const-simplification */
1199 : 35459 : rte->functions = (List *)
1200 : 35459 : eval_const_expressions(root, (Node *) rte->functions);
1201 : :
1202 : : /* Check safety of expansion, and expand if possible */
1203 : 35459 : funcquery = inline_function_in_from(root, rte);
1204 [ + + ]: 35455 : if (funcquery)
1205 : : {
1206 : : /* Successful expansion, convert the RTE to a subquery */
1207 : 205 : rte->rtekind = RTE_SUBQUERY;
1208 : 205 : rte->subquery = funcquery;
1209 : 205 : rte->security_barrier = false;
1210 : :
1211 : : /*
1212 : : * Clear fields that should not be set in a subquery RTE.
1213 : : * However, we leave rte->functions filled in for the moment,
1214 : : * in case makeWholeRowVar needs to consult it. We'll clear
1215 : : * it in setrefs.c (see add_rte_to_flat_rtable) so that this
1216 : : * abuse of the data structure doesn't escape the planner.
1217 : : */
1218 : 205 : rte->funcordinality = false;
1219 : : }
1220 : : }
1221 : : }
1222 : 423480 : }
1223 : :
1224 : : /*
1225 : : * pull_up_subqueries
1226 : : * Look for subqueries in the rangetable that can be pulled up into
1227 : : * the parent query. If the subquery has no special features like
1228 : : * grouping/aggregation then we can merge it into the parent's jointree.
1229 : : * Also, subqueries that are simple UNION ALL structures can be
1230 : : * converted into "append relations".
1231 : : */
1232 : : void
1233 : 423480 : pull_up_subqueries(PlannerInfo *root)
1234 : : {
1235 : : /* Top level of jointree must always be a FromExpr */
1236 : : Assert(IsA(root->parse->jointree, FromExpr));
1237 : : /* Recursion starts with no containing join nor appendrel */
1238 : 846960 : root->parse->jointree = (FromExpr *)
1239 : 423480 : pull_up_subqueries_recurse(root, (Node *) root->parse->jointree,
1240 : : NULL, NULL);
1241 : : /* We should still have a FromExpr */
1242 : : Assert(IsA(root->parse->jointree, FromExpr));
1243 : 423480 : }
1244 : :
1245 : : /*
1246 : : * pull_up_subqueries_recurse
1247 : : * Recursive guts of pull_up_subqueries.
1248 : : *
1249 : : * This recursively processes the jointree and returns a modified jointree.
1250 : : *
1251 : : * If this jointree node is within either side of an outer join, then
1252 : : * lowest_outer_join references the lowest such JoinExpr node; otherwise
1253 : : * it is NULL. We use this to constrain the effects of LATERAL subqueries.
1254 : : *
1255 : : * If we are looking at a member subquery of an append relation,
1256 : : * containing_appendrel describes that relation; else it is NULL.
1257 : : * This forces use of the PlaceHolderVar mechanism for all non-Var targetlist
1258 : : * items, and puts some additional restrictions on what can be pulled up.
1259 : : *
1260 : : * A tricky aspect of this code is that if we pull up a subquery we have
1261 : : * to replace Vars that reference the subquery's outputs throughout the
1262 : : * parent query, including quals attached to jointree nodes above the one
1263 : : * we are currently processing! We handle this by being careful to maintain
1264 : : * validity of the jointree structure while recursing, in the following sense:
1265 : : * whenever we recurse, all qual expressions in the tree must be reachable
1266 : : * from the top level, in case the recursive call needs to modify them.
1267 : : *
1268 : : * Notice also that we can't turn pullup_replace_vars loose on the whole
1269 : : * jointree, because it'd return a mutated copy of the tree; we have to
1270 : : * invoke it just on the quals, instead. This behavior is what makes it
1271 : : * reasonable to pass lowest_outer_join as a pointer rather than some
1272 : : * more-indirect way of identifying the lowest OJ. Likewise, we don't
1273 : : * replace append_rel_list members but only their substructure, so the
1274 : : * containing_appendrel reference is safe to use.
1275 : : */
1276 : : static Node *
1277 : 1069665 : pull_up_subqueries_recurse(PlannerInfo *root, Node *jtnode,
1278 : : JoinExpr *lowest_outer_join,
1279 : : AppendRelInfo *containing_appendrel)
1280 : : {
1281 : : /* Since this function recurses, it could be driven to stack overflow. */
1282 : 1069665 : check_stack_depth();
1283 : : /* Also, since it's a bit expensive, let's check for query cancel. */
1284 [ + + ]: 1069665 : CHECK_FOR_INTERRUPTS();
1285 : :
1286 : : Assert(jtnode != NULL);
1287 [ + + ]: 1069665 : if (IsA(jtnode, RangeTblRef))
1288 : : {
1289 : 548948 : int varno = ((RangeTblRef *) jtnode)->rtindex;
1290 : 548948 : RangeTblEntry *rte = rt_fetch(varno, root->parse->rtable);
1291 : :
1292 : : /*
1293 : : * Is this a subquery RTE, and if so, is the subquery simple enough to
1294 : : * pull up?
1295 : : *
1296 : : * If we are looking at an append-relation member, we can't pull it up
1297 : : * unless is_safe_append_member says so.
1298 : : */
1299 [ + + + + ]: 599286 : if (rte->rtekind == RTE_SUBQUERY &&
1300 [ + + ]: 83464 : is_simple_subquery(root, rte->subquery, rte, lowest_outer_join) &&
1301 [ + + ]: 8840 : (containing_appendrel == NULL ||
1302 : 8840 : is_safe_append_member(rte->subquery)))
1303 : 29620 : return pull_up_simple_subquery(root, jtnode, rte,
1304 : : lowest_outer_join,
1305 : : containing_appendrel);
1306 : :
1307 : : /*
1308 : : * Alternatively, is it a simple UNION ALL subquery? If so, flatten
1309 : : * into an "append relation".
1310 : : *
1311 : : * It's safe to do this regardless of whether this query is itself an
1312 : : * appendrel member. (If you're thinking we should try to flatten the
1313 : : * two levels of appendrel together, you're right; but we handle that
1314 : : * in set_append_rel_pathlist, not here.)
1315 : : */
1316 [ + + + + ]: 540046 : if (rte->rtekind == RTE_SUBQUERY &&
1317 : 20718 : is_simple_union_all(rte->subquery))
1318 : 3863 : return pull_up_simple_union_all(root, jtnode, rte);
1319 : :
1320 : : /*
1321 : : * Or perhaps it's a simple VALUES RTE?
1322 : : *
1323 : : * We don't allow VALUES pullup below an outer join nor into an
1324 : : * appendrel (such cases are impossible anyway at the moment).
1325 : : */
1326 [ + + + - ]: 515465 : if (rte->rtekind == RTE_VALUES &&
1327 [ + - ]: 10607 : lowest_outer_join == NULL &&
1328 [ + + ]: 10607 : containing_appendrel == NULL &&
1329 : 10607 : is_simple_values(root, rte))
1330 : 3808 : return pull_up_simple_values(root, jtnode, rte);
1331 : :
1332 : : /*
1333 : : * Or perhaps it's a FUNCTION RTE that we could inline?
1334 : : */
1335 [ + + ]: 511657 : if (rte->rtekind == RTE_FUNCTION)
1336 : 35250 : return pull_up_constant_function(root, jtnode, rte,
1337 : : containing_appendrel);
1338 : :
1339 : : /* Otherwise, do nothing at this node. */
1340 : : }
1341 [ + + ]: 520717 : else if (IsA(jtnode, FromExpr))
1342 : : {
1343 : 436685 : FromExpr *f = (FromExpr *) jtnode;
1344 : : ListCell *l;
1345 : :
1346 : : Assert(containing_appendrel == NULL);
1347 : : /* Recursively transform all the child nodes */
1348 [ + + + + : 902944 : foreach(l, f->fromlist)
+ + ]
1349 : : {
1350 : 466259 : lfirst(l) = pull_up_subqueries_recurse(root, lfirst(l),
1351 : : lowest_outer_join,
1352 : : NULL);
1353 : : }
1354 : : }
1355 [ + - ]: 84032 : else if (IsA(jtnode, JoinExpr))
1356 : : {
1357 : 84032 : JoinExpr *j = (JoinExpr *) jtnode;
1358 : :
1359 : : Assert(containing_appendrel == NULL);
1360 : : /* Recurse, being careful to tell myself when inside outer join */
1361 [ + + + + : 84032 : switch (j->jointype)
- ]
1362 : : {
1363 : 35255 : case JOIN_INNER:
1364 : 35255 : j->larg = pull_up_subqueries_recurse(root, j->larg,
1365 : : lowest_outer_join,
1366 : : NULL);
1367 : 35255 : j->rarg = pull_up_subqueries_recurse(root, j->rarg,
1368 : : lowest_outer_join,
1369 : : NULL);
1370 : 35255 : break;
1371 : 46752 : case JOIN_LEFT:
1372 : : case JOIN_SEMI:
1373 : : case JOIN_ANTI:
1374 : 46752 : j->larg = pull_up_subqueries_recurse(root, j->larg,
1375 : : j,
1376 : : NULL);
1377 : 46752 : j->rarg = pull_up_subqueries_recurse(root, j->rarg,
1378 : : j,
1379 : : NULL);
1380 : 46752 : break;
1381 : 1007 : case JOIN_FULL:
1382 : 1007 : j->larg = pull_up_subqueries_recurse(root, j->larg,
1383 : : j,
1384 : : NULL);
1385 : 1007 : j->rarg = pull_up_subqueries_recurse(root, j->rarg,
1386 : : j,
1387 : : NULL);
1388 : 1007 : break;
1389 : 1018 : case JOIN_RIGHT:
1390 : 1018 : j->larg = pull_up_subqueries_recurse(root, j->larg,
1391 : : j,
1392 : : NULL);
1393 : 1018 : j->rarg = pull_up_subqueries_recurse(root, j->rarg,
1394 : : j,
1395 : : NULL);
1396 : 1018 : break;
1397 : 0 : default:
1398 [ # # ]: 0 : elog(ERROR, "unrecognized join type: %d",
1399 : : (int) j->jointype);
1400 : : break;
1401 : : }
1402 : : }
1403 : : else
1404 [ # # ]: 0 : elog(ERROR, "unrecognized node type: %d",
1405 : : (int) nodeTag(jtnode));
1406 : 997124 : return jtnode;
1407 : : }
1408 : :
1409 : : /*
1410 : : * pull_up_simple_subquery
1411 : : * Attempt to pull up a single simple subquery.
1412 : : *
1413 : : * jtnode is a RangeTblRef that has been tentatively identified as a simple
1414 : : * subquery by pull_up_subqueries. We return the replacement jointree node,
1415 : : * or jtnode itself if we determine that the subquery can't be pulled up
1416 : : * after all.
1417 : : *
1418 : : * rte is the RangeTblEntry referenced by jtnode. Remaining parameters are
1419 : : * as for pull_up_subqueries_recurse.
1420 : : */
1421 : : static Node *
1422 : 29620 : pull_up_simple_subquery(PlannerInfo *root, Node *jtnode, RangeTblEntry *rte,
1423 : : JoinExpr *lowest_outer_join,
1424 : : AppendRelInfo *containing_appendrel)
1425 : : {
1426 : 29620 : Query *parse = root->parse;
1427 : 29620 : int varno = ((RangeTblRef *) jtnode)->rtindex;
1428 : : Query *subquery;
1429 : : PlannerInfo *subroot;
1430 : : int rtoffset;
1431 : : pullup_replace_vars_context rvcontext;
1432 : : ListCell *lc;
1433 : :
1434 : : /*
1435 : : * Make a modifiable copy of the subquery to hack on, so that the RTE will
1436 : : * be left unchanged in case we decide below that we can't pull it up
1437 : : * after all.
1438 : : */
1439 : 29620 : subquery = copyObject(rte->subquery);
1440 : :
1441 : : /*
1442 : : * Create a PlannerInfo data structure for this subquery.
1443 : : *
1444 : : * NOTE: the next few steps should match the first processing in
1445 : : * subquery_planner(). Can we refactor to avoid code duplication, or
1446 : : * would that just make things uglier?
1447 : : */
1448 : 29620 : subroot = makeNode(PlannerInfo);
1449 : 29620 : subroot->parse = subquery;
1450 : 29620 : subroot->glob = root->glob;
1451 : 29620 : subroot->query_level = root->query_level;
1452 : 29620 : subroot->plan_name = root->plan_name;
1453 : 29620 : subroot->alternative_plan_name = root->alternative_plan_name;
1454 : 29620 : subroot->parent_root = root->parent_root;
1455 : 29620 : subroot->plan_params = NIL;
1456 : 29620 : subroot->outer_params = NULL;
1457 : 29620 : subroot->planner_cxt = CurrentMemoryContext;
1458 : 29620 : subroot->init_plans = NIL;
1459 : 29620 : subroot->cte_plan_ids = NIL;
1460 : 29620 : subroot->multiexpr_params = NIL;
1461 : 29620 : subroot->join_domains = NIL;
1462 : 29620 : subroot->eq_classes = NIL;
1463 : 29620 : subroot->ec_merging_done = false;
1464 : 29620 : subroot->last_rinfo_serial = 0;
1465 : 29620 : subroot->all_result_relids = NULL;
1466 : 29620 : subroot->leaf_result_relids = NULL;
1467 : 29620 : subroot->append_rel_list = NIL;
1468 : 29620 : subroot->row_identity_vars = NIL;
1469 : 29620 : subroot->rowMarks = NIL;
1470 : 29620 : memset(subroot->upper_rels, 0, sizeof(subroot->upper_rels));
1471 : 29620 : memset(subroot->upper_targets, 0, sizeof(subroot->upper_targets));
1472 : 29620 : subroot->processed_groupClause = NIL;
1473 : 29620 : subroot->processed_distinctClause = NIL;
1474 : 29620 : subroot->processed_tlist = NIL;
1475 : 29620 : subroot->update_colnos = NIL;
1476 : 29620 : subroot->grouping_map = NULL;
1477 : 29620 : subroot->minmax_aggs = NIL;
1478 : 29620 : subroot->qual_security_level = 0;
1479 : 29620 : subroot->placeholdersFrozen = false;
1480 : 29620 : subroot->hasRecursion = false;
1481 : 29620 : subroot->assumeReplanning = false;
1482 : 29620 : subroot->wt_param_id = -1;
1483 : 29620 : subroot->non_recursive_path = NULL;
1484 : : /* We don't currently need a top JoinDomain for the subroot */
1485 : :
1486 : : /* No CTEs to worry about */
1487 : : Assert(subquery->cteList == NIL);
1488 : :
1489 : : /*
1490 : : * Scan the rangetable for relation RTEs and retrieve the necessary
1491 : : * catalog information for each relation. Using this information, clear
1492 : : * the inh flag for any relation that has no children, collect not-null
1493 : : * attribute numbers for any relation that has column not-null
1494 : : * constraints, and expand virtual generated columns for any relation that
1495 : : * contains them.
1496 : : */
1497 : 29620 : subquery = subroot->parse = preprocess_relation_rtes(subroot);
1498 : :
1499 : : /*
1500 : : * If the FROM clause is empty, replace it with a dummy RTE_RESULT RTE, so
1501 : : * that we don't need so many special cases to deal with that situation.
1502 : : */
1503 : 29620 : replace_empty_jointree(subquery);
1504 : :
1505 : : /*
1506 : : * Pull up any SubLinks within the subquery's quals, so that we don't
1507 : : * leave unoptimized SubLinks behind.
1508 : : */
1509 [ + + ]: 29620 : if (subquery->hasSubLinks)
1510 : 1688 : pull_up_sublinks(subroot);
1511 : :
1512 : : /*
1513 : : * Similarly, preprocess its function RTEs to inline any set-returning
1514 : : * functions in its rangetable.
1515 : : */
1516 : 29620 : preprocess_function_rtes(subroot);
1517 : :
1518 : : /*
1519 : : * Recursively pull up the subquery's subqueries, so that
1520 : : * pull_up_subqueries' processing is complete for its jointree and
1521 : : * rangetable.
1522 : : *
1523 : : * Note: it's okay that the subquery's recursion starts with NULL for
1524 : : * containing-join info, even if we are within an outer join in the upper
1525 : : * query; the lower query starts with a clean slate for outer-join
1526 : : * semantics. Likewise, we needn't pass down appendrel state.
1527 : : */
1528 : 29620 : pull_up_subqueries(subroot);
1529 : :
1530 : : /*
1531 : : * We must flatten any join alias Vars in the subquery's targetlist,
1532 : : * because pulling up the subquery's subqueries might have changed their
1533 : : * expansions into arbitrary expressions. That could affect
1534 : : * pullup_replace_vars' decisions about whether PlaceHolderVar wrappers
1535 : : * are needed for tlist entries, and if the subquery is LATERAL, the
1536 : : * expansions might contain lateral references that the is_simple_subquery
1537 : : * recheck below has to see. The latter also requires flattening join
1538 : : * alias Vars in the jointree quals of a LATERAL subquery. (Likely it'd
1539 : : * be better to do flatten_join_alias_vars on the whole query tree at some
1540 : : * earlier stage, maybe even in the rewriter; but for now let's just fix
1541 : : * these cases here.)
1542 : : */
1543 : 29620 : subquery->targetList = (List *)
1544 : 29620 : flatten_join_alias_vars(subroot, subroot->parse,
1545 : 29620 : (Node *) subquery->targetList);
1546 [ + + ]: 29620 : if (rte->lateral)
1547 : 1064 : flatten_join_alias_vars_in_jointree(subroot,
1548 : 1064 : (Node *) subquery->jointree);
1549 : :
1550 : : /*
1551 : : * Now we must recheck whether the subquery is still simple enough to pull
1552 : : * up. If not, abandon processing it.
1553 : : *
1554 : : * We don't really need to recheck all the conditions involved, but it's
1555 : : * easier just to keep this "if" looking the same as the one in
1556 : : * pull_up_subqueries_recurse.
1557 : : */
1558 [ + + + + ]: 34818 : if (is_simple_subquery(root, subquery, rte, lowest_outer_join) &&
1559 [ + + ]: 5334 : (containing_appendrel == NULL || is_safe_append_member(subquery)))
1560 : : {
1561 : : /* good to go */
1562 : : }
1563 : : else
1564 : : {
1565 : : /*
1566 : : * Give up, return unmodified RangeTblRef.
1567 : : *
1568 : : * Note: The work we just did will be redone when the subquery gets
1569 : : * planned on its own. Perhaps we could avoid that by storing the
1570 : : * modified subquery back into the rangetable, but I'm not gonna risk
1571 : : * it now.
1572 : : */
1573 : 166 : return jtnode;
1574 : : }
1575 : :
1576 : : /*
1577 : : * Adjust level-0 varnos in subquery so that we can append its rangetable
1578 : : * to upper query's. We have to fix the subquery's append_rel_list as
1579 : : * well.
1580 : : */
1581 : 29454 : rtoffset = list_length(parse->rtable);
1582 : 29454 : OffsetVarNodes((Node *) subquery, rtoffset, 0);
1583 : 29454 : OffsetVarNodes((Node *) subroot->append_rel_list, rtoffset, 0);
1584 : :
1585 : : /*
1586 : : * Upper-level vars in subquery are now one level closer to their parent
1587 : : * than before.
1588 : : */
1589 : 29454 : IncrementVarSublevelsUp((Node *) subquery, -1, 1);
1590 : 29454 : IncrementVarSublevelsUp((Node *) subroot->append_rel_list, -1, 1);
1591 : :
1592 : : /*
1593 : : * The subquery's targetlist items are now in the appropriate form to
1594 : : * insert into the top query, except that we may need to wrap them in
1595 : : * PlaceHolderVars. Set up required context data for pullup_replace_vars.
1596 : : * (Note that we should include the subquery's inner joins in relids,
1597 : : * since it may include join alias vars referencing them.)
1598 : : */
1599 : 29454 : rvcontext.root = root;
1600 : 29454 : rvcontext.targetlist = subquery->targetList;
1601 : 29454 : rvcontext.target_rte = rte;
1602 : 29454 : rvcontext.result_relation = 0;
1603 [ + + ]: 29454 : if (rte->lateral)
1604 : : {
1605 : 1034 : rvcontext.relids = get_relids_in_jointree((Node *) subquery->jointree,
1606 : : true, true);
1607 : 1034 : rvcontext.nullinfo = get_nullingrels(parse);
1608 : : }
1609 : : else /* won't need these values */
1610 : : {
1611 : 28420 : rvcontext.relids = NULL;
1612 : 28420 : rvcontext.nullinfo = NULL;
1613 : : }
1614 : 29454 : rvcontext.outer_hasSubLinks = &parse->hasSubLinks;
1615 : 29454 : rvcontext.varno = varno;
1616 : : /* this flag will be set below, if needed */
1617 : 29454 : rvcontext.wrap_option = REPLACE_WRAP_NONE;
1618 : : /* initialize cache array with indexes 0 .. length(tlist) */
1619 : 29454 : rvcontext.rv_cache = palloc0_array(Node *, list_length(subquery->targetList) + 1);
1620 : :
1621 : : /*
1622 : : * If the parent query uses grouping sets, we need a PlaceHolderVar for
1623 : : * each expression of the subquery's targetlist items. This ensures that
1624 : : * expressions retain their separate identity so that they will match
1625 : : * grouping set columns when appropriate. (It'd be sufficient to wrap
1626 : : * values used in grouping set columns, and do so only in non-aggregated
1627 : : * portions of the tlist and havingQual, but that would require a lot of
1628 : : * infrastructure that pullup_replace_vars hasn't currently got.)
1629 : : */
1630 [ + + ]: 29454 : if (parse->groupingSets)
1631 : 401 : rvcontext.wrap_option = REPLACE_WRAP_ALL;
1632 : :
1633 : : /*
1634 : : * Replace all of the top query's references to the subquery's outputs
1635 : : * with copies of the adjusted subtlist items, being careful not to
1636 : : * replace any of the jointree structure.
1637 : : */
1638 : 29454 : perform_pullup_replace_vars(root, &rvcontext,
1639 : : containing_appendrel);
1640 : :
1641 : : /*
1642 : : * If the subquery had a LATERAL marker, propagate that to any of its
1643 : : * child RTEs that could possibly now contain lateral cross-references.
1644 : : * The children might or might not contain any actual lateral
1645 : : * cross-references, but we have to mark the pulled-up child RTEs so that
1646 : : * later planner stages will check for such.
1647 : : */
1648 [ + + ]: 29454 : if (rte->lateral)
1649 : : {
1650 [ + - + + : 2439 : foreach(lc, subquery->rtable)
+ + ]
1651 : : {
1652 : 1405 : RangeTblEntry *child_rte = (RangeTblEntry *) lfirst(lc);
1653 : :
1654 [ + + + - ]: 1405 : switch (child_rte->rtekind)
1655 : : {
1656 : 617 : case RTE_RELATION:
1657 [ + + ]: 617 : if (child_rte->tablesample)
1658 : 41 : child_rte->lateral = true;
1659 : 617 : break;
1660 : 252 : case RTE_SUBQUERY:
1661 : : case RTE_FUNCTION:
1662 : : case RTE_VALUES:
1663 : : case RTE_TABLEFUNC:
1664 : 252 : child_rte->lateral = true;
1665 : 252 : break;
1666 : 536 : case RTE_JOIN:
1667 : : case RTE_CTE:
1668 : : case RTE_NAMEDTUPLESTORE:
1669 : : case RTE_RESULT:
1670 : : case RTE_GROUP:
1671 : : /* these can't contain any lateral references */
1672 : 536 : break;
1673 : : }
1674 : : }
1675 : : }
1676 : :
1677 : : /*
1678 : : * Now append the adjusted rtable entries and their perminfos to upper
1679 : : * query. (We hold off until after fixing the upper rtable entries; no
1680 : : * point in running that code on the subquery ones too.)
1681 : : */
1682 : 29454 : CombineRangeTables(&parse->rtable, &parse->rteperminfos,
1683 : : subquery->rtable, subquery->rteperminfos);
1684 : :
1685 : : /*
1686 : : * Pull up any FOR UPDATE/SHARE markers, too. (OffsetVarNodes already
1687 : : * adjusted the marker rtindexes, so just concat the lists.)
1688 : : */
1689 : 29454 : parse->rowMarks = list_concat(parse->rowMarks, subquery->rowMarks);
1690 : :
1691 : : /*
1692 : : * We also have to fix the relid sets of any PlaceHolderVar nodes in the
1693 : : * parent query. (This could perhaps be done by pullup_replace_vars(),
1694 : : * but it seems cleaner to use two passes.) Note in particular that any
1695 : : * PlaceHolderVar nodes just created by pullup_replace_vars() will be
1696 : : * adjusted, so having created them with the subquery's varno is correct.
1697 : : *
1698 : : * Likewise, relids appearing in AppendRelInfo nodes have to be fixed. We
1699 : : * already checked that this won't require introducing multiple subrelids
1700 : : * into the single-slot AppendRelInfo structs.
1701 : : */
1702 [ + + + + ]: 29454 : if (root->glob->lastPHId != 0 || root->append_rel_list)
1703 : : {
1704 : : Relids subrelids;
1705 : :
1706 : 7207 : subrelids = get_relids_in_jointree((Node *) subquery->jointree,
1707 : : true, false);
1708 [ + + ]: 7207 : if (root->glob->lastPHId != 0)
1709 : 2064 : substitute_phv_relids((Node *) parse, varno, subrelids);
1710 : 7207 : fix_append_rel_relids(root, varno, subrelids);
1711 : : }
1712 : :
1713 : : /*
1714 : : * And now add subquery's AppendRelInfos to our list.
1715 : : */
1716 : 58908 : root->append_rel_list = list_concat(root->append_rel_list,
1717 : 29454 : subroot->append_rel_list);
1718 : :
1719 : : /*
1720 : : * We don't have to do the equivalent bookkeeping for outer-join info,
1721 : : * because that hasn't been set up yet. placeholder_list likewise.
1722 : : */
1723 : : Assert(root->join_info_list == NIL);
1724 : : Assert(subroot->join_info_list == NIL);
1725 : : Assert(root->placeholder_list == NIL);
1726 : : Assert(subroot->placeholder_list == NIL);
1727 : :
1728 : : /*
1729 : : * We no longer need the RTE's copy of the subquery's query tree. Getting
1730 : : * rid of it saves nothing in particular so far as this level of query is
1731 : : * concerned; but if this query level is in turn pulled up into a parent,
1732 : : * we'd waste cycles copying the now-unused query tree.
1733 : : */
1734 : 29454 : rte->subquery = NULL;
1735 : :
1736 : : /*
1737 : : * Miscellaneous housekeeping.
1738 : : *
1739 : : * Although replace_rte_variables() faithfully updated parse->hasSubLinks
1740 : : * if it copied any SubLinks out of the subquery's targetlist, we still
1741 : : * could have SubLinks added to the query in the expressions of FUNCTION
1742 : : * and VALUES RTEs copied up from the subquery. So it's necessary to copy
1743 : : * subquery->hasSubLinks anyway. Perhaps this can be improved someday.
1744 : : */
1745 : 29454 : parse->hasSubLinks |= subquery->hasSubLinks;
1746 : :
1747 : : /* If subquery had any RLS conditions, now main query does too */
1748 : 29454 : parse->hasRowSecurity |= subquery->hasRowSecurity;
1749 : :
1750 : : /*
1751 : : * subquery won't be pulled up if it hasAggs, hasWindowFuncs, or
1752 : : * hasTargetSRFs, so no work needed on those flags
1753 : : */
1754 : :
1755 : : /*
1756 : : * Return the adjusted subquery jointree to replace the RangeTblRef entry
1757 : : * in parent's jointree; or, if the FromExpr is degenerate, just return
1758 : : * its single member.
1759 : : */
1760 : : Assert(IsA(subquery->jointree, FromExpr));
1761 : : Assert(subquery->jointree->fromlist != NIL);
1762 [ + + + + ]: 54696 : if (subquery->jointree->quals == NULL &&
1763 : 25242 : list_length(subquery->jointree->fromlist) == 1)
1764 : 24966 : return (Node *) linitial(subquery->jointree->fromlist);
1765 : :
1766 : 4488 : return (Node *) subquery->jointree;
1767 : : }
1768 : :
1769 : : /*
1770 : : * pull_up_simple_union_all
1771 : : * Pull up a single simple UNION ALL subquery.
1772 : : *
1773 : : * jtnode is a RangeTblRef that has been identified as a simple UNION ALL
1774 : : * subquery by pull_up_subqueries. We pull up the leaf subqueries and
1775 : : * build an "append relation" for the union set. The result value is just
1776 : : * jtnode, since we don't actually need to change the query jointree.
1777 : : */
1778 : : static Node *
1779 : 3863 : pull_up_simple_union_all(PlannerInfo *root, Node *jtnode, RangeTblEntry *rte)
1780 : : {
1781 : 3863 : int varno = ((RangeTblRef *) jtnode)->rtindex;
1782 : 3863 : Query *subquery = rte->subquery;
1783 : 3863 : int rtoffset = list_length(root->parse->rtable);
1784 : : List *rtable;
1785 : :
1786 : : /*
1787 : : * Make a modifiable copy of the subquery's rtable, so we can adjust
1788 : : * upper-level Vars in it. There are no such Vars in the setOperations
1789 : : * tree proper, so fixing the rtable should be sufficient.
1790 : : */
1791 : 3863 : rtable = copyObject(subquery->rtable);
1792 : :
1793 : : /*
1794 : : * Upper-level vars in subquery are now one level closer to their parent
1795 : : * than before. We don't have to worry about offsetting varnos, though,
1796 : : * because the UNION leaf queries can't cross-reference each other.
1797 : : */
1798 : 3863 : IncrementVarSublevelsUp_rtable(rtable, -1, 1);
1799 : :
1800 : : /*
1801 : : * If the UNION ALL subquery had a LATERAL marker, propagate that to all
1802 : : * its children. The individual children might or might not contain any
1803 : : * actual lateral cross-references, but we have to mark the pulled-up
1804 : : * child RTEs so that later planner stages will check for such.
1805 : : */
1806 [ + + ]: 3863 : if (rte->lateral)
1807 : : {
1808 : : ListCell *rt;
1809 : :
1810 [ + - + + : 285 : foreach(rt, rtable)
+ + ]
1811 : : {
1812 : 190 : RangeTblEntry *child_rte = (RangeTblEntry *) lfirst(rt);
1813 : :
1814 : : Assert(child_rte->rtekind == RTE_SUBQUERY);
1815 : 190 : child_rte->lateral = true;
1816 : : }
1817 : : }
1818 : :
1819 : : /*
1820 : : * Append child RTEs (and their perminfos) to parent rtable.
1821 : : */
1822 : 3863 : CombineRangeTables(&root->parse->rtable, &root->parse->rteperminfos,
1823 : : rtable, subquery->rteperminfos);
1824 : :
1825 : : /*
1826 : : * Recursively scan the subquery's setOperations tree and add
1827 : : * AppendRelInfo nodes for leaf subqueries to the parent's
1828 : : * append_rel_list. Also apply pull_up_subqueries to the leaf subqueries.
1829 : : */
1830 : : Assert(subquery->setOperations);
1831 : 3863 : pull_up_union_leaf_queries(subquery->setOperations, root, varno, subquery,
1832 : : rtoffset);
1833 : :
1834 : : /*
1835 : : * Mark the parent as an append relation.
1836 : : */
1837 : 3863 : rte->inh = true;
1838 : :
1839 : 3863 : return jtnode;
1840 : : }
1841 : :
1842 : : /*
1843 : : * pull_up_union_leaf_queries -- recursive guts of pull_up_simple_union_all
1844 : : *
1845 : : * Build an AppendRelInfo for each leaf query in the setop tree, and then
1846 : : * apply pull_up_subqueries to the leaf query.
1847 : : *
1848 : : * Note that setOpQuery is the Query containing the setOp node, whose tlist
1849 : : * contains references to all the setop output columns. When called from
1850 : : * pull_up_simple_union_all, this is *not* the same as root->parse, which is
1851 : : * the parent Query we are pulling up into.
1852 : : *
1853 : : * parentRTindex is the appendrel parent's index in root->parse->rtable.
1854 : : *
1855 : : * The child RTEs have already been copied to the parent. childRToffset
1856 : : * tells us where in the parent's range table they were copied. When called
1857 : : * from flatten_simple_union_all, childRToffset is 0 since the child RTEs
1858 : : * were already in root->parse->rtable and no RT index adjustment is needed.
1859 : : */
1860 : : static void
1861 : 19227 : pull_up_union_leaf_queries(Node *setOp, PlannerInfo *root, int parentRTindex,
1862 : : Query *setOpQuery, int childRToffset)
1863 : : {
1864 [ + + ]: 19227 : if (IsA(setOp, RangeTblRef))
1865 : : {
1866 : 11862 : RangeTblRef *rtr = (RangeTblRef *) setOp;
1867 : : int childRTindex;
1868 : : AppendRelInfo *appinfo;
1869 : :
1870 : : /*
1871 : : * Calculate the index in the parent's range table
1872 : : */
1873 : 11862 : childRTindex = childRToffset + rtr->rtindex;
1874 : :
1875 : : /*
1876 : : * Build a suitable AppendRelInfo, and attach to parent's list.
1877 : : */
1878 : 11862 : appinfo = makeNode(AppendRelInfo);
1879 : 11862 : appinfo->parent_relid = parentRTindex;
1880 : 11862 : appinfo->child_relid = childRTindex;
1881 : 11862 : appinfo->parent_reltype = InvalidOid;
1882 : 11862 : appinfo->child_reltype = InvalidOid;
1883 : 11862 : make_setop_translation_list(setOpQuery, childRTindex, appinfo);
1884 : 11862 : appinfo->parent_reloid = InvalidOid;
1885 : 11862 : root->append_rel_list = lappend(root->append_rel_list, appinfo);
1886 : :
1887 : : /*
1888 : : * Recursively apply pull_up_subqueries to the new child RTE. (We
1889 : : * must build the AppendRelInfo first, because this will modify it;
1890 : : * indeed, that's the only part of the upper query where Vars
1891 : : * referencing childRTindex can exist at this point.)
1892 : : *
1893 : : * Note that we can pass NULL for containing-join info even if we're
1894 : : * actually under an outer join, because the child's expressions
1895 : : * aren't going to propagate up to the join. Also, we ignore the
1896 : : * possibility that pull_up_subqueries_recurse() returns a different
1897 : : * jointree node than what we pass it; if it does, the important thing
1898 : : * is that it replaced the child relid in the AppendRelInfo node.
1899 : : */
1900 : 11862 : rtr = makeNode(RangeTblRef);
1901 : 11862 : rtr->rtindex = childRTindex;
1902 : 11862 : (void) pull_up_subqueries_recurse(root, (Node *) rtr,
1903 : : NULL, appinfo);
1904 : : }
1905 [ + - ]: 7365 : else if (IsA(setOp, SetOperationStmt))
1906 : : {
1907 : 7365 : SetOperationStmt *op = (SetOperationStmt *) setOp;
1908 : :
1909 : : /* Recurse to reach leaf queries */
1910 : 7365 : pull_up_union_leaf_queries(op->larg, root, parentRTindex, setOpQuery,
1911 : : childRToffset);
1912 : 7365 : pull_up_union_leaf_queries(op->rarg, root, parentRTindex, setOpQuery,
1913 : : childRToffset);
1914 : : }
1915 : : else
1916 : : {
1917 [ # # ]: 0 : elog(ERROR, "unrecognized node type: %d",
1918 : : (int) nodeTag(setOp));
1919 : : }
1920 : 19227 : }
1921 : :
1922 : : /*
1923 : : * make_setop_translation_list
1924 : : * Build the list of translations from parent Vars to child Vars for
1925 : : * a UNION ALL member. (At this point it's just a simple list of
1926 : : * referencing Vars, but if we succeed in pulling up the member
1927 : : * subquery, the Vars will get replaced by pulled-up expressions.)
1928 : : * Also create the rather trivial reverse-translation array.
1929 : : */
1930 : : static void
1931 : 11862 : make_setop_translation_list(Query *query, int newvarno,
1932 : : AppendRelInfo *appinfo)
1933 : : {
1934 : 11862 : List *vars = NIL;
1935 : : AttrNumber *pcolnos;
1936 : : ListCell *l;
1937 : :
1938 : : /* Initialize reverse-translation array with all entries zero */
1939 : : /* (entries for resjunk columns will stay that way) */
1940 : 11862 : appinfo->num_child_cols = list_length(query->targetList);
1941 : 11862 : appinfo->parent_colnos = pcolnos = palloc0_array(AttrNumber, appinfo->num_child_cols);
1942 : :
1943 [ + + + + : 46935 : foreach(l, query->targetList)
+ + ]
1944 : : {
1945 : 35073 : TargetEntry *tle = (TargetEntry *) lfirst(l);
1946 : :
1947 [ - + ]: 35073 : if (tle->resjunk)
1948 : 0 : continue;
1949 : :
1950 : 35073 : vars = lappend(vars, makeVarFromTargetEntry(newvarno, tle));
1951 : 35073 : pcolnos[tle->resno - 1] = tle->resno;
1952 : : }
1953 : :
1954 : 11862 : appinfo->translated_vars = vars;
1955 : 11862 : }
1956 : :
1957 : : /*
1958 : : * is_simple_subquery
1959 : : * Check a subquery in the range table to see if it's simple enough
1960 : : * to pull up into the parent query.
1961 : : *
1962 : : * rte is the RTE_SUBQUERY RangeTblEntry that contained the subquery.
1963 : : * (Note subquery is not necessarily equal to rte->subquery; it could be a
1964 : : * processed copy of that.)
1965 : : * lowest_outer_join is the lowest outer join above the subquery, or NULL.
1966 : : */
1967 : : static bool
1968 : 79958 : is_simple_subquery(PlannerInfo *root, Query *subquery, RangeTblEntry *rte,
1969 : : JoinExpr *lowest_outer_join)
1970 : : {
1971 : : /*
1972 : : * Let's just make sure it's a valid subselect ...
1973 : : */
1974 [ + - ]: 79958 : if (!IsA(subquery, Query) ||
1975 [ - + ]: 79958 : subquery->commandType != CMD_SELECT)
1976 [ # # ]: 0 : elog(ERROR, "subquery is bogus");
1977 : :
1978 : : /*
1979 : : * Can't currently pull up a query with setops (unless it's simple UNION
1980 : : * ALL, which is handled by a different code path). Maybe after querytree
1981 : : * redesign...
1982 : : */
1983 [ + + ]: 79958 : if (subquery->setOperations)
1984 : 4662 : return false;
1985 : :
1986 : : /*
1987 : : * Can't pull up a subquery involving grouping, aggregation, SRFs,
1988 : : * sorting, limiting, or WITH. (XXX WITH could possibly be allowed later)
1989 : : *
1990 : : * We also don't pull up a subquery that has explicit FOR UPDATE/SHARE
1991 : : * clauses, because pullup would cause the locking to occur semantically
1992 : : * higher than it should. Implicit FOR UPDATE/SHARE is okay because in
1993 : : * that case the locking was originally declared in the upper query
1994 : : * anyway.
1995 : : */
1996 [ + + ]: 75296 : if (subquery->hasAggs ||
1997 [ + + ]: 73739 : subquery->hasWindowFuncs ||
1998 [ + + ]: 73328 : subquery->hasTargetSRFs ||
1999 [ + + ]: 69680 : subquery->groupClause ||
2000 [ + + ]: 69596 : subquery->groupingSets ||
2001 [ + - ]: 69566 : subquery->havingQual ||
2002 [ + + ]: 69566 : subquery->sortClause ||
2003 [ + + ]: 68786 : subquery->distinctClause ||
2004 [ + + ]: 68153 : subquery->limitOffset ||
2005 [ + + ]: 67708 : subquery->limitCount ||
2006 [ + + ]: 67444 : subquery->hasForUpdate ||
2007 [ + + ]: 64203 : subquery->cteList)
2008 : 11238 : return false;
2009 : :
2010 : : /*
2011 : : * Don't pull up if the RTE represents a security-barrier view; we
2012 : : * couldn't prevent information leakage once the RTE's Vars are scattered
2013 : : * about in the upper query.
2014 : : */
2015 [ + + ]: 64058 : if (rte->security_barrier)
2016 : 1070 : return false;
2017 : :
2018 : : /*
2019 : : * If the subquery is LATERAL, check for pullup restrictions from that.
2020 : : */
2021 [ + + ]: 62988 : if (rte->lateral)
2022 : : {
2023 : : bool restricted;
2024 : : Relids safe_upper_varnos;
2025 : :
2026 : : /*
2027 : : * The subquery's WHERE and JOIN/ON quals mustn't contain any lateral
2028 : : * references to rels outside a higher outer join (including the case
2029 : : * where the outer join is within the subquery itself). In such a
2030 : : * case, pulling up would result in a situation where we need to
2031 : : * postpone quals from below an outer join to above it, which is
2032 : : * probably completely wrong and in any case is a complication that
2033 : : * doesn't seem worth addressing at the moment.
2034 : : */
2035 [ + + ]: 2188 : if (lowest_outer_join != NULL)
2036 : : {
2037 : 1136 : restricted = true;
2038 : 1136 : safe_upper_varnos = get_relids_in_jointree((Node *) lowest_outer_join,
2039 : : true, true);
2040 : : }
2041 : : else
2042 : : {
2043 : 1052 : restricted = false;
2044 : 1052 : safe_upper_varnos = NULL; /* doesn't matter */
2045 : : }
2046 : :
2047 [ + + ]: 2188 : if (jointree_contains_lateral_outer_refs(root,
2048 : 2188 : (Node *) subquery->jointree,
2049 : : restricted, safe_upper_varnos))
2050 : 30 : return false;
2051 : :
2052 : : /*
2053 : : * If there's an outer join above the LATERAL subquery, also disallow
2054 : : * pullup if the subquery's targetlist has any references to rels
2055 : : * outside the outer join, since these might get pulled into quals
2056 : : * above the subquery (but in or below the outer join) and then lead
2057 : : * to qual-postponement issues similar to the case checked for above.
2058 : : * (We wouldn't need to prevent pullup if no such references appear in
2059 : : * outer-query quals, but we don't have enough info here to check
2060 : : * that. Also, maybe this restriction could be removed if we forced
2061 : : * such refs to be wrapped in PlaceHolderVars, even when they're below
2062 : : * the nearest outer join? But it's a pretty hokey usage, so not
2063 : : * clear this is worth sweating over.)
2064 : : *
2065 : : * If you change this, see also the comments about lateral references
2066 : : * in pullup_replace_vars_callback().
2067 : : */
2068 [ + + ]: 2158 : if (lowest_outer_join != NULL)
2069 : : {
2070 : 1126 : Relids lvarnos = pull_varnos_of_level(root,
2071 : 1126 : (Node *) subquery->targetList,
2072 : : 1);
2073 : :
2074 [ + + ]: 1126 : if (!bms_is_subset(lvarnos, safe_upper_varnos))
2075 : 20 : return false;
2076 : : }
2077 : : }
2078 : :
2079 : : /*
2080 : : * Don't pull up a subquery that has any volatile functions in its
2081 : : * targetlist. Otherwise we might introduce multiple evaluations of these
2082 : : * functions, if they get copied to multiple places in the upper query,
2083 : : * leading to surprising results. (Note: the PlaceHolderVar mechanism
2084 : : * doesn't quite guarantee single evaluation; else we could pull up anyway
2085 : : * and just wrap such items in PlaceHolderVars ...)
2086 : : */
2087 [ + + ]: 62938 : if (contain_volatile_functions((Node *) subquery->targetList))
2088 : 222 : return false;
2089 : :
2090 : 62716 : return true;
2091 : : }
2092 : :
2093 : : /*
2094 : : * pull_up_simple_values
2095 : : * Pull up a single simple VALUES RTE.
2096 : : *
2097 : : * jtnode is a RangeTblRef that has been identified as a simple VALUES RTE
2098 : : * by pull_up_subqueries. We always return a RangeTblRef representing a
2099 : : * RESULT RTE to replace it (all failure cases should have been detected by
2100 : : * is_simple_values()). Actually, what we return is just jtnode, because
2101 : : * we replace the VALUES RTE in the rangetable with the RESULT RTE.
2102 : : *
2103 : : * rte is the RangeTblEntry referenced by jtnode. Because of the limited
2104 : : * possible usage of VALUES RTEs, we do not need the remaining parameters
2105 : : * of pull_up_subqueries_recurse.
2106 : : */
2107 : : static Node *
2108 : 3808 : pull_up_simple_values(PlannerInfo *root, Node *jtnode, RangeTblEntry *rte)
2109 : : {
2110 : 3808 : Query *parse = root->parse;
2111 : 3808 : int varno = ((RangeTblRef *) jtnode)->rtindex;
2112 : : List *values_list;
2113 : : List *tlist;
2114 : : AttrNumber attrno;
2115 : : pullup_replace_vars_context rvcontext;
2116 : : ListCell *lc;
2117 : :
2118 : : Assert(rte->rtekind == RTE_VALUES);
2119 : : Assert(list_length(rte->values_lists) == 1);
2120 : :
2121 : : /*
2122 : : * Need a modifiable copy of the VALUES list to hack on, just in case it's
2123 : : * multiply referenced.
2124 : : */
2125 : 3808 : values_list = copyObject(linitial(rte->values_lists));
2126 : :
2127 : : /*
2128 : : * The VALUES RTE can't contain any Vars of level zero, let alone any that
2129 : : * are join aliases, so no need to flatten join alias Vars.
2130 : : */
2131 : : Assert(!contain_vars_of_level((Node *) values_list, 0));
2132 : :
2133 : : /*
2134 : : * Set up required context data for pullup_replace_vars. In particular,
2135 : : * we have to make the VALUES list look like a subquery targetlist.
2136 : : */
2137 : 3808 : tlist = NIL;
2138 : 3808 : attrno = 1;
2139 [ + + + + : 8140 : foreach(lc, values_list)
+ + ]
2140 : : {
2141 : 4332 : tlist = lappend(tlist,
2142 : 4332 : makeTargetEntry((Expr *) lfirst(lc),
2143 : : attrno,
2144 : : NULL,
2145 : : false));
2146 : 4332 : attrno++;
2147 : : }
2148 : 3808 : rvcontext.root = root;
2149 : 3808 : rvcontext.targetlist = tlist;
2150 : 3808 : rvcontext.target_rte = rte;
2151 : 3808 : rvcontext.result_relation = 0;
2152 : 3808 : rvcontext.relids = NULL; /* can't be any lateral references here */
2153 : 3808 : rvcontext.nullinfo = NULL;
2154 : 3808 : rvcontext.outer_hasSubLinks = &parse->hasSubLinks;
2155 : 3808 : rvcontext.varno = varno;
2156 : 3808 : rvcontext.wrap_option = REPLACE_WRAP_NONE;
2157 : : /* initialize cache array with indexes 0 .. length(tlist) */
2158 : 3808 : rvcontext.rv_cache = palloc0_array(Node *, list_length(tlist) + 1);
2159 : :
2160 : : /*
2161 : : * Replace all of the top query's references to the RTE's outputs with
2162 : : * copies of the adjusted VALUES expressions, being careful not to replace
2163 : : * any of the jointree structure. We can assume there's no outer joins or
2164 : : * appendrels in the dummy Query that surrounds a VALUES RTE.
2165 : : */
2166 : 3808 : perform_pullup_replace_vars(root, &rvcontext, NULL);
2167 : :
2168 : : /*
2169 : : * There should be no appendrels to fix, nor any outer joins and hence no
2170 : : * PlaceHolderVars.
2171 : : */
2172 : : Assert(root->append_rel_list == NIL);
2173 : : Assert(root->join_info_list == NIL);
2174 : : Assert(root->placeholder_list == NIL);
2175 : :
2176 : : /*
2177 : : * Replace the VALUES RTE with a RESULT RTE. The VALUES RTE is the only
2178 : : * rtable entry in the current query level, so this is easy.
2179 : : */
2180 : : Assert(list_length(parse->rtable) == 1);
2181 : :
2182 : : /* Create suitable RTE */
2183 : 3808 : rte = makeNode(RangeTblEntry);
2184 : 3808 : rte->rtekind = RTE_RESULT;
2185 : 3808 : rte->eref = makeAlias("*RESULT*", NIL);
2186 : :
2187 : : /* Replace rangetable */
2188 : 3808 : parse->rtable = list_make1(rte);
2189 : :
2190 : : /* We could manufacture a new RangeTblRef, but the one we have is fine */
2191 : : Assert(varno == 1);
2192 : :
2193 : 3808 : return jtnode;
2194 : : }
2195 : :
2196 : : /*
2197 : : * is_simple_values
2198 : : * Check a VALUES RTE in the range table to see if it's simple enough
2199 : : * to pull up into the parent query.
2200 : : *
2201 : : * rte is the RTE_VALUES RangeTblEntry to check.
2202 : : */
2203 : : static bool
2204 : 10607 : is_simple_values(PlannerInfo *root, RangeTblEntry *rte)
2205 : : {
2206 : : Assert(rte->rtekind == RTE_VALUES);
2207 : :
2208 : : /*
2209 : : * There must be exactly one VALUES list, else it's not semantically
2210 : : * correct to replace the VALUES RTE with a RESULT RTE, nor would we have
2211 : : * a unique set of expressions to substitute into the parent query.
2212 : : */
2213 [ + + ]: 10607 : if (list_length(rte->values_lists) != 1)
2214 : 6799 : return false;
2215 : :
2216 : : /*
2217 : : * Because VALUES can't appear under an outer join (or at least, we won't
2218 : : * try to pull it up if it does), we need not worry about LATERAL, nor
2219 : : * about validity of PHVs for the VALUES' outputs.
2220 : : */
2221 : :
2222 : : /*
2223 : : * Don't pull up a VALUES that contains any set-returning or volatile
2224 : : * functions. The considerations here are basically identical to the
2225 : : * restrictions on a pull-able subquery's targetlist.
2226 : : */
2227 [ + - - + ]: 7616 : if (expression_returns_set((Node *) rte->values_lists) ||
2228 : 3808 : contain_volatile_functions((Node *) rte->values_lists))
2229 : 0 : return false;
2230 : :
2231 : : /*
2232 : : * Do not pull up a VALUES that's not the only RTE in its parent query.
2233 : : * This is actually the only case that the parser will generate at the
2234 : : * moment, and assuming this is true greatly simplifies
2235 : : * pull_up_simple_values().
2236 : : */
2237 [ + - ]: 3808 : if (list_length(root->parse->rtable) != 1 ||
2238 [ - + ]: 3808 : rte != (RangeTblEntry *) linitial(root->parse->rtable))
2239 : 0 : return false;
2240 : :
2241 : 3808 : return true;
2242 : : }
2243 : :
2244 : : /*
2245 : : * pull_up_constant_function
2246 : : * Pull up an RTE_FUNCTION expression that was simplified to a constant.
2247 : : *
2248 : : * jtnode is a RangeTblRef that has been identified as a FUNCTION RTE by
2249 : : * pull_up_subqueries. If its expression is just a Const, hoist that value
2250 : : * up into the parent query, and replace the RTE_FUNCTION with RTE_RESULT.
2251 : : *
2252 : : * In principle we could pull up any immutable expression, but we don't.
2253 : : * That might result in multiple evaluations of the expression, which could
2254 : : * be costly if it's not just a Const. Also, the main value of this is
2255 : : * to let the constant participate in further const-folding, and of course
2256 : : * that won't happen for a non-Const.
2257 : : *
2258 : : * The pulled-up value might need to be wrapped in a PlaceHolderVar if the
2259 : : * RTE is below an outer join or is part of an appendrel; the extra
2260 : : * parameters show whether that's needed.
2261 : : */
2262 : : static Node *
2263 : 35250 : pull_up_constant_function(PlannerInfo *root, Node *jtnode,
2264 : : RangeTblEntry *rte,
2265 : : AppendRelInfo *containing_appendrel)
2266 : : {
2267 : 35250 : Query *parse = root->parse;
2268 : : RangeTblFunction *rtf;
2269 : : TypeFuncClass functypclass;
2270 : : Oid funcrettype;
2271 : : TupleDesc tupdesc;
2272 : : pullup_replace_vars_context rvcontext;
2273 : :
2274 : : /* Fail if the RTE has ORDINALITY - we don't implement that here. */
2275 [ + + ]: 35250 : if (rte->funcordinality)
2276 : 730 : return jtnode;
2277 : :
2278 : : /* Fail if RTE isn't a single, simple Const expr */
2279 [ + + ]: 34520 : if (list_length(rte->functions) != 1)
2280 : 74 : return jtnode;
2281 : 34446 : rtf = linitial_node(RangeTblFunction, rte->functions);
2282 [ + + ]: 34446 : if (!IsA(rtf->funcexpr, Const))
2283 : 34136 : return jtnode;
2284 : :
2285 : : /*
2286 : : * If the function's result is not a scalar, we punt. In principle we
2287 : : * could break the composite constant value apart into per-column
2288 : : * constants, but for now it seems not worth the work.
2289 : : */
2290 [ + + ]: 310 : if (rtf->funccolcount != 1)
2291 : 25 : return jtnode; /* definitely composite */
2292 : :
2293 : : /* If it has a coldeflist, it certainly returns RECORD */
2294 [ - + ]: 285 : if (rtf->funccolnames != NIL)
2295 : 0 : return jtnode; /* must be a one-column RECORD type */
2296 : :
2297 : 285 : functypclass = get_expr_result_type(rtf->funcexpr,
2298 : : &funcrettype,
2299 : : &tupdesc);
2300 [ + + ]: 285 : if (functypclass != TYPEFUNC_SCALAR)
2301 : 10 : return jtnode; /* must be a one-column composite type */
2302 : :
2303 : : /* Create context for applying pullup_replace_vars */
2304 : 275 : rvcontext.root = root;
2305 : 275 : rvcontext.targetlist = list_make1(makeTargetEntry((Expr *) rtf->funcexpr,
2306 : : 1, /* resno */
2307 : : NULL, /* resname */
2308 : : false)); /* resjunk */
2309 : 275 : rvcontext.target_rte = rte;
2310 : 275 : rvcontext.result_relation = 0;
2311 : :
2312 : : /*
2313 : : * Since this function was reduced to a Const, it doesn't contain any
2314 : : * lateral references, even if it's marked as LATERAL. This means we
2315 : : * don't need to fill relids or nullinfo.
2316 : : */
2317 : 275 : rvcontext.relids = NULL;
2318 : 275 : rvcontext.nullinfo = NULL;
2319 : :
2320 : 275 : rvcontext.outer_hasSubLinks = &parse->hasSubLinks;
2321 : 275 : rvcontext.varno = ((RangeTblRef *) jtnode)->rtindex;
2322 : : /* this flag will be set below, if needed */
2323 : 275 : rvcontext.wrap_option = REPLACE_WRAP_NONE;
2324 : : /* initialize cache array with indexes 0 .. length(tlist) */
2325 : 275 : rvcontext.rv_cache = palloc0_array(Node *, list_length(rvcontext.targetlist) + 1);
2326 : :
2327 : : /*
2328 : : * If the parent query uses grouping sets, we need a PlaceHolderVar for
2329 : : * each expression of the subquery's targetlist items. (See comments in
2330 : : * pull_up_simple_subquery().)
2331 : : */
2332 [ - + ]: 275 : if (parse->groupingSets)
2333 : 0 : rvcontext.wrap_option = REPLACE_WRAP_ALL;
2334 : :
2335 : : /*
2336 : : * Replace all of the top query's references to the RTE's output with
2337 : : * copies of the funcexpr, being careful not to replace any of the
2338 : : * jointree structure.
2339 : : */
2340 : 275 : perform_pullup_replace_vars(root, &rvcontext,
2341 : : containing_appendrel);
2342 : :
2343 : : /*
2344 : : * We don't need to bother with changing PlaceHolderVars in the parent
2345 : : * query. Their references to the RT index are still good for now, and
2346 : : * will get removed later if we're able to drop the RTE_RESULT.
2347 : : */
2348 : :
2349 : : /*
2350 : : * Convert the RTE to be RTE_RESULT type, signifying that we don't need to
2351 : : * scan it anymore, and zero out RTE_FUNCTION-specific fields. Also make
2352 : : * sure the RTE is not marked LATERAL, since elsewhere we don't expect
2353 : : * RTE_RESULTs to be LATERAL.
2354 : : */
2355 : 275 : rte->rtekind = RTE_RESULT;
2356 : 275 : rte->functions = NIL;
2357 : 275 : rte->lateral = false;
2358 : :
2359 : : /*
2360 : : * We can reuse the RangeTblRef node.
2361 : : */
2362 : 275 : return jtnode;
2363 : : }
2364 : :
2365 : : /*
2366 : : * is_simple_union_all
2367 : : * Check a subquery to see if it's a simple UNION ALL.
2368 : : *
2369 : : * We require all the setops to be UNION ALL (no mixing) and there can't be
2370 : : * any datatype coercions involved, ie, all the leaf queries must emit the
2371 : : * same datatypes.
2372 : : */
2373 : : static bool
2374 : 20718 : is_simple_union_all(Query *subquery)
2375 : : {
2376 : : SetOperationStmt *topop;
2377 : :
2378 : : /* Let's just make sure it's a valid subselect ... */
2379 [ + - ]: 20718 : if (!IsA(subquery, Query) ||
2380 [ - + ]: 20718 : subquery->commandType != CMD_SELECT)
2381 [ # # ]: 0 : elog(ERROR, "subquery is bogus");
2382 : :
2383 : : /* Is it a set-operation query at all? */
2384 : 20718 : topop = castNode(SetOperationStmt, subquery->setOperations);
2385 [ + + ]: 20718 : if (!topop)
2386 : 16056 : return false;
2387 : :
2388 : : /* Can't handle ORDER BY, LIMIT/OFFSET, locking, or WITH */
2389 [ + + ]: 4662 : if (subquery->sortClause ||
2390 [ + - ]: 4610 : subquery->limitOffset ||
2391 [ + - ]: 4610 : subquery->limitCount ||
2392 [ + - ]: 4610 : subquery->rowMarks ||
2393 [ + + ]: 4610 : subquery->cteList)
2394 : 230 : return false;
2395 : :
2396 : : /* Recursively check the tree of set operations */
2397 : 4432 : return is_simple_union_all_recurse((Node *) topop, subquery,
2398 : : topop->colTypes);
2399 : : }
2400 : :
2401 : : static bool
2402 : 25155 : is_simple_union_all_recurse(Node *setOp, Query *setOpQuery, List *colTypes)
2403 : : {
2404 : : /* Since this function recurses, it could be driven to stack overflow. */
2405 : 25155 : check_stack_depth();
2406 : :
2407 [ + + ]: 25155 : if (IsA(setOp, RangeTblRef))
2408 : : {
2409 : 12617 : RangeTblRef *rtr = (RangeTblRef *) setOp;
2410 : 12617 : RangeTblEntry *rte = rt_fetch(rtr->rtindex, setOpQuery->rtable);
2411 : 12617 : Query *subquery = rte->subquery;
2412 : :
2413 : : Assert(subquery != NULL);
2414 : :
2415 : : /* Leaf nodes are OK if they match the toplevel column types */
2416 : : /* We don't have to compare typmods or collations here */
2417 : 12617 : return tlist_same_datatypes(subquery->targetList, colTypes, true);
2418 : : }
2419 [ + - ]: 12538 : else if (IsA(setOp, SetOperationStmt))
2420 : : {
2421 : 12538 : SetOperationStmt *op = (SetOperationStmt *) setOp;
2422 : :
2423 : : /* Must be UNION ALL */
2424 [ + + + + ]: 12538 : if (op->op != SETOP_UNION || !op->all)
2425 : 4415 : return false;
2426 : :
2427 : : /* Recurse to check inputs */
2428 [ + + + + ]: 15782 : return is_simple_union_all_recurse(op->larg, setOpQuery, colTypes) &&
2429 : 7659 : is_simple_union_all_recurse(op->rarg, setOpQuery, colTypes);
2430 : : }
2431 : : else
2432 : : {
2433 [ # # ]: 0 : elog(ERROR, "unrecognized node type: %d",
2434 : : (int) nodeTag(setOp));
2435 : : return false; /* keep compiler quiet */
2436 : : }
2437 : : }
2438 : :
2439 : : /*
2440 : : * is_safe_append_member
2441 : : * Check a subquery that is a leaf of a UNION ALL appendrel to see if it's
2442 : : * safe to pull up.
2443 : : */
2444 : : static bool
2445 : 14174 : is_safe_append_member(Query *subquery)
2446 : : {
2447 : : FromExpr *jtnode;
2448 : :
2449 : : /*
2450 : : * It's only safe to pull up the child if its jointree contains exactly
2451 : : * one RTE, else the AppendRelInfo data structure breaks. The one base RTE
2452 : : * could be buried in several levels of FromExpr, however. Also, if the
2453 : : * child's jointree is completely empty, we can pull up because
2454 : : * pull_up_simple_subquery will insert a single RTE_RESULT RTE instead.
2455 : : *
2456 : : * Also, the child can't have any WHERE quals because there's no place to
2457 : : * put them in an appendrel. (This is a bit annoying...) If we didn't
2458 : : * need to check this, we'd just test whether get_relids_in_jointree()
2459 : : * yields a singleton set, to be more consistent with the coding of
2460 : : * fix_append_rel_relids().
2461 : : */
2462 : 14174 : jtnode = subquery->jointree;
2463 : : Assert(IsA(jtnode, FromExpr));
2464 : : /* Check the completely-empty case */
2465 [ + + + + ]: 14174 : if (jtnode->fromlist == NIL && jtnode->quals == NULL)
2466 : 614 : return true;
2467 : : /* Check the more general case */
2468 [ + + ]: 24421 : while (IsA(jtnode, FromExpr))
2469 : : {
2470 [ + + ]: 13570 : if (jtnode->quals != NULL)
2471 : 2709 : return false;
2472 [ - + ]: 10861 : if (list_length(jtnode->fromlist) != 1)
2473 : 0 : return false;
2474 : 10861 : jtnode = linitial(jtnode->fromlist);
2475 : : }
2476 [ + + ]: 10851 : if (!IsA(jtnode, RangeTblRef))
2477 : 933 : return false;
2478 : :
2479 : 9918 : return true;
2480 : : }
2481 : :
2482 : : /*
2483 : : * jointree_contains_lateral_outer_refs
2484 : : * Check for disallowed lateral references in a jointree's quals
2485 : : *
2486 : : * If restricted is false, all level-1 Vars are allowed (but we still must
2487 : : * search the jointree, since it might contain outer joins below which there
2488 : : * will be restrictions). If restricted is true, return true when any qual
2489 : : * in the jointree contains level-1 Vars coming from outside the rels listed
2490 : : * in safe_upper_varnos.
2491 : : */
2492 : : static bool
2493 : 4795 : jointree_contains_lateral_outer_refs(PlannerInfo *root, Node *jtnode,
2494 : : bool restricted,
2495 : : Relids safe_upper_varnos)
2496 : : {
2497 [ - + ]: 4795 : if (jtnode == NULL)
2498 : 0 : return false;
2499 [ + + ]: 4795 : if (IsA(jtnode, RangeTblRef))
2500 : 2248 : return false;
2501 [ + + ]: 2547 : else if (IsA(jtnode, FromExpr))
2502 : : {
2503 : 2228 : FromExpr *f = (FromExpr *) jtnode;
2504 : : ListCell *l;
2505 : :
2506 : : /* First, recurse to check child joins */
2507 [ + + + + : 4177 : foreach(l, f->fromlist)
+ + ]
2508 : : {
2509 [ + + ]: 1969 : if (jointree_contains_lateral_outer_refs(root,
2510 : 1969 : lfirst(l),
2511 : : restricted,
2512 : : safe_upper_varnos))
2513 : 20 : return true;
2514 : : }
2515 : :
2516 : : /* Then check the top-level quals */
2517 [ + + ]: 2208 : if (restricted &&
2518 [ + + ]: 1176 : !bms_is_subset(pull_varnos_of_level(root, f->quals, 1),
2519 : : safe_upper_varnos))
2520 : 10 : return true;
2521 : : }
2522 [ + - ]: 319 : else if (IsA(jtnode, JoinExpr))
2523 : : {
2524 : 319 : JoinExpr *j = (JoinExpr *) jtnode;
2525 : :
2526 : : /*
2527 : : * If this is an outer join, we mustn't allow any upper lateral
2528 : : * references in or below it.
2529 : : */
2530 [ + + ]: 319 : if (j->jointype != JOIN_INNER)
2531 : : {
2532 : 169 : restricted = true;
2533 : 169 : safe_upper_varnos = NULL;
2534 : : }
2535 : :
2536 : : /* Check the child joins */
2537 [ - + ]: 319 : if (jointree_contains_lateral_outer_refs(root,
2538 : : j->larg,
2539 : : restricted,
2540 : : safe_upper_varnos))
2541 : 0 : return true;
2542 [ - + ]: 319 : if (jointree_contains_lateral_outer_refs(root,
2543 : : j->rarg,
2544 : : restricted,
2545 : : safe_upper_varnos))
2546 : 0 : return true;
2547 : :
2548 : : /* Check the JOIN's qual clauses */
2549 [ + + ]: 319 : if (restricted &&
2550 [ + + ]: 279 : !bms_is_subset(pull_varnos_of_level(root, j->quals, 1),
2551 : : safe_upper_varnos))
2552 : 20 : return true;
2553 : : }
2554 : : else
2555 [ # # ]: 0 : elog(ERROR, "unrecognized node type: %d",
2556 : : (int) nodeTag(jtnode));
2557 : 2497 : return false;
2558 : : }
2559 : :
2560 : : /*
2561 : : * flatten_join_alias_vars_in_jointree
2562 : : * Apply flatten_join_alias_vars to all quals in the given jointree,
2563 : : * replacing them in place. The jointree must belong to root->parse.
2564 : : */
2565 : : static void
2566 : 2557 : flatten_join_alias_vars_in_jointree(PlannerInfo *root, Node *jtnode)
2567 : : {
2568 [ - + ]: 2557 : if (jtnode == NULL)
2569 : 0 : return;
2570 [ + + ]: 2557 : if (IsA(jtnode, RangeTblRef))
2571 : 1281 : return;
2572 [ + + ]: 1276 : else if (IsA(jtnode, FromExpr))
2573 : : {
2574 : 1104 : FromExpr *f = (FromExpr *) jtnode;
2575 : : ListCell *l;
2576 : :
2577 [ + - + + : 2253 : foreach(l, f->fromlist)
+ + ]
2578 : 1149 : flatten_join_alias_vars_in_jointree(root, lfirst(l));
2579 : 1104 : f->quals = flatten_join_alias_vars(root, root->parse, f->quals);
2580 : : }
2581 [ + - ]: 172 : else if (IsA(jtnode, JoinExpr))
2582 : : {
2583 : 172 : JoinExpr *j = (JoinExpr *) jtnode;
2584 : :
2585 : 172 : flatten_join_alias_vars_in_jointree(root, j->larg);
2586 : 172 : flatten_join_alias_vars_in_jointree(root, j->rarg);
2587 : 172 : j->quals = flatten_join_alias_vars(root, root->parse, j->quals);
2588 : : }
2589 : : else
2590 [ # # ]: 0 : elog(ERROR, "unrecognized node type: %d",
2591 : : (int) nodeTag(jtnode));
2592 : : }
2593 : :
2594 : : /*
2595 : : * Perform pullup_replace_vars everyplace it's needed in the query tree.
2596 : : *
2597 : : * Caller has already filled *rvcontext with data describing what to
2598 : : * substitute for Vars referencing the target subquery. In addition
2599 : : * we need the identity of the containing appendrel if any.
2600 : : */
2601 : : static void
2602 : 33537 : perform_pullup_replace_vars(PlannerInfo *root,
2603 : : pullup_replace_vars_context *rvcontext,
2604 : : AppendRelInfo *containing_appendrel)
2605 : : {
2606 : 33537 : Query *parse = root->parse;
2607 : : ListCell *lc;
2608 : :
2609 : : /*
2610 : : * If we are considering an appendrel child subquery (that is, a UNION ALL
2611 : : * member query that we're pulling up), then the only part of the upper
2612 : : * query that could reference the child yet is the translated_vars list of
2613 : : * the associated AppendRelInfo. Furthermore, we do not want to force use
2614 : : * of PHVs in the AppendRelInfo --- there isn't any outer join between.
2615 : : */
2616 [ + + ]: 33537 : if (containing_appendrel)
2617 : : {
2618 : 5198 : ReplaceWrapOption save_wrap_option = rvcontext->wrap_option;
2619 : :
2620 : 5198 : rvcontext->wrap_option = REPLACE_WRAP_NONE;
2621 : 5198 : containing_appendrel->translated_vars = (List *)
2622 : 5198 : pullup_replace_vars((Node *) containing_appendrel->translated_vars,
2623 : : rvcontext);
2624 : 5198 : rvcontext->wrap_option = save_wrap_option;
2625 : 5198 : return;
2626 : : }
2627 : :
2628 : : /*
2629 : : * Replace all of the top query's references to the subquery's outputs
2630 : : * with copies of the adjusted subtlist items, being careful not to
2631 : : * replace any of the jointree structure. (This'd be a lot cleaner if we
2632 : : * could use query_tree_mutator.) We have to use PHVs in the targetList,
2633 : : * returningList, and havingQual, since those are certainly above any
2634 : : * outer join. replace_vars_in_jointree tracks its location in the
2635 : : * jointree and uses PHVs or not appropriately.
2636 : : */
2637 : 28339 : parse->targetList = (List *)
2638 : 28339 : pullup_replace_vars((Node *) parse->targetList, rvcontext);
2639 : 28339 : parse->returningList = (List *)
2640 : 28339 : pullup_replace_vars((Node *) parse->returningList, rvcontext);
2641 : :
2642 [ + + ]: 28339 : if (parse->onConflict)
2643 : : {
2644 : 34 : parse->onConflict->onConflictSet = (List *)
2645 : 17 : pullup_replace_vars((Node *) parse->onConflict->onConflictSet,
2646 : : rvcontext);
2647 : 17 : parse->onConflict->onConflictWhere =
2648 : 17 : pullup_replace_vars(parse->onConflict->onConflictWhere,
2649 : : rvcontext);
2650 : :
2651 : : /*
2652 : : * We assume ON CONFLICT's arbiterElems, arbiterWhere, exclRelTlist
2653 : : * can't contain any references to a subquery.
2654 : : */
2655 : : }
2656 [ + + ]: 28339 : if (parse->mergeActionList)
2657 : : {
2658 [ + - + + : 2398 : foreach(lc, parse->mergeActionList)
+ + ]
2659 : : {
2660 : 1429 : MergeAction *action = lfirst(lc);
2661 : :
2662 : 1429 : action->qual = pullup_replace_vars(action->qual, rvcontext);
2663 : 1429 : action->targetList = (List *)
2664 : 1429 : pullup_replace_vars((Node *) action->targetList, rvcontext);
2665 : : }
2666 : : }
2667 : 28339 : parse->mergeJoinCondition = pullup_replace_vars(parse->mergeJoinCondition,
2668 : : rvcontext);
2669 : 28339 : replace_vars_in_jointree((Node *) parse->jointree, rvcontext);
2670 : : Assert(parse->setOperations == NULL);
2671 : 28339 : parse->havingQual = pullup_replace_vars(parse->havingQual, rvcontext);
2672 : :
2673 : : /*
2674 : : * Replace references in the translated_vars lists of appendrels.
2675 : : */
2676 [ + + + + : 28379 : foreach(lc, root->append_rel_list)
+ + ]
2677 : : {
2678 : 40 : AppendRelInfo *appinfo = (AppendRelInfo *) lfirst(lc);
2679 : :
2680 : 40 : appinfo->translated_vars = (List *)
2681 : 40 : pullup_replace_vars((Node *) appinfo->translated_vars, rvcontext);
2682 : : }
2683 : :
2684 : : /*
2685 : : * Replace references in the joinaliasvars lists of join RTEs and the
2686 : : * groupexprs list of group RTE.
2687 : : */
2688 [ + - + + : 80648 : foreach(lc, parse->rtable)
+ + ]
2689 : : {
2690 : 52309 : RangeTblEntry *otherrte = (RangeTblEntry *) lfirst(lc);
2691 : :
2692 [ + + ]: 52309 : if (otherrte->rtekind == RTE_JOIN)
2693 : 5933 : otherrte->joinaliasvars = (List *)
2694 : 5933 : pullup_replace_vars((Node *) otherrte->joinaliasvars,
2695 : : rvcontext);
2696 [ + + ]: 46376 : else if (otherrte->rtekind == RTE_GROUP)
2697 : 753 : otherrte->groupexprs = (List *)
2698 : 753 : pullup_replace_vars((Node *) otherrte->groupexprs,
2699 : : rvcontext);
2700 : : }
2701 : : }
2702 : :
2703 : : /*
2704 : : * Helper routine for perform_pullup_replace_vars: do pullup_replace_vars on
2705 : : * every expression in the jointree, without changing the jointree structure
2706 : : * itself. Ugly, but there's no other way...
2707 : : */
2708 : : static void
2709 : 75626 : replace_vars_in_jointree(Node *jtnode,
2710 : : pullup_replace_vars_context *context)
2711 : : {
2712 [ - + ]: 75626 : if (jtnode == NULL)
2713 : 0 : return;
2714 [ + + ]: 75626 : if (IsA(jtnode, RangeTblRef))
2715 : : {
2716 : : /*
2717 : : * If the RangeTblRef refers to a LATERAL subquery (that isn't the
2718 : : * same subquery we're pulling up), it might contain references to the
2719 : : * target subquery, which we must replace. We drive this from the
2720 : : * jointree scan, rather than a scan of the rtable, so that we can
2721 : : * avoid processing no-longer-referenced RTEs.
2722 : : */
2723 : 38000 : int varno = ((RangeTblRef *) jtnode)->rtindex;
2724 : :
2725 [ + + ]: 38000 : if (varno != context->varno) /* ignore target subquery itself */
2726 : : {
2727 : 9661 : RangeTblEntry *rte = rt_fetch(varno, context->root->parse->rtable);
2728 : :
2729 : : Assert(rte != context->target_rte);
2730 [ + + ]: 9661 : if (rte->lateral)
2731 : : {
2732 [ - + + + : 858 : switch (rte->rtekind)
- - - ]
2733 : : {
2734 : 0 : case RTE_RELATION:
2735 : : /* shouldn't be marked LATERAL unless tablesample */
2736 : : Assert(rte->tablesample);
2737 : 0 : rte->tablesample = (TableSampleClause *)
2738 : 0 : pullup_replace_vars((Node *) rte->tablesample,
2739 : : context);
2740 : 0 : break;
2741 : 446 : case RTE_SUBQUERY:
2742 : 446 : rte->subquery =
2743 : 446 : pullup_replace_vars_subquery(rte->subquery,
2744 : : context);
2745 : 446 : break;
2746 : 322 : case RTE_FUNCTION:
2747 : 322 : rte->functions = (List *)
2748 : 322 : pullup_replace_vars((Node *) rte->functions,
2749 : : context);
2750 : 322 : break;
2751 : 90 : case RTE_TABLEFUNC:
2752 : 90 : rte->tablefunc = (TableFunc *)
2753 : 90 : pullup_replace_vars((Node *) rte->tablefunc,
2754 : : context);
2755 : 90 : break;
2756 : 0 : case RTE_VALUES:
2757 : 0 : rte->values_lists = (List *)
2758 : 0 : pullup_replace_vars((Node *) rte->values_lists,
2759 : : context);
2760 : 0 : break;
2761 : 0 : case RTE_JOIN:
2762 : : case RTE_CTE:
2763 : : case RTE_NAMEDTUPLESTORE:
2764 : : case RTE_RESULT:
2765 : : case RTE_GROUP:
2766 : : /* these shouldn't be marked LATERAL */
2767 : : Assert(false);
2768 : 0 : break;
2769 : : }
2770 : : }
2771 : : }
2772 : : }
2773 [ + + ]: 37626 : else if (IsA(jtnode, FromExpr))
2774 : : {
2775 : 30630 : FromExpr *f = (FromExpr *) jtnode;
2776 : : ListCell *l;
2777 : :
2778 [ + - + + : 63925 : foreach(l, f->fromlist)
+ + ]
2779 : 33295 : replace_vars_in_jointree(lfirst(l), context);
2780 : 30630 : f->quals = pullup_replace_vars(f->quals, context);
2781 : : }
2782 [ + - ]: 6996 : else if (IsA(jtnode, JoinExpr))
2783 : : {
2784 : 6996 : JoinExpr *j = (JoinExpr *) jtnode;
2785 : 6996 : ReplaceWrapOption save_wrap_option = context->wrap_option;
2786 : :
2787 : 6996 : replace_vars_in_jointree(j->larg, context);
2788 : 6996 : replace_vars_in_jointree(j->rarg, context);
2789 : :
2790 : : /*
2791 : : * Use PHVs within the join quals of a full join for variable-free
2792 : : * expressions. Otherwise, we cannot identify which side of the join
2793 : : * a pulled-up variable-free expression came from, which can lead to
2794 : : * failure to make a plan at all because none of the quals appear to
2795 : : * be mergeable or hashable conditions.
2796 : : */
2797 [ + + ]: 6996 : if (j->jointype == JOIN_FULL)
2798 : 581 : context->wrap_option = REPLACE_WRAP_VARFREE;
2799 : :
2800 : 6996 : j->quals = pullup_replace_vars(j->quals, context);
2801 : :
2802 : 6996 : context->wrap_option = save_wrap_option;
2803 : : }
2804 : : else
2805 [ # # ]: 0 : elog(ERROR, "unrecognized node type: %d",
2806 : : (int) nodeTag(jtnode));
2807 : : }
2808 : :
2809 : : /*
2810 : : * Apply pullup variable replacement throughout an expression tree
2811 : : *
2812 : : * Returns a modified copy of the tree, so this can't be used where we
2813 : : * need to do in-place replacement.
2814 : : */
2815 : : static Node *
2816 : 167321 : pullup_replace_vars(Node *expr, pullup_replace_vars_context *context)
2817 : : {
2818 : 167321 : return replace_rte_variables(expr,
2819 : : context->varno, 0,
2820 : : pullup_replace_vars_callback,
2821 : : context,
2822 : : context->outer_hasSubLinks);
2823 : : }
2824 : :
2825 : : static Node *
2826 : 95398 : pullup_replace_vars_callback(const Var *var,
2827 : : replace_rte_variables_context *context)
2828 : : {
2829 : 95398 : pullup_replace_vars_context *rcon = (pullup_replace_vars_context *) context->callback_arg;
2830 : 95398 : int varattno = var->varattno;
2831 : : bool need_phv;
2832 : : Node *newnode;
2833 : :
2834 : : /* System columns are not replaced. */
2835 [ + + ]: 95398 : if (varattno < InvalidAttrNumber)
2836 : 35 : return (Node *) copyObject(var);
2837 : :
2838 : : /*
2839 : : * We need a PlaceHolderVar if the Var-to-be-replaced has nonempty
2840 : : * varnullingrels (unless we find below that the replacement expression is
2841 : : * a Var or PlaceHolderVar that we can just add the nullingrels to). We
2842 : : * also need one if the caller has instructed us that certain expression
2843 : : * replacements need to be wrapped for identification purposes.
2844 : : */
2845 [ + + ]: 180457 : need_phv = (var->varnullingrels != NULL) ||
2846 [ + + ]: 85094 : (rcon->wrap_option != REPLACE_WRAP_NONE);
2847 : :
2848 : : /*
2849 : : * If PlaceHolderVars are needed, we cache the modified expressions in
2850 : : * rcon->rv_cache[]. This is not in hopes of any material speed gain
2851 : : * within this function, but to avoid generating identical PHVs with
2852 : : * different IDs. That would result in duplicate evaluations at runtime,
2853 : : * and possibly prevent optimizations that rely on recognizing different
2854 : : * references to the same subquery output as being equal(). So it's worth
2855 : : * a bit of extra effort to avoid it.
2856 : : *
2857 : : * The cached items have phlevelsup = 0 and phnullingrels = NULL; we'll
2858 : : * copy them and adjust those values for this reference site below.
2859 : : */
2860 [ + + + - ]: 95363 : if (need_phv &&
2861 [ + - ]: 12263 : varattno >= InvalidAttrNumber &&
2862 : 12263 : varattno <= list_length(rcon->targetlist) &&
2863 [ + + ]: 12263 : rcon->rv_cache[varattno] != NULL)
2864 : : {
2865 : : /* Just copy the entry and fall through to adjust phlevelsup etc */
2866 : 2718 : newnode = copyObject(rcon->rv_cache[varattno]);
2867 : : }
2868 : : else
2869 : : {
2870 : : /*
2871 : : * Generate the replacement expression. This takes care of expanding
2872 : : * wholerow references and dealing with non-default varreturningtype.
2873 : : */
2874 : 92645 : newnode = ReplaceVarFromTargetList(var,
2875 : : rcon->target_rte,
2876 : : rcon->targetlist,
2877 : : rcon->result_relation,
2878 : : REPLACEVARS_REPORT_ERROR,
2879 : : 0);
2880 : :
2881 : : /* Insert PlaceHolderVar if needed */
2882 [ + + ]: 92645 : if (need_phv)
2883 : : {
2884 : : bool wrap;
2885 : :
2886 [ + + ]: 9545 : if (rcon->wrap_option == REPLACE_WRAP_ALL)
2887 : : {
2888 : : /* Caller told us to wrap all expressions in a PlaceHolderVar */
2889 : 907 : wrap = true;
2890 : : }
2891 [ + + ]: 8638 : else if (varattno == InvalidAttrNumber)
2892 : : {
2893 : : /*
2894 : : * Insert PlaceHolderVar for whole-tuple reference. Notice
2895 : : * that we are wrapping one PlaceHolderVar around the whole
2896 : : * RowExpr, rather than putting one around each element of the
2897 : : * row. This is because we need the expression to yield NULL,
2898 : : * not ROW(NULL,NULL,...) when it is forced to null by an
2899 : : * outer join.
2900 : : */
2901 : 61 : wrap = true;
2902 : : }
2903 [ + - + + ]: 8577 : else if (newnode && IsA(newnode, Var) &&
2904 [ + + ]: 6735 : ((Var *) newnode)->varlevelsup == 0)
2905 : : {
2906 : : /*
2907 : : * Simple Vars always escape being wrapped, unless they are
2908 : : * lateral references to something outside the subquery being
2909 : : * pulled up and the referenced rel is not under the same
2910 : : * lowest nulling outer join.
2911 : : */
2912 : 6723 : wrap = false;
2913 [ + + ]: 6723 : if (rcon->target_rte->lateral &&
2914 [ + + ]: 1215 : !bms_is_member(((Var *) newnode)->varno, rcon->relids))
2915 : : {
2916 : 140 : nullingrel_info *nullinfo = rcon->nullinfo;
2917 : 140 : int lvarno = ((Var *) newnode)->varno;
2918 : :
2919 : : Assert(lvarno > 0 && lvarno <= nullinfo->rtlength);
2920 [ + + ]: 140 : if (!bms_is_subset(nullinfo->nullingrels[rcon->varno],
2921 : 140 : nullinfo->nullingrels[lvarno]))
2922 : 120 : wrap = true;
2923 : : }
2924 : : }
2925 [ + - + + ]: 1854 : else if (newnode && IsA(newnode, PlaceHolderVar) &&
2926 [ + - ]: 150 : ((PlaceHolderVar *) newnode)->phlevelsup == 0)
2927 : : {
2928 : : /* The same rules apply for a PlaceHolderVar */
2929 : 150 : wrap = false;
2930 [ + + ]: 150 : if (rcon->target_rte->lateral &&
2931 [ + - ]: 40 : !bms_is_subset(((PlaceHolderVar *) newnode)->phrels,
2932 : 40 : rcon->relids))
2933 : : {
2934 : 40 : nullingrel_info *nullinfo = rcon->nullinfo;
2935 : 40 : Relids lvarnos = ((PlaceHolderVar *) newnode)->phrels;
2936 : : int lvarno;
2937 : :
2938 : 40 : lvarno = -1;
2939 [ + + ]: 60 : while ((lvarno = bms_next_member(lvarnos, lvarno)) >= 0)
2940 : : {
2941 : : Assert(lvarno > 0 && lvarno <= nullinfo->rtlength);
2942 [ + + ]: 40 : if (!bms_is_subset(nullinfo->nullingrels[rcon->varno],
2943 : 40 : nullinfo->nullingrels[lvarno]))
2944 : : {
2945 : 20 : wrap = true;
2946 : 20 : break;
2947 : : }
2948 : : }
2949 : : }
2950 : : }
2951 : : else
2952 : : {
2953 : : /*
2954 : : * If the node contains Var(s) or PlaceHolderVar(s) of the
2955 : : * subquery being pulled up, or of rels that are under the
2956 : : * same lowest nulling outer join as the subquery, and does
2957 : : * not contain any non-strict constructs, then instead of
2958 : : * adding a PHV on top we can add the required nullingrels to
2959 : : * those Vars/PHVs. (This is fundamentally a generalization
2960 : : * of the above cases for bare Vars and PHVs.)
2961 : : *
2962 : : * This test is somewhat expensive, but it avoids pessimizing
2963 : : * the plan in cases where the nullingrels get removed again
2964 : : * later by outer join reduction.
2965 : : *
2966 : : * Note that we don't force wrapping of expressions containing
2967 : : * lateral references, so long as they also contain Vars/PHVs
2968 : : * of the subquery, or of rels that are under the same lowest
2969 : : * nulling outer join as the subquery. This is okay because
2970 : : * of the restriction to strict constructs: if those Vars/PHVs
2971 : : * have been forced to NULL by an outer join then the end
2972 : : * result of the expression will be NULL too, regardless of
2973 : : * the lateral references. So it's not necessary to force the
2974 : : * expression to be evaluated below the outer join. This can
2975 : : * be a very valuable optimization, because it may allow us to
2976 : : * avoid using a nested loop to pass the lateral reference
2977 : : * down.
2978 : : *
2979 : : * This analysis could be tighter: in particular, a non-strict
2980 : : * construct hidden within a lower-level PlaceHolderVar is not
2981 : : * reason to add another PHV. But for now it doesn't seem
2982 : : * worth the code to be more exact. This is also why it's
2983 : : * preferable to handle bare PHVs in the above branch, rather
2984 : : * than this branch. We also prefer to handle bare Vars in a
2985 : : * separate branch, as it's cheaper this way and parallels the
2986 : : * handling of PHVs.
2987 : : *
2988 : : * For a LATERAL subquery, we have to check the actual var
2989 : : * membership of the node, but if it's non-lateral then any
2990 : : * level-zero var must belong to the subquery.
2991 : : */
2992 : 1704 : bool contain_nullable_vars = false;
2993 : :
2994 [ + + ]: 1704 : if (!rcon->target_rte->lateral)
2995 : : {
2996 [ + + ]: 1514 : if (contain_vars_of_level(newnode, 0))
2997 : 518 : contain_nullable_vars = true;
2998 : : }
2999 : : else
3000 : : {
3001 : : Relids all_varnos;
3002 : :
3003 : 190 : all_varnos = pull_varnos(rcon->root, newnode);
3004 [ + + ]: 190 : if (bms_overlap(all_varnos, rcon->relids))
3005 : 110 : contain_nullable_vars = true;
3006 : : else
3007 : : {
3008 : 80 : nullingrel_info *nullinfo = rcon->nullinfo;
3009 : : int varno;
3010 : :
3011 : 80 : varno = -1;
3012 [ + + ]: 150 : while ((varno = bms_next_member(all_varnos, varno)) >= 0)
3013 : : {
3014 : : Assert(varno > 0 && varno <= nullinfo->rtlength);
3015 [ + + ]: 90 : if (bms_is_subset(nullinfo->nullingrels[rcon->varno],
3016 : 90 : nullinfo->nullingrels[varno]))
3017 : : {
3018 : 20 : contain_nullable_vars = true;
3019 : 20 : break;
3020 : : }
3021 : : }
3022 : : }
3023 : : }
3024 : :
3025 [ + + ]: 1704 : if (contain_nullable_vars &&
3026 [ + + ]: 648 : !contain_nonstrict_functions(newnode))
3027 : : {
3028 : : /* No wrap needed */
3029 : 240 : wrap = false;
3030 : : }
3031 : : else
3032 : : {
3033 : : /* Else wrap it in a PlaceHolderVar */
3034 : 1464 : wrap = true;
3035 : : }
3036 : : }
3037 : :
3038 [ + + ]: 9545 : if (wrap)
3039 : : {
3040 : : newnode = (Node *)
3041 : 2572 : make_placeholder_expr(rcon->root,
3042 : : (Expr *) newnode,
3043 : : bms_make_singleton(rcon->varno));
3044 : :
3045 : : /*
3046 : : * Cache it if possible (ie, if the attno is in range, which
3047 : : * it probably always should be).
3048 : : */
3049 [ + - + - ]: 5144 : if (varattno >= InvalidAttrNumber &&
3050 : 2572 : varattno <= list_length(rcon->targetlist))
3051 : 2572 : rcon->rv_cache[varattno] = copyObject(newnode);
3052 : : }
3053 : : }
3054 : : }
3055 : :
3056 : : /* Propagate any varnullingrels into the replacement expression */
3057 [ + + ]: 95363 : if (var->varnullingrels != NULL)
3058 : : {
3059 [ + + ]: 10269 : if (IsA(newnode, Var))
3060 : : {
3061 : 6224 : Var *newvar = (Var *) newnode;
3062 : :
3063 : : Assert(newvar->varlevelsup == 0);
3064 : 6224 : newvar->varnullingrels = bms_add_members(newvar->varnullingrels,
3065 : 6224 : var->varnullingrels);
3066 : : }
3067 [ + + ]: 4045 : else if (IsA(newnode, PlaceHolderVar))
3068 : : {
3069 : 3805 : PlaceHolderVar *newphv = (PlaceHolderVar *) newnode;
3070 : :
3071 : : Assert(newphv->phlevelsup == 0);
3072 : 3805 : newphv->phnullingrels = bms_add_members(newphv->phnullingrels,
3073 : 3805 : var->varnullingrels);
3074 : : }
3075 : : else
3076 : : {
3077 : : /*
3078 : : * There should be Vars/PHVs within the expression that we can
3079 : : * modify. Vars/PHVs of the subquery should have the full
3080 : : * var->varnullingrels added to them, but if there are lateral
3081 : : * references within the expression, those must be marked with
3082 : : * only the nullingrels that potentially apply to them. (This
3083 : : * corresponds to the fact that the expression will now be
3084 : : * evaluated at the join level of the Var that we are replacing:
3085 : : * the lateral references may have bubbled up through fewer outer
3086 : : * joins than the subquery's Vars have. Per the discussion above,
3087 : : * we'll still get the right answers.) That relid set could be
3088 : : * different for different lateral relations, so we have to do
3089 : : * this work for each one.
3090 : : *
3091 : : * (Currently, the restrictions in is_simple_subquery() mean that
3092 : : * at most we have to remove the lowest outer join's relid from
3093 : : * the nullingrels of a lateral reference. However, we might
3094 : : * relax those restrictions someday, so let's do this right.)
3095 : : */
3096 [ + + ]: 240 : if (rcon->target_rte->lateral)
3097 : : {
3098 : 70 : nullingrel_info *nullinfo = rcon->nullinfo;
3099 : : Relids lvarnos;
3100 : : int lvarno;
3101 : :
3102 : : /*
3103 : : * Identify lateral varnos used within newnode. We must do
3104 : : * this before injecting var->varnullingrels into the tree.
3105 : : */
3106 : 70 : lvarnos = pull_varnos(rcon->root, newnode);
3107 : 70 : lvarnos = bms_del_members(lvarnos, rcon->relids);
3108 : : /* For each one, add relevant nullingrels if any */
3109 : 70 : lvarno = -1;
3110 [ + + ]: 140 : while ((lvarno = bms_next_member(lvarnos, lvarno)) >= 0)
3111 : : {
3112 : : Relids lnullingrels;
3113 : :
3114 : : Assert(lvarno > 0 && lvarno <= nullinfo->rtlength);
3115 : 70 : lnullingrels = bms_intersect(var->varnullingrels,
3116 : 70 : nullinfo->nullingrels[lvarno]);
3117 [ + + ]: 70 : if (!bms_is_empty(lnullingrels))
3118 : 40 : newnode = add_nulling_relids(newnode,
3119 : 40 : bms_make_singleton(lvarno),
3120 : : lnullingrels);
3121 : : }
3122 : : }
3123 : :
3124 : : /* Finally, deal with Vars/PHVs of the subquery itself */
3125 : 240 : newnode = add_nulling_relids(newnode,
3126 : 240 : rcon->relids,
3127 : 240 : var->varnullingrels);
3128 : : /* Assert we did put the varnullingrels into the expression */
3129 : : Assert(bms_is_subset(var->varnullingrels,
3130 : : pull_varnos(rcon->root, newnode)));
3131 : : }
3132 : : }
3133 : :
3134 : : /* Must adjust varlevelsup if replaced Var is within a subquery */
3135 [ + + ]: 95363 : if (var->varlevelsup > 0)
3136 : 969 : IncrementVarSublevelsUp(newnode, var->varlevelsup, 0);
3137 : :
3138 : 95363 : return newnode;
3139 : : }
3140 : :
3141 : : /*
3142 : : * Apply pullup variable replacement to a subquery
3143 : : *
3144 : : * This needs to be different from pullup_replace_vars() because
3145 : : * replace_rte_variables will think that it shouldn't increment sublevels_up
3146 : : * before entering the Query; so we need to call it with sublevels_up == 1.
3147 : : */
3148 : : static Query *
3149 : 446 : pullup_replace_vars_subquery(Query *query,
3150 : : pullup_replace_vars_context *context)
3151 : : {
3152 : : Assert(IsA(query, Query));
3153 : 446 : return (Query *) replace_rte_variables((Node *) query,
3154 : : context->varno, 1,
3155 : : pullup_replace_vars_callback,
3156 : : context,
3157 : : NULL);
3158 : : }
3159 : :
3160 : :
3161 : : /*
3162 : : * flatten_simple_union_all
3163 : : * Try to optimize top-level UNION ALL structure into an appendrel
3164 : : *
3165 : : * If a query's setOperations tree consists entirely of simple UNION ALL
3166 : : * operations, flatten it into an append relation, which we can process more
3167 : : * intelligently than the general setops case. Otherwise, do nothing.
3168 : : *
3169 : : * In most cases, this can succeed only for a top-level query, because for a
3170 : : * subquery in FROM, the parent query's invocation of pull_up_subqueries would
3171 : : * already have flattened the UNION via pull_up_simple_union_all. But there
3172 : : * are a few cases we can support here but not in that code path, for example
3173 : : * when the subquery also contains ORDER BY.
3174 : : */
3175 : : void
3176 : 5637 : flatten_simple_union_all(PlannerInfo *root)
3177 : : {
3178 : 5637 : Query *parse = root->parse;
3179 : : SetOperationStmt *topop;
3180 : : Node *leftmostjtnode;
3181 : : int leftmostRTI;
3182 : : RangeTblEntry *leftmostRTE;
3183 : : int childRTI;
3184 : : RangeTblEntry *childRTE;
3185 : : RangeTblRef *rtr;
3186 : :
3187 : : /* Shouldn't be called unless query has setops */
3188 : 5637 : topop = castNode(SetOperationStmt, parse->setOperations);
3189 : : Assert(topop);
3190 : :
3191 : : /* Can't optimize away a recursive UNION */
3192 [ + + ]: 5637 : if (root->hasRecursion)
3193 : 696 : return;
3194 : :
3195 : : /*
3196 : : * Recursively check the tree of set operations. If not all UNION ALL
3197 : : * with identical column types, punt.
3198 : : */
3199 [ + + ]: 4941 : if (!is_simple_union_all_recurse((Node *) topop, parse, topop->colTypes))
3200 : 4307 : return;
3201 : :
3202 : : /*
3203 : : * Locate the leftmost leaf query in the setops tree. The upper query's
3204 : : * Vars all refer to this RTE (see transformSetOperationStmt).
3205 : : */
3206 : 634 : leftmostjtnode = topop->larg;
3207 [ + - + + ]: 1008 : while (leftmostjtnode && IsA(leftmostjtnode, SetOperationStmt))
3208 : 374 : leftmostjtnode = ((SetOperationStmt *) leftmostjtnode)->larg;
3209 : : Assert(leftmostjtnode && IsA(leftmostjtnode, RangeTblRef));
3210 : 634 : leftmostRTI = ((RangeTblRef *) leftmostjtnode)->rtindex;
3211 : 634 : leftmostRTE = rt_fetch(leftmostRTI, parse->rtable);
3212 : : Assert(leftmostRTE->rtekind == RTE_SUBQUERY);
3213 : :
3214 : : /*
3215 : : * Make a copy of the leftmost RTE and add it to the rtable. This copy
3216 : : * will represent the leftmost leaf query in its capacity as a member of
3217 : : * the appendrel. The original will represent the appendrel as a whole.
3218 : : * (We must do things this way because the upper query's Vars have to be
3219 : : * seen as referring to the whole appendrel.)
3220 : : */
3221 : 634 : childRTE = copyObject(leftmostRTE);
3222 : 634 : parse->rtable = lappend(parse->rtable, childRTE);
3223 : 634 : childRTI = list_length(parse->rtable);
3224 : :
3225 : : /* Modify the setops tree to reference the child copy */
3226 : 634 : ((RangeTblRef *) leftmostjtnode)->rtindex = childRTI;
3227 : :
3228 : : /* Modify the formerly-leftmost RTE to mark it as an appendrel parent */
3229 : 634 : leftmostRTE->inh = true;
3230 : :
3231 : : /*
3232 : : * Form a RangeTblRef for the appendrel, and insert it into FROM. The top
3233 : : * Query of a setops tree should have had an empty FromClause initially.
3234 : : */
3235 : 634 : rtr = makeNode(RangeTblRef);
3236 : 634 : rtr->rtindex = leftmostRTI;
3237 : : Assert(parse->jointree->fromlist == NIL);
3238 : 634 : parse->jointree->fromlist = list_make1(rtr);
3239 : :
3240 : : /*
3241 : : * Now pretend the query has no setops. We must do this before trying to
3242 : : * do subquery pullup, because of Assert in pull_up_simple_subquery.
3243 : : */
3244 : 634 : parse->setOperations = NULL;
3245 : :
3246 : : /*
3247 : : * Build AppendRelInfo information, and apply pull_up_subqueries to the
3248 : : * leaf queries of the UNION ALL. (We must do that now because they
3249 : : * weren't previously referenced by the jointree, and so were missed by
3250 : : * the main invocation of pull_up_subqueries.)
3251 : : */
3252 : 634 : pull_up_union_leaf_queries((Node *) topop, root, leftmostRTI, parse, 0);
3253 : : }
3254 : :
3255 : :
3256 : : /*
3257 : : * reduce_outer_joins
3258 : : * Attempt to reduce outer joins to plain inner joins.
3259 : : *
3260 : : * The idea here is that given a query like
3261 : : * SELECT ... FROM a LEFT JOIN b ON (...) WHERE b.y = 42;
3262 : : * we can reduce the LEFT JOIN to a plain JOIN if the "=" operator in WHERE
3263 : : * is strict. The strict operator will always return NULL, causing the outer
3264 : : * WHERE to fail, on any row where the LEFT JOIN filled in NULLs for b's
3265 : : * columns. Therefore, there's no need for the join to produce null-extended
3266 : : * rows in the first place --- which makes it a plain join not an outer join.
3267 : : * (This scenario may not be very likely in a query written out by hand, but
3268 : : * it's reasonably likely when pushing quals down into complex views.)
3269 : : *
3270 : : * More generally, an outer join can be reduced in strength if there is a
3271 : : * strict qual above it in the qual tree that constrains a Var from the
3272 : : * nullable side of the join to be non-null. (For FULL joins this applies
3273 : : * to each side separately.)
3274 : : *
3275 : : * Another transformation we apply here is to recognize cases like
3276 : : * SELECT ... FROM a LEFT JOIN b ON (a.x = b.y) WHERE b.z IS NULL;
3277 : : * If we can prove that b.z must be non-null for any matching row, because
3278 : : * the join clause is strict for b.z and b.z happens to be the join key b.y,
3279 : : * because a strict qual within b's own subtree forces b.z non-null, or
3280 : : * because b.z is defined NOT NULL by table constraints and is not nullable
3281 : : * due to lower-level outer joins, then only null-extended rows could pass
3282 : : * the upper WHERE, and we can conclude that what the query is really
3283 : : * specifying is an anti-semijoin. We change the join type from JOIN_LEFT
3284 : : * to JOIN_ANTI. The IS NULL clause then becomes redundant, and is removed
3285 : : * at the end of this phase; see remove_redundant_nullability_quals.
3286 : : *
3287 : : * A whole-row Var works too. "WHERE b IS NULL" in row-format semantics is
3288 : : * true when b's whole-row value is NULL or when every column of b is NULL;
3289 : : * for a matching row only the latter is possible, so proving any one column
3290 : : * of b non-null in matching rows justifies the same reduction.
3291 : : *
3292 : : * The same recognition reduces a FULL join to an anti-semijoin when a
3293 : : * forced-null Var on either side is proven non-null: only the other side's
3294 : : * unmatched rows can survive. If that surviving side is the right-hand
3295 : : * input, we switch the inputs (as we do for JOIN_RIGHT below) so that it
3296 : : * ends up on the left, where JOIN_ANTI requires the surviving side to be.
3297 : : *
3298 : : * Also, we get rid of JOIN_RIGHT cases by flipping them around to become
3299 : : * JOIN_LEFT. This saves some code here and in some later planner routines;
3300 : : * the main benefit is to reduce the number of jointypes that can appear in
3301 : : * SpecialJoinInfo nodes. Note that we can still generate Paths and Plans
3302 : : * that use JOIN_RIGHT (or JOIN_RIGHT_ANTI) by switching the inputs again.
3303 : : *
3304 : : * To ease recognition of strict qual clauses, we require this routine to be
3305 : : * run after expression preprocessing (i.e., qual canonicalization and JOIN
3306 : : * alias-var expansion).
3307 : : */
3308 : : void
3309 : 25670 : reduce_outer_joins(PlannerInfo *root)
3310 : : {
3311 : : reduce_outer_joins_pass1_state *state1;
3312 : : reduce_outer_joins_pass2_state state2;
3313 : : ListCell *lc;
3314 : :
3315 : : /*
3316 : : * To avoid doing strictness checks on more quals than necessary, we want
3317 : : * to stop descending the jointree as soon as there are no outer joins
3318 : : * below our current point. This consideration forces a two-pass process.
3319 : : * The first pass gathers information about which base rels appear below
3320 : : * each side of each join clause, about whether there are outer join(s)
3321 : : * below each side of each join clause, and about which base rels are from
3322 : : * the nullable side of those outer join(s). The second pass examines
3323 : : * qual clauses and changes join types as it descends the tree.
3324 : : */
3325 : 25670 : state1 = reduce_outer_joins_pass1((Node *) root->parse->jointree);
3326 : :
3327 : : /* planner.c shouldn't have called me if no outer joins */
3328 [ + - - + ]: 25670 : if (state1 == NULL || !state1->contains_outer)
3329 [ # # ]: 0 : elog(ERROR, "so where are the outer joins?");
3330 : :
3331 : 25670 : state2.inner_reduced = NULL;
3332 : 25670 : state2.partial_reduced = NIL;
3333 : 25670 : state2.anti_reduced = NULL;
3334 : :
3335 : 25670 : reduce_outer_joins_pass2((Node *) root->parse->jointree,
3336 : : state1, &state2,
3337 : : root, NULL, NIL);
3338 : :
3339 : : /*
3340 : : * If we successfully reduced the strength of any outer joins, we must
3341 : : * remove references to those joins as nulling rels. This is handled as
3342 : : * an additional pass, for simplicity and because we can handle all
3343 : : * fully-reduced joins in a single pass over the parse tree.
3344 : : */
3345 [ + + ]: 25670 : if (!bms_is_empty(state2.inner_reduced))
3346 : : {
3347 : 2202 : root->parse = (Query *)
3348 : 2202 : remove_nulling_relids((Node *) root->parse,
3349 : 2202 : state2.inner_reduced,
3350 : : NULL);
3351 : : /* There could be references in the append_rel_list, too */
3352 : 2202 : root->append_rel_list = (List *)
3353 : 2202 : remove_nulling_relids((Node *) root->append_rel_list,
3354 : 2202 : state2.inner_reduced,
3355 : : NULL);
3356 : : }
3357 : :
3358 : : /*
3359 : : * Partially-reduced full joins have to be done one at a time, since
3360 : : * they'll each need a different setting of except_relids.
3361 : : */
3362 [ + + + + : 25789 : foreach(lc, state2.partial_reduced)
+ + ]
3363 : : {
3364 : 119 : reduce_outer_joins_partial_state *statep = lfirst(lc);
3365 : 119 : Relids full_join_relids = bms_make_singleton(statep->full_join_rti);
3366 : :
3367 : 119 : root->parse = (Query *)
3368 : 119 : remove_nulling_relids((Node *) root->parse,
3369 : : full_join_relids,
3370 : 119 : statep->unreduced_side);
3371 : 119 : root->append_rel_list = (List *)
3372 : 119 : remove_nulling_relids((Node *) root->append_rel_list,
3373 : : full_join_relids,
3374 : 119 : statep->unreduced_side);
3375 : : }
3376 : :
3377 : : /*
3378 : : * Finally, remove any quals made redundant by reducing outer joins to
3379 : : * antijoins.
3380 : : */
3381 [ + + ]: 25670 : if (!bms_is_empty(state2.anti_reduced))
3382 : 1069 : remove_redundant_nullability_quals((Node *) root->parse->jointree,
3383 : : state2.anti_reduced);
3384 : 25670 : }
3385 : :
3386 : : /*
3387 : : * remove_redundant_nullability_quals
3388 : : * Remove quals made redundant by reducing outer joins to antijoins.
3389 : : *
3390 : : * An IS NULL qual on a Var from the nullable side of a lower antijoin is
3391 : : * necessarily true. Keeping such a qual would not be wrong, but it would
3392 : : * generate bogus selectivity estimates, and it could prevent join removal
3393 : : * from later removing the rel(s) it references.
3394 : : */
3395 : : static void
3396 : 4543 : remove_redundant_nullability_quals(Node *jtnode, Relids antijoins)
3397 : : {
3398 [ - + ]: 4543 : if (jtnode == NULL)
3399 : 0 : return;
3400 [ + + ]: 4543 : if (IsA(jtnode, RangeTblRef))
3401 : : {
3402 : : /* nothing to do here */
3403 : : }
3404 [ + + ]: 2274 : else if (IsA(jtnode, FromExpr))
3405 : : {
3406 : 1079 : FromExpr *f = (FromExpr *) jtnode;
3407 : : ListCell *l;
3408 : :
3409 [ + - + + : 2163 : foreach(l, f->fromlist)
+ + ]
3410 : 1084 : remove_redundant_nullability_quals(lfirst(l), antijoins);
3411 : 1079 : f->quals = strip_redundant_nullability_quals(f->quals, antijoins);
3412 : : }
3413 [ + - ]: 1195 : else if (IsA(jtnode, JoinExpr))
3414 : : {
3415 : 1195 : JoinExpr *j = (JoinExpr *) jtnode;
3416 : :
3417 : 1195 : remove_redundant_nullability_quals(j->larg, antijoins);
3418 : 1195 : remove_redundant_nullability_quals(j->rarg, antijoins);
3419 : 1195 : j->quals = strip_redundant_nullability_quals(j->quals, antijoins);
3420 : : }
3421 : : else
3422 [ # # ]: 0 : elog(ERROR, "unrecognized jointree node type: %d",
3423 : : (int) nodeTag(jtnode));
3424 : : }
3425 : :
3426 : : /*
3427 : : * strip_redundant_nullability_quals
3428 : : * Strip redundant IS NULL quals from one implicit-AND qual list.
3429 : : */
3430 : : static Node *
3431 : 2274 : strip_redundant_nullability_quals(Node *quals, Relids antijoins)
3432 : : {
3433 : 2274 : List *newquals = NIL;
3434 : :
3435 [ + + + + : 8240 : foreach_ptr(Node, clause, castNode(List, quals))
+ + ]
3436 : : {
3437 : 3692 : Var *var = find_forced_null_var(clause);
3438 : :
3439 [ + + + + ]: 3692 : if (var && bms_overlap(var->varnullingrels, antijoins))
3440 : 1084 : continue;
3441 : 2608 : newquals = lappend(newquals, clause);
3442 : : }
3443 : 2274 : return (Node *) newquals;
3444 : : }
3445 : :
3446 : : /*
3447 : : * reduce_outer_joins_pass1 - phase 1 data collection
3448 : : *
3449 : : * Returns a state node describing the given jointree node.
3450 : : */
3451 : : static reduce_outer_joins_pass1_state *
3452 : 145922 : reduce_outer_joins_pass1(Node *jtnode)
3453 : : {
3454 : : reduce_outer_joins_pass1_state *result;
3455 : :
3456 : 145922 : result = palloc_object(reduce_outer_joins_pass1_state);
3457 : 145922 : result->relids = NULL;
3458 : 145922 : result->contains_outer = false;
3459 : 145922 : result->nullable_rels = NULL;
3460 : 145922 : result->jtnode = jtnode;
3461 : 145922 : result->sub_states = NIL;
3462 : :
3463 [ - + ]: 145922 : if (jtnode == NULL)
3464 : 0 : return result;
3465 [ + + ]: 145922 : if (IsA(jtnode, RangeTblRef))
3466 : : {
3467 : 72856 : int varno = ((RangeTblRef *) jtnode)->rtindex;
3468 : :
3469 : 72856 : result->relids = bms_make_singleton(varno);
3470 : : }
3471 [ + + ]: 73066 : else if (IsA(jtnode, FromExpr))
3472 : : {
3473 : 28293 : FromExpr *f = (FromExpr *) jtnode;
3474 : : ListCell *l;
3475 : :
3476 [ + - + + : 58999 : foreach(l, f->fromlist)
+ + ]
3477 : : {
3478 : : reduce_outer_joins_pass1_state *sub_state;
3479 : :
3480 : 30706 : sub_state = reduce_outer_joins_pass1(lfirst(l));
3481 : 61412 : result->relids = bms_add_members(result->relids,
3482 : 30706 : sub_state->relids);
3483 : 30706 : result->contains_outer |= sub_state->contains_outer;
3484 : 61412 : result->nullable_rels = bms_add_members(result->nullable_rels,
3485 : 30706 : sub_state->nullable_rels);
3486 : 30706 : result->sub_states = lappend(result->sub_states, sub_state);
3487 : : }
3488 : : }
3489 [ + - ]: 44773 : else if (IsA(jtnode, JoinExpr))
3490 : : {
3491 : 44773 : JoinExpr *j = (JoinExpr *) jtnode;
3492 : : reduce_outer_joins_pass1_state *left_state;
3493 : : reduce_outer_joins_pass1_state *right_state;
3494 : :
3495 : : /* Recurse to children */
3496 : 44773 : left_state = reduce_outer_joins_pass1(j->larg);
3497 : 44773 : right_state = reduce_outer_joins_pass1(j->rarg);
3498 : :
3499 : : /* join's own RT index is not wanted in result->relids */
3500 : 44773 : result->relids = bms_union(left_state->relids, right_state->relids);
3501 : :
3502 : : /* Store children's states for pass 2 */
3503 : 44773 : result->sub_states = list_make2(left_state, right_state);
3504 : :
3505 : : /* Collect outer join information */
3506 [ + + + + : 44773 : switch (j->jointype)
- ]
3507 : : {
3508 : 7526 : case JOIN_INNER:
3509 : : case JOIN_SEMI:
3510 : : /* No new nullability; propagate state from children */
3511 [ + + ]: 14404 : result->contains_outer = left_state->contains_outer ||
3512 [ + + ]: 6878 : right_state->contains_outer;
3513 : 15052 : result->nullable_rels = bms_union(left_state->nullable_rels,
3514 : 7526 : right_state->nullable_rels);
3515 : 7526 : break;
3516 : 35230 : case JOIN_LEFT:
3517 : : case JOIN_ANTI:
3518 : : /* RHS is nullable; LHS keeps existing status */
3519 : 35230 : result->contains_outer = true;
3520 : 70460 : result->nullable_rels = bms_union(left_state->nullable_rels,
3521 : 35230 : right_state->relids);
3522 : 35230 : break;
3523 : 1010 : case JOIN_RIGHT:
3524 : : /* LHS is nullable; RHS keeps existing status */
3525 : 1010 : result->contains_outer = true;
3526 : 2020 : result->nullable_rels = bms_union(left_state->relids,
3527 : 1010 : right_state->nullable_rels);
3528 : 1010 : break;
3529 : 1007 : case JOIN_FULL:
3530 : : /* Both sides are nullable */
3531 : 1007 : result->contains_outer = true;
3532 : 2014 : result->nullable_rels = bms_union(left_state->relids,
3533 : 1007 : right_state->relids);
3534 : 1007 : break;
3535 : 0 : default:
3536 [ # # ]: 0 : elog(ERROR, "unrecognized join type: %d",
3537 : : (int) j->jointype);
3538 : : break;
3539 : : }
3540 : : }
3541 : : else
3542 [ # # ]: 0 : elog(ERROR, "unrecognized node type: %d",
3543 : : (int) nodeTag(jtnode));
3544 : 145922 : return result;
3545 : : }
3546 : :
3547 : : /*
3548 : : * reduce_outer_joins_pass2 - phase 2 processing
3549 : : *
3550 : : * jtnode: current jointree node
3551 : : * state1: state data collected by phase 1 for this node
3552 : : * state2: where to accumulate info about successfully-reduced joins
3553 : : * root: toplevel planner state
3554 : : * nonnullable_rels: set of base relids forced non-null by upper quals
3555 : : * forced_null_vars: multibitmapset of Vars forced null by upper quals
3556 : : *
3557 : : * Returns info in state2 about outer joins that were successfully simplified.
3558 : : * Joins that were fully reduced to inner joins are all added to
3559 : : * state2->inner_reduced, and joins that became antijoins are all added to
3560 : : * state2->anti_reduced. If a full join is reduced to a left join or an
3561 : : * antijoin, it also needs its own entry in state2->partial_reduced, since
3562 : : * that will require custom processing to remove only the correct nullingrel
3563 : : * markers.
3564 : : */
3565 : : static void
3566 : 64739 : reduce_outer_joins_pass2(Node *jtnode,
3567 : : reduce_outer_joins_pass1_state *state1,
3568 : : reduce_outer_joins_pass2_state *state2,
3569 : : PlannerInfo *root,
3570 : : Relids nonnullable_rels,
3571 : : List *forced_null_vars)
3572 : : {
3573 : : /*
3574 : : * pass 2 should never descend as far as an empty subnode or base rel,
3575 : : * because it's only called on subtrees marked as contains_outer.
3576 : : */
3577 [ - + ]: 64739 : if (jtnode == NULL)
3578 [ # # ]: 0 : elog(ERROR, "reached empty jointree");
3579 [ - + ]: 64739 : if (IsA(jtnode, RangeTblRef))
3580 [ # # ]: 0 : elog(ERROR, "reached base rel");
3581 [ + + ]: 64739 : else if (IsA(jtnode, FromExpr))
3582 : : {
3583 : 26719 : FromExpr *f = (FromExpr *) jtnode;
3584 : : ListCell *l;
3585 : : ListCell *s;
3586 : : Relids pass_nonnullable_rels;
3587 : : List *pass_forced_null_vars;
3588 : :
3589 : : /* Scan quals to see if we can add any constraints */
3590 : 26719 : pass_nonnullable_rels = find_nonnullable_rels(f->quals);
3591 : 26719 : pass_nonnullable_rels = bms_add_members(pass_nonnullable_rels,
3592 : : nonnullable_rels);
3593 : 26719 : pass_forced_null_vars = find_forced_null_vars(f->quals);
3594 : 26719 : pass_forced_null_vars = mbms_add_members(pass_forced_null_vars,
3595 : : forced_null_vars);
3596 : : /* And recurse --- but only into interesting subtrees */
3597 : : Assert(list_length(f->fromlist) == list_length(state1->sub_states));
3598 [ + - + + : 55706 : forboth(l, f->fromlist, s, state1->sub_states)
+ - + + +
+ + - +
+ ]
3599 : : {
3600 : 28987 : reduce_outer_joins_pass1_state *sub_state = lfirst(s);
3601 : :
3602 [ + + ]: 28987 : if (sub_state->contains_outer)
3603 : 26744 : reduce_outer_joins_pass2(lfirst(l), sub_state,
3604 : : state2, root,
3605 : : pass_nonnullable_rels,
3606 : : pass_forced_null_vars);
3607 : : }
3608 : 26719 : bms_free(pass_nonnullable_rels);
3609 : : /* can't so easily clean up var lists, unfortunately */
3610 : : }
3611 [ + - ]: 38020 : else if (IsA(jtnode, JoinExpr))
3612 : : {
3613 : 38020 : JoinExpr *j = (JoinExpr *) jtnode;
3614 : 38020 : int rtindex = j->rtindex;
3615 : 38020 : JoinType jointype = j->jointype;
3616 : 38020 : reduce_outer_joins_pass1_state *left_state = linitial(state1->sub_states);
3617 : 38020 : reduce_outer_joins_pass1_state *right_state = lsecond(state1->sub_states);
3618 : :
3619 : : /* Can we simplify this join? */
3620 [ + + + + : 38020 : switch (jointype)
+ - ]
3621 : : {
3622 : 725 : case JOIN_INNER:
3623 : 725 : break;
3624 : 34966 : case JOIN_LEFT:
3625 [ + + ]: 34966 : if (bms_overlap(nonnullable_rels, right_state->relids))
3626 : 2471 : jointype = JOIN_INNER;
3627 : 34966 : break;
3628 : 1010 : case JOIN_RIGHT:
3629 [ + + ]: 1010 : if (bms_overlap(nonnullable_rels, left_state->relids))
3630 : 69 : jointype = JOIN_INNER;
3631 : 1010 : break;
3632 : 1007 : case JOIN_FULL:
3633 [ + + ]: 1007 : if (bms_overlap(nonnullable_rels, left_state->relids))
3634 : : {
3635 [ + + ]: 35 : if (bms_overlap(nonnullable_rels, right_state->relids))
3636 : 10 : jointype = JOIN_INNER;
3637 : : else
3638 : : {
3639 : 25 : jointype = JOIN_LEFT;
3640 : : /* Also report partial reduction in state2 */
3641 : 25 : report_reduced_full_join(state2, rtindex,
3642 : : right_state->relids);
3643 : : }
3644 : : }
3645 [ + + ]: 972 : else if (bms_overlap(nonnullable_rels, right_state->relids))
3646 : : {
3647 : 29 : jointype = JOIN_RIGHT;
3648 : : /* Also report partial reduction in state2 */
3649 : 29 : report_reduced_full_join(state2, rtindex,
3650 : : left_state->relids);
3651 : : }
3652 [ + + ]: 943 : else if (forced_null_vars != NIL)
3653 : : {
3654 : : /*
3655 : : * Neither side is forced non-null by a strict upper qual,
3656 : : * but an upper qual may force a Var on one side to be
3657 : : * NULL while that Var is non-null in every row that side
3658 : : * emits (proven by quals within the side's own subtree,
3659 : : * or a NOT NULL constraint). Then only rows where that
3660 : : * side was null-extended can satisfy the upper qual: the
3661 : : * matched rows and that side's unmatched rows all drop
3662 : : * out, leaving an anti-join.
3663 : : *
3664 : : * Unlike the JOIN_LEFT case below, we must not consult
3665 : : * the join's own ON quals here: they do not hold for the
3666 : : * unmatched rows that this proof has to cover.
3667 : : *
3668 : : * If the constrained Var is on the RHS the result is a
3669 : : * plain anti-join; if it is on the LHS it is a right
3670 : : * anti-join, which the input-switching step below
3671 : : * normalizes to a plain anti-join (just as it does for
3672 : : * JOIN_RIGHT).
3673 : : */
3674 [ + + ]: 85 : if (forced_null_var_is_nonnullable(root,
3675 : : forced_null_vars,
3676 : : right_state, NIL))
3677 : : {
3678 : 45 : jointype = JOIN_ANTI;
3679 : 45 : report_reduced_full_join(state2, rtindex,
3680 : : right_state->relids);
3681 : : }
3682 [ + + ]: 40 : else if (forced_null_var_is_nonnullable(root,
3683 : : forced_null_vars,
3684 : : left_state, NIL))
3685 : : {
3686 : 20 : jointype = JOIN_RIGHT_ANTI;
3687 : 20 : report_reduced_full_join(state2, rtindex,
3688 : : left_state->relids);
3689 : : }
3690 : : }
3691 : 1007 : break;
3692 : 312 : case JOIN_SEMI:
3693 : : case JOIN_ANTI:
3694 : :
3695 : : /*
3696 : : * These could only have been introduced by pull_up_sublinks,
3697 : : * so there's no way that upper quals could refer to their
3698 : : * righthand sides, and no point in checking. We don't expect
3699 : : * a JOIN_RIGHT_SEMI or JOIN_RIGHT_ANTI input here; the
3700 : : * JOIN_FULL case above produces JOIN_RIGHT_ANTI only as a
3701 : : * transient, which is converted to JOIN_ANTI below.
3702 : : */
3703 : 312 : break;
3704 : 0 : default:
3705 [ # # ]: 0 : elog(ERROR, "unrecognized join type: %d",
3706 : : (int) jointype);
3707 : : break;
3708 : : }
3709 : :
3710 : : /*
3711 : : * Convert JOIN_RIGHT to JOIN_LEFT, and likewise the JOIN_RIGHT_ANTI
3712 : : * that the JOIN_FULL arm may have produced just above to JOIN_ANTI,
3713 : : * by switching the inputs. Note that in the case where we reduced
3714 : : * JOIN_FULL this way, this will mean the JoinExpr no longer matches
3715 : : * the internal ordering of any CoalesceExpr's built to represent
3716 : : * merged join variables. We don't care about that at present, but be
3717 : : * wary of it ...
3718 : : */
3719 [ + + + + ]: 38020 : if (jointype == JOIN_RIGHT || jointype == JOIN_RIGHT_ANTI)
3720 : : {
3721 : : Node *tmparg;
3722 : :
3723 : 990 : tmparg = j->larg;
3724 : 990 : j->larg = j->rarg;
3725 : 990 : j->rarg = tmparg;
3726 [ + + ]: 990 : jointype = (jointype == JOIN_RIGHT) ? JOIN_LEFT : JOIN_ANTI;
3727 : 990 : right_state = linitial(state1->sub_states);
3728 : 990 : left_state = lsecond(state1->sub_states);
3729 : : }
3730 : :
3731 : : /*
3732 : : * See if we can reduce JOIN_LEFT to JOIN_ANTI. This is the case if
3733 : : * any var from the RHS was forced null by higher qual levels, but is
3734 : : * known to be non-nullable in any matching row. We can prove that in
3735 : : * any of these ways: the join's own quals are strict for the var;
3736 : : * strict quals applied within the RHS subtree prove it; or the var is
3737 : : * defined NOT NULL by table constraints (being careful to exclude
3738 : : * vars that are nullable due to lower-level outer joins). In each
3739 : : * such case, the only way the higher qual clause's requirement for
3740 : : * NULL can be met is if the join fails to match, producing a
3741 : : * null-extended row. Thus, we can treat this as an anti-join.
3742 : : */
3743 [ + + + + ]: 38020 : if (jointype == JOIN_LEFT && forced_null_vars != NIL)
3744 : : {
3745 : : /*
3746 : : * A forced-null RHS Var that is proven non-null can be NULL here
3747 : : * only by null-extension. That makes this an anti-join.
3748 : : */
3749 [ + + ]: 1188 : if (forced_null_var_is_nonnullable(root, forced_null_vars,
3750 : 1188 : right_state, (List *) j->quals))
3751 : 1004 : jointype = JOIN_ANTI;
3752 : : }
3753 : :
3754 : : /*
3755 : : * Apply the jointype change, if any, to both jointree node and RTE.
3756 : : * Also, if we changed an RTE to INNER, add its RTI to inner_reduced;
3757 : : * if we changed it to ANTI, add its RTI to anti_reduced.
3758 : : */
3759 [ + + + + ]: 38020 : if (rtindex && jointype != j->jointype)
3760 : : {
3761 : 4614 : RangeTblEntry *rte = rt_fetch(rtindex, root->parse->rtable);
3762 : :
3763 : : Assert(rte->rtekind == RTE_JOIN);
3764 : : Assert(rte->jointype == j->jointype);
3765 : 4614 : rte->jointype = jointype;
3766 [ + + ]: 4614 : if (jointype == JOIN_INNER)
3767 : 2550 : state2->inner_reduced = bms_add_member(state2->inner_reduced,
3768 : : rtindex);
3769 [ + + ]: 2064 : else if (jointype == JOIN_ANTI)
3770 : 1069 : state2->anti_reduced = bms_add_member(state2->anti_reduced,
3771 : : rtindex);
3772 : : }
3773 : 38020 : j->jointype = jointype;
3774 : :
3775 : : /* Only recurse if there's more to do below here */
3776 [ + + + + ]: 38020 : if (left_state->contains_outer || right_state->contains_outer)
3777 : : {
3778 : : Relids local_nonnullable_rels;
3779 : : List *local_forced_null_vars;
3780 : : Relids pass_nonnullable_rels;
3781 : : List *pass_forced_null_vars;
3782 : :
3783 : : /*
3784 : : * If this join is (now) inner, we can add any constraints its
3785 : : * quals provide to those we got from above. But if it is outer,
3786 : : * we can pass down the local constraints only into the nullable
3787 : : * side, because an outer join never eliminates any rows from its
3788 : : * non-nullable side. Also, there is no point in passing upper
3789 : : * constraints into the nullable side, since if there were any
3790 : : * we'd have been able to reduce the join. (In the case of upper
3791 : : * forced-null constraints, we *must not* pass them into the
3792 : : * nullable side --- they either applied here, or not.) The upshot
3793 : : * is that we pass either the local or the upper constraints,
3794 : : * never both, to the children of an outer join.
3795 : : *
3796 : : * Note that a SEMI join works like an inner join here: it's okay
3797 : : * to pass down both local and upper constraints. (There can't be
3798 : : * any upper constraints affecting its inner side, but it's not
3799 : : * worth having a separate code path to avoid passing them.)
3800 : : *
3801 : : * At a FULL join we just punt and pass nothing down --- is it
3802 : : * possible to be smarter?
3803 : : */
3804 [ + + ]: 12271 : if (jointype != JOIN_FULL)
3805 : : {
3806 : 12148 : local_nonnullable_rels = find_nonnullable_rels(j->quals);
3807 : 12148 : local_forced_null_vars = find_forced_null_vars(j->quals);
3808 [ + + + + ]: 12148 : if (jointype == JOIN_INNER || jointype == JOIN_SEMI)
3809 : : {
3810 : : /* OK to merge upper and local constraints */
3811 : 1595 : local_nonnullable_rels = bms_add_members(local_nonnullable_rels,
3812 : : nonnullable_rels);
3813 : 1595 : local_forced_null_vars = mbms_add_members(local_forced_null_vars,
3814 : : forced_null_vars);
3815 : : }
3816 : : }
3817 : : else
3818 : : {
3819 : : /* no use in calculating these */
3820 : 123 : local_nonnullable_rels = NULL;
3821 : 123 : local_forced_null_vars = NIL;
3822 : : }
3823 : :
3824 [ + + ]: 12271 : if (left_state->contains_outer)
3825 : : {
3826 [ + + + + ]: 11476 : if (jointype == JOIN_INNER || jointype == JOIN_SEMI)
3827 : : {
3828 : : /* pass union of local and upper constraints */
3829 : 1414 : pass_nonnullable_rels = local_nonnullable_rels;
3830 : 1414 : pass_forced_null_vars = local_forced_null_vars;
3831 : : }
3832 [ + + ]: 10062 : else if (jointype != JOIN_FULL) /* ie, LEFT or ANTI */
3833 : : {
3834 : : /* can't pass local constraints to non-nullable side */
3835 : 9972 : pass_nonnullable_rels = nonnullable_rels;
3836 : 9972 : pass_forced_null_vars = forced_null_vars;
3837 : : }
3838 : : else
3839 : : {
3840 : : /* no constraints pass through JOIN_FULL */
3841 : 90 : pass_nonnullable_rels = NULL;
3842 : 90 : pass_forced_null_vars = NIL;
3843 : : }
3844 : 11476 : reduce_outer_joins_pass2(j->larg, left_state,
3845 : : state2, root,
3846 : : pass_nonnullable_rels,
3847 : : pass_forced_null_vars);
3848 : : }
3849 : :
3850 [ + + ]: 12271 : if (right_state->contains_outer)
3851 : : {
3852 [ + + ]: 849 : if (jointype != JOIN_FULL) /* ie, INNER/LEFT/SEMI/ANTI */
3853 : : {
3854 : : /* pass appropriate constraints, per comment above */
3855 : 816 : pass_nonnullable_rels = local_nonnullable_rels;
3856 : 816 : pass_forced_null_vars = local_forced_null_vars;
3857 : : }
3858 : : else
3859 : : {
3860 : : /* no constraints pass through JOIN_FULL */
3861 : 33 : pass_nonnullable_rels = NULL;
3862 : 33 : pass_forced_null_vars = NIL;
3863 : : }
3864 : 849 : reduce_outer_joins_pass2(j->rarg, right_state,
3865 : : state2, root,
3866 : : pass_nonnullable_rels,
3867 : : pass_forced_null_vars);
3868 : : }
3869 : 12271 : bms_free(local_nonnullable_rels);
3870 : : }
3871 : : }
3872 : : else
3873 [ # # ]: 0 : elog(ERROR, "unrecognized node type: %d",
3874 : : (int) nodeTag(jtnode));
3875 : 64739 : }
3876 : :
3877 : : /* Helper for reduce_outer_joins_pass2 */
3878 : : static void
3879 : 119 : report_reduced_full_join(reduce_outer_joins_pass2_state *state2,
3880 : : int rtindex, Relids relids)
3881 : : {
3882 : : reduce_outer_joins_partial_state *statep;
3883 : :
3884 : 119 : statep = palloc_object(reduce_outer_joins_partial_state);
3885 : 119 : statep->full_join_rti = rtindex;
3886 : 119 : statep->unreduced_side = relids;
3887 : 119 : state2->partial_reduced = lappend(state2->partial_reduced, statep);
3888 : 119 : }
3889 : :
3890 : : /*
3891 : : * forced_null_var_is_attnotnull
3892 : : * Check if "forced_null_vars" contains any Vars belonging to the subtree
3893 : : * indicated by "state" that are known to be non-nullable due to table
3894 : : * constraints.
3895 : : *
3896 : : * A whole-row Var, in any matching row, requires every column of its relation
3897 : : * to be NULL, so any NOT NULL column of the relation refutes it.
3898 : : *
3899 : : * Note that we must also consider the situation where a NOT NULL Var can be
3900 : : * nulled by lower-level outer joins.
3901 : : *
3902 : : * Helper for reduce_outer_joins_pass2.
3903 : : */
3904 : : static bool
3905 : 324 : forced_null_var_is_attnotnull(PlannerInfo *root, List *forced_null_vars,
3906 : : reduce_outer_joins_pass1_state *state)
3907 : : {
3908 : 324 : int varno = -1;
3909 : :
3910 [ + - + + : 1946 : foreach_node(Bitmapset, attrs, forced_null_vars)
+ + ]
3911 : : {
3912 : : RangeTblEntry *rte;
3913 : : Bitmapset *notnullattnums;
3914 : : Bitmapset *forcednullattnums;
3915 : 1458 : bool wholerow = false;
3916 : : int lowest_attno;
3917 : :
3918 : 1458 : varno++;
3919 : :
3920 : : /* Skip empty bitmaps */
3921 [ + + ]: 1458 : if (bms_is_empty(attrs))
3922 : 1129 : continue;
3923 : :
3924 : : /* Skip Vars that do not belong to the target relations */
3925 [ + + ]: 329 : if (!bms_is_member(varno, state->relids))
3926 : 115 : continue;
3927 : :
3928 : : /*
3929 : : * Skip Vars that can be nulled by lower-level outer joins within the
3930 : : * given subtree. These Vars might be NULL even if the schema defines
3931 : : * them as NOT NULL.
3932 : : */
3933 [ + + ]: 214 : if (bms_is_member(varno, state->nullable_rels))
3934 : 25 : continue;
3935 : :
3936 : : /* find the lowest member to check if system columns are present */
3937 : 189 : lowest_attno = bms_next_member(attrs, -1);
3938 : :
3939 : : /* we checked for an empty set above */
3940 : : Assert(lowest_attno >= 0);
3941 : :
3942 : : /* system columns cannot be NULL */
3943 [ - + ]: 189 : if (lowest_attno + FirstLowInvalidHeapAttributeNumber < 0)
3944 : 80 : return true;
3945 : :
3946 : : /* attno 0 is a whole-row Var, which forces every column null */
3947 [ + + ]: 189 : if (lowest_attno + FirstLowInvalidHeapAttributeNumber == 0)
3948 : 40 : wholerow = true;
3949 : :
3950 : 189 : rte = rt_fetch(varno, root->parse->rtable);
3951 : :
3952 : : /* We can only reason about ordinary relations */
3953 [ + + ]: 189 : if (rte->rtekind != RTE_RELATION)
3954 : 34 : continue;
3955 : :
3956 : : /*
3957 : : * We must skip inheritance parent tables, as some child tables may
3958 : : * have a NOT NULL constraint for a column while others may not. This
3959 : : * cannot happen with partitioned tables, though.
3960 : : */
3961 [ - + - - ]: 155 : if (rte->inh && rte->relkind != RELKIND_PARTITIONED_TABLE)
3962 : 0 : continue;
3963 : :
3964 : : /* Get the column not-null constraint information for this relation */
3965 : 155 : notnullattnums = find_relation_notnullatts(root, rte->relid);
3966 : :
3967 : : /*
3968 : : * A forced-null whole-row Var, in any matching row, requires every
3969 : : * column of the relation to be NULL, so any NOT NULL column refutes
3970 : : * it.
3971 : : */
3972 [ + + + + ]: 155 : if (wholerow && !bms_is_empty(notnullattnums))
3973 : 10 : return true;
3974 : :
3975 : : /*
3976 : : * Offset the bitmap members by FirstLowInvalidHeapAttributeNumber to
3977 : : * get the actual attribute numbers.
3978 : : */
3979 : 145 : forcednullattnums = bms_offset_members(attrs,
3980 : : FirstLowInvalidHeapAttributeNumber);
3981 : :
3982 : : /*
3983 : : * Check if any forced-null attributes are defined as NOT NULL by
3984 : : * table constraints.
3985 : : */
3986 [ + + ]: 145 : if (bms_overlap(notnullattnums, forcednullattnums))
3987 : : {
3988 : 70 : bms_free(forcednullattnums);
3989 : 70 : return true;
3990 : : }
3991 : :
3992 : 75 : bms_free(forcednullattnums);
3993 : : }
3994 : :
3995 : 244 : return false;
3996 : : }
3997 : :
3998 : : /*
3999 : : * forced_null_var_is_nonnullable
4000 : : * Detect whether some Var that "forced_null_vars" requires to be NULL is
4001 : : * actually non-nullable in every row that the given subtree emits.
4002 : : *
4003 : : * We prove non-nullness from quals that hold for every such row: the subtree's
4004 : : * safe quals, plus any "extra_quals" the caller knows also constrain the Var,
4005 : : * or a NOT NULL table constraint (excluding Vars nullable due to lower-level
4006 : : * outer joins).
4007 : : *
4008 : : * A whole-row Var in "forced_null_vars" requires, in any matching row, every
4009 : : * column of its relation to be NULL, so it is refuted by proving any one of
4010 : : * those columns non-null.
4011 : : *
4012 : : * Helper for reduce_outer_joins_pass2.
4013 : : */
4014 : : static bool
4015 : 1313 : forced_null_var_is_nonnullable(PlannerInfo *root, List *forced_null_vars,
4016 : : reduce_outer_joins_pass1_state *state,
4017 : : List *extra_quals)
4018 : : {
4019 : 1313 : List *all_quals = NIL;
4020 : : List *nonnullable_vars;
4021 : 1313 : int wholerow_attno = 0 - FirstLowInvalidHeapAttributeNumber;
4022 : 1313 : int varno = -1;
4023 : :
4024 : 1313 : find_safe_quals(state->jtnode, &all_quals);
4025 : 1313 : all_quals = list_concat(all_quals, extra_quals);
4026 : 1313 : nonnullable_vars = find_nonnullable_vars((Node *) all_quals);
4027 : :
4028 : : /*
4029 : : * It's not sufficient to consider all matches between nonnullable_vars
4030 : : * and forced_null_vars: a match counts only for a Var belonging to this
4031 : : * subtree, and the whole-row attribute needs special treatment.
4032 : : */
4033 [ + - + + : 4551 : foreach_node(Bitmapset, attrs, forced_null_vars)
+ + ]
4034 : : {
4035 : : Bitmapset *nonnull_attrs;
4036 : :
4037 : 4109 : varno++;
4038 : :
4039 : : /* Beyond the end of nonnullable_vars there is nothing left to prove */
4040 [ + + ]: 4109 : if (varno >= list_length(nonnullable_vars))
4041 : 206 : break;
4042 : :
4043 : : /* Skip empty bitmaps */
4044 [ + + ]: 3903 : if (bms_is_empty(attrs))
4045 : 2796 : continue;
4046 : :
4047 : : /* Skip Vars that do not belong to the target relations */
4048 [ + + ]: 1107 : if (!bms_is_member(varno, state->relids))
4049 : 44 : continue;
4050 : :
4051 : : /* Get what the quals prove non-null for this relation, if anything */
4052 : 1063 : nonnull_attrs = list_nth_node(Bitmapset, nonnullable_vars, varno);
4053 : :
4054 : : /*
4055 : : * A proof for the whole-row attribute refutes nothing: it shows only
4056 : : * that the composite datum is non-null, and such a datum can still
4057 : : * have all columns NULL. Discard it up front.
4058 : : */
4059 : 1063 : nonnull_attrs = bms_del_member(nonnull_attrs, wholerow_attno);
4060 : :
4061 : : /* A forced-null attribute that is proven non-null settles it. */
4062 [ + + ]: 1063 : if (bms_overlap(attrs, nonnull_attrs))
4063 : 989 : return true;
4064 : :
4065 : : /*
4066 : : * So does any real column proven non-null, if the whole-row Var is
4067 : : * forced null: in a matching row (whose whole-row datum is non-null)
4068 : : * the row-format IS NULL test is true only when every column is NULL.
4069 : : * System attributes don't count, since they are not part of the row
4070 : : * value; conveniently they sort below the whole-row attribute in the
4071 : : * bitmap.
4072 : : */
4073 [ + + + + ]: 124 : if (bms_is_member(wholerow_attno, attrs) &&
4074 : 35 : bms_next_member(nonnull_attrs, wholerow_attno) >= 0)
4075 : 15 : return true;
4076 : : }
4077 : :
4078 : : /*
4079 : : * Otherwise, check if any forced-null var is defined NOT NULL by table
4080 : : * constraints.
4081 : : */
4082 : 324 : return forced_null_var_is_attnotnull(root, forced_null_vars, state);
4083 : : }
4084 : :
4085 : :
4086 : : /*
4087 : : * remove_useless_result_rtes
4088 : : * Attempt to remove RTE_RESULT RTEs from the join tree.
4089 : : * Also, elide single-child FromExprs where possible.
4090 : : *
4091 : : * We can remove RTE_RESULT entries from the join tree using the knowledge
4092 : : * that RTE_RESULT returns exactly one row and has no output columns. Hence,
4093 : : * if one is inner-joined to anything else, we can delete it. Optimizations
4094 : : * are also possible for some outer-join cases, as detailed below.
4095 : : *
4096 : : * This pass also replaces single-child FromExprs with their child node
4097 : : * where possible. It's appropriate to do that here and not earlier because
4098 : : * RTE_RESULT removal might reduce a multiple-child FromExpr to have only one
4099 : : * child. We can remove such a FromExpr if its quals are empty, or if it's
4100 : : * semantically valid to merge the quals into those of the parent node.
4101 : : * While removing unnecessary join tree nodes has some micro-efficiency value,
4102 : : * the real reason to do this is to eliminate cases where the nullable side of
4103 : : * an outer join node is a FromExpr whose single child is another outer join.
4104 : : * To correctly determine whether the two outer joins can commute,
4105 : : * deconstruct_jointree() must treat any quals of such a FromExpr as being
4106 : : * degenerate quals of the upper outer join. The best way to do that is to
4107 : : * make them actually *be* quals of the upper join, by dropping the FromExpr
4108 : : * and hoisting the quals up into the upper join's quals. (Note that there is
4109 : : * no hazard when the intermediate FromExpr has multiple children, since then
4110 : : * it represents an inner join that cannot commute with the upper outer join.)
4111 : : * As long as we have to do that, we might as well elide such FromExprs
4112 : : * everywhere.
4113 : : *
4114 : : * Some of these optimizations depend on recognizing empty (constant-true)
4115 : : * quals for FromExprs and JoinExprs. That makes it useful to apply this
4116 : : * optimization pass after expression preprocessing, since that will have
4117 : : * eliminated constant-true quals, allowing more cases to be recognized as
4118 : : * optimizable. What's more, the usual reason for an RTE_RESULT to be present
4119 : : * is that we pulled up a subquery or VALUES clause, thus very possibly
4120 : : * replacing Vars with constants, making it more likely that a qual can be
4121 : : * reduced to constant true. Also, because some optimizations depend on
4122 : : * the outer-join type, it's best to have done reduce_outer_joins() first.
4123 : : *
4124 : : * A PlaceHolderVar referencing an RTE_RESULT RTE poses an obstacle to this
4125 : : * process: we must remove the RTE_RESULT's relid from the PHV's phrels, but
4126 : : * we must not reduce the phrels set to empty. If that would happen, and
4127 : : * the RTE_RESULT is an immediate child of an outer join, we have to give up
4128 : : * and not remove the RTE_RESULT: there is noplace else to evaluate the
4129 : : * PlaceHolderVar. (That is, in such cases the RTE_RESULT *does* have output
4130 : : * columns.) But if the RTE_RESULT is an immediate child of an inner join,
4131 : : * we can usually change the PlaceHolderVar's phrels so as to evaluate it at
4132 : : * the inner join instead. This is OK because we really only care that PHVs
4133 : : * are evaluated above or below the correct outer joins. We can't, however,
4134 : : * postpone the evaluation of a PHV to above where it is used; so there are
4135 : : * some checks below on whether output PHVs are laterally referenced in the
4136 : : * other join input rel(s).
4137 : : *
4138 : : * We used to try to do this work as part of pull_up_subqueries() where the
4139 : : * potentially-optimizable cases get introduced; but it's way simpler, and
4140 : : * more effective, to do it separately.
4141 : : */
4142 : : void
4143 : 169927 : remove_useless_result_rtes(PlannerInfo *root)
4144 : : {
4145 : 169927 : Relids baserels = NULL;
4146 : 169927 : Relids dropped_outer_joins = NULL;
4147 : : ListCell *cell;
4148 : :
4149 : : /*
4150 : : * We'll need the set of baserels in the jointree to perform
4151 : : * find_dependent_phvs() checks. But if there are no PHVs anywhere in the
4152 : : * query, those checks are no-ops, so we can skip the work.
4153 : : */
4154 [ + + ]: 169927 : if (root->glob->lastPHId != 0)
4155 : 1612 : baserels = get_relids_in_jointree((Node *) root->parse->jointree,
4156 : : false, false);
4157 : :
4158 : : /* Top level of jointree must always be a FromExpr */
4159 : : Assert(IsA(root->parse->jointree, FromExpr));
4160 : : /* Recurse ... */
4161 : 339854 : root->parse->jointree = (FromExpr *)
4162 : 169927 : remove_useless_results_recurse(root,
4163 : 169927 : (Node *) root->parse->jointree,
4164 : : baserels,
4165 : : NULL,
4166 : : &dropped_outer_joins);
4167 : : /* We should still have a FromExpr */
4168 : : Assert(IsA(root->parse->jointree, FromExpr));
4169 : :
4170 : : /*
4171 : : * If we removed any outer-join nodes from the jointree, run around and
4172 : : * remove references to those joins as nulling rels. (There could be such
4173 : : * references in PHVs that we pulled up out of the original subquery that
4174 : : * the RESULT rel replaced. This is kosher on the grounds that we now
4175 : : * know that such an outer join wouldn't really have nulled anything.) We
4176 : : * don't do this during the main recursion, for simplicity and because we
4177 : : * can handle all such joins in a single pass over the parse tree.
4178 : : */
4179 [ + + ]: 169927 : if (!bms_is_empty(dropped_outer_joins))
4180 : : {
4181 : 65 : root->parse = (Query *)
4182 : 65 : remove_nulling_relids((Node *) root->parse,
4183 : : dropped_outer_joins,
4184 : : NULL);
4185 : : /* There could be references in the append_rel_list, too */
4186 : 65 : root->append_rel_list = (List *)
4187 : 65 : remove_nulling_relids((Node *) root->append_rel_list,
4188 : : dropped_outer_joins,
4189 : : NULL);
4190 : : }
4191 : :
4192 : : /*
4193 : : * Remove any PlanRowMark referencing an RTE_RESULT RTE. We obviously
4194 : : * must do that for any RTE_RESULT that we just removed. But one for a
4195 : : * RTE that we did not remove can be dropped anyway: since the RTE has
4196 : : * only one possible output row, there is no need for EPQ to mark and
4197 : : * restore that row.
4198 : : *
4199 : : * It's necessary, not optional, to remove the PlanRowMark for a surviving
4200 : : * RTE_RESULT RTE; otherwise we'll generate a whole-row Var for the
4201 : : * RTE_RESULT, which the executor has no support for.
4202 : : */
4203 [ + + + + : 171503 : foreach(cell, root->rowMarks)
+ + ]
4204 : : {
4205 : 1576 : PlanRowMark *rc = (PlanRowMark *) lfirst(cell);
4206 : :
4207 [ + + ]: 1576 : if (rt_fetch(rc->rti, root->parse->rtable)->rtekind == RTE_RESULT)
4208 : 655 : root->rowMarks = foreach_delete_current(root->rowMarks, cell);
4209 : : }
4210 : 169927 : }
4211 : :
4212 : : /*
4213 : : * remove_useless_results_recurse
4214 : : * Recursive guts of remove_useless_result_rtes.
4215 : : *
4216 : : * This recursively processes the jointree and returns a modified jointree.
4217 : : * In addition, the RT indexes of any removed outer-join nodes are added to
4218 : : * *dropped_outer_joins.
4219 : : *
4220 : : * jtnode is the current jointree node. If it could be valid to merge
4221 : : * its quals into those of the parent node, parent_quals should point to
4222 : : * the parent's quals list; otherwise, pass NULL for parent_quals.
4223 : : * (Note that in some cases, parent_quals points to the quals of a parent
4224 : : * more than one level up in the tree.)
4225 : : *
4226 : : * baserels is the set of base (non-join) RT indexes in the whole jointree;
4227 : : * it can be NULL if the query contains no PHVs.
4228 : : */
4229 : : static Node *
4230 : 444266 : remove_useless_results_recurse(PlannerInfo *root, Node *jtnode,
4231 : : Relids baserels,
4232 : : Node **parent_quals,
4233 : : Relids *dropped_outer_joins)
4234 : : {
4235 : : Assert(jtnode != NULL);
4236 [ + + ]: 444266 : if (IsA(jtnode, RangeTblRef))
4237 : : {
4238 : : /* Can't immediately do anything with a RangeTblRef */
4239 : : }
4240 [ + + ]: 223455 : else if (IsA(jtnode, FromExpr))
4241 : : {
4242 : 175559 : FromExpr *f = (FromExpr *) jtnode;
4243 : 175559 : Relids result_relids = NULL;
4244 : : ListCell *cell;
4245 : :
4246 : : /*
4247 : : * We can drop RTE_RESULT rels from the fromlist so long as at least
4248 : : * one child remains, since joining to a one-row table changes
4249 : : * nothing. (But we can't drop a RTE_RESULT that computes PHV(s) that
4250 : : * are needed by some sibling. The cleanup transformation below would
4251 : : * reassign the PHVs to be computed at the join, which is too late for
4252 : : * the sibling's use.) The easiest way to mechanize this rule is to
4253 : : * modify the list in-place.
4254 : : */
4255 [ + - + + : 354106 : foreach(cell, f->fromlist)
+ + ]
4256 : : {
4257 : 178547 : Node *child = (Node *) lfirst(cell);
4258 : : int varno;
4259 : :
4260 : : /* Recursively transform child, allowing it to push up quals ... */
4261 : 178547 : child = remove_useless_results_recurse(root, child,
4262 : : baserels,
4263 : : &f->quals,
4264 : : dropped_outer_joins);
4265 : : /* ... and stick it back into the tree */
4266 : 178547 : lfirst(cell) = child;
4267 : :
4268 : : /*
4269 : : * If it's an RTE_RESULT with at least one sibling, and no sibling
4270 : : * references dependent PHVs, we can drop it. We don't yet know
4271 : : * what the inner join's final relid set will be, so postpone
4272 : : * cleanup of PHVs etc till after this loop.
4273 : : */
4274 [ + + + + ]: 183363 : if (list_length(f->fromlist) > 1 &&
4275 : 4816 : (varno = get_result_relid(root, child)) != 0 &&
4276 [ + + ]: 280 : !find_dependent_phvs_in_jointree(root, (Node *) f, varno,
4277 : : baserels))
4278 : : {
4279 : 260 : f->fromlist = foreach_delete_current(f->fromlist, cell);
4280 : 260 : result_relids = bms_add_member(result_relids, varno);
4281 : : }
4282 : : }
4283 : :
4284 : : /*
4285 : : * Clean up if we dropped any RTE_RESULT RTEs. This is a bit
4286 : : * inefficient if there's more than one, but it seems better to
4287 : : * optimize the support code for the single-relid case.
4288 : : */
4289 [ + + ]: 175559 : if (result_relids)
4290 : : {
4291 : 250 : int varno = -1;
4292 : :
4293 [ + + ]: 510 : while ((varno = bms_next_member(result_relids, varno)) >= 0)
4294 : 260 : remove_result_refs(root, varno, (Node *) f);
4295 : : }
4296 : :
4297 : : /*
4298 : : * If the FromExpr now has only one child, see if we can elide it.
4299 : : * This is always valid if there are no quals, except at the top of
4300 : : * the jointree (since Query.jointree is required to point to a
4301 : : * FromExpr). Otherwise, we can do it if we can push the quals up to
4302 : : * the parent node.
4303 : : *
4304 : : * Note: while it would not be terribly hard to generalize this
4305 : : * transformation to merge multi-child FromExprs into their parent
4306 : : * FromExpr, that risks making the parent join too expensive to plan.
4307 : : * We leave it to later processing to decide heuristically whether
4308 : : * that's a good idea. Pulling up a single child is always OK,
4309 : : * however.
4310 : : */
4311 [ + + ]: 175559 : if (list_length(f->fromlist) == 1 &&
4312 [ + + ]: 173894 : f != root->parse->jointree &&
4313 [ + + + + ]: 5426 : (f->quals == NULL || parent_quals != NULL))
4314 : : {
4315 : : /*
4316 : : * Merge any quals up to parent. They should be in implicit-AND
4317 : : * format by now, so we just need to concatenate lists. Put the
4318 : : * child quals at the front, on the grounds that they should
4319 : : * nominally be evaluated earlier.
4320 : : */
4321 [ + + ]: 2345 : if (f->quals != NULL)
4322 : 1220 : *parent_quals = (Node *)
4323 : 1220 : list_concat(castNode(List, f->quals),
4324 : : castNode(List, *parent_quals));
4325 : 2345 : return (Node *) linitial(f->fromlist);
4326 : : }
4327 : : }
4328 [ + - ]: 47896 : else if (IsA(jtnode, JoinExpr))
4329 : : {
4330 : 47896 : JoinExpr *j = (JoinExpr *) jtnode;
4331 : : int varno;
4332 : :
4333 : : /*
4334 : : * First, recurse. We can absorb pushed-up FromExpr quals from either
4335 : : * child into this node if the jointype is INNER, since then this is
4336 : : * equivalent to a FromExpr. When the jointype is LEFT, we can absorb
4337 : : * quals from the RHS child into the current node, as they're
4338 : : * essentially degenerate quals of the outer join. Moreover, if we've
4339 : : * been passed down a parent_quals pointer then we can allow quals of
4340 : : * the LHS child to be absorbed into the parent. (This is important
4341 : : * to ensure we remove single-child FromExprs immediately below
4342 : : * commutable left joins.) For other jointypes, we can't move child
4343 : : * quals up, or at least there's no particular reason to.
4344 : : */
4345 : 47896 : j->larg = remove_useless_results_recurse(root, j->larg,
4346 : : baserels,
4347 [ + + ]: 47896 : (j->jointype == JOIN_INNER) ?
4348 : : &j->quals :
4349 : 37393 : (j->jointype == JOIN_LEFT) ?
4350 [ + + ]: 37393 : parent_quals : NULL,
4351 : : dropped_outer_joins);
4352 : 47896 : j->rarg = remove_useless_results_recurse(root, j->rarg,
4353 : : baserels,
4354 [ + + ]: 47896 : (j->jointype == JOIN_INNER ||
4355 [ + + ]: 37393 : j->jointype == JOIN_LEFT) ?
4356 : : &j->quals : NULL,
4357 : : dropped_outer_joins);
4358 : :
4359 : : /* Apply join-type-specific optimization rules */
4360 [ + + + + : 47896 : switch (j->jointype)
- ]
4361 : : {
4362 : 10503 : case JOIN_INNER:
4363 : :
4364 : : /*
4365 : : * An inner join is equivalent to a FromExpr, so if either
4366 : : * side was simplified to an RTE_RESULT rel, we can replace
4367 : : * the join with a FromExpr with just the other side.
4368 : : * Furthermore, we can elide that FromExpr according to the
4369 : : * same rules as above.
4370 : : *
4371 : : * Just as in the FromExpr case, we can't simplify if the
4372 : : * other input rel references any PHVs that are marked as to
4373 : : * be evaluated at the RTE_RESULT rel, because we can't
4374 : : * postpone their evaluation in that case. But we only have
4375 : : * to check this in cases where it's syntactically legal for
4376 : : * the other input to have a LATERAL reference to the
4377 : : * RTE_RESULT rel. Only RHSes of inner and left joins are
4378 : : * allowed to have such refs.
4379 : : */
4380 [ + + ]: 10503 : if ((varno = get_result_relid(root, j->larg)) != 0 &&
4381 [ + - ]: 121 : !find_dependent_phvs_in_jointree(root, j->rarg, varno,
4382 : : baserels))
4383 : : {
4384 : 121 : remove_result_refs(root, varno, j->rarg);
4385 [ + + + + ]: 121 : if (j->quals != NULL && parent_quals == NULL)
4386 : 10 : jtnode = (Node *)
4387 : 10 : makeFromExpr(list_make1(j->rarg), j->quals);
4388 : : else
4389 : : {
4390 : : /* Merge any quals up to parent */
4391 [ + + ]: 111 : if (j->quals != NULL)
4392 : 58 : *parent_quals = (Node *)
4393 : 58 : list_concat(castNode(List, j->quals),
4394 : : castNode(List, *parent_quals));
4395 : 111 : jtnode = j->rarg;
4396 : : }
4397 : : }
4398 [ + + ]: 10382 : else if ((varno = get_result_relid(root, j->rarg)) != 0)
4399 : : {
4400 : 593 : remove_result_refs(root, varno, j->larg);
4401 [ + + + + ]: 593 : if (j->quals != NULL && parent_quals == NULL)
4402 : 10 : jtnode = (Node *)
4403 : 10 : makeFromExpr(list_make1(j->larg), j->quals);
4404 : : else
4405 : : {
4406 : : /* Merge any quals up to parent */
4407 [ + + ]: 583 : if (j->quals != NULL)
4408 : 399 : *parent_quals = (Node *)
4409 : 399 : list_concat(castNode(List, j->quals),
4410 : : castNode(List, *parent_quals));
4411 : 583 : jtnode = j->larg;
4412 : : }
4413 : : }
4414 : 10503 : break;
4415 : 32486 : case JOIN_LEFT:
4416 : :
4417 : : /*
4418 : : * We can simplify this case if the RHS is an RTE_RESULT, with
4419 : : * two different possibilities:
4420 : : *
4421 : : * If the qual is empty (JOIN ON TRUE), then the join can be
4422 : : * strength-reduced to a plain inner join, since each LHS row
4423 : : * necessarily has exactly one join partner. So we can always
4424 : : * discard the RHS, much as in the JOIN_INNER case above.
4425 : : * (Again, the LHS could not contain a lateral reference to
4426 : : * the RHS.)
4427 : : *
4428 : : * Otherwise, it's still true that each LHS row should be
4429 : : * returned exactly once, and since the RHS returns no columns
4430 : : * (unless there are PHVs that have to be evaluated there), we
4431 : : * don't much care if it's null-extended or not. So in this
4432 : : * case also, we can just ignore the qual and discard the left
4433 : : * join.
4434 : : */
4435 [ + + ]: 32486 : if ((varno = get_result_relid(root, j->rarg)) != 0 &&
4436 [ + + ]: 164 : (j->quals == NULL ||
4437 [ - + ]: 99 : !find_dependent_phvs(root, varno, baserels)))
4438 : : {
4439 : 65 : remove_result_refs(root, varno, j->larg);
4440 : 65 : *dropped_outer_joins = bms_add_member(*dropped_outer_joins,
4441 : : j->rtindex);
4442 : 65 : jtnode = j->larg;
4443 : : }
4444 : 32486 : break;
4445 : 2696 : case JOIN_SEMI:
4446 : :
4447 : : /*
4448 : : * We may simplify this case if the RHS is an RTE_RESULT; the
4449 : : * join qual becomes effectively just a filter qual for the
4450 : : * LHS, since we should either return the LHS row or not. The
4451 : : * filter clause must go into a new FromExpr if we can't push
4452 : : * it up to the parent.
4453 : : *
4454 : : * There is a fine point about PHVs that are supposed to be
4455 : : * evaluated at the RHS. Such PHVs could only appear in the
4456 : : * semijoin's qual, since the rest of the query cannot
4457 : : * reference any outputs of the semijoin's RHS. Therefore,
4458 : : * they can't actually go to null before being examined, and
4459 : : * it'd be OK to just remove the PHV wrapping. We don't have
4460 : : * infrastructure for that, but remove_result_refs() will
4461 : : * relabel them as to be evaluated at the LHS, which is fine.
4462 : : *
4463 : : * Also, we don't need to worry about removing traces of the
4464 : : * join's rtindex, since it hasn't got one.
4465 : : */
4466 [ + + ]: 2696 : if ((varno = get_result_relid(root, j->rarg)) != 0)
4467 : : {
4468 : : Assert(j->rtindex == 0);
4469 : 30 : remove_result_refs(root, varno, j->larg);
4470 [ + - - + ]: 30 : if (j->quals != NULL && parent_quals == NULL)
4471 : 0 : jtnode = (Node *)
4472 : 0 : makeFromExpr(list_make1(j->larg), j->quals);
4473 : : else
4474 : : {
4475 : : /* Merge any quals up to parent */
4476 [ + - ]: 30 : if (j->quals != NULL)
4477 : 30 : *parent_quals = (Node *)
4478 : 30 : list_concat(castNode(List, j->quals),
4479 : : castNode(List, *parent_quals));
4480 : 30 : jtnode = j->larg;
4481 : : }
4482 : : }
4483 : 2696 : break;
4484 : 2211 : case JOIN_FULL:
4485 : : case JOIN_ANTI:
4486 : : /* We have no special smarts for these cases */
4487 : 2211 : break;
4488 : 0 : default:
4489 : : /* Note: JOIN_RIGHT should be gone at this point */
4490 [ # # ]: 0 : elog(ERROR, "unrecognized join type: %d",
4491 : : (int) j->jointype);
4492 : : break;
4493 : : }
4494 : : }
4495 : : else
4496 [ # # ]: 0 : elog(ERROR, "unrecognized node type: %d",
4497 : : (int) nodeTag(jtnode));
4498 : 441921 : return jtnode;
4499 : : }
4500 : :
4501 : : /*
4502 : : * get_result_relid
4503 : : * If jtnode is a RangeTblRef for an RTE_RESULT RTE, return its relid;
4504 : : * otherwise return 0.
4505 : : */
4506 : : static int
4507 : 60883 : get_result_relid(PlannerInfo *root, Node *jtnode)
4508 : : {
4509 : : int varno;
4510 : :
4511 [ + + ]: 60883 : if (!IsA(jtnode, RangeTblRef))
4512 : 6596 : return 0;
4513 : 54287 : varno = ((RangeTblRef *) jtnode)->rtindex;
4514 [ + + ]: 54287 : if (rt_fetch(varno, root->parse->rtable)->rtekind != RTE_RESULT)
4515 : 53099 : return 0;
4516 : 1188 : return varno;
4517 : : }
4518 : :
4519 : : /*
4520 : : * remove_result_refs
4521 : : * Helper routine for dropping an unneeded RTE_RESULT RTE.
4522 : : *
4523 : : * This doesn't physically remove the RTE from the jointree, because that's
4524 : : * more easily handled in remove_useless_results_recurse. What it does do
4525 : : * is the necessary cleanup in the rest of the tree: we must adjust any PHVs
4526 : : * that may reference the RTE. Be sure to call this at a point where the
4527 : : * jointree is valid (no disconnected nodes).
4528 : : *
4529 : : * Note that we don't need to process the append_rel_list, since RTEs
4530 : : * referenced directly in the jointree won't be appendrel members.
4531 : : *
4532 : : * varno is the RTE_RESULT's relid.
4533 : : * newjtloc is the jointree location at which any PHVs referencing the
4534 : : * RTE_RESULT should be evaluated instead.
4535 : : */
4536 : : static void
4537 : 1069 : remove_result_refs(PlannerInfo *root, int varno, Node *newjtloc)
4538 : : {
4539 : : /* Fix up PlaceHolderVars as needed */
4540 : : /* If there are no PHVs anywhere, we can skip this bit */
4541 [ + + ]: 1069 : if (root->glob->lastPHId != 0)
4542 : : {
4543 : : Relids subrelids;
4544 : :
4545 : 255 : subrelids = get_relids_in_jointree(newjtloc, true, false);
4546 : : Assert(!bms_is_empty(subrelids));
4547 : 255 : substitute_phv_relids((Node *) root->parse, varno, subrelids);
4548 : 255 : fix_append_rel_relids(root, varno, subrelids);
4549 : : }
4550 : :
4551 : : /*
4552 : : * We also need to remove any PlanRowMark referencing the RTE, but we
4553 : : * postpone that work until we return to remove_useless_result_rtes.
4554 : : */
4555 : 1069 : }
4556 : :
4557 : :
4558 : : /*
4559 : : * find_dependent_phvs - are there any PlaceHolderVars whose base relids are
4560 : : * exactly the given varno?
4561 : : *
4562 : : * We ignore outer-join relids present in a PHV's phrels, by intersecting
4563 : : * with the caller-supplied "baserels" set. This is necessary in part
4564 : : * because some of the OJ relids may be stale, that is we may have
4565 : : * already decided to remove those joins in remove_useless_result_rtes
4566 : : * and not yet have cleaned their relid bits out of upper PHVs.
4567 : : * But in general, it's the set of baserels that identify possible places
4568 : : * to evaluate a PHV, and we mustn't let that go to empty. (The caller is
4569 : : * allowed to pass baserels as NULL if the query contains no PHVs at all,
4570 : : * since then there is no work to do anyway.)
4571 : : *
4572 : : * find_dependent_phvs should be used when we want to see if there are
4573 : : * any such PHVs anywhere in the Query. Another use-case is to see if
4574 : : * a subtree of the join tree contains such PHVs; but for that, we have
4575 : : * to look not only at the join tree nodes themselves but at the
4576 : : * referenced RTEs. For that, use find_dependent_phvs_in_jointree.
4577 : : */
4578 : :
4579 : : typedef struct
4580 : : {
4581 : : Relids relids; /* target relid, represented as a relid set */
4582 : : Relids baserels; /* base RT indexes in query, NULL if no PHVs */
4583 : : int sublevels_up; /* current nesting level */
4584 : : } find_dependent_phvs_context;
4585 : :
4586 : : static bool
4587 : 2124 : find_dependent_phvs_walker(Node *node,
4588 : : find_dependent_phvs_context *context)
4589 : : {
4590 [ + + ]: 2124 : if (node == NULL)
4591 : 460 : return false;
4592 [ + + ]: 1664 : if (IsA(node, PlaceHolderVar))
4593 : : {
4594 : 154 : PlaceHolderVar *phv = (PlaceHolderVar *) node;
4595 : :
4596 [ + - ]: 154 : if (phv->phlevelsup == context->sublevels_up)
4597 : : {
4598 : 154 : Relids phbaserels = bms_intersect(phv->phrels,
4599 : 154 : context->baserels);
4600 : 154 : bool match = bms_equal(context->relids, phbaserels);
4601 : :
4602 : 154 : bms_free(phbaserels);
4603 [ + + ]: 154 : if (match)
4604 : 119 : return true;
4605 : : }
4606 : : /* fall through to examine children */
4607 : : }
4608 [ + + ]: 1545 : if (IsA(node, Query))
4609 : : {
4610 : : /* Recurse into subselects */
4611 : : bool result;
4612 : :
4613 : 40 : context->sublevels_up++;
4614 : 40 : result = query_tree_walker((Query *) node,
4615 : : find_dependent_phvs_walker,
4616 : : context, 0);
4617 : 40 : context->sublevels_up--;
4618 : 40 : return result;
4619 : : }
4620 : : /* Shouldn't need to handle most planner auxiliary nodes here */
4621 : : Assert(!IsA(node, SpecialJoinInfo));
4622 : : Assert(!IsA(node, PlaceHolderInfo));
4623 : : Assert(!IsA(node, MinMaxAggInfo));
4624 : :
4625 : 1505 : return expression_tree_walker(node, find_dependent_phvs_walker, context);
4626 : : }
4627 : :
4628 : : static bool
4629 : 99 : find_dependent_phvs(PlannerInfo *root, int varno, Relids baserels)
4630 : : {
4631 : : find_dependent_phvs_context context;
4632 : :
4633 : : /* If there are no PHVs anywhere, we needn't work hard */
4634 [ - + ]: 99 : if (root->glob->lastPHId == 0)
4635 : 0 : return false;
4636 : :
4637 : 99 : context.relids = bms_make_singleton(varno);
4638 : 99 : context.baserels = baserels;
4639 : 99 : context.sublevels_up = 0;
4640 : :
4641 [ + - ]: 99 : if (query_tree_walker(root->parse, find_dependent_phvs_walker, &context, 0))
4642 : 99 : return true;
4643 : : /* The append_rel_list could be populated already, so check it too */
4644 [ # # ]: 0 : if (expression_tree_walker((Node *) root->append_rel_list,
4645 : : find_dependent_phvs_walker,
4646 : : &context))
4647 : 0 : return true;
4648 : 0 : return false;
4649 : : }
4650 : :
4651 : : static bool
4652 : 401 : find_dependent_phvs_in_jointree(PlannerInfo *root, Node *node, int varno,
4653 : : Relids baserels)
4654 : : {
4655 : : find_dependent_phvs_context context;
4656 : : Relids subrelids;
4657 : : int relid;
4658 : :
4659 : : /* If there are no PHVs anywhere, we needn't work hard */
4660 [ + + ]: 401 : if (root->glob->lastPHId == 0)
4661 : 326 : return false;
4662 : :
4663 : 75 : context.relids = bms_make_singleton(varno);
4664 : 75 : context.baserels = baserels;
4665 : 75 : context.sublevels_up = 0;
4666 : :
4667 : : /*
4668 : : * See if the jointree fragment itself contains references (in join quals)
4669 : : */
4670 [ - + ]: 75 : if (find_dependent_phvs_walker(node, &context))
4671 : 0 : return true;
4672 : :
4673 : : /*
4674 : : * Otherwise, identify the set of referenced RTEs (we can ignore joins,
4675 : : * since they should be flattened already, so their join alias lists no
4676 : : * longer matter), and tediously check each RTE. We can ignore RTEs that
4677 : : * are not marked LATERAL, though, since they couldn't possibly contain
4678 : : * any cross-references to other RTEs.
4679 : : */
4680 : 75 : subrelids = get_relids_in_jointree(node, false, false);
4681 : 75 : relid = -1;
4682 [ + + ]: 160 : while ((relid = bms_next_member(subrelids, relid)) >= 0)
4683 : : {
4684 : 105 : RangeTblEntry *rte = rt_fetch(relid, root->parse->rtable);
4685 : :
4686 [ + + + - ]: 125 : if (rte->lateral &&
4687 : 20 : range_table_entry_walker(rte, find_dependent_phvs_walker, &context, 0))
4688 : 20 : return true;
4689 : : }
4690 : :
4691 : 55 : return false;
4692 : : }
4693 : :
4694 : : /*
4695 : : * substitute_phv_relids - adjust PlaceHolderVar relid sets after pulling up
4696 : : * a subquery or removing an RTE_RESULT jointree item
4697 : : *
4698 : : * Find any PlaceHolderVar nodes in the given tree that reference the
4699 : : * pulled-up relid, and change them to reference the replacement relid(s).
4700 : : *
4701 : : * NOTE: although this has the form of a walker, we cheat and modify the
4702 : : * nodes in-place. This should be OK since the tree was copied by
4703 : : * pullup_replace_vars earlier. Avoid scribbling on the original values of
4704 : : * the bitmapsets, though, because expression_tree_mutator doesn't copy those.
4705 : : */
4706 : :
4707 : : typedef struct
4708 : : {
4709 : : int varno;
4710 : : int sublevels_up;
4711 : : Relids subrelids;
4712 : : } substitute_phv_relids_context;
4713 : :
4714 : : static bool
4715 : 256093 : substitute_phv_relids_walker(Node *node,
4716 : : substitute_phv_relids_context *context)
4717 : : {
4718 [ + + ]: 256093 : if (node == NULL)
4719 : 104520 : return false;
4720 [ + + ]: 151573 : if (IsA(node, PlaceHolderVar))
4721 : : {
4722 : 7368 : PlaceHolderVar *phv = (PlaceHolderVar *) node;
4723 : :
4724 [ + + + + ]: 14712 : if (phv->phlevelsup == context->sublevels_up &&
4725 : 7344 : bms_is_member(context->varno, phv->phrels))
4726 : : {
4727 : 10674 : phv->phrels = bms_union(phv->phrels,
4728 : 5337 : context->subrelids);
4729 : 5337 : phv->phrels = bms_del_member(phv->phrels,
4730 : : context->varno);
4731 : : /* Assert we haven't broken the PHV */
4732 : : Assert(!bms_is_empty(phv->phrels));
4733 : : }
4734 : : /* fall through to examine children */
4735 : : }
4736 [ + + ]: 151573 : if (IsA(node, Query))
4737 : : {
4738 : : /* Recurse into subselects */
4739 : : bool result;
4740 : :
4741 : 4593 : context->sublevels_up++;
4742 : 4593 : result = query_tree_walker((Query *) node,
4743 : : substitute_phv_relids_walker,
4744 : : context, 0);
4745 : 4593 : context->sublevels_up--;
4746 : 4593 : return result;
4747 : : }
4748 : : /* Shouldn't need to handle planner auxiliary nodes here */
4749 : : Assert(!IsA(node, SpecialJoinInfo));
4750 : : Assert(!IsA(node, AppendRelInfo));
4751 : : Assert(!IsA(node, PlaceHolderInfo));
4752 : : Assert(!IsA(node, MinMaxAggInfo));
4753 : :
4754 : 146980 : return expression_tree_walker(node, substitute_phv_relids_walker, context);
4755 : : }
4756 : :
4757 : : static void
4758 : 2489 : substitute_phv_relids(Node *node, int varno, Relids subrelids)
4759 : : {
4760 : : substitute_phv_relids_context context;
4761 : :
4762 : 2489 : context.varno = varno;
4763 : 2489 : context.sublevels_up = 0;
4764 : 2489 : context.subrelids = subrelids;
4765 : :
4766 : : /*
4767 : : * Must be prepared to start with a Query or a bare expression tree.
4768 : : */
4769 : 2489 : query_or_expression_tree_walker(node,
4770 : : substitute_phv_relids_walker,
4771 : : &context,
4772 : : 0);
4773 : 2489 : }
4774 : :
4775 : : /*
4776 : : * fix_append_rel_relids: update RT-index fields of AppendRelInfo nodes
4777 : : *
4778 : : * When we pull up a subquery, any AppendRelInfo references to the subquery's
4779 : : * RT index have to be replaced by the substituted relid (and there had better
4780 : : * be only one). We also need to apply substitute_phv_relids to their
4781 : : * translated_vars lists, since those might contain PlaceHolderVars.
4782 : : *
4783 : : * We assume we may modify the AppendRelInfo nodes in-place.
4784 : : */
4785 : : static void
4786 : 7462 : fix_append_rel_relids(PlannerInfo *root, int varno, Relids subrelids)
4787 : : {
4788 : : ListCell *l;
4789 : 7462 : int subvarno = -1;
4790 : :
4791 : : /*
4792 : : * We only want to extract the member relid once, but we mustn't fail
4793 : : * immediately if there are multiple members; it could be that none of the
4794 : : * AppendRelInfo nodes refer to it. So compute it on first use. Note that
4795 : : * bms_singleton_member will complain if set is not singleton.
4796 : : */
4797 [ + + + + : 17113 : foreach(l, root->append_rel_list)
+ + ]
4798 : : {
4799 : 9651 : AppendRelInfo *appinfo = (AppendRelInfo *) lfirst(l);
4800 : :
4801 : : /* The parent_relid shouldn't ever be a pullup target */
4802 : : Assert(appinfo->parent_relid != varno);
4803 : :
4804 [ + + ]: 9651 : if (appinfo->child_relid == varno)
4805 : : {
4806 [ + - ]: 5198 : if (subvarno < 0)
4807 : 5198 : subvarno = bms_singleton_member(subrelids);
4808 : 5198 : appinfo->child_relid = subvarno;
4809 : : }
4810 : :
4811 : : /* Also fix up any PHVs in its translated vars */
4812 [ + + ]: 9651 : if (root->glob->lastPHId != 0)
4813 : 170 : substitute_phv_relids((Node *) appinfo->translated_vars,
4814 : : varno, subrelids);
4815 : : }
4816 : 7462 : }
4817 : :
4818 : : /*
4819 : : * get_relids_in_jointree: get set of RT indexes present in a jointree
4820 : : *
4821 : : * Base-relation relids are always included in the result.
4822 : : * If include_outer_joins is true, outer-join RT indexes are included.
4823 : : * If include_inner_joins is true, inner-join RT indexes are included.
4824 : : *
4825 : : * Note that for most purposes in the planner, outer joins are included
4826 : : * in standard relid sets. Setting include_inner_joins true is only
4827 : : * appropriate for special purposes during subquery flattening.
4828 : : */
4829 : : Relids
4830 : 83349 : get_relids_in_jointree(Node *jtnode, bool include_outer_joins,
4831 : : bool include_inner_joins)
4832 : : {
4833 : 83349 : Relids result = NULL;
4834 : :
4835 [ - + ]: 83349 : if (jtnode == NULL)
4836 : 0 : return result;
4837 [ + + ]: 83349 : if (IsA(jtnode, RangeTblRef))
4838 : : {
4839 : 42159 : int varno = ((RangeTblRef *) jtnode)->rtindex;
4840 : :
4841 : 42159 : result = bms_make_singleton(varno);
4842 : : }
4843 [ + + ]: 41190 : else if (IsA(jtnode, FromExpr))
4844 : : {
4845 : 33608 : FromExpr *f = (FromExpr *) jtnode;
4846 : : ListCell *l;
4847 : :
4848 [ + - + + : 68531 : foreach(l, f->fromlist)
+ + ]
4849 : : {
4850 : 34923 : result = bms_join(result,
4851 : 34923 : get_relids_in_jointree(lfirst(l),
4852 : : include_outer_joins,
4853 : : include_inner_joins));
4854 : : }
4855 : : }
4856 [ + - ]: 7582 : else if (IsA(jtnode, JoinExpr))
4857 : : {
4858 : 7582 : JoinExpr *j = (JoinExpr *) jtnode;
4859 : :
4860 : 7582 : result = get_relids_in_jointree(j->larg,
4861 : : include_outer_joins,
4862 : : include_inner_joins);
4863 : 7582 : result = bms_join(result,
4864 : : get_relids_in_jointree(j->rarg,
4865 : : include_outer_joins,
4866 : : include_inner_joins));
4867 [ + + ]: 7582 : if (j->rtindex)
4868 : : {
4869 [ + + ]: 7312 : if (j->jointype == JOIN_INNER)
4870 : : {
4871 [ + + ]: 2736 : if (include_inner_joins)
4872 : 717 : result = bms_add_member(result, j->rtindex);
4873 : : }
4874 : : else
4875 : : {
4876 [ + + ]: 4576 : if (include_outer_joins)
4877 : 2053 : result = bms_add_member(result, j->rtindex);
4878 : : }
4879 : : }
4880 : : }
4881 : : else
4882 [ # # ]: 0 : elog(ERROR, "unrecognized node type: %d",
4883 : : (int) nodeTag(jtnode));
4884 : 83349 : return result;
4885 : : }
4886 : :
4887 : : /*
4888 : : * get_relids_for_join: get set of base+OJ RT indexes making up a join
4889 : : */
4890 : : Relids
4891 : 517 : get_relids_for_join(Query *query, int joinrelid)
4892 : : {
4893 : : Node *jtnode;
4894 : :
4895 : 517 : jtnode = find_jointree_node_for_rel((Node *) query->jointree,
4896 : : joinrelid);
4897 [ - + ]: 517 : if (!jtnode)
4898 [ # # ]: 0 : elog(ERROR, "could not find join node %d", joinrelid);
4899 : 517 : return get_relids_in_jointree(jtnode, true, false);
4900 : : }
4901 : :
4902 : : /*
4903 : : * find_jointree_node_for_rel: locate jointree node for a base or join RT index
4904 : : *
4905 : : * Returns NULL if not found
4906 : : */
4907 : : static Node *
4908 : 2240 : find_jointree_node_for_rel(Node *jtnode, int relid)
4909 : : {
4910 [ - + ]: 2240 : if (jtnode == NULL)
4911 : 0 : return NULL;
4912 [ + + ]: 2240 : if (IsA(jtnode, RangeTblRef))
4913 : : {
4914 : 507 : int varno = ((RangeTblRef *) jtnode)->rtindex;
4915 : :
4916 [ - + ]: 507 : if (relid == varno)
4917 : 0 : return jtnode;
4918 : : }
4919 [ + + ]: 1733 : else if (IsA(jtnode, FromExpr))
4920 : : {
4921 : 524 : FromExpr *f = (FromExpr *) jtnode;
4922 : : ListCell *l;
4923 : :
4924 [ + - + - : 539 : foreach(l, f->fromlist)
+ - ]
4925 : : {
4926 : 539 : jtnode = find_jointree_node_for_rel(lfirst(l), relid);
4927 [ + + ]: 539 : if (jtnode)
4928 : 524 : return jtnode;
4929 : : }
4930 : : }
4931 [ + - ]: 1209 : else if (IsA(jtnode, JoinExpr))
4932 : : {
4933 : 1209 : JoinExpr *j = (JoinExpr *) jtnode;
4934 : :
4935 [ + + ]: 1209 : if (relid == j->rtindex)
4936 : 517 : return jtnode;
4937 : 692 : jtnode = find_jointree_node_for_rel(j->larg, relid);
4938 [ + + ]: 692 : if (jtnode)
4939 : 200 : return jtnode;
4940 : 492 : jtnode = find_jointree_node_for_rel(j->rarg, relid);
4941 [ + - ]: 492 : if (jtnode)
4942 : 492 : return jtnode;
4943 : : }
4944 : : else
4945 [ # # ]: 0 : elog(ERROR, "unrecognized node type: %d",
4946 : : (int) nodeTag(jtnode));
4947 : 507 : return NULL;
4948 : : }
4949 : :
4950 : : /*
4951 : : * get_nullingrels: collect info about which outer joins null which relations
4952 : : *
4953 : : * The result struct contains, for each leaf relation used in the query,
4954 : : * the set of relids of outer joins that potentially null that rel.
4955 : : */
4956 : : static nullingrel_info *
4957 : 1034 : get_nullingrels(Query *parse)
4958 : : {
4959 : 1034 : nullingrel_info *result = palloc_object(nullingrel_info);
4960 : :
4961 : 1034 : result->rtlength = list_length(parse->rtable);
4962 : 1034 : result->nullingrels = palloc0_array(Relids, result->rtlength + 1);
4963 : 1034 : get_nullingrels_recurse((Node *) parse->jointree, NULL, result);
4964 : 1034 : return result;
4965 : : }
4966 : :
4967 : : /*
4968 : : * Recursive guts of get_nullingrels().
4969 : : *
4970 : : * Note: at any recursion level, the passed-down upper_nullingrels must be
4971 : : * treated as a constant, but it can be stored directly into *info
4972 : : * if we're at leaf level. Upper recursion levels do not free their mutated
4973 : : * copies of the nullingrels, because those are probably referenced by
4974 : : * at least one leaf rel.
4975 : : */
4976 : : static void
4977 : 5356 : get_nullingrels_recurse(Node *jtnode, Relids upper_nullingrels,
4978 : : nullingrel_info *info)
4979 : : {
4980 [ - + ]: 5356 : if (jtnode == NULL)
4981 : 0 : return;
4982 [ + + ]: 5356 : if (IsA(jtnode, RangeTblRef))
4983 : : {
4984 : 2856 : int varno = ((RangeTblRef *) jtnode)->rtindex;
4985 : :
4986 : : Assert(varno > 0 && varno <= info->rtlength);
4987 : 2856 : info->nullingrels[varno] = upper_nullingrels;
4988 : : }
4989 [ + + ]: 2500 : else if (IsA(jtnode, FromExpr))
4990 : : {
4991 : 1104 : FromExpr *f = (FromExpr *) jtnode;
4992 : : ListCell *l;
4993 : :
4994 [ + - + + : 2634 : foreach(l, f->fromlist)
+ + ]
4995 : : {
4996 : 1530 : get_nullingrels_recurse(lfirst(l), upper_nullingrels, info);
4997 : : }
4998 : : }
4999 [ + - ]: 1396 : else if (IsA(jtnode, JoinExpr))
5000 : : {
5001 : 1396 : JoinExpr *j = (JoinExpr *) jtnode;
5002 : : Relids local_nullingrels;
5003 : :
5004 [ + + + + : 1396 : switch (j->jointype)
- ]
5005 : : {
5006 : 451 : case JOIN_INNER:
5007 : 451 : get_nullingrels_recurse(j->larg, upper_nullingrels, info);
5008 : 451 : get_nullingrels_recurse(j->rarg, upper_nullingrels, info);
5009 : 451 : break;
5010 : 920 : case JOIN_LEFT:
5011 : : case JOIN_SEMI:
5012 : : case JOIN_ANTI:
5013 : 920 : local_nullingrels = bms_add_member(bms_copy(upper_nullingrels),
5014 : : j->rtindex);
5015 : 920 : get_nullingrels_recurse(j->larg, upper_nullingrels, info);
5016 : 920 : get_nullingrels_recurse(j->rarg, local_nullingrels, info);
5017 : 920 : break;
5018 : 15 : case JOIN_FULL:
5019 : 15 : local_nullingrels = bms_add_member(bms_copy(upper_nullingrels),
5020 : : j->rtindex);
5021 : 15 : get_nullingrels_recurse(j->larg, local_nullingrels, info);
5022 : 15 : get_nullingrels_recurse(j->rarg, local_nullingrels, info);
5023 : 15 : break;
5024 : 10 : case JOIN_RIGHT:
5025 : 10 : local_nullingrels = bms_add_member(bms_copy(upper_nullingrels),
5026 : : j->rtindex);
5027 : 10 : get_nullingrels_recurse(j->larg, local_nullingrels, info);
5028 : 10 : get_nullingrels_recurse(j->rarg, upper_nullingrels, info);
5029 : 10 : break;
5030 : 0 : default:
5031 [ # # ]: 0 : elog(ERROR, "unrecognized join type: %d",
5032 : : (int) j->jointype);
5033 : : break;
5034 : : }
5035 : : }
5036 : : else
5037 [ # # ]: 0 : elog(ERROR, "unrecognized node type: %d",
5038 : : (int) nodeTag(jtnode));
5039 : : }
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