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 : List *sub_states; /* List of states for subtree components */
94 : } reduce_outer_joins_pass1_state;
95 :
96 : typedef struct reduce_outer_joins_pass2_state
97 : {
98 : Relids inner_reduced; /* OJ relids reduced to plain inner joins */
99 : List *partial_reduced; /* List of partially reduced FULL joins */
100 : } reduce_outer_joins_pass2_state;
101 :
102 : typedef struct reduce_outer_joins_partial_state
103 : {
104 : int full_join_rti; /* RT index of a formerly-FULL join */
105 : Relids unreduced_side; /* relids in its still-nullable side */
106 : } reduce_outer_joins_partial_state;
107 :
108 : static Query *expand_virtual_generated_columns(PlannerInfo *root, Query *parse,
109 : RangeTblEntry *rte, int rt_index,
110 : Relation relation);
111 : static Node *pull_up_sublinks_jointree_recurse(PlannerInfo *root, Node *jtnode,
112 : Relids *relids);
113 : static Node *pull_up_sublinks_qual_recurse(PlannerInfo *root, Node *node,
114 : Node **jtlink1, Relids available_rels1,
115 : Node **jtlink2, Relids available_rels2);
116 : static Node *pull_up_subqueries_recurse(PlannerInfo *root, Node *jtnode,
117 : JoinExpr *lowest_outer_join,
118 : AppendRelInfo *containing_appendrel);
119 : static Node *pull_up_simple_subquery(PlannerInfo *root, Node *jtnode,
120 : RangeTblEntry *rte,
121 : JoinExpr *lowest_outer_join,
122 : AppendRelInfo *containing_appendrel);
123 : static Node *pull_up_simple_union_all(PlannerInfo *root, Node *jtnode,
124 : RangeTblEntry *rte);
125 : static void pull_up_union_leaf_queries(Node *setOp, PlannerInfo *root,
126 : int parentRTindex, Query *setOpQuery,
127 : int childRToffset);
128 : static void make_setop_translation_list(Query *query, int newvarno,
129 : AppendRelInfo *appinfo);
130 : static bool is_simple_subquery(PlannerInfo *root, Query *subquery,
131 : RangeTblEntry *rte,
132 : JoinExpr *lowest_outer_join);
133 : static Node *pull_up_simple_values(PlannerInfo *root, Node *jtnode,
134 : RangeTblEntry *rte);
135 : static bool is_simple_values(PlannerInfo *root, RangeTblEntry *rte);
136 : static Node *pull_up_constant_function(PlannerInfo *root, Node *jtnode,
137 : RangeTblEntry *rte,
138 : AppendRelInfo *containing_appendrel);
139 : static bool is_simple_union_all(Query *subquery);
140 : static bool is_simple_union_all_recurse(Node *setOp, Query *setOpQuery,
141 : List *colTypes);
142 : static bool is_safe_append_member(Query *subquery);
143 : static bool jointree_contains_lateral_outer_refs(PlannerInfo *root,
144 : Node *jtnode, bool restricted,
145 : Relids safe_upper_varnos);
146 : static void perform_pullup_replace_vars(PlannerInfo *root,
147 : pullup_replace_vars_context *rvcontext,
148 : AppendRelInfo *containing_appendrel);
149 : static void replace_vars_in_jointree(Node *jtnode,
150 : pullup_replace_vars_context *context);
151 : static Node *pullup_replace_vars(Node *expr,
152 : pullup_replace_vars_context *context);
153 : static Node *pullup_replace_vars_callback(Var *var,
154 : replace_rte_variables_context *context);
155 : static Query *pullup_replace_vars_subquery(Query *query,
156 : pullup_replace_vars_context *context);
157 : static reduce_outer_joins_pass1_state *reduce_outer_joins_pass1(Node *jtnode);
158 : static void reduce_outer_joins_pass2(Node *jtnode,
159 : reduce_outer_joins_pass1_state *state1,
160 : reduce_outer_joins_pass2_state *state2,
161 : PlannerInfo *root,
162 : Relids nonnullable_rels,
163 : List *forced_null_vars);
164 : static void report_reduced_full_join(reduce_outer_joins_pass2_state *state2,
165 : int rtindex, Relids relids);
166 : static bool has_notnull_forced_var(PlannerInfo *root, List *forced_null_vars,
167 : reduce_outer_joins_pass1_state *right_state);
168 : static Node *remove_useless_results_recurse(PlannerInfo *root, Node *jtnode,
169 : Node **parent_quals,
170 : Relids *dropped_outer_joins);
171 : static int get_result_relid(PlannerInfo *root, Node *jtnode);
172 : static void remove_result_refs(PlannerInfo *root, int varno, Node *newjtloc);
173 : static bool find_dependent_phvs(PlannerInfo *root, int varno);
174 : static bool find_dependent_phvs_in_jointree(PlannerInfo *root,
175 : Node *node, int varno);
176 : static void substitute_phv_relids(Node *node,
177 : int varno, Relids subrelids);
178 : static void fix_append_rel_relids(PlannerInfo *root, int varno,
179 : Relids subrelids);
180 : static Node *find_jointree_node_for_rel(Node *jtnode, int relid);
181 : static nullingrel_info *get_nullingrels(Query *parse);
182 : static void get_nullingrels_recurse(Node *jtnode, Relids upper_nullingrels,
183 : nullingrel_info *info);
184 :
185 :
186 : /*
187 : * transform_MERGE_to_join
188 : * Replace a MERGE's jointree to also include the target relation.
189 : */
190 : void
191 282335 : transform_MERGE_to_join(Query *parse)
192 : {
193 : RangeTblEntry *joinrte;
194 : JoinExpr *joinexpr;
195 : bool have_action[NUM_MERGE_MATCH_KINDS];
196 : JoinType jointype;
197 : int joinrti;
198 : List *vars;
199 : RangeTblRef *rtr;
200 : FromExpr *target;
201 : Node *source;
202 : int sourcerti;
203 :
204 282335 : if (parse->commandType != CMD_MERGE)
205 281348 : return;
206 :
207 : /* XXX probably bogus */
208 987 : vars = NIL;
209 :
210 : /*
211 : * Work out what kind of join is required. If there any WHEN NOT MATCHED
212 : * BY SOURCE/TARGET actions, an outer join is required so that we process
213 : * all unmatched tuples from the source and/or target relations.
214 : * Otherwise, we can use an inner join.
215 : */
216 987 : have_action[MERGE_WHEN_MATCHED] = false;
217 987 : have_action[MERGE_WHEN_NOT_MATCHED_BY_SOURCE] = false;
218 987 : have_action[MERGE_WHEN_NOT_MATCHED_BY_TARGET] = false;
219 :
220 3475 : foreach_node(MergeAction, action, parse->mergeActionList)
221 : {
222 1501 : if (action->commandType != CMD_NOTHING)
223 1459 : have_action[action->matchKind] = true;
224 : }
225 :
226 987 : if (have_action[MERGE_WHEN_NOT_MATCHED_BY_SOURCE] &&
227 66 : have_action[MERGE_WHEN_NOT_MATCHED_BY_TARGET])
228 51 : jointype = JOIN_FULL;
229 936 : else if (have_action[MERGE_WHEN_NOT_MATCHED_BY_SOURCE])
230 15 : jointype = JOIN_LEFT;
231 921 : else if (have_action[MERGE_WHEN_NOT_MATCHED_BY_TARGET])
232 428 : jointype = JOIN_RIGHT;
233 : else
234 493 : jointype = JOIN_INNER;
235 :
236 : /* Manufacture a join RTE to use. */
237 987 : joinrte = makeNode(RangeTblEntry);
238 987 : joinrte->rtekind = RTE_JOIN;
239 987 : joinrte->jointype = jointype;
240 987 : joinrte->joinmergedcols = 0;
241 987 : joinrte->joinaliasvars = vars;
242 987 : joinrte->joinleftcols = NIL; /* MERGE does not allow JOIN USING */
243 987 : joinrte->joinrightcols = NIL; /* ditto */
244 987 : joinrte->join_using_alias = NULL;
245 :
246 987 : joinrte->alias = NULL;
247 987 : joinrte->eref = makeAlias("*MERGE*", NIL);
248 987 : joinrte->lateral = false;
249 987 : joinrte->inh = false;
250 987 : joinrte->inFromCl = true;
251 :
252 : /*
253 : * Add completed RTE to pstate's range table list, so that we know its
254 : * index.
255 : */
256 987 : parse->rtable = lappend(parse->rtable, joinrte);
257 987 : joinrti = list_length(parse->rtable);
258 :
259 : /*
260 : * Create a JOIN between the target and the source relation.
261 : *
262 : * Here the target is identified by parse->mergeTargetRelation. For a
263 : * regular table, this will equal parse->resultRelation, but for a
264 : * trigger-updatable view, it will be the expanded view subquery that we
265 : * need to pull data from.
266 : *
267 : * The source relation is in parse->jointree->fromlist, but any quals in
268 : * parse->jointree->quals are restrictions on the target relation (if the
269 : * target relation is an auto-updatable view).
270 : */
271 : /* target rel, with any quals */
272 987 : rtr = makeNode(RangeTblRef);
273 987 : rtr->rtindex = parse->mergeTargetRelation;
274 987 : target = makeFromExpr(list_make1(rtr), parse->jointree->quals);
275 :
276 : /* source rel (expect exactly one -- see transformMergeStmt()) */
277 : Assert(list_length(parse->jointree->fromlist) == 1);
278 987 : source = linitial(parse->jointree->fromlist);
279 :
280 : /*
281 : * index of source rel (expect either a RangeTblRef or a JoinExpr -- see
282 : * transformFromClauseItem()).
283 : */
284 987 : if (IsA(source, RangeTblRef))
285 945 : sourcerti = ((RangeTblRef *) source)->rtindex;
286 42 : else if (IsA(source, JoinExpr))
287 42 : sourcerti = ((JoinExpr *) source)->rtindex;
288 : else
289 : {
290 0 : elog(ERROR, "unrecognized source node type: %d",
291 : (int) nodeTag(source));
292 : sourcerti = 0; /* keep compiler quiet */
293 : }
294 :
295 : /* Join the source and target */
296 987 : joinexpr = makeNode(JoinExpr);
297 987 : joinexpr->jointype = jointype;
298 987 : joinexpr->isNatural = false;
299 987 : joinexpr->larg = (Node *) target;
300 987 : joinexpr->rarg = source;
301 987 : joinexpr->usingClause = NIL;
302 987 : joinexpr->join_using_alias = NULL;
303 987 : joinexpr->quals = parse->mergeJoinCondition;
304 987 : joinexpr->alias = NULL;
305 987 : joinexpr->rtindex = joinrti;
306 :
307 : /* Make the new join be the sole entry in the query's jointree */
308 987 : parse->jointree->fromlist = list_make1(joinexpr);
309 987 : parse->jointree->quals = NULL;
310 :
311 : /*
312 : * If necessary, mark parse->targetlist entries that refer to the target
313 : * as nullable by the join. Normally the targetlist will be empty for a
314 : * MERGE, but if the target is a trigger-updatable view, it will contain a
315 : * whole-row Var referring to the expanded view query.
316 : */
317 987 : if (parse->targetList != NIL &&
318 21 : (jointype == JOIN_RIGHT || jointype == JOIN_FULL))
319 21 : parse->targetList = (List *)
320 21 : add_nulling_relids((Node *) parse->targetList,
321 21 : bms_make_singleton(parse->mergeTargetRelation),
322 21 : bms_make_singleton(joinrti));
323 :
324 : /*
325 : * If the source relation is on the outer side of the join, mark any
326 : * source relation Vars in the join condition, actions, and RETURNING list
327 : * as nullable by the join. These Vars will be added to the targetlist by
328 : * preprocess_targetlist(), so it's important to mark them correctly here.
329 : *
330 : * It might seem that this is not necessary for Vars in the join
331 : * condition, since it is inside the join, but it is also needed above the
332 : * join (in the ModifyTable node) to distinguish between the MATCHED and
333 : * NOT MATCHED BY SOURCE cases -- see ExecMergeMatched(). Note that this
334 : * creates a modified copy of the join condition, for use above the join,
335 : * without modifying the original join condition, inside the join.
336 : */
337 987 : if (jointype == JOIN_LEFT || jointype == JOIN_FULL)
338 : {
339 66 : parse->mergeJoinCondition =
340 66 : add_nulling_relids(parse->mergeJoinCondition,
341 66 : bms_make_singleton(sourcerti),
342 66 : bms_make_singleton(joinrti));
343 :
344 315 : foreach_node(MergeAction, action, parse->mergeActionList)
345 : {
346 183 : action->qual =
347 183 : add_nulling_relids(action->qual,
348 183 : bms_make_singleton(sourcerti),
349 183 : bms_make_singleton(joinrti));
350 :
351 183 : action->targetList = (List *)
352 183 : add_nulling_relids((Node *) action->targetList,
353 183 : bms_make_singleton(sourcerti),
354 183 : bms_make_singleton(joinrti));
355 : }
356 :
357 66 : parse->returningList = (List *)
358 66 : add_nulling_relids((Node *) parse->returningList,
359 66 : bms_make_singleton(sourcerti),
360 66 : bms_make_singleton(joinrti));
361 : }
362 :
363 : /*
364 : * If there are any WHEN NOT MATCHED BY SOURCE actions, the executor will
365 : * use the join condition to distinguish between MATCHED and NOT MATCHED
366 : * BY SOURCE cases. Otherwise, it's no longer needed, and we set it to
367 : * NULL, saving cycles during planning and execution.
368 : *
369 : * We need to be careful though: the executor evaluates this condition
370 : * using the output of the join subplan node, which nulls the output from
371 : * the source relation when the join condition doesn't match. That risks
372 : * producing incorrect results when rechecking using a "non-strict" join
373 : * condition, such as "src.col IS NOT DISTINCT FROM tgt.col". To guard
374 : * against that, we add an additional "src IS NOT NULL" check to the join
375 : * condition, so that it does the right thing when performing a recheck
376 : * based on the output of the join subplan.
377 : */
378 987 : if (have_action[MERGE_WHEN_NOT_MATCHED_BY_SOURCE])
379 : {
380 : Var *var;
381 : NullTest *ntest;
382 :
383 : /* source wholerow Var (nullable by the new join) */
384 66 : var = makeWholeRowVar(rt_fetch(sourcerti, parse->rtable),
385 : sourcerti, 0, false);
386 66 : var->varnullingrels = bms_make_singleton(joinrti);
387 :
388 : /* "src IS NOT NULL" check */
389 66 : ntest = makeNode(NullTest);
390 66 : ntest->arg = (Expr *) var;
391 66 : ntest->nulltesttype = IS_NOT_NULL;
392 66 : ntest->argisrow = false;
393 66 : ntest->location = -1;
394 :
395 : /* combine it with the original join condition */
396 66 : parse->mergeJoinCondition =
397 66 : (Node *) make_and_qual((Node *) ntest, parse->mergeJoinCondition);
398 : }
399 : else
400 921 : parse->mergeJoinCondition = NULL; /* join condition not needed */
401 : }
402 :
403 : /*
404 : * preprocess_relation_rtes
405 : * Do the preprocessing work for any relation RTEs in the FROM clause.
406 : *
407 : * This scans the rangetable for relation RTEs and retrieves the necessary
408 : * catalog information for each relation. Using this information, it clears
409 : * the inh flag for any relation that has no children, collects not-null
410 : * attribute numbers for any relation that has column not-null constraints, and
411 : * expands virtual generated columns for any relation that contains them.
412 : *
413 : * Note that expanding virtual generated columns may cause the query tree to
414 : * have new copies of rangetable entries. Therefore, we have to use list_nth
415 : * instead of foreach when iterating over the query's rangetable.
416 : *
417 : * Returns a modified copy of the query tree, if any relations with virtual
418 : * generated columns are present.
419 : */
420 : Query *
421 303836 : preprocess_relation_rtes(PlannerInfo *root)
422 : {
423 303836 : Query *parse = root->parse;
424 : int rtable_size;
425 : int rt_index;
426 :
427 303836 : rtable_size = list_length(parse->rtable);
428 :
429 684714 : for (rt_index = 0; rt_index < rtable_size; rt_index++)
430 : {
431 380878 : RangeTblEntry *rte = rt_fetch(rt_index + 1, parse->rtable);
432 : Relation relation;
433 :
434 : /* We only care about relation RTEs. */
435 380878 : if (rte->rtekind != RTE_RELATION)
436 125553 : continue;
437 :
438 : /*
439 : * We need not lock the relation since it was already locked by the
440 : * rewriter.
441 : */
442 255325 : relation = table_open(rte->relid, NoLock);
443 :
444 : /*
445 : * Check to see if the relation actually has any children; if not,
446 : * clear the inh flag so we can treat it as a plain base relation.
447 : *
448 : * Note: this could give a false-positive result, if the rel once had
449 : * children but no longer does. We used to be able to clear rte->inh
450 : * later on when we discovered that, but no more; we have to handle
451 : * such cases as full-fledged inheritance.
452 : */
453 255325 : if (rte->inh)
454 213367 : rte->inh = relation->rd_rel->relhassubclass;
455 :
456 : /*
457 : * Check to see if the relation has any column not-null constraints;
458 : * if so, retrieve the constraint information and store it in a
459 : * relation OID based hash table.
460 : */
461 255325 : get_relation_notnullatts(root, relation);
462 :
463 : /*
464 : * Check to see if the relation has any virtual generated columns; if
465 : * so, replace all Var nodes in the query that reference these columns
466 : * with the generation expressions.
467 : */
468 255325 : parse = expand_virtual_generated_columns(root, parse,
469 : rte, rt_index + 1,
470 : relation);
471 :
472 255325 : table_close(relation, NoLock);
473 : }
474 :
475 303836 : return parse;
476 : }
477 :
478 : /*
479 : * expand_virtual_generated_columns
480 : * Expand virtual generated columns for the given relation.
481 : *
482 : * This checks whether the given relation has any virtual generated columns,
483 : * and if so, replaces all Var nodes in the query that reference those columns
484 : * with their generation expressions.
485 : *
486 : * Returns a modified copy of the query tree if the relation contains virtual
487 : * generated columns.
488 : */
489 : static Query *
490 255325 : expand_virtual_generated_columns(PlannerInfo *root, Query *parse,
491 : RangeTblEntry *rte, int rt_index,
492 : Relation relation)
493 : {
494 : TupleDesc tupdesc;
495 :
496 : /* Only normal relations can have virtual generated columns */
497 : Assert(rte->rtekind == RTE_RELATION);
498 :
499 255325 : tupdesc = RelationGetDescr(relation);
500 255325 : if (tupdesc->constr && tupdesc->constr->has_generated_virtual)
501 : {
502 551 : List *tlist = NIL;
503 : pullup_replace_vars_context rvcontext;
504 :
505 2168 : for (int i = 0; i < tupdesc->natts; i++)
506 : {
507 1617 : Form_pg_attribute attr = TupleDescAttr(tupdesc, i);
508 : TargetEntry *tle;
509 :
510 1617 : if (attr->attgenerated == ATTRIBUTE_GENERATED_VIRTUAL)
511 : {
512 : Node *defexpr;
513 :
514 722 : defexpr = build_generation_expression(relation, i + 1);
515 722 : ChangeVarNodes(defexpr, 1, rt_index, 0);
516 :
517 722 : tle = makeTargetEntry((Expr *) defexpr, i + 1, 0, false);
518 722 : tlist = lappend(tlist, tle);
519 : }
520 : else
521 : {
522 : Var *var;
523 :
524 895 : var = makeVar(rt_index,
525 895 : i + 1,
526 : attr->atttypid,
527 : attr->atttypmod,
528 : attr->attcollation,
529 : 0);
530 :
531 895 : tle = makeTargetEntry((Expr *) var, i + 1, 0, false);
532 895 : tlist = lappend(tlist, tle);
533 : }
534 : }
535 :
536 : Assert(list_length(tlist) > 0);
537 : Assert(!rte->lateral);
538 :
539 : /*
540 : * The relation's targetlist items are now in the appropriate form to
541 : * insert into the query, except that we may need to wrap them in
542 : * PlaceHolderVars. Set up required context data for
543 : * pullup_replace_vars.
544 : */
545 551 : rvcontext.root = root;
546 551 : rvcontext.targetlist = tlist;
547 551 : rvcontext.target_rte = rte;
548 551 : rvcontext.result_relation = parse->resultRelation;
549 : /* won't need these values */
550 551 : rvcontext.relids = NULL;
551 551 : rvcontext.nullinfo = NULL;
552 : /* pass NULL for outer_hasSubLinks */
553 551 : rvcontext.outer_hasSubLinks = NULL;
554 551 : rvcontext.varno = rt_index;
555 : /* this flag will be set below, if needed */
556 551 : rvcontext.wrap_option = REPLACE_WRAP_NONE;
557 : /* initialize cache array with indexes 0 .. length(tlist) */
558 551 : rvcontext.rv_cache = palloc0((list_length(tlist) + 1) *
559 : sizeof(Node *));
560 :
561 : /*
562 : * If the query uses grouping sets, we need a PlaceHolderVar for each
563 : * expression of the relation's targetlist items. (See comments in
564 : * pull_up_simple_subquery().)
565 : */
566 551 : if (parse->groupingSets)
567 6 : rvcontext.wrap_option = REPLACE_WRAP_ALL;
568 :
569 : /*
570 : * Apply pullup variable replacement throughout the query tree.
571 : */
572 551 : parse = (Query *) pullup_replace_vars((Node *) parse, &rvcontext);
573 : }
574 :
575 255325 : return parse;
576 : }
577 :
578 : /*
579 : * replace_empty_jointree
580 : * If the Query's jointree is empty, replace it with a dummy RTE_RESULT
581 : * relation.
582 : *
583 : * By doing this, we can avoid a bunch of corner cases that formerly existed
584 : * for SELECTs with omitted FROM clauses. An example is that a subquery
585 : * with empty jointree previously could not be pulled up, because that would
586 : * have resulted in an empty relid set, making the subquery not uniquely
587 : * identifiable for join or PlaceHolderVar processing.
588 : *
589 : * Unlike most other functions in this file, this function doesn't recurse;
590 : * we rely on other processing to invoke it on sub-queries at suitable times.
591 : */
592 : void
593 303836 : replace_empty_jointree(Query *parse)
594 : {
595 : RangeTblEntry *rte;
596 : Index rti;
597 : RangeTblRef *rtr;
598 :
599 : /* Nothing to do if jointree is already nonempty */
600 303836 : if (parse->jointree->fromlist != NIL)
601 203037 : return;
602 :
603 : /* We mustn't change it in the top level of a setop tree, either */
604 104432 : if (parse->setOperations)
605 3633 : return;
606 :
607 : /* Create suitable RTE */
608 100799 : rte = makeNode(RangeTblEntry);
609 100799 : rte->rtekind = RTE_RESULT;
610 100799 : rte->eref = makeAlias("*RESULT*", NIL);
611 :
612 : /* Add it to rangetable */
613 100799 : parse->rtable = lappend(parse->rtable, rte);
614 100799 : rti = list_length(parse->rtable);
615 :
616 : /* And jam a reference into the jointree */
617 100799 : rtr = makeNode(RangeTblRef);
618 100799 : rtr->rtindex = rti;
619 100799 : parse->jointree->fromlist = list_make1(rtr);
620 : }
621 :
622 : /*
623 : * pull_up_sublinks
624 : * Attempt to pull up ANY and EXISTS SubLinks to be treated as
625 : * semijoins or anti-semijoins.
626 : *
627 : * A clause "foo op ANY (sub-SELECT)" can be processed by pulling the
628 : * sub-SELECT up to become a rangetable entry and treating the implied
629 : * comparisons as quals of a semijoin. However, this optimization *only*
630 : * works at the top level of WHERE or a JOIN/ON clause, because we cannot
631 : * distinguish whether the ANY ought to return FALSE or NULL in cases
632 : * involving NULL inputs. Also, in an outer join's ON clause we can only
633 : * do this if the sublink is degenerate (ie, references only the nullable
634 : * side of the join). In that case it is legal to push the semijoin
635 : * down into the nullable side of the join. If the sublink references any
636 : * nonnullable-side variables then it would have to be evaluated as part
637 : * of the outer join, which makes things way too complicated.
638 : *
639 : * Under similar conditions, EXISTS and NOT EXISTS clauses can be handled
640 : * by pulling up the sub-SELECT and creating a semijoin or anti-semijoin.
641 : *
642 : * This routine searches for such clauses and does the necessary parsetree
643 : * transformations if any are found.
644 : *
645 : * This routine has to run before preprocess_expression(), so the quals
646 : * clauses are not yet reduced to implicit-AND format, and are not guaranteed
647 : * to be AND/OR-flat either. That means we need to recursively search through
648 : * explicit AND clauses. We stop as soon as we hit a non-AND item.
649 : */
650 : void
651 21104 : pull_up_sublinks(PlannerInfo *root)
652 : {
653 : Node *jtnode;
654 : Relids relids;
655 :
656 : /* Begin recursion through the jointree */
657 21104 : jtnode = pull_up_sublinks_jointree_recurse(root,
658 21104 : (Node *) root->parse->jointree,
659 : &relids);
660 :
661 : /*
662 : * root->parse->jointree must always be a FromExpr, so insert a dummy one
663 : * if we got a bare RangeTblRef or JoinExpr out of the recursion.
664 : */
665 21104 : if (IsA(jtnode, FromExpr))
666 16991 : root->parse->jointree = (FromExpr *) jtnode;
667 : else
668 4113 : root->parse->jointree = makeFromExpr(list_make1(jtnode), NULL);
669 21104 : }
670 :
671 : /*
672 : * Recurse through jointree nodes for pull_up_sublinks()
673 : *
674 : * In addition to returning the possibly-modified jointree node, we return
675 : * a relids set of the contained rels into *relids.
676 : */
677 : static Node *
678 72787 : pull_up_sublinks_jointree_recurse(PlannerInfo *root, Node *jtnode,
679 : Relids *relids)
680 : {
681 : /* Since this function recurses, it could be driven to stack overflow. */
682 72787 : check_stack_depth();
683 :
684 72787 : if (jtnode == NULL)
685 : {
686 0 : *relids = NULL;
687 : }
688 72787 : else if (IsA(jtnode, RangeTblRef))
689 : {
690 39332 : int varno = ((RangeTblRef *) jtnode)->rtindex;
691 :
692 39332 : *relids = bms_make_singleton(varno);
693 : /* jtnode is returned unmodified */
694 : }
695 33455 : else if (IsA(jtnode, FromExpr))
696 : {
697 21218 : FromExpr *f = (FromExpr *) jtnode;
698 21218 : List *newfromlist = NIL;
699 21218 : Relids frelids = NULL;
700 : FromExpr *newf;
701 : Node *jtlink;
702 : ListCell *l;
703 :
704 : /* First, recurse to process children and collect their relids */
705 44202 : foreach(l, f->fromlist)
706 : {
707 : Node *newchild;
708 : Relids childrelids;
709 :
710 22984 : newchild = pull_up_sublinks_jointree_recurse(root,
711 22984 : lfirst(l),
712 : &childrelids);
713 22984 : newfromlist = lappend(newfromlist, newchild);
714 22984 : frelids = bms_join(frelids, childrelids);
715 : }
716 : /* Build the replacement FromExpr; no quals yet */
717 21218 : newf = makeFromExpr(newfromlist, NULL);
718 : /* Set up a link representing the rebuilt jointree */
719 21218 : jtlink = (Node *) newf;
720 : /* Now process qual --- all children are available for use */
721 21218 : newf->quals = pull_up_sublinks_qual_recurse(root, f->quals,
722 : &jtlink, frelids,
723 : NULL, NULL);
724 :
725 : /*
726 : * Note that the result will be either newf, or a stack of JoinExprs
727 : * with newf at the base. We rely on subsequent optimization steps to
728 : * flatten this and rearrange the joins as needed.
729 : *
730 : * Although we could include the pulled-up subqueries in the returned
731 : * relids, there's no need since upper quals couldn't refer to their
732 : * outputs anyway.
733 : */
734 21218 : *relids = frelids;
735 21218 : jtnode = jtlink;
736 : }
737 12237 : else if (IsA(jtnode, JoinExpr))
738 : {
739 : JoinExpr *j;
740 : Relids leftrelids;
741 : Relids rightrelids;
742 : Node *jtlink;
743 :
744 : /*
745 : * Make a modifiable copy of join node, but don't bother copying its
746 : * subnodes (yet).
747 : */
748 12237 : j = palloc_object(JoinExpr);
749 12237 : memcpy(j, jtnode, sizeof(JoinExpr));
750 12237 : jtlink = (Node *) j;
751 :
752 : /* Recurse to process children and collect their relids */
753 12237 : j->larg = pull_up_sublinks_jointree_recurse(root, j->larg,
754 : &leftrelids);
755 12237 : j->rarg = pull_up_sublinks_jointree_recurse(root, j->rarg,
756 : &rightrelids);
757 :
758 : /*
759 : * Now process qual, showing appropriate child relids as available,
760 : * and attach any pulled-up jointree items at the right place. In the
761 : * inner-join case we put new JoinExprs above the existing one (much
762 : * as for a FromExpr-style join). In outer-join cases the new
763 : * JoinExprs must go into the nullable side of the outer join. The
764 : * point of the available_rels machinations is to ensure that we only
765 : * pull up quals for which that's okay.
766 : *
767 : * We don't expect to see any pre-existing JOIN_SEMI, JOIN_ANTI,
768 : * JOIN_RIGHT_SEMI, or JOIN_RIGHT_ANTI jointypes here.
769 : */
770 12237 : switch (j->jointype)
771 : {
772 5342 : case JOIN_INNER:
773 5342 : j->quals = pull_up_sublinks_qual_recurse(root, j->quals,
774 : &jtlink,
775 : bms_union(leftrelids,
776 : rightrelids),
777 : NULL, NULL);
778 5342 : break;
779 6841 : case JOIN_LEFT:
780 6841 : j->quals = pull_up_sublinks_qual_recurse(root, j->quals,
781 : &j->rarg,
782 : rightrelids,
783 : NULL, NULL);
784 6841 : break;
785 6 : case JOIN_FULL:
786 : /* can't do anything with full-join quals */
787 6 : break;
788 48 : case JOIN_RIGHT:
789 48 : j->quals = pull_up_sublinks_qual_recurse(root, j->quals,
790 : &j->larg,
791 : leftrelids,
792 : NULL, NULL);
793 48 : break;
794 0 : default:
795 0 : elog(ERROR, "unrecognized join type: %d",
796 : (int) j->jointype);
797 : break;
798 : }
799 :
800 : /*
801 : * Although we could include the pulled-up subqueries in the returned
802 : * relids, there's no need since upper quals couldn't refer to their
803 : * outputs anyway. But we *do* need to include the join's own rtindex
804 : * because we haven't yet collapsed join alias variables, so upper
805 : * levels would mistakenly think they couldn't use references to this
806 : * join.
807 : */
808 12237 : *relids = bms_join(leftrelids, rightrelids);
809 12237 : if (j->rtindex)
810 12237 : *relids = bms_add_member(*relids, j->rtindex);
811 12237 : jtnode = jtlink;
812 : }
813 : else
814 0 : elog(ERROR, "unrecognized node type: %d",
815 : (int) nodeTag(jtnode));
816 72787 : return jtnode;
817 : }
818 :
819 : /*
820 : * Recurse through top-level qual nodes for pull_up_sublinks()
821 : *
822 : * jtlink1 points to the link in the jointree where any new JoinExprs should
823 : * be inserted if they reference available_rels1 (i.e., available_rels1
824 : * denotes the relations present underneath jtlink1). Optionally, jtlink2 can
825 : * point to a second link where new JoinExprs should be inserted if they
826 : * reference available_rels2 (pass NULL for both those arguments if not used).
827 : * Note that SubLinks referencing both sets of variables cannot be optimized.
828 : * If we find multiple pull-up-able SubLinks, they'll get stacked onto jtlink1
829 : * and/or jtlink2 in the order we encounter them. We rely on subsequent
830 : * optimization to rearrange the stack if appropriate.
831 : *
832 : * Returns the replacement qual node, or NULL if the qual should be removed.
833 : */
834 : static Node *
835 69335 : pull_up_sublinks_qual_recurse(PlannerInfo *root, Node *node,
836 : Node **jtlink1, Relids available_rels1,
837 : Node **jtlink2, Relids available_rels2)
838 : {
839 69335 : if (node == NULL)
840 4153 : return NULL;
841 65182 : if (IsA(node, SubLink))
842 : {
843 2899 : SubLink *sublink = (SubLink *) node;
844 : JoinExpr *j;
845 : Relids child_rels;
846 :
847 : /* Is it a convertible ANY or EXISTS clause? */
848 2899 : if (sublink->subLinkType == ANY_SUBLINK)
849 : {
850 : ScalarArrayOpExpr *saop;
851 :
852 2408 : if ((saop = convert_VALUES_to_ANY(root,
853 : sublink->testexpr,
854 2408 : (Query *) sublink->subselect)) != NULL)
855 :
856 : /*
857 : * The VALUES sequence was simplified. Nothing more to do
858 : * here.
859 : */
860 42 : return (Node *) saop;
861 :
862 2366 : if ((j = convert_ANY_sublink_to_join(root, sublink,
863 : available_rels1)) != NULL)
864 : {
865 : /* Yes; insert the new join node into the join tree */
866 2313 : j->larg = *jtlink1;
867 2313 : *jtlink1 = (Node *) j;
868 : /* Recursively process pulled-up jointree nodes */
869 2313 : j->rarg = pull_up_sublinks_jointree_recurse(root,
870 : j->rarg,
871 : &child_rels);
872 :
873 : /*
874 : * Now recursively process the pulled-up quals. Any inserted
875 : * joins can get stacked onto either j->larg or j->rarg,
876 : * depending on which rels they reference.
877 : */
878 2313 : j->quals = pull_up_sublinks_qual_recurse(root,
879 : j->quals,
880 : &j->larg,
881 : available_rels1,
882 : &j->rarg,
883 : child_rels);
884 : /* Return NULL representing constant TRUE */
885 2313 : return NULL;
886 : }
887 56 : if (available_rels2 != NULL &&
888 3 : (j = convert_ANY_sublink_to_join(root, sublink,
889 : available_rels2)) != NULL)
890 : {
891 : /* Yes; insert the new join node into the join tree */
892 0 : j->larg = *jtlink2;
893 0 : *jtlink2 = (Node *) j;
894 : /* Recursively process pulled-up jointree nodes */
895 0 : j->rarg = pull_up_sublinks_jointree_recurse(root,
896 : j->rarg,
897 : &child_rels);
898 :
899 : /*
900 : * Now recursively process the pulled-up quals. Any inserted
901 : * joins can get stacked onto either j->larg or j->rarg,
902 : * depending on which rels they reference.
903 : */
904 0 : j->quals = pull_up_sublinks_qual_recurse(root,
905 : j->quals,
906 : &j->larg,
907 : available_rels2,
908 : &j->rarg,
909 : child_rels);
910 : /* Return NULL representing constant TRUE */
911 0 : return NULL;
912 : }
913 : }
914 491 : else if (sublink->subLinkType == EXISTS_SUBLINK)
915 : {
916 461 : if ((j = convert_EXISTS_sublink_to_join(root, sublink, false,
917 : available_rels1)) != NULL)
918 : {
919 : /* Yes; insert the new join node into the join tree */
920 377 : j->larg = *jtlink1;
921 377 : *jtlink1 = (Node *) j;
922 : /* Recursively process pulled-up jointree nodes */
923 377 : j->rarg = pull_up_sublinks_jointree_recurse(root,
924 : j->rarg,
925 : &child_rels);
926 :
927 : /*
928 : * Now recursively process the pulled-up quals. Any inserted
929 : * joins can get stacked onto either j->larg or j->rarg,
930 : * depending on which rels they reference.
931 : */
932 377 : j->quals = pull_up_sublinks_qual_recurse(root,
933 : j->quals,
934 : &j->larg,
935 : available_rels1,
936 : &j->rarg,
937 : child_rels);
938 : /* Return NULL representing constant TRUE */
939 377 : return NULL;
940 : }
941 100 : if (available_rels2 != NULL &&
942 16 : (j = convert_EXISTS_sublink_to_join(root, sublink, false,
943 : available_rels2)) != NULL)
944 : {
945 : /* Yes; insert the new join node into the join tree */
946 16 : j->larg = *jtlink2;
947 16 : *jtlink2 = (Node *) j;
948 : /* Recursively process pulled-up jointree nodes */
949 16 : j->rarg = pull_up_sublinks_jointree_recurse(root,
950 : j->rarg,
951 : &child_rels);
952 :
953 : /*
954 : * Now recursively process the pulled-up quals. Any inserted
955 : * joins can get stacked onto either j->larg or j->rarg,
956 : * depending on which rels they reference.
957 : */
958 16 : j->quals = pull_up_sublinks_qual_recurse(root,
959 : j->quals,
960 : &j->larg,
961 : available_rels2,
962 : &j->rarg,
963 : child_rels);
964 : /* Return NULL representing constant TRUE */
965 16 : return NULL;
966 : }
967 : }
968 : /* Else return it unmodified */
969 151 : return node;
970 : }
971 62283 : if (is_notclause(node))
972 : {
973 : /* If the immediate argument of NOT is EXISTS, try to convert */
974 3946 : SubLink *sublink = (SubLink *) get_notclausearg((Expr *) node);
975 : JoinExpr *j;
976 : Relids child_rels;
977 :
978 3946 : if (sublink && IsA(sublink, SubLink))
979 : {
980 1574 : if (sublink->subLinkType == EXISTS_SUBLINK)
981 : {
982 1526 : if ((j = convert_EXISTS_sublink_to_join(root, sublink, true,
983 : available_rels1)) != NULL)
984 : {
985 : /* Yes; insert the new join node into the join tree */
986 1519 : j->larg = *jtlink1;
987 1519 : *jtlink1 = (Node *) j;
988 : /* Recursively process pulled-up jointree nodes */
989 1519 : j->rarg = pull_up_sublinks_jointree_recurse(root,
990 : j->rarg,
991 : &child_rels);
992 :
993 : /*
994 : * Now recursively process the pulled-up quals. Because
995 : * we are underneath a NOT, we can't pull up sublinks that
996 : * reference the left-hand stuff, but it's still okay to
997 : * pull up sublinks referencing j->rarg.
998 : */
999 1519 : j->quals = pull_up_sublinks_qual_recurse(root,
1000 : j->quals,
1001 : &j->rarg,
1002 : child_rels,
1003 : NULL, NULL);
1004 : /* Return NULL representing constant TRUE */
1005 1519 : return NULL;
1006 : }
1007 7 : if (available_rels2 != NULL &&
1008 0 : (j = convert_EXISTS_sublink_to_join(root, sublink, true,
1009 : available_rels2)) != NULL)
1010 : {
1011 : /* Yes; insert the new join node into the join tree */
1012 0 : j->larg = *jtlink2;
1013 0 : *jtlink2 = (Node *) j;
1014 : /* Recursively process pulled-up jointree nodes */
1015 0 : j->rarg = pull_up_sublinks_jointree_recurse(root,
1016 : j->rarg,
1017 : &child_rels);
1018 :
1019 : /*
1020 : * Now recursively process the pulled-up quals. Because
1021 : * we are underneath a NOT, we can't pull up sublinks that
1022 : * reference the left-hand stuff, but it's still okay to
1023 : * pull up sublinks referencing j->rarg.
1024 : */
1025 0 : j->quals = pull_up_sublinks_qual_recurse(root,
1026 : j->quals,
1027 : &j->rarg,
1028 : child_rels,
1029 : NULL, NULL);
1030 : /* Return NULL representing constant TRUE */
1031 0 : return NULL;
1032 : }
1033 : }
1034 : }
1035 : /* Else return it unmodified */
1036 2427 : return node;
1037 : }
1038 58337 : if (is_andclause(node))
1039 : {
1040 : /* Recurse into AND clause */
1041 11232 : List *newclauses = NIL;
1042 : ListCell *l;
1043 :
1044 42893 : foreach(l, ((BoolExpr *) node)->args)
1045 : {
1046 31661 : Node *oldclause = (Node *) lfirst(l);
1047 : Node *newclause;
1048 :
1049 31661 : newclause = pull_up_sublinks_qual_recurse(root,
1050 : oldclause,
1051 : jtlink1,
1052 : available_rels1,
1053 : jtlink2,
1054 : available_rels2);
1055 31661 : if (newclause)
1056 28704 : newclauses = lappend(newclauses, newclause);
1057 : }
1058 : /* We might have got back fewer clauses than we started with */
1059 11232 : if (newclauses == NIL)
1060 63 : return NULL;
1061 11169 : else if (list_length(newclauses) == 1)
1062 582 : return (Node *) linitial(newclauses);
1063 : else
1064 10587 : return (Node *) make_andclause(newclauses);
1065 : }
1066 : /* Stop if not an AND */
1067 47105 : return node;
1068 : }
1069 :
1070 : /*
1071 : * preprocess_function_rtes
1072 : * Constant-simplify any FUNCTION RTEs in the FROM clause, and then
1073 : * attempt to "inline" any that can be converted to simple subqueries.
1074 : *
1075 : * If an RTE_FUNCTION rtable entry invokes a set-returning SQL function that
1076 : * contains just a simple SELECT, we can convert the rtable entry to an
1077 : * RTE_SUBQUERY entry exposing the SELECT directly. Other sorts of functions
1078 : * are also inline-able if they have a support function that can generate
1079 : * the replacement sub-Query. This is especially useful if the subquery can
1080 : * then be "pulled up" for further optimization, but we do it even if not,
1081 : * to reduce executor overhead.
1082 : *
1083 : * This has to be done before we have started to do any optimization of
1084 : * subqueries, else any such steps wouldn't get applied to subqueries
1085 : * obtained via inlining. However, we do it after pull_up_sublinks
1086 : * so that we can inline any functions used in SubLink subselects.
1087 : *
1088 : * The reason for applying const-simplification at this stage is that
1089 : * (a) we'd need to do it anyway to inline a SRF, and (b) by doing it now,
1090 : * we can be sure that pull_up_constant_function() will see constants
1091 : * if there are constants to be seen. This approach also guarantees
1092 : * that every FUNCTION RTE has been const-simplified, allowing planner.c's
1093 : * preprocess_expression() to skip doing it again.
1094 : *
1095 : * Like most of the planner, this feels free to scribble on its input data
1096 : * structure.
1097 : */
1098 : void
1099 301902 : preprocess_function_rtes(PlannerInfo *root)
1100 : {
1101 : ListCell *rt;
1102 :
1103 785849 : foreach(rt, root->parse->rtable)
1104 : {
1105 483950 : RangeTblEntry *rte = (RangeTblEntry *) lfirst(rt);
1106 :
1107 483950 : if (rte->rtekind == RTE_FUNCTION)
1108 : {
1109 : Query *funcquery;
1110 :
1111 : /* Apply const-simplification */
1112 27720 : rte->functions = (List *)
1113 27720 : eval_const_expressions(root, (Node *) rte->functions);
1114 :
1115 : /* Check safety of expansion, and expand if possible */
1116 27720 : funcquery = inline_function_in_from(root, rte);
1117 27717 : if (funcquery)
1118 : {
1119 : /* Successful expansion, convert the RTE to a subquery */
1120 123 : rte->rtekind = RTE_SUBQUERY;
1121 123 : rte->subquery = funcquery;
1122 123 : rte->security_barrier = false;
1123 :
1124 : /*
1125 : * Clear fields that should not be set in a subquery RTE.
1126 : * However, we leave rte->functions filled in for the moment,
1127 : * in case makeWholeRowVar needs to consult it. We'll clear
1128 : * it in setrefs.c (see add_rte_to_flat_rtable) so that this
1129 : * abuse of the data structure doesn't escape the planner.
1130 : */
1131 123 : rte->funcordinality = false;
1132 : }
1133 : }
1134 : }
1135 301899 : }
1136 :
1137 : /*
1138 : * pull_up_subqueries
1139 : * Look for subqueries in the rangetable that can be pulled up into
1140 : * the parent query. If the subquery has no special features like
1141 : * grouping/aggregation then we can merge it into the parent's jointree.
1142 : * Also, subqueries that are simple UNION ALL structures can be
1143 : * converted into "append relations".
1144 : */
1145 : void
1146 301899 : pull_up_subqueries(PlannerInfo *root)
1147 : {
1148 : /* Top level of jointree must always be a FromExpr */
1149 : Assert(IsA(root->parse->jointree, FromExpr));
1150 : /* Recursion starts with no containing join nor appendrel */
1151 603795 : root->parse->jointree = (FromExpr *)
1152 301899 : pull_up_subqueries_recurse(root, (Node *) root->parse->jointree,
1153 : NULL, NULL);
1154 : /* We should still have a FromExpr */
1155 : Assert(IsA(root->parse->jointree, FromExpr));
1156 301896 : }
1157 :
1158 : /*
1159 : * pull_up_subqueries_recurse
1160 : * Recursive guts of pull_up_subqueries.
1161 : *
1162 : * This recursively processes the jointree and returns a modified jointree.
1163 : *
1164 : * If this jointree node is within either side of an outer join, then
1165 : * lowest_outer_join references the lowest such JoinExpr node; otherwise
1166 : * it is NULL. We use this to constrain the effects of LATERAL subqueries.
1167 : *
1168 : * If we are looking at a member subquery of an append relation,
1169 : * containing_appendrel describes that relation; else it is NULL.
1170 : * This forces use of the PlaceHolderVar mechanism for all non-Var targetlist
1171 : * items, and puts some additional restrictions on what can be pulled up.
1172 : *
1173 : * A tricky aspect of this code is that if we pull up a subquery we have
1174 : * to replace Vars that reference the subquery's outputs throughout the
1175 : * parent query, including quals attached to jointree nodes above the one
1176 : * we are currently processing! We handle this by being careful to maintain
1177 : * validity of the jointree structure while recursing, in the following sense:
1178 : * whenever we recurse, all qual expressions in the tree must be reachable
1179 : * from the top level, in case the recursive call needs to modify them.
1180 : *
1181 : * Notice also that we can't turn pullup_replace_vars loose on the whole
1182 : * jointree, because it'd return a mutated copy of the tree; we have to
1183 : * invoke it just on the quals, instead. This behavior is what makes it
1184 : * reasonable to pass lowest_outer_join as a pointer rather than some
1185 : * more-indirect way of identifying the lowest OJ. Likewise, we don't
1186 : * replace append_rel_list members but only their substructure, so the
1187 : * containing_appendrel reference is safe to use.
1188 : */
1189 : static Node *
1190 752910 : pull_up_subqueries_recurse(PlannerInfo *root, Node *jtnode,
1191 : JoinExpr *lowest_outer_join,
1192 : AppendRelInfo *containing_appendrel)
1193 : {
1194 : /* Since this function recurses, it could be driven to stack overflow. */
1195 752910 : check_stack_depth();
1196 : /* Also, since it's a bit expensive, let's check for query cancel. */
1197 752910 : CHECK_FOR_INTERRUPTS();
1198 :
1199 : Assert(jtnode != NULL);
1200 752910 : if (IsA(jtnode, RangeTblRef))
1201 : {
1202 389604 : int varno = ((RangeTblRef *) jtnode)->rtindex;
1203 389604 : RangeTblEntry *rte = rt_fetch(varno, root->parse->rtable);
1204 :
1205 : /*
1206 : * Is this a subquery RTE, and if so, is the subquery simple enough to
1207 : * pull up?
1208 : *
1209 : * If we are looking at an append-relation member, we can't pull it up
1210 : * unless is_safe_append_member says so.
1211 : */
1212 424563 : if (rte->rtekind == RTE_SUBQUERY &&
1213 58330 : is_simple_subquery(root, rte->subquery, rte, lowest_outer_join) &&
1214 7123 : (containing_appendrel == NULL ||
1215 7123 : is_safe_append_member(rte->subquery)))
1216 19567 : return pull_up_simple_subquery(root, jtnode, rte,
1217 : lowest_outer_join,
1218 : containing_appendrel);
1219 :
1220 : /*
1221 : * Alternatively, is it a simple UNION ALL subquery? If so, flatten
1222 : * into an "append relation".
1223 : *
1224 : * It's safe to do this regardless of whether this query is itself an
1225 : * appendrel member. (If you're thinking we should try to flatten the
1226 : * two levels of appendrel together, you're right; but we handle that
1227 : * in set_append_rel_pathlist, not here.)
1228 : */
1229 385429 : if (rte->rtekind == RTE_SUBQUERY &&
1230 15392 : is_simple_union_all(rte->subquery))
1231 2531 : return pull_up_simple_union_all(root, jtnode, rte);
1232 :
1233 : /*
1234 : * Or perhaps it's a simple VALUES RTE?
1235 : *
1236 : * We don't allow VALUES pullup below an outer join nor into an
1237 : * appendrel (such cases are impossible anyway at the moment).
1238 : */
1239 367506 : if (rte->rtekind == RTE_VALUES &&
1240 6631 : lowest_outer_join == NULL &&
1241 6631 : containing_appendrel == NULL &&
1242 6631 : is_simple_values(root, rte))
1243 2319 : return pull_up_simple_values(root, jtnode, rte);
1244 :
1245 : /*
1246 : * Or perhaps it's a FUNCTION RTE that we could inline?
1247 : */
1248 365187 : if (rte->rtekind == RTE_FUNCTION)
1249 27594 : return pull_up_constant_function(root, jtnode, rte,
1250 : containing_appendrel);
1251 :
1252 : /* Otherwise, do nothing at this node. */
1253 : }
1254 363306 : else if (IsA(jtnode, FromExpr))
1255 : {
1256 307008 : FromExpr *f = (FromExpr *) jtnode;
1257 : ListCell *l;
1258 :
1259 : Assert(containing_appendrel == NULL);
1260 : /* Recursively transform all the child nodes */
1261 636364 : foreach(l, f->fromlist)
1262 : {
1263 329359 : lfirst(l) = pull_up_subqueries_recurse(root, lfirst(l),
1264 : lowest_outer_join,
1265 : NULL);
1266 : }
1267 : }
1268 56298 : else if (IsA(jtnode, JoinExpr))
1269 : {
1270 56298 : JoinExpr *j = (JoinExpr *) jtnode;
1271 :
1272 : Assert(containing_appendrel == NULL);
1273 : /* Recurse, being careful to tell myself when inside outer join */
1274 56298 : switch (j->jointype)
1275 : {
1276 25649 : case JOIN_INNER:
1277 25649 : j->larg = pull_up_subqueries_recurse(root, j->larg,
1278 : lowest_outer_join,
1279 : NULL);
1280 25649 : j->rarg = pull_up_subqueries_recurse(root, j->rarg,
1281 : lowest_outer_join,
1282 : NULL);
1283 25649 : break;
1284 29487 : case JOIN_LEFT:
1285 : case JOIN_SEMI:
1286 : case JOIN_ANTI:
1287 29487 : j->larg = pull_up_subqueries_recurse(root, j->larg,
1288 : j,
1289 : NULL);
1290 29487 : j->rarg = pull_up_subqueries_recurse(root, j->rarg,
1291 : j,
1292 : NULL);
1293 29487 : break;
1294 548 : case JOIN_FULL:
1295 548 : j->larg = pull_up_subqueries_recurse(root, j->larg,
1296 : j,
1297 : NULL);
1298 548 : j->rarg = pull_up_subqueries_recurse(root, j->rarg,
1299 : j,
1300 : NULL);
1301 548 : break;
1302 614 : case JOIN_RIGHT:
1303 614 : j->larg = pull_up_subqueries_recurse(root, j->larg,
1304 : j,
1305 : NULL);
1306 614 : j->rarg = pull_up_subqueries_recurse(root, j->rarg,
1307 : j,
1308 : NULL);
1309 614 : break;
1310 0 : default:
1311 0 : elog(ERROR, "unrecognized join type: %d",
1312 : (int) j->jointype);
1313 : break;
1314 : }
1315 : }
1316 : else
1317 0 : elog(ERROR, "unrecognized node type: %d",
1318 : (int) nodeTag(jtnode));
1319 700896 : return jtnode;
1320 : }
1321 :
1322 : /*
1323 : * pull_up_simple_subquery
1324 : * Attempt to pull up a single simple subquery.
1325 : *
1326 : * jtnode is a RangeTblRef that has been tentatively identified as a simple
1327 : * subquery by pull_up_subqueries. We return the replacement jointree node,
1328 : * or jtnode itself if we determine that the subquery can't be pulled up
1329 : * after all.
1330 : *
1331 : * rte is the RangeTblEntry referenced by jtnode. Remaining parameters are
1332 : * as for pull_up_subqueries_recurse.
1333 : */
1334 : static Node *
1335 19567 : pull_up_simple_subquery(PlannerInfo *root, Node *jtnode, RangeTblEntry *rte,
1336 : JoinExpr *lowest_outer_join,
1337 : AppendRelInfo *containing_appendrel)
1338 : {
1339 19567 : Query *parse = root->parse;
1340 19567 : int varno = ((RangeTblRef *) jtnode)->rtindex;
1341 : Query *subquery;
1342 : PlannerInfo *subroot;
1343 : int rtoffset;
1344 : pullup_replace_vars_context rvcontext;
1345 : ListCell *lc;
1346 :
1347 : /*
1348 : * Make a modifiable copy of the subquery to hack on, so that the RTE will
1349 : * be left unchanged in case we decide below that we can't pull it up
1350 : * after all.
1351 : */
1352 19567 : subquery = copyObject(rte->subquery);
1353 :
1354 : /*
1355 : * Create a PlannerInfo data structure for this subquery.
1356 : *
1357 : * NOTE: the next few steps should match the first processing in
1358 : * subquery_planner(). Can we refactor to avoid code duplication, or
1359 : * would that just make things uglier?
1360 : */
1361 19567 : subroot = makeNode(PlannerInfo);
1362 19567 : subroot->parse = subquery;
1363 19567 : subroot->glob = root->glob;
1364 19567 : subroot->query_level = root->query_level;
1365 19567 : subroot->plan_name = root->plan_name;
1366 19567 : subroot->parent_root = root->parent_root;
1367 19567 : subroot->plan_params = NIL;
1368 19567 : subroot->outer_params = NULL;
1369 19567 : subroot->planner_cxt = CurrentMemoryContext;
1370 19567 : subroot->init_plans = NIL;
1371 19567 : subroot->cte_plan_ids = NIL;
1372 19567 : subroot->multiexpr_params = NIL;
1373 19567 : subroot->join_domains = NIL;
1374 19567 : subroot->eq_classes = NIL;
1375 19567 : subroot->ec_merging_done = false;
1376 19567 : subroot->last_rinfo_serial = 0;
1377 19567 : subroot->all_result_relids = NULL;
1378 19567 : subroot->leaf_result_relids = NULL;
1379 19567 : subroot->append_rel_list = NIL;
1380 19567 : subroot->row_identity_vars = NIL;
1381 19567 : subroot->rowMarks = NIL;
1382 19567 : memset(subroot->upper_rels, 0, sizeof(subroot->upper_rels));
1383 19567 : memset(subroot->upper_targets, 0, sizeof(subroot->upper_targets));
1384 19567 : subroot->processed_groupClause = NIL;
1385 19567 : subroot->processed_distinctClause = NIL;
1386 19567 : subroot->processed_tlist = NIL;
1387 19567 : subroot->update_colnos = NIL;
1388 19567 : subroot->grouping_map = NULL;
1389 19567 : subroot->minmax_aggs = NIL;
1390 19567 : subroot->qual_security_level = 0;
1391 19567 : subroot->placeholdersFrozen = false;
1392 19567 : subroot->hasRecursion = false;
1393 19567 : subroot->assumeReplanning = false;
1394 19567 : subroot->wt_param_id = -1;
1395 19567 : subroot->non_recursive_path = NULL;
1396 : /* We don't currently need a top JoinDomain for the subroot */
1397 :
1398 : /* No CTEs to worry about */
1399 : Assert(subquery->cteList == NIL);
1400 :
1401 : /*
1402 : * Scan the rangetable for relation RTEs and retrieve the necessary
1403 : * catalog information for each relation. Using this information, clear
1404 : * the inh flag for any relation that has no children, collect not-null
1405 : * attribute numbers for any relation that has column not-null
1406 : * constraints, and expand virtual generated columns for any relation that
1407 : * contains them.
1408 : */
1409 19567 : subquery = subroot->parse = preprocess_relation_rtes(subroot);
1410 :
1411 : /*
1412 : * If the FROM clause is empty, replace it with a dummy RTE_RESULT RTE, so
1413 : * that we don't need so many special cases to deal with that situation.
1414 : */
1415 19567 : replace_empty_jointree(subquery);
1416 :
1417 : /*
1418 : * Pull up any SubLinks within the subquery's quals, so that we don't
1419 : * leave unoptimized SubLinks behind.
1420 : */
1421 19567 : if (subquery->hasSubLinks)
1422 1214 : pull_up_sublinks(subroot);
1423 :
1424 : /*
1425 : * Similarly, preprocess its function RTEs to inline any set-returning
1426 : * functions in its rangetable.
1427 : */
1428 19567 : preprocess_function_rtes(subroot);
1429 :
1430 : /*
1431 : * Recursively pull up the subquery's subqueries, so that
1432 : * pull_up_subqueries' processing is complete for its jointree and
1433 : * rangetable.
1434 : *
1435 : * Note: it's okay that the subquery's recursion starts with NULL for
1436 : * containing-join info, even if we are within an outer join in the upper
1437 : * query; the lower query starts with a clean slate for outer-join
1438 : * semantics. Likewise, we needn't pass down appendrel state.
1439 : */
1440 19567 : pull_up_subqueries(subroot);
1441 :
1442 : /*
1443 : * Now we must recheck whether the subquery is still simple enough to pull
1444 : * up. If not, abandon processing it.
1445 : *
1446 : * We don't really need to recheck all the conditions involved, but it's
1447 : * easier just to keep this "if" looking the same as the one in
1448 : * pull_up_subqueries_recurse.
1449 : */
1450 22772 : if (is_simple_subquery(root, subquery, rte, lowest_outer_join) &&
1451 3319 : (containing_appendrel == NULL || is_safe_append_member(subquery)))
1452 : {
1453 : /* good to go */
1454 : }
1455 : else
1456 : {
1457 : /*
1458 : * Give up, return unmodified RangeTblRef.
1459 : *
1460 : * Note: The work we just did will be redone when the subquery gets
1461 : * planned on its own. Perhaps we could avoid that by storing the
1462 : * modified subquery back into the rangetable, but I'm not gonna risk
1463 : * it now.
1464 : */
1465 120 : return jtnode;
1466 : }
1467 :
1468 : /*
1469 : * We must flatten any join alias Vars in the subquery's targetlist,
1470 : * because pulling up the subquery's subqueries might have changed their
1471 : * expansions into arbitrary expressions, which could affect
1472 : * pullup_replace_vars' decisions about whether PlaceHolderVar wrappers
1473 : * are needed for tlist entries. (Likely it'd be better to do
1474 : * flatten_join_alias_vars on the whole query tree at some earlier stage,
1475 : * maybe even in the rewriter; but for now let's just fix this case here.)
1476 : */
1477 19447 : subquery->targetList = (List *)
1478 19447 : flatten_join_alias_vars(subroot, subroot->parse,
1479 19447 : (Node *) subquery->targetList);
1480 :
1481 : /*
1482 : * Adjust level-0 varnos in subquery so that we can append its rangetable
1483 : * to upper query's. We have to fix the subquery's append_rel_list as
1484 : * well.
1485 : */
1486 19447 : rtoffset = list_length(parse->rtable);
1487 19447 : OffsetVarNodes((Node *) subquery, rtoffset, 0);
1488 19447 : OffsetVarNodes((Node *) subroot->append_rel_list, rtoffset, 0);
1489 :
1490 : /*
1491 : * Upper-level vars in subquery are now one level closer to their parent
1492 : * than before.
1493 : */
1494 19447 : IncrementVarSublevelsUp((Node *) subquery, -1, 1);
1495 19447 : IncrementVarSublevelsUp((Node *) subroot->append_rel_list, -1, 1);
1496 :
1497 : /*
1498 : * The subquery's targetlist items are now in the appropriate form to
1499 : * insert into the top query, except that we may need to wrap them in
1500 : * PlaceHolderVars. Set up required context data for pullup_replace_vars.
1501 : * (Note that we should include the subquery's inner joins in relids,
1502 : * since it may include join alias vars referencing them.)
1503 : */
1504 19447 : rvcontext.root = root;
1505 19447 : rvcontext.targetlist = subquery->targetList;
1506 19447 : rvcontext.target_rte = rte;
1507 19447 : rvcontext.result_relation = 0;
1508 19447 : if (rte->lateral)
1509 : {
1510 597 : rvcontext.relids = get_relids_in_jointree((Node *) subquery->jointree,
1511 : true, true);
1512 597 : rvcontext.nullinfo = get_nullingrels(parse);
1513 : }
1514 : else /* won't need these values */
1515 : {
1516 18850 : rvcontext.relids = NULL;
1517 18850 : rvcontext.nullinfo = NULL;
1518 : }
1519 19447 : rvcontext.outer_hasSubLinks = &parse->hasSubLinks;
1520 19447 : rvcontext.varno = varno;
1521 : /* this flag will be set below, if needed */
1522 19447 : rvcontext.wrap_option = REPLACE_WRAP_NONE;
1523 : /* initialize cache array with indexes 0 .. length(tlist) */
1524 19447 : rvcontext.rv_cache = palloc0((list_length(subquery->targetList) + 1) *
1525 : sizeof(Node *));
1526 :
1527 : /*
1528 : * If the parent query uses grouping sets, we need a PlaceHolderVar for
1529 : * each expression of the subquery's targetlist items. This ensures that
1530 : * expressions retain their separate identity so that they will match
1531 : * grouping set columns when appropriate. (It'd be sufficient to wrap
1532 : * values used in grouping set columns, and do so only in non-aggregated
1533 : * portions of the tlist and havingQual, but that would require a lot of
1534 : * infrastructure that pullup_replace_vars hasn't currently got.)
1535 : */
1536 19447 : if (parse->groupingSets)
1537 198 : rvcontext.wrap_option = REPLACE_WRAP_ALL;
1538 :
1539 : /*
1540 : * Replace all of the top query's references to the subquery's outputs
1541 : * with copies of the adjusted subtlist items, being careful not to
1542 : * replace any of the jointree structure.
1543 : */
1544 19447 : perform_pullup_replace_vars(root, &rvcontext,
1545 : containing_appendrel);
1546 :
1547 : /*
1548 : * If the subquery had a LATERAL marker, propagate that to any of its
1549 : * child RTEs that could possibly now contain lateral cross-references.
1550 : * The children might or might not contain any actual lateral
1551 : * cross-references, but we have to mark the pulled-up child RTEs so that
1552 : * later planner stages will check for such.
1553 : */
1554 19444 : if (rte->lateral)
1555 : {
1556 1392 : foreach(lc, subquery->rtable)
1557 : {
1558 795 : RangeTblEntry *child_rte = (RangeTblEntry *) lfirst(lc);
1559 :
1560 795 : switch (child_rte->rtekind)
1561 : {
1562 348 : case RTE_RELATION:
1563 348 : if (child_rte->tablesample)
1564 18 : child_rte->lateral = true;
1565 348 : break;
1566 140 : case RTE_SUBQUERY:
1567 : case RTE_FUNCTION:
1568 : case RTE_VALUES:
1569 : case RTE_TABLEFUNC:
1570 140 : child_rte->lateral = true;
1571 140 : break;
1572 307 : case RTE_JOIN:
1573 : case RTE_CTE:
1574 : case RTE_NAMEDTUPLESTORE:
1575 : case RTE_RESULT:
1576 : case RTE_GROUP:
1577 : /* these can't contain any lateral references */
1578 307 : break;
1579 : }
1580 : }
1581 : }
1582 :
1583 : /*
1584 : * Now append the adjusted rtable entries and their perminfos to upper
1585 : * query. (We hold off until after fixing the upper rtable entries; no
1586 : * point in running that code on the subquery ones too.)
1587 : */
1588 19444 : CombineRangeTables(&parse->rtable, &parse->rteperminfos,
1589 : subquery->rtable, subquery->rteperminfos);
1590 :
1591 : /*
1592 : * Pull up any FOR UPDATE/SHARE markers, too. (OffsetVarNodes already
1593 : * adjusted the marker rtindexes, so just concat the lists.)
1594 : */
1595 19444 : parse->rowMarks = list_concat(parse->rowMarks, subquery->rowMarks);
1596 :
1597 : /*
1598 : * We also have to fix the relid sets of any PlaceHolderVar nodes in the
1599 : * parent query. (This could perhaps be done by pullup_replace_vars(),
1600 : * but it seems cleaner to use two passes.) Note in particular that any
1601 : * PlaceHolderVar nodes just created by pullup_replace_vars() will be
1602 : * adjusted, so having created them with the subquery's varno is correct.
1603 : *
1604 : * Likewise, relids appearing in AppendRelInfo nodes have to be fixed. We
1605 : * already checked that this won't require introducing multiple subrelids
1606 : * into the single-slot AppendRelInfo structs.
1607 : */
1608 19444 : if (root->glob->lastPHId != 0 || root->append_rel_list)
1609 : {
1610 : Relids subrelids;
1611 :
1612 4213 : subrelids = get_relids_in_jointree((Node *) subquery->jointree,
1613 : true, false);
1614 4213 : if (root->glob->lastPHId != 0)
1615 1035 : substitute_phv_relids((Node *) parse, varno, subrelids);
1616 4213 : fix_append_rel_relids(root, varno, subrelids);
1617 : }
1618 :
1619 : /*
1620 : * And now add subquery's AppendRelInfos to our list.
1621 : */
1622 38888 : root->append_rel_list = list_concat(root->append_rel_list,
1623 19444 : subroot->append_rel_list);
1624 :
1625 : /*
1626 : * We don't have to do the equivalent bookkeeping for outer-join info,
1627 : * because that hasn't been set up yet. placeholder_list likewise.
1628 : */
1629 : Assert(root->join_info_list == NIL);
1630 : Assert(subroot->join_info_list == NIL);
1631 : Assert(root->placeholder_list == NIL);
1632 : Assert(subroot->placeholder_list == NIL);
1633 :
1634 : /*
1635 : * We no longer need the RTE's copy of the subquery's query tree. Getting
1636 : * rid of it saves nothing in particular so far as this level of query is
1637 : * concerned; but if this query level is in turn pulled up into a parent,
1638 : * we'd waste cycles copying the now-unused query tree.
1639 : */
1640 19444 : rte->subquery = NULL;
1641 :
1642 : /*
1643 : * Miscellaneous housekeeping.
1644 : *
1645 : * Although replace_rte_variables() faithfully updated parse->hasSubLinks
1646 : * if it copied any SubLinks out of the subquery's targetlist, we still
1647 : * could have SubLinks added to the query in the expressions of FUNCTION
1648 : * and VALUES RTEs copied up from the subquery. So it's necessary to copy
1649 : * subquery->hasSubLinks anyway. Perhaps this can be improved someday.
1650 : */
1651 19444 : parse->hasSubLinks |= subquery->hasSubLinks;
1652 :
1653 : /* If subquery had any RLS conditions, now main query does too */
1654 19444 : parse->hasRowSecurity |= subquery->hasRowSecurity;
1655 :
1656 : /*
1657 : * subquery won't be pulled up if it hasAggs, hasWindowFuncs, or
1658 : * hasTargetSRFs, so no work needed on those flags
1659 : */
1660 :
1661 : /*
1662 : * Return the adjusted subquery jointree to replace the RangeTblRef entry
1663 : * in parent's jointree; or, if the FromExpr is degenerate, just return
1664 : * its single member.
1665 : */
1666 : Assert(IsA(subquery->jointree, FromExpr));
1667 : Assert(subquery->jointree->fromlist != NIL);
1668 36117 : if (subquery->jointree->quals == NULL &&
1669 16673 : list_length(subquery->jointree->fromlist) == 1)
1670 16507 : return (Node *) linitial(subquery->jointree->fromlist);
1671 :
1672 2937 : return (Node *) subquery->jointree;
1673 : }
1674 :
1675 : /*
1676 : * pull_up_simple_union_all
1677 : * Pull up a single simple UNION ALL subquery.
1678 : *
1679 : * jtnode is a RangeTblRef that has been identified as a simple UNION ALL
1680 : * subquery by pull_up_subqueries. We pull up the leaf subqueries and
1681 : * build an "append relation" for the union set. The result value is just
1682 : * jtnode, since we don't actually need to change the query jointree.
1683 : */
1684 : static Node *
1685 2531 : pull_up_simple_union_all(PlannerInfo *root, Node *jtnode, RangeTblEntry *rte)
1686 : {
1687 2531 : int varno = ((RangeTblRef *) jtnode)->rtindex;
1688 2531 : Query *subquery = rte->subquery;
1689 2531 : int rtoffset = list_length(root->parse->rtable);
1690 : List *rtable;
1691 :
1692 : /*
1693 : * Make a modifiable copy of the subquery's rtable, so we can adjust
1694 : * upper-level Vars in it. There are no such Vars in the setOperations
1695 : * tree proper, so fixing the rtable should be sufficient.
1696 : */
1697 2531 : rtable = copyObject(subquery->rtable);
1698 :
1699 : /*
1700 : * Upper-level vars in subquery are now one level closer to their parent
1701 : * than before. We don't have to worry about offsetting varnos, though,
1702 : * because the UNION leaf queries can't cross-reference each other.
1703 : */
1704 2531 : IncrementVarSublevelsUp_rtable(rtable, -1, 1);
1705 :
1706 : /*
1707 : * If the UNION ALL subquery had a LATERAL marker, propagate that to all
1708 : * its children. The individual children might or might not contain any
1709 : * actual lateral cross-references, but we have to mark the pulled-up
1710 : * child RTEs so that later planner stages will check for such.
1711 : */
1712 2531 : if (rte->lateral)
1713 : {
1714 : ListCell *rt;
1715 :
1716 117 : foreach(rt, rtable)
1717 : {
1718 78 : RangeTblEntry *child_rte = (RangeTblEntry *) lfirst(rt);
1719 :
1720 : Assert(child_rte->rtekind == RTE_SUBQUERY);
1721 78 : child_rte->lateral = true;
1722 : }
1723 : }
1724 :
1725 : /*
1726 : * Append child RTEs (and their perminfos) to parent rtable.
1727 : */
1728 2531 : CombineRangeTables(&root->parse->rtable, &root->parse->rteperminfos,
1729 : rtable, subquery->rteperminfos);
1730 :
1731 : /*
1732 : * Recursively scan the subquery's setOperations tree and add
1733 : * AppendRelInfo nodes for leaf subqueries to the parent's
1734 : * append_rel_list. Also apply pull_up_subqueries to the leaf subqueries.
1735 : */
1736 : Assert(subquery->setOperations);
1737 2531 : pull_up_union_leaf_queries(subquery->setOperations, root, varno, subquery,
1738 : rtoffset);
1739 :
1740 : /*
1741 : * Mark the parent as an append relation.
1742 : */
1743 2531 : rte->inh = true;
1744 :
1745 2531 : return jtnode;
1746 : }
1747 :
1748 : /*
1749 : * pull_up_union_leaf_queries -- recursive guts of pull_up_simple_union_all
1750 : *
1751 : * Build an AppendRelInfo for each leaf query in the setop tree, and then
1752 : * apply pull_up_subqueries to the leaf query.
1753 : *
1754 : * Note that setOpQuery is the Query containing the setOp node, whose tlist
1755 : * contains references to all the setop output columns. When called from
1756 : * pull_up_simple_union_all, this is *not* the same as root->parse, which is
1757 : * the parent Query we are pulling up into.
1758 : *
1759 : * parentRTindex is the appendrel parent's index in root->parse->rtable.
1760 : *
1761 : * The child RTEs have already been copied to the parent. childRToffset
1762 : * tells us where in the parent's range table they were copied. When called
1763 : * from flatten_simple_union_all, childRToffset is 0 since the child RTEs
1764 : * were already in root->parse->rtable and no RT index adjustment is needed.
1765 : */
1766 : static void
1767 15185 : pull_up_union_leaf_queries(Node *setOp, PlannerInfo *root, int parentRTindex,
1768 : Query *setOpQuery, int childRToffset)
1769 : {
1770 15185 : if (IsA(setOp, RangeTblRef))
1771 : {
1772 9056 : RangeTblRef *rtr = (RangeTblRef *) setOp;
1773 : int childRTindex;
1774 : AppendRelInfo *appinfo;
1775 :
1776 : /*
1777 : * Calculate the index in the parent's range table
1778 : */
1779 9056 : childRTindex = childRToffset + rtr->rtindex;
1780 :
1781 : /*
1782 : * Build a suitable AppendRelInfo, and attach to parent's list.
1783 : */
1784 9056 : appinfo = makeNode(AppendRelInfo);
1785 9056 : appinfo->parent_relid = parentRTindex;
1786 9056 : appinfo->child_relid = childRTindex;
1787 9056 : appinfo->parent_reltype = InvalidOid;
1788 9056 : appinfo->child_reltype = InvalidOid;
1789 9056 : make_setop_translation_list(setOpQuery, childRTindex, appinfo);
1790 9056 : appinfo->parent_reloid = InvalidOid;
1791 9056 : root->append_rel_list = lappend(root->append_rel_list, appinfo);
1792 :
1793 : /*
1794 : * Recursively apply pull_up_subqueries to the new child RTE. (We
1795 : * must build the AppendRelInfo first, because this will modify it;
1796 : * indeed, that's the only part of the upper query where Vars
1797 : * referencing childRTindex can exist at this point.)
1798 : *
1799 : * Note that we can pass NULL for containing-join info even if we're
1800 : * actually under an outer join, because the child's expressions
1801 : * aren't going to propagate up to the join. Also, we ignore the
1802 : * possibility that pull_up_subqueries_recurse() returns a different
1803 : * jointree node than what we pass it; if it does, the important thing
1804 : * is that it replaced the child relid in the AppendRelInfo node.
1805 : */
1806 9056 : rtr = makeNode(RangeTblRef);
1807 9056 : rtr->rtindex = childRTindex;
1808 9056 : (void) pull_up_subqueries_recurse(root, (Node *) rtr,
1809 : NULL, appinfo);
1810 : }
1811 6129 : else if (IsA(setOp, SetOperationStmt))
1812 : {
1813 6129 : SetOperationStmt *op = (SetOperationStmt *) setOp;
1814 :
1815 : /* Recurse to reach leaf queries */
1816 6129 : pull_up_union_leaf_queries(op->larg, root, parentRTindex, setOpQuery,
1817 : childRToffset);
1818 6129 : pull_up_union_leaf_queries(op->rarg, root, parentRTindex, setOpQuery,
1819 : childRToffset);
1820 : }
1821 : else
1822 : {
1823 0 : elog(ERROR, "unrecognized node type: %d",
1824 : (int) nodeTag(setOp));
1825 : }
1826 15185 : }
1827 :
1828 : /*
1829 : * make_setop_translation_list
1830 : * Build the list of translations from parent Vars to child Vars for
1831 : * a UNION ALL member. (At this point it's just a simple list of
1832 : * referencing Vars, but if we succeed in pulling up the member
1833 : * subquery, the Vars will get replaced by pulled-up expressions.)
1834 : * Also create the rather trivial reverse-translation array.
1835 : */
1836 : static void
1837 9056 : make_setop_translation_list(Query *query, int newvarno,
1838 : AppendRelInfo *appinfo)
1839 : {
1840 9056 : List *vars = NIL;
1841 : AttrNumber *pcolnos;
1842 : ListCell *l;
1843 :
1844 : /* Initialize reverse-translation array with all entries zero */
1845 : /* (entries for resjunk columns will stay that way) */
1846 9056 : appinfo->num_child_cols = list_length(query->targetList);
1847 9056 : appinfo->parent_colnos = pcolnos =
1848 9056 : (AttrNumber *) palloc0(appinfo->num_child_cols * sizeof(AttrNumber));
1849 :
1850 44627 : foreach(l, query->targetList)
1851 : {
1852 35571 : TargetEntry *tle = (TargetEntry *) lfirst(l);
1853 :
1854 35571 : if (tle->resjunk)
1855 0 : continue;
1856 :
1857 35571 : vars = lappend(vars, makeVarFromTargetEntry(newvarno, tle));
1858 35571 : pcolnos[tle->resno - 1] = tle->resno;
1859 : }
1860 :
1861 9056 : appinfo->translated_vars = vars;
1862 9056 : }
1863 :
1864 : /*
1865 : * is_simple_subquery
1866 : * Check a subquery in the range table to see if it's simple enough
1867 : * to pull up into the parent query.
1868 : *
1869 : * rte is the RTE_SUBQUERY RangeTblEntry that contained the subquery.
1870 : * (Note subquery is not necessarily equal to rte->subquery; it could be a
1871 : * processed copy of that.)
1872 : * lowest_outer_join is the lowest outer join above the subquery, or NULL.
1873 : */
1874 : static bool
1875 54526 : is_simple_subquery(PlannerInfo *root, Query *subquery, RangeTblEntry *rte,
1876 : JoinExpr *lowest_outer_join)
1877 : {
1878 : /*
1879 : * Let's just make sure it's a valid subselect ...
1880 : */
1881 54526 : if (!IsA(subquery, Query) ||
1882 54526 : subquery->commandType != CMD_SELECT)
1883 0 : elog(ERROR, "subquery is bogus");
1884 :
1885 : /*
1886 : * Can't currently pull up a query with setops (unless it's simple UNION
1887 : * ALL, which is handled by a different code path). Maybe after querytree
1888 : * redesign...
1889 : */
1890 54526 : if (subquery->setOperations)
1891 2959 : return false;
1892 :
1893 : /*
1894 : * Can't pull up a subquery involving grouping, aggregation, SRFs,
1895 : * sorting, limiting, or WITH. (XXX WITH could possibly be allowed later)
1896 : *
1897 : * We also don't pull up a subquery that has explicit FOR UPDATE/SHARE
1898 : * clauses, because pullup would cause the locking to occur semantically
1899 : * higher than it should. Implicit FOR UPDATE/SHARE is okay because in
1900 : * that case the locking was originally declared in the upper query
1901 : * anyway.
1902 : */
1903 51567 : if (subquery->hasAggs ||
1904 50453 : subquery->hasWindowFuncs ||
1905 50260 : subquery->hasTargetSRFs ||
1906 48113 : subquery->groupClause ||
1907 48070 : subquery->groupingSets ||
1908 48052 : subquery->havingQual ||
1909 48052 : subquery->sortClause ||
1910 47613 : subquery->distinctClause ||
1911 47164 : subquery->limitOffset ||
1912 46937 : subquery->limitCount ||
1913 46782 : subquery->hasForUpdate ||
1914 43708 : subquery->cteList)
1915 7943 : return false;
1916 :
1917 : /*
1918 : * Don't pull up if the RTE represents a security-barrier view; we
1919 : * couldn't prevent information leakage once the RTE's Vars are scattered
1920 : * about in the upper query.
1921 : */
1922 43624 : if (rte->security_barrier)
1923 541 : return false;
1924 :
1925 : /*
1926 : * If the subquery is LATERAL, check for pullup restrictions from that.
1927 : */
1928 43083 : if (rte->lateral)
1929 : {
1930 : bool restricted;
1931 : Relids safe_upper_varnos;
1932 :
1933 : /*
1934 : * The subquery's WHERE and JOIN/ON quals mustn't contain any lateral
1935 : * references to rels outside a higher outer join (including the case
1936 : * where the outer join is within the subquery itself). In such a
1937 : * case, pulling up would result in a situation where we need to
1938 : * postpone quals from below an outer join to above it, which is
1939 : * probably completely wrong and in any case is a complication that
1940 : * doesn't seem worth addressing at the moment.
1941 : */
1942 1242 : if (lowest_outer_join != NULL)
1943 : {
1944 694 : restricted = true;
1945 694 : safe_upper_varnos = get_relids_in_jointree((Node *) lowest_outer_join,
1946 : true, true);
1947 : }
1948 : else
1949 : {
1950 548 : restricted = false;
1951 548 : safe_upper_varnos = NULL; /* doesn't matter */
1952 : }
1953 :
1954 1242 : if (jointree_contains_lateral_outer_refs(root,
1955 1242 : (Node *) subquery->jointree,
1956 : restricted, safe_upper_varnos))
1957 12 : return false;
1958 :
1959 : /*
1960 : * If there's an outer join above the LATERAL subquery, also disallow
1961 : * pullup if the subquery's targetlist has any references to rels
1962 : * outside the outer join, since these might get pulled into quals
1963 : * above the subquery (but in or below the outer join) and then lead
1964 : * to qual-postponement issues similar to the case checked for above.
1965 : * (We wouldn't need to prevent pullup if no such references appear in
1966 : * outer-query quals, but we don't have enough info here to check
1967 : * that. Also, maybe this restriction could be removed if we forced
1968 : * such refs to be wrapped in PlaceHolderVars, even when they're below
1969 : * the nearest outer join? But it's a pretty hokey usage, so not
1970 : * clear this is worth sweating over.)
1971 : *
1972 : * If you change this, see also the comments about lateral references
1973 : * in pullup_replace_vars_callback().
1974 : */
1975 1230 : if (lowest_outer_join != NULL)
1976 : {
1977 694 : Relids lvarnos = pull_varnos_of_level(root,
1978 694 : (Node *) subquery->targetList,
1979 : 1);
1980 :
1981 694 : if (!bms_is_subset(lvarnos, safe_upper_varnos))
1982 6 : return false;
1983 : }
1984 : }
1985 :
1986 : /*
1987 : * Don't pull up a subquery that has any volatile functions in its
1988 : * targetlist. Otherwise we might introduce multiple evaluations of these
1989 : * functions, if they get copied to multiple places in the upper query,
1990 : * leading to surprising results. (Note: the PlaceHolderVar mechanism
1991 : * doesn't quite guarantee single evaluation; else we could pull up anyway
1992 : * and just wrap such items in PlaceHolderVars ...)
1993 : */
1994 43065 : if (contain_volatile_functions((Node *) subquery->targetList))
1995 133 : return false;
1996 :
1997 42932 : return true;
1998 : }
1999 :
2000 : /*
2001 : * pull_up_simple_values
2002 : * Pull up a single simple VALUES RTE.
2003 : *
2004 : * jtnode is a RangeTblRef that has been identified as a simple VALUES RTE
2005 : * by pull_up_subqueries. We always return a RangeTblRef representing a
2006 : * RESULT RTE to replace it (all failure cases should have been detected by
2007 : * is_simple_values()). Actually, what we return is just jtnode, because
2008 : * we replace the VALUES RTE in the rangetable with the RESULT RTE.
2009 : *
2010 : * rte is the RangeTblEntry referenced by jtnode. Because of the limited
2011 : * possible usage of VALUES RTEs, we do not need the remaining parameters
2012 : * of pull_up_subqueries_recurse.
2013 : */
2014 : static Node *
2015 2319 : pull_up_simple_values(PlannerInfo *root, Node *jtnode, RangeTblEntry *rte)
2016 : {
2017 2319 : Query *parse = root->parse;
2018 2319 : int varno = ((RangeTblRef *) jtnode)->rtindex;
2019 : List *values_list;
2020 : List *tlist;
2021 : AttrNumber attrno;
2022 : pullup_replace_vars_context rvcontext;
2023 : ListCell *lc;
2024 :
2025 : Assert(rte->rtekind == RTE_VALUES);
2026 : Assert(list_length(rte->values_lists) == 1);
2027 :
2028 : /*
2029 : * Need a modifiable copy of the VALUES list to hack on, just in case it's
2030 : * multiply referenced.
2031 : */
2032 2319 : values_list = copyObject(linitial(rte->values_lists));
2033 :
2034 : /*
2035 : * The VALUES RTE can't contain any Vars of level zero, let alone any that
2036 : * are join aliases, so no need to flatten join alias Vars.
2037 : */
2038 : Assert(!contain_vars_of_level((Node *) values_list, 0));
2039 :
2040 : /*
2041 : * Set up required context data for pullup_replace_vars. In particular,
2042 : * we have to make the VALUES list look like a subquery targetlist.
2043 : */
2044 2319 : tlist = NIL;
2045 2319 : attrno = 1;
2046 5023 : foreach(lc, values_list)
2047 : {
2048 2704 : tlist = lappend(tlist,
2049 2704 : makeTargetEntry((Expr *) lfirst(lc),
2050 : attrno,
2051 : NULL,
2052 : false));
2053 2704 : attrno++;
2054 : }
2055 2319 : rvcontext.root = root;
2056 2319 : rvcontext.targetlist = tlist;
2057 2319 : rvcontext.target_rte = rte;
2058 2319 : rvcontext.result_relation = 0;
2059 2319 : rvcontext.relids = NULL; /* can't be any lateral references here */
2060 2319 : rvcontext.nullinfo = NULL;
2061 2319 : rvcontext.outer_hasSubLinks = &parse->hasSubLinks;
2062 2319 : rvcontext.varno = varno;
2063 2319 : rvcontext.wrap_option = REPLACE_WRAP_NONE;
2064 : /* initialize cache array with indexes 0 .. length(tlist) */
2065 2319 : rvcontext.rv_cache = palloc0((list_length(tlist) + 1) *
2066 : sizeof(Node *));
2067 :
2068 : /*
2069 : * Replace all of the top query's references to the RTE's outputs with
2070 : * copies of the adjusted VALUES expressions, being careful not to replace
2071 : * any of the jointree structure. We can assume there's no outer joins or
2072 : * appendrels in the dummy Query that surrounds a VALUES RTE.
2073 : */
2074 2319 : perform_pullup_replace_vars(root, &rvcontext, NULL);
2075 :
2076 : /*
2077 : * There should be no appendrels to fix, nor any outer joins and hence no
2078 : * PlaceHolderVars.
2079 : */
2080 : Assert(root->append_rel_list == NIL);
2081 : Assert(root->join_info_list == NIL);
2082 : Assert(root->placeholder_list == NIL);
2083 :
2084 : /*
2085 : * Replace the VALUES RTE with a RESULT RTE. The VALUES RTE is the only
2086 : * rtable entry in the current query level, so this is easy.
2087 : */
2088 : Assert(list_length(parse->rtable) == 1);
2089 :
2090 : /* Create suitable RTE */
2091 2319 : rte = makeNode(RangeTblEntry);
2092 2319 : rte->rtekind = RTE_RESULT;
2093 2319 : rte->eref = makeAlias("*RESULT*", NIL);
2094 :
2095 : /* Replace rangetable */
2096 2319 : parse->rtable = list_make1(rte);
2097 :
2098 : /* We could manufacture a new RangeTblRef, but the one we have is fine */
2099 : Assert(varno == 1);
2100 :
2101 2319 : return jtnode;
2102 : }
2103 :
2104 : /*
2105 : * is_simple_values
2106 : * Check a VALUES RTE in the range table to see if it's simple enough
2107 : * to pull up into the parent query.
2108 : *
2109 : * rte is the RTE_VALUES RangeTblEntry to check.
2110 : */
2111 : static bool
2112 6631 : is_simple_values(PlannerInfo *root, RangeTblEntry *rte)
2113 : {
2114 : Assert(rte->rtekind == RTE_VALUES);
2115 :
2116 : /*
2117 : * There must be exactly one VALUES list, else it's not semantically
2118 : * correct to replace the VALUES RTE with a RESULT RTE, nor would we have
2119 : * a unique set of expressions to substitute into the parent query.
2120 : */
2121 6631 : if (list_length(rte->values_lists) != 1)
2122 4312 : return false;
2123 :
2124 : /*
2125 : * Because VALUES can't appear under an outer join (or at least, we won't
2126 : * try to pull it up if it does), we need not worry about LATERAL, nor
2127 : * about validity of PHVs for the VALUES' outputs.
2128 : */
2129 :
2130 : /*
2131 : * Don't pull up a VALUES that contains any set-returning or volatile
2132 : * functions. The considerations here are basically identical to the
2133 : * restrictions on a pull-able subquery's targetlist.
2134 : */
2135 4638 : if (expression_returns_set((Node *) rte->values_lists) ||
2136 2319 : contain_volatile_functions((Node *) rte->values_lists))
2137 0 : return false;
2138 :
2139 : /*
2140 : * Do not pull up a VALUES that's not the only RTE in its parent query.
2141 : * This is actually the only case that the parser will generate at the
2142 : * moment, and assuming this is true greatly simplifies
2143 : * pull_up_simple_values().
2144 : */
2145 2319 : if (list_length(root->parse->rtable) != 1 ||
2146 2319 : rte != (RangeTblEntry *) linitial(root->parse->rtable))
2147 0 : return false;
2148 :
2149 2319 : return true;
2150 : }
2151 :
2152 : /*
2153 : * pull_up_constant_function
2154 : * Pull up an RTE_FUNCTION expression that was simplified to a constant.
2155 : *
2156 : * jtnode is a RangeTblRef that has been identified as a FUNCTION RTE by
2157 : * pull_up_subqueries. If its expression is just a Const, hoist that value
2158 : * up into the parent query, and replace the RTE_FUNCTION with RTE_RESULT.
2159 : *
2160 : * In principle we could pull up any immutable expression, but we don't.
2161 : * That might result in multiple evaluations of the expression, which could
2162 : * be costly if it's not just a Const. Also, the main value of this is
2163 : * to let the constant participate in further const-folding, and of course
2164 : * that won't happen for a non-Const.
2165 : *
2166 : * The pulled-up value might need to be wrapped in a PlaceHolderVar if the
2167 : * RTE is below an outer join or is part of an appendrel; the extra
2168 : * parameters show whether that's needed.
2169 : */
2170 : static Node *
2171 27594 : pull_up_constant_function(PlannerInfo *root, Node *jtnode,
2172 : RangeTblEntry *rte,
2173 : AppendRelInfo *containing_appendrel)
2174 : {
2175 27594 : Query *parse = root->parse;
2176 : RangeTblFunction *rtf;
2177 : TypeFuncClass functypclass;
2178 : Oid funcrettype;
2179 : TupleDesc tupdesc;
2180 : pullup_replace_vars_context rvcontext;
2181 :
2182 : /* Fail if the RTE has ORDINALITY - we don't implement that here. */
2183 27594 : if (rte->funcordinality)
2184 477 : return jtnode;
2185 :
2186 : /* Fail if RTE isn't a single, simple Const expr */
2187 27117 : if (list_length(rte->functions) != 1)
2188 37 : return jtnode;
2189 27080 : rtf = linitial_node(RangeTblFunction, rte->functions);
2190 27080 : if (!IsA(rtf->funcexpr, Const))
2191 26894 : return jtnode;
2192 :
2193 : /*
2194 : * If the function's result is not a scalar, we punt. In principle we
2195 : * could break the composite constant value apart into per-column
2196 : * constants, but for now it seems not worth the work.
2197 : */
2198 186 : if (rtf->funccolcount != 1)
2199 15 : return jtnode; /* definitely composite */
2200 :
2201 : /* If it has a coldeflist, it certainly returns RECORD */
2202 171 : if (rtf->funccolnames != NIL)
2203 0 : return jtnode; /* must be a one-column RECORD type */
2204 :
2205 171 : functypclass = get_expr_result_type(rtf->funcexpr,
2206 : &funcrettype,
2207 : &tupdesc);
2208 171 : if (functypclass != TYPEFUNC_SCALAR)
2209 6 : return jtnode; /* must be a one-column composite type */
2210 :
2211 : /* Create context for applying pullup_replace_vars */
2212 165 : rvcontext.root = root;
2213 165 : rvcontext.targetlist = list_make1(makeTargetEntry((Expr *) rtf->funcexpr,
2214 : 1, /* resno */
2215 : NULL, /* resname */
2216 : false)); /* resjunk */
2217 165 : rvcontext.target_rte = rte;
2218 165 : rvcontext.result_relation = 0;
2219 :
2220 : /*
2221 : * Since this function was reduced to a Const, it doesn't contain any
2222 : * lateral references, even if it's marked as LATERAL. This means we
2223 : * don't need to fill relids or nullinfo.
2224 : */
2225 165 : rvcontext.relids = NULL;
2226 165 : rvcontext.nullinfo = NULL;
2227 :
2228 165 : rvcontext.outer_hasSubLinks = &parse->hasSubLinks;
2229 165 : rvcontext.varno = ((RangeTblRef *) jtnode)->rtindex;
2230 : /* this flag will be set below, if needed */
2231 165 : rvcontext.wrap_option = REPLACE_WRAP_NONE;
2232 : /* initialize cache array with indexes 0 .. length(tlist) */
2233 165 : rvcontext.rv_cache = palloc0((list_length(rvcontext.targetlist) + 1) *
2234 : sizeof(Node *));
2235 :
2236 : /*
2237 : * If the parent query uses grouping sets, we need a PlaceHolderVar for
2238 : * each expression of the subquery's targetlist items. (See comments in
2239 : * pull_up_simple_subquery().)
2240 : */
2241 165 : if (parse->groupingSets)
2242 0 : rvcontext.wrap_option = REPLACE_WRAP_ALL;
2243 :
2244 : /*
2245 : * Replace all of the top query's references to the RTE's output with
2246 : * copies of the funcexpr, being careful not to replace any of the
2247 : * jointree structure.
2248 : */
2249 165 : perform_pullup_replace_vars(root, &rvcontext,
2250 : containing_appendrel);
2251 :
2252 : /*
2253 : * We don't need to bother with changing PlaceHolderVars in the parent
2254 : * query. Their references to the RT index are still good for now, and
2255 : * will get removed later if we're able to drop the RTE_RESULT.
2256 : */
2257 :
2258 : /*
2259 : * Convert the RTE to be RTE_RESULT type, signifying that we don't need to
2260 : * scan it anymore, and zero out RTE_FUNCTION-specific fields. Also make
2261 : * sure the RTE is not marked LATERAL, since elsewhere we don't expect
2262 : * RTE_RESULTs to be LATERAL.
2263 : */
2264 165 : rte->rtekind = RTE_RESULT;
2265 165 : rte->functions = NIL;
2266 165 : rte->lateral = false;
2267 :
2268 : /*
2269 : * We can reuse the RangeTblRef node.
2270 : */
2271 165 : return jtnode;
2272 : }
2273 :
2274 : /*
2275 : * is_simple_union_all
2276 : * Check a subquery to see if it's a simple UNION ALL.
2277 : *
2278 : * We require all the setops to be UNION ALL (no mixing) and there can't be
2279 : * any datatype coercions involved, ie, all the leaf queries must emit the
2280 : * same datatypes.
2281 : */
2282 : static bool
2283 15392 : is_simple_union_all(Query *subquery)
2284 : {
2285 : SetOperationStmt *topop;
2286 :
2287 : /* Let's just make sure it's a valid subselect ... */
2288 15392 : if (!IsA(subquery, Query) ||
2289 15392 : subquery->commandType != CMD_SELECT)
2290 0 : elog(ERROR, "subquery is bogus");
2291 :
2292 : /* Is it a set-operation query at all? */
2293 15392 : topop = castNode(SetOperationStmt, subquery->setOperations);
2294 15392 : if (!topop)
2295 12433 : return false;
2296 :
2297 : /* Can't handle ORDER BY, LIMIT/OFFSET, locking, or WITH */
2298 2959 : if (subquery->sortClause ||
2299 2927 : subquery->limitOffset ||
2300 2927 : subquery->limitCount ||
2301 2927 : subquery->rowMarks ||
2302 2927 : subquery->cteList)
2303 130 : return false;
2304 :
2305 : /* Recursively check the tree of set operations */
2306 2829 : return is_simple_union_all_recurse((Node *) topop, subquery,
2307 : topop->colTypes);
2308 : }
2309 :
2310 : static bool
2311 19258 : is_simple_union_all_recurse(Node *setOp, Query *setOpQuery, List *colTypes)
2312 : {
2313 : /* Since this function recurses, it could be driven to stack overflow. */
2314 19258 : check_stack_depth();
2315 :
2316 19258 : if (IsA(setOp, RangeTblRef))
2317 : {
2318 9830 : RangeTblRef *rtr = (RangeTblRef *) setOp;
2319 9830 : RangeTblEntry *rte = rt_fetch(rtr->rtindex, setOpQuery->rtable);
2320 9830 : Query *subquery = rte->subquery;
2321 :
2322 : Assert(subquery != NULL);
2323 :
2324 : /* Leaf nodes are OK if they match the toplevel column types */
2325 : /* We don't have to compare typmods or collations here */
2326 9830 : return tlist_same_datatypes(subquery->targetList, colTypes, true);
2327 : }
2328 9428 : else if (IsA(setOp, SetOperationStmt))
2329 : {
2330 9428 : SetOperationStmt *op = (SetOperationStmt *) setOp;
2331 :
2332 : /* Must be UNION ALL */
2333 9428 : if (op->op != SETOP_UNION || !op->all)
2334 2561 : return false;
2335 :
2336 : /* Recurse to check inputs */
2337 13328 : return is_simple_union_all_recurse(op->larg, setOpQuery, colTypes) &&
2338 6461 : is_simple_union_all_recurse(op->rarg, setOpQuery, colTypes);
2339 : }
2340 : else
2341 : {
2342 0 : elog(ERROR, "unrecognized node type: %d",
2343 : (int) nodeTag(setOp));
2344 : return false; /* keep compiler quiet */
2345 : }
2346 : }
2347 :
2348 : /*
2349 : * is_safe_append_member
2350 : * Check a subquery that is a leaf of a UNION ALL appendrel to see if it's
2351 : * safe to pull up.
2352 : */
2353 : static bool
2354 10442 : is_safe_append_member(Query *subquery)
2355 : {
2356 : FromExpr *jtnode;
2357 :
2358 : /*
2359 : * It's only safe to pull up the child if its jointree contains exactly
2360 : * one RTE, else the AppendRelInfo data structure breaks. The one base RTE
2361 : * could be buried in several levels of FromExpr, however. Also, if the
2362 : * child's jointree is completely empty, we can pull up because
2363 : * pull_up_simple_subquery will insert a single RTE_RESULT RTE instead.
2364 : *
2365 : * Also, the child can't have any WHERE quals because there's no place to
2366 : * put them in an appendrel. (This is a bit annoying...) If we didn't
2367 : * need to check this, we'd just test whether get_relids_in_jointree()
2368 : * yields a singleton set, to be more consistent with the coding of
2369 : * fix_append_rel_relids().
2370 : */
2371 10442 : jtnode = subquery->jointree;
2372 : Assert(IsA(jtnode, FromExpr));
2373 : /* Check the completely-empty case */
2374 10442 : if (jtnode->fromlist == NIL && jtnode->quals == NULL)
2375 304 : return true;
2376 : /* Check the more general case */
2377 17489 : while (IsA(jtnode, FromExpr))
2378 : {
2379 10144 : if (jtnode->quals != NULL)
2380 2793 : return false;
2381 7351 : if (list_length(jtnode->fromlist) != 1)
2382 0 : return false;
2383 7351 : jtnode = linitial(jtnode->fromlist);
2384 : }
2385 7345 : if (!IsA(jtnode, RangeTblRef))
2386 1125 : return false;
2387 :
2388 6220 : return true;
2389 : }
2390 :
2391 : /*
2392 : * jointree_contains_lateral_outer_refs
2393 : * Check for disallowed lateral references in a jointree's quals
2394 : *
2395 : * If restricted is false, all level-1 Vars are allowed (but we still must
2396 : * search the jointree, since it might contain outer joins below which there
2397 : * will be restrictions). If restricted is true, return true when any qual
2398 : * in the jointree contains level-1 Vars coming from outside the rels listed
2399 : * in safe_upper_varnos.
2400 : */
2401 : static bool
2402 2646 : jointree_contains_lateral_outer_refs(PlannerInfo *root, Node *jtnode,
2403 : bool restricted,
2404 : Relids safe_upper_varnos)
2405 : {
2406 2646 : if (jtnode == NULL)
2407 0 : return false;
2408 2646 : if (IsA(jtnode, RangeTblRef))
2409 1223 : return false;
2410 1423 : else if (IsA(jtnode, FromExpr))
2411 : {
2412 1266 : FromExpr *f = (FromExpr *) jtnode;
2413 : ListCell *l;
2414 :
2415 : /* First, recurse to check child joins */
2416 2344 : foreach(l, f->fromlist)
2417 : {
2418 1090 : if (jointree_contains_lateral_outer_refs(root,
2419 1090 : lfirst(l),
2420 : restricted,
2421 : safe_upper_varnos))
2422 12 : return true;
2423 : }
2424 :
2425 : /* Then check the top-level quals */
2426 1254 : if (restricted &&
2427 718 : !bms_is_subset(pull_varnos_of_level(root, f->quals, 1),
2428 : safe_upper_varnos))
2429 0 : return true;
2430 : }
2431 157 : else if (IsA(jtnode, JoinExpr))
2432 : {
2433 157 : JoinExpr *j = (JoinExpr *) jtnode;
2434 :
2435 : /*
2436 : * If this is an outer join, we mustn't allow any upper lateral
2437 : * references in or below it.
2438 : */
2439 157 : if (j->jointype != JOIN_INNER)
2440 : {
2441 79 : restricted = true;
2442 79 : safe_upper_varnos = NULL;
2443 : }
2444 :
2445 : /* Check the child joins */
2446 157 : if (jointree_contains_lateral_outer_refs(root,
2447 : j->larg,
2448 : restricted,
2449 : safe_upper_varnos))
2450 0 : return true;
2451 157 : if (jointree_contains_lateral_outer_refs(root,
2452 : j->rarg,
2453 : restricted,
2454 : safe_upper_varnos))
2455 0 : return true;
2456 :
2457 : /* Check the JOIN's qual clauses */
2458 157 : if (restricted &&
2459 145 : !bms_is_subset(pull_varnos_of_level(root, j->quals, 1),
2460 : safe_upper_varnos))
2461 12 : return true;
2462 : }
2463 : else
2464 0 : elog(ERROR, "unrecognized node type: %d",
2465 : (int) nodeTag(jtnode));
2466 1399 : return false;
2467 : }
2468 :
2469 : /*
2470 : * Perform pullup_replace_vars everyplace it's needed in the query tree.
2471 : *
2472 : * Caller has already filled *rvcontext with data describing what to
2473 : * substitute for Vars referencing the target subquery. In addition
2474 : * we need the identity of the containing appendrel if any.
2475 : */
2476 : static void
2477 21931 : perform_pullup_replace_vars(PlannerInfo *root,
2478 : pullup_replace_vars_context *rvcontext,
2479 : AppendRelInfo *containing_appendrel)
2480 : {
2481 21931 : Query *parse = root->parse;
2482 : ListCell *lc;
2483 :
2484 : /*
2485 : * If we are considering an appendrel child subquery (that is, a UNION ALL
2486 : * member query that we're pulling up), then the only part of the upper
2487 : * query that could reference the child yet is the translated_vars list of
2488 : * the associated AppendRelInfo. Furthermore, we do not want to force use
2489 : * of PHVs in the AppendRelInfo --- there isn't any outer join between.
2490 : */
2491 21931 : if (containing_appendrel)
2492 : {
2493 3205 : ReplaceWrapOption save_wrap_option = rvcontext->wrap_option;
2494 :
2495 3205 : rvcontext->wrap_option = REPLACE_WRAP_NONE;
2496 3205 : containing_appendrel->translated_vars = (List *)
2497 3205 : pullup_replace_vars((Node *) containing_appendrel->translated_vars,
2498 : rvcontext);
2499 3205 : rvcontext->wrap_option = save_wrap_option;
2500 3205 : return;
2501 : }
2502 :
2503 : /*
2504 : * Replace all of the top query's references to the subquery's outputs
2505 : * with copies of the adjusted subtlist items, being careful not to
2506 : * replace any of the jointree structure. (This'd be a lot cleaner if we
2507 : * could use query_tree_mutator.) We have to use PHVs in the targetList,
2508 : * returningList, and havingQual, since those are certainly above any
2509 : * outer join. replace_vars_in_jointree tracks its location in the
2510 : * jointree and uses PHVs or not appropriately.
2511 : */
2512 18726 : parse->targetList = (List *)
2513 18726 : pullup_replace_vars((Node *) parse->targetList, rvcontext);
2514 18726 : parse->returningList = (List *)
2515 18726 : pullup_replace_vars((Node *) parse->returningList, rvcontext);
2516 :
2517 18726 : if (parse->onConflict)
2518 : {
2519 22 : parse->onConflict->onConflictSet = (List *)
2520 11 : pullup_replace_vars((Node *) parse->onConflict->onConflictSet,
2521 : rvcontext);
2522 11 : parse->onConflict->onConflictWhere =
2523 11 : pullup_replace_vars(parse->onConflict->onConflictWhere,
2524 : rvcontext);
2525 :
2526 : /*
2527 : * We assume ON CONFLICT's arbiterElems, arbiterWhere, exclRelTlist
2528 : * can't contain any references to a subquery.
2529 : */
2530 : }
2531 18726 : if (parse->mergeActionList)
2532 : {
2533 1532 : foreach(lc, parse->mergeActionList)
2534 : {
2535 914 : MergeAction *action = lfirst(lc);
2536 :
2537 914 : action->qual = pullup_replace_vars(action->qual, rvcontext);
2538 914 : action->targetList = (List *)
2539 914 : pullup_replace_vars((Node *) action->targetList, rvcontext);
2540 : }
2541 : }
2542 18726 : parse->mergeJoinCondition = pullup_replace_vars(parse->mergeJoinCondition,
2543 : rvcontext);
2544 18726 : replace_vars_in_jointree((Node *) parse->jointree, rvcontext);
2545 : Assert(parse->setOperations == NULL);
2546 18723 : parse->havingQual = pullup_replace_vars(parse->havingQual, rvcontext);
2547 :
2548 : /*
2549 : * Replace references in the translated_vars lists of appendrels.
2550 : */
2551 18741 : foreach(lc, root->append_rel_list)
2552 : {
2553 18 : AppendRelInfo *appinfo = (AppendRelInfo *) lfirst(lc);
2554 :
2555 18 : appinfo->translated_vars = (List *)
2556 18 : pullup_replace_vars((Node *) appinfo->translated_vars, rvcontext);
2557 : }
2558 :
2559 : /*
2560 : * Replace references in the joinaliasvars lists of join RTEs and the
2561 : * groupexprs list of group RTE.
2562 : */
2563 52051 : foreach(lc, parse->rtable)
2564 : {
2565 33328 : RangeTblEntry *otherrte = (RangeTblEntry *) lfirst(lc);
2566 :
2567 33328 : if (otherrte->rtekind == RTE_JOIN)
2568 3470 : otherrte->joinaliasvars = (List *)
2569 3470 : pullup_replace_vars((Node *) otherrte->joinaliasvars,
2570 : rvcontext);
2571 29858 : else if (otherrte->rtekind == RTE_GROUP)
2572 412 : otherrte->groupexprs = (List *)
2573 412 : pullup_replace_vars((Node *) otherrte->groupexprs,
2574 : rvcontext);
2575 : }
2576 : }
2577 :
2578 : /*
2579 : * Helper routine for perform_pullup_replace_vars: do pullup_replace_vars on
2580 : * every expression in the jointree, without changing the jointree structure
2581 : * itself. Ugly, but there's no other way...
2582 : */
2583 : static void
2584 48714 : replace_vars_in_jointree(Node *jtnode,
2585 : pullup_replace_vars_context *context)
2586 : {
2587 48714 : if (jtnode == NULL)
2588 0 : return;
2589 48714 : if (IsA(jtnode, RangeTblRef))
2590 : {
2591 : /*
2592 : * If the RangeTblRef refers to a LATERAL subquery (that isn't the
2593 : * same subquery we're pulling up), it might contain references to the
2594 : * target subquery, which we must replace. We drive this from the
2595 : * jointree scan, rather than a scan of the rtable, so that we can
2596 : * avoid processing no-longer-referenced RTEs.
2597 : */
2598 24505 : int varno = ((RangeTblRef *) jtnode)->rtindex;
2599 :
2600 24505 : if (varno != context->varno) /* ignore target subquery itself */
2601 : {
2602 5779 : RangeTblEntry *rte = rt_fetch(varno, context->root->parse->rtable);
2603 :
2604 : Assert(rte != context->target_rte);
2605 5779 : if (rte->lateral)
2606 : {
2607 463 : switch (rte->rtekind)
2608 : {
2609 0 : case RTE_RELATION:
2610 : /* shouldn't be marked LATERAL unless tablesample */
2611 : Assert(rte->tablesample);
2612 0 : rte->tablesample = (TableSampleClause *)
2613 0 : pullup_replace_vars((Node *) rte->tablesample,
2614 : context);
2615 0 : break;
2616 225 : case RTE_SUBQUERY:
2617 225 : rte->subquery =
2618 225 : pullup_replace_vars_subquery(rte->subquery,
2619 : context);
2620 225 : break;
2621 184 : case RTE_FUNCTION:
2622 184 : rte->functions = (List *)
2623 184 : pullup_replace_vars((Node *) rte->functions,
2624 : context);
2625 184 : break;
2626 54 : case RTE_TABLEFUNC:
2627 54 : rte->tablefunc = (TableFunc *)
2628 54 : pullup_replace_vars((Node *) rte->tablefunc,
2629 : context);
2630 54 : break;
2631 0 : case RTE_VALUES:
2632 0 : rte->values_lists = (List *)
2633 0 : pullup_replace_vars((Node *) rte->values_lists,
2634 : context);
2635 0 : break;
2636 0 : case RTE_JOIN:
2637 : case RTE_CTE:
2638 : case RTE_NAMEDTUPLESTORE:
2639 : case RTE_RESULT:
2640 : case RTE_GROUP:
2641 : /* these shouldn't be marked LATERAL */
2642 : Assert(false);
2643 0 : break;
2644 : }
2645 : }
2646 : }
2647 : }
2648 24209 : else if (IsA(jtnode, FromExpr))
2649 : {
2650 20110 : FromExpr *f = (FromExpr *) jtnode;
2651 : ListCell *l;
2652 :
2653 41900 : foreach(l, f->fromlist)
2654 21790 : replace_vars_in_jointree(lfirst(l), context);
2655 20110 : f->quals = pullup_replace_vars(f->quals, context);
2656 : }
2657 4099 : else if (IsA(jtnode, JoinExpr))
2658 : {
2659 4099 : JoinExpr *j = (JoinExpr *) jtnode;
2660 4099 : ReplaceWrapOption save_wrap_option = context->wrap_option;
2661 :
2662 4099 : replace_vars_in_jointree(j->larg, context);
2663 4099 : replace_vars_in_jointree(j->rarg, context);
2664 :
2665 : /*
2666 : * Use PHVs within the join quals of a full join for variable-free
2667 : * expressions. Otherwise, we cannot identify which side of the join
2668 : * a pulled-up variable-free expression came from, which can lead to
2669 : * failure to make a plan at all because none of the quals appear to
2670 : * be mergeable or hashable conditions.
2671 : */
2672 4099 : if (j->jointype == JOIN_FULL)
2673 314 : context->wrap_option = REPLACE_WRAP_VARFREE;
2674 :
2675 4099 : j->quals = pullup_replace_vars(j->quals, context);
2676 :
2677 4099 : context->wrap_option = save_wrap_option;
2678 : }
2679 : else
2680 0 : elog(ERROR, "unrecognized node type: %d",
2681 : (int) nodeTag(jtnode));
2682 : }
2683 :
2684 : /*
2685 : * Apply pullup variable replacement throughout an expression tree
2686 : *
2687 : * Returns a modified copy of the tree, so this can't be used where we
2688 : * need to do in-place replacement.
2689 : */
2690 : static Node *
2691 108854 : pullup_replace_vars(Node *expr, pullup_replace_vars_context *context)
2692 : {
2693 108854 : return replace_rte_variables(expr,
2694 : context->varno, 0,
2695 : pullup_replace_vars_callback,
2696 : context,
2697 : context->outer_hasSubLinks);
2698 : }
2699 :
2700 : static Node *
2701 60684 : pullup_replace_vars_callback(Var *var,
2702 : replace_rte_variables_context *context)
2703 : {
2704 60684 : pullup_replace_vars_context *rcon = (pullup_replace_vars_context *) context->callback_arg;
2705 60684 : int varattno = var->varattno;
2706 : bool need_phv;
2707 : Node *newnode;
2708 :
2709 : /* System columns are not replaced. */
2710 60684 : if (varattno < InvalidAttrNumber)
2711 21 : return (Node *) copyObject(var);
2712 :
2713 : /*
2714 : * We need a PlaceHolderVar if the Var-to-be-replaced has nonempty
2715 : * varnullingrels (unless we find below that the replacement expression is
2716 : * a Var or PlaceHolderVar that we can just add the nullingrels to). We
2717 : * also need one if the caller has instructed us that certain expression
2718 : * replacements need to be wrapped for identification purposes.
2719 : */
2720 115236 : need_phv = (var->varnullingrels != NULL) ||
2721 54573 : (rcon->wrap_option != REPLACE_WRAP_NONE);
2722 :
2723 : /*
2724 : * If PlaceHolderVars are needed, we cache the modified expressions in
2725 : * rcon->rv_cache[]. This is not in hopes of any material speed gain
2726 : * within this function, but to avoid generating identical PHVs with
2727 : * different IDs. That would result in duplicate evaluations at runtime,
2728 : * and possibly prevent optimizations that rely on recognizing different
2729 : * references to the same subquery output as being equal(). So it's worth
2730 : * a bit of extra effort to avoid it.
2731 : *
2732 : * The cached items have phlevelsup = 0 and phnullingrels = NULL; we'll
2733 : * copy them and adjust those values for this reference site below.
2734 : */
2735 60663 : if (need_phv &&
2736 7159 : varattno >= InvalidAttrNumber &&
2737 7159 : varattno <= list_length(rcon->targetlist) &&
2738 7159 : rcon->rv_cache[varattno] != NULL)
2739 : {
2740 : /* Just copy the entry and fall through to adjust phlevelsup etc */
2741 1448 : newnode = copyObject(rcon->rv_cache[varattno]);
2742 : }
2743 : else
2744 : {
2745 : /*
2746 : * Generate the replacement expression. This takes care of expanding
2747 : * wholerow references and dealing with non-default varreturningtype.
2748 : */
2749 59215 : newnode = ReplaceVarFromTargetList(var,
2750 : rcon->target_rte,
2751 : rcon->targetlist,
2752 : rcon->result_relation,
2753 : REPLACEVARS_REPORT_ERROR,
2754 : 0);
2755 :
2756 : /* Insert PlaceHolderVar if needed */
2757 59215 : if (need_phv)
2758 : {
2759 : bool wrap;
2760 :
2761 5711 : if (rcon->wrap_option == REPLACE_WRAP_ALL)
2762 : {
2763 : /* Caller told us to wrap all expressions in a PlaceHolderVar */
2764 462 : wrap = true;
2765 : }
2766 5249 : else if (varattno == InvalidAttrNumber)
2767 : {
2768 : /*
2769 : * Insert PlaceHolderVar for whole-tuple reference. Notice
2770 : * that we are wrapping one PlaceHolderVar around the whole
2771 : * RowExpr, rather than putting one around each element of the
2772 : * row. This is because we need the expression to yield NULL,
2773 : * not ROW(NULL,NULL,...) when it is forced to null by an
2774 : * outer join.
2775 : */
2776 36 : wrap = true;
2777 : }
2778 5213 : else if (newnode && IsA(newnode, Var) &&
2779 4190 : ((Var *) newnode)->varlevelsup == 0)
2780 : {
2781 : /*
2782 : * Simple Vars always escape being wrapped, unless they are
2783 : * lateral references to something outside the subquery being
2784 : * pulled up and the referenced rel is not under the same
2785 : * lowest nulling outer join.
2786 : */
2787 4182 : wrap = false;
2788 4182 : if (rcon->target_rte->lateral &&
2789 705 : !bms_is_member(((Var *) newnode)->varno, rcon->relids))
2790 : {
2791 66 : nullingrel_info *nullinfo = rcon->nullinfo;
2792 66 : int lvarno = ((Var *) newnode)->varno;
2793 :
2794 : Assert(lvarno > 0 && lvarno <= nullinfo->rtlength);
2795 66 : if (!bms_is_subset(nullinfo->nullingrels[rcon->varno],
2796 66 : nullinfo->nullingrels[lvarno]))
2797 54 : wrap = true;
2798 : }
2799 : }
2800 1031 : else if (newnode && IsA(newnode, PlaceHolderVar) &&
2801 90 : ((PlaceHolderVar *) newnode)->phlevelsup == 0)
2802 : {
2803 : /* The same rules apply for a PlaceHolderVar */
2804 90 : wrap = false;
2805 90 : if (rcon->target_rte->lateral &&
2806 24 : !bms_is_subset(((PlaceHolderVar *) newnode)->phrels,
2807 24 : rcon->relids))
2808 : {
2809 24 : nullingrel_info *nullinfo = rcon->nullinfo;
2810 24 : Relids lvarnos = ((PlaceHolderVar *) newnode)->phrels;
2811 : int lvarno;
2812 :
2813 24 : lvarno = -1;
2814 36 : while ((lvarno = bms_next_member(lvarnos, lvarno)) >= 0)
2815 : {
2816 : Assert(lvarno > 0 && lvarno <= nullinfo->rtlength);
2817 24 : if (!bms_is_subset(nullinfo->nullingrels[rcon->varno],
2818 24 : nullinfo->nullingrels[lvarno]))
2819 : {
2820 12 : wrap = true;
2821 12 : break;
2822 : }
2823 : }
2824 : }
2825 : }
2826 : else
2827 : {
2828 : /*
2829 : * If the node contains Var(s) or PlaceHolderVar(s) of the
2830 : * subquery being pulled up, or of rels that are under the
2831 : * same lowest nulling outer join as the subquery, and does
2832 : * not contain any non-strict constructs, then instead of
2833 : * adding a PHV on top we can add the required nullingrels to
2834 : * those Vars/PHVs. (This is fundamentally a generalization
2835 : * of the above cases for bare Vars and PHVs.)
2836 : *
2837 : * This test is somewhat expensive, but it avoids pessimizing
2838 : * the plan in cases where the nullingrels get removed again
2839 : * later by outer join reduction.
2840 : *
2841 : * Note that we don't force wrapping of expressions containing
2842 : * lateral references, so long as they also contain Vars/PHVs
2843 : * of the subquery, or of rels that are under the same lowest
2844 : * nulling outer join as the subquery. This is okay because
2845 : * of the restriction to strict constructs: if those Vars/PHVs
2846 : * have been forced to NULL by an outer join then the end
2847 : * result of the expression will be NULL too, regardless of
2848 : * the lateral references. So it's not necessary to force the
2849 : * expression to be evaluated below the outer join. This can
2850 : * be a very valuable optimization, because it may allow us to
2851 : * avoid using a nested loop to pass the lateral reference
2852 : * down.
2853 : *
2854 : * This analysis could be tighter: in particular, a non-strict
2855 : * construct hidden within a lower-level PlaceHolderVar is not
2856 : * reason to add another PHV. But for now it doesn't seem
2857 : * worth the code to be more exact. This is also why it's
2858 : * preferable to handle bare PHVs in the above branch, rather
2859 : * than this branch. We also prefer to handle bare Vars in a
2860 : * separate branch, as it's cheaper this way and parallels the
2861 : * handling of PHVs.
2862 : *
2863 : * For a LATERAL subquery, we have to check the actual var
2864 : * membership of the node, but if it's non-lateral then any
2865 : * level-zero var must belong to the subquery.
2866 : */
2867 941 : bool contain_nullable_vars = false;
2868 :
2869 941 : if (!rcon->target_rte->lateral)
2870 : {
2871 827 : if (contain_vars_of_level(newnode, 0))
2872 267 : contain_nullable_vars = true;
2873 : }
2874 : else
2875 : {
2876 : Relids all_varnos;
2877 :
2878 114 : all_varnos = pull_varnos(rcon->root, newnode);
2879 114 : if (bms_overlap(all_varnos, rcon->relids))
2880 66 : contain_nullable_vars = true;
2881 : else
2882 : {
2883 48 : nullingrel_info *nullinfo = rcon->nullinfo;
2884 : int varno;
2885 :
2886 48 : varno = -1;
2887 90 : while ((varno = bms_next_member(all_varnos, varno)) >= 0)
2888 : {
2889 : Assert(varno > 0 && varno <= nullinfo->rtlength);
2890 54 : if (bms_is_subset(nullinfo->nullingrels[rcon->varno],
2891 54 : nullinfo->nullingrels[varno]))
2892 : {
2893 12 : contain_nullable_vars = true;
2894 12 : break;
2895 : }
2896 : }
2897 : }
2898 : }
2899 :
2900 941 : if (contain_nullable_vars &&
2901 345 : !contain_nonstrict_functions(newnode))
2902 : {
2903 : /* No wrap needed */
2904 144 : wrap = false;
2905 : }
2906 : else
2907 : {
2908 : /* Else wrap it in a PlaceHolderVar */
2909 797 : wrap = true;
2910 : }
2911 : }
2912 :
2913 5711 : if (wrap)
2914 : {
2915 : newnode = (Node *)
2916 1361 : make_placeholder_expr(rcon->root,
2917 : (Expr *) newnode,
2918 : bms_make_singleton(rcon->varno));
2919 :
2920 : /*
2921 : * Cache it if possible (ie, if the attno is in range, which
2922 : * it probably always should be).
2923 : */
2924 2722 : if (varattno >= InvalidAttrNumber &&
2925 1361 : varattno <= list_length(rcon->targetlist))
2926 1361 : rcon->rv_cache[varattno] = copyObject(newnode);
2927 : }
2928 : }
2929 : }
2930 :
2931 : /* Propagate any varnullingrels into the replacement expression */
2932 60663 : if (var->varnullingrels != NULL)
2933 : {
2934 6090 : if (IsA(newnode, Var))
2935 : {
2936 3883 : Var *newvar = (Var *) newnode;
2937 :
2938 : Assert(newvar->varlevelsup == 0);
2939 3883 : newvar->varnullingrels = bms_add_members(newvar->varnullingrels,
2940 3883 : var->varnullingrels);
2941 : }
2942 2207 : else if (IsA(newnode, PlaceHolderVar))
2943 : {
2944 2063 : PlaceHolderVar *newphv = (PlaceHolderVar *) newnode;
2945 :
2946 : Assert(newphv->phlevelsup == 0);
2947 2063 : newphv->phnullingrels = bms_add_members(newphv->phnullingrels,
2948 2063 : var->varnullingrels);
2949 : }
2950 : else
2951 : {
2952 : /*
2953 : * There should be Vars/PHVs within the expression that we can
2954 : * modify. Vars/PHVs of the subquery should have the full
2955 : * var->varnullingrels added to them, but if there are lateral
2956 : * references within the expression, those must be marked with
2957 : * only the nullingrels that potentially apply to them. (This
2958 : * corresponds to the fact that the expression will now be
2959 : * evaluated at the join level of the Var that we are replacing:
2960 : * the lateral references may have bubbled up through fewer outer
2961 : * joins than the subquery's Vars have. Per the discussion above,
2962 : * we'll still get the right answers.) That relid set could be
2963 : * different for different lateral relations, so we have to do
2964 : * this work for each one.
2965 : *
2966 : * (Currently, the restrictions in is_simple_subquery() mean that
2967 : * at most we have to remove the lowest outer join's relid from
2968 : * the nullingrels of a lateral reference. However, we might
2969 : * relax those restrictions someday, so let's do this right.)
2970 : */
2971 144 : if (rcon->target_rte->lateral)
2972 : {
2973 42 : nullingrel_info *nullinfo = rcon->nullinfo;
2974 : Relids lvarnos;
2975 : int lvarno;
2976 :
2977 : /*
2978 : * Identify lateral varnos used within newnode. We must do
2979 : * this before injecting var->varnullingrels into the tree.
2980 : */
2981 42 : lvarnos = pull_varnos(rcon->root, newnode);
2982 42 : lvarnos = bms_del_members(lvarnos, rcon->relids);
2983 : /* For each one, add relevant nullingrels if any */
2984 42 : lvarno = -1;
2985 84 : while ((lvarno = bms_next_member(lvarnos, lvarno)) >= 0)
2986 : {
2987 : Relids lnullingrels;
2988 :
2989 : Assert(lvarno > 0 && lvarno <= nullinfo->rtlength);
2990 42 : lnullingrels = bms_intersect(var->varnullingrels,
2991 42 : nullinfo->nullingrels[lvarno]);
2992 42 : if (!bms_is_empty(lnullingrels))
2993 24 : newnode = add_nulling_relids(newnode,
2994 24 : bms_make_singleton(lvarno),
2995 : lnullingrels);
2996 : }
2997 : }
2998 :
2999 : /* Finally, deal with Vars/PHVs of the subquery itself */
3000 144 : newnode = add_nulling_relids(newnode,
3001 144 : rcon->relids,
3002 144 : var->varnullingrels);
3003 : /* Assert we did put the varnullingrels into the expression */
3004 : Assert(bms_is_subset(var->varnullingrels,
3005 : pull_varnos(rcon->root, newnode)));
3006 : }
3007 : }
3008 :
3009 : /* Must adjust varlevelsup if replaced Var is within a subquery */
3010 60663 : if (var->varlevelsup > 0)
3011 563 : IncrementVarSublevelsUp(newnode, var->varlevelsup, 0);
3012 :
3013 60663 : return newnode;
3014 : }
3015 :
3016 : /*
3017 : * Apply pullup variable replacement to a subquery
3018 : *
3019 : * This needs to be different from pullup_replace_vars() because
3020 : * replace_rte_variables will think that it shouldn't increment sublevels_up
3021 : * before entering the Query; so we need to call it with sublevels_up == 1.
3022 : */
3023 : static Query *
3024 225 : pullup_replace_vars_subquery(Query *query,
3025 : pullup_replace_vars_context *context)
3026 : {
3027 : Assert(IsA(query, Query));
3028 225 : return (Query *) replace_rte_variables((Node *) query,
3029 : context->varno, 1,
3030 : pullup_replace_vars_callback,
3031 : context,
3032 : NULL);
3033 : }
3034 :
3035 :
3036 : /*
3037 : * flatten_simple_union_all
3038 : * Try to optimize top-level UNION ALL structure into an appendrel
3039 : *
3040 : * If a query's setOperations tree consists entirely of simple UNION ALL
3041 : * operations, flatten it into an append relation, which we can process more
3042 : * intelligently than the general setops case. Otherwise, do nothing.
3043 : *
3044 : * In most cases, this can succeed only for a top-level query, because for a
3045 : * subquery in FROM, the parent query's invocation of pull_up_subqueries would
3046 : * already have flattened the UNION via pull_up_simple_union_all. But there
3047 : * are a few cases we can support here but not in that code path, for example
3048 : * when the subquery also contains ORDER BY.
3049 : */
3050 : void
3051 3633 : flatten_simple_union_all(PlannerInfo *root)
3052 : {
3053 3633 : Query *parse = root->parse;
3054 : SetOperationStmt *topop;
3055 : Node *leftmostjtnode;
3056 : int leftmostRTI;
3057 : RangeTblEntry *leftmostRTE;
3058 : int childRTI;
3059 : RangeTblEntry *childRTE;
3060 : RangeTblRef *rtr;
3061 :
3062 : /* Shouldn't be called unless query has setops */
3063 3633 : topop = castNode(SetOperationStmt, parse->setOperations);
3064 : Assert(topop);
3065 :
3066 : /* Can't optimize away a recursive UNION */
3067 3633 : if (root->hasRecursion)
3068 3237 : return;
3069 :
3070 : /*
3071 : * Recursively check the tree of set operations. If not all UNION ALL
3072 : * with identical column types, punt.
3073 : */
3074 3101 : if (!is_simple_union_all_recurse((Node *) topop, parse, topop->colTypes))
3075 2705 : return;
3076 :
3077 : /*
3078 : * Locate the leftmost leaf query in the setops tree. The upper query's
3079 : * Vars all refer to this RTE (see transformSetOperationStmt).
3080 : */
3081 396 : leftmostjtnode = topop->larg;
3082 604 : while (leftmostjtnode && IsA(leftmostjtnode, SetOperationStmt))
3083 208 : leftmostjtnode = ((SetOperationStmt *) leftmostjtnode)->larg;
3084 : Assert(leftmostjtnode && IsA(leftmostjtnode, RangeTblRef));
3085 396 : leftmostRTI = ((RangeTblRef *) leftmostjtnode)->rtindex;
3086 396 : leftmostRTE = rt_fetch(leftmostRTI, parse->rtable);
3087 : Assert(leftmostRTE->rtekind == RTE_SUBQUERY);
3088 :
3089 : /*
3090 : * Make a copy of the leftmost RTE and add it to the rtable. This copy
3091 : * will represent the leftmost leaf query in its capacity as a member of
3092 : * the appendrel. The original will represent the appendrel as a whole.
3093 : * (We must do things this way because the upper query's Vars have to be
3094 : * seen as referring to the whole appendrel.)
3095 : */
3096 396 : childRTE = copyObject(leftmostRTE);
3097 396 : parse->rtable = lappend(parse->rtable, childRTE);
3098 396 : childRTI = list_length(parse->rtable);
3099 :
3100 : /* Modify the setops tree to reference the child copy */
3101 396 : ((RangeTblRef *) leftmostjtnode)->rtindex = childRTI;
3102 :
3103 : /* Modify the formerly-leftmost RTE to mark it as an appendrel parent */
3104 396 : leftmostRTE->inh = true;
3105 :
3106 : /*
3107 : * Form a RangeTblRef for the appendrel, and insert it into FROM. The top
3108 : * Query of a setops tree should have had an empty FromClause initially.
3109 : */
3110 396 : rtr = makeNode(RangeTblRef);
3111 396 : rtr->rtindex = leftmostRTI;
3112 : Assert(parse->jointree->fromlist == NIL);
3113 396 : parse->jointree->fromlist = list_make1(rtr);
3114 :
3115 : /*
3116 : * Now pretend the query has no setops. We must do this before trying to
3117 : * do subquery pullup, because of Assert in pull_up_simple_subquery.
3118 : */
3119 396 : parse->setOperations = NULL;
3120 :
3121 : /*
3122 : * Build AppendRelInfo information, and apply pull_up_subqueries to the
3123 : * leaf queries of the UNION ALL. (We must do that now because they
3124 : * weren't previously referenced by the jointree, and so were missed by
3125 : * the main invocation of pull_up_subqueries.)
3126 : */
3127 396 : pull_up_union_leaf_queries((Node *) topop, root, leftmostRTI, parse, 0);
3128 : }
3129 :
3130 :
3131 : /*
3132 : * reduce_outer_joins
3133 : * Attempt to reduce outer joins to plain inner joins.
3134 : *
3135 : * The idea here is that given a query like
3136 : * SELECT ... FROM a LEFT JOIN b ON (...) WHERE b.y = 42;
3137 : * we can reduce the LEFT JOIN to a plain JOIN if the "=" operator in WHERE
3138 : * is strict. The strict operator will always return NULL, causing the outer
3139 : * WHERE to fail, on any row where the LEFT JOIN filled in NULLs for b's
3140 : * columns. Therefore, there's no need for the join to produce null-extended
3141 : * rows in the first place --- which makes it a plain join not an outer join.
3142 : * (This scenario may not be very likely in a query written out by hand, but
3143 : * it's reasonably likely when pushing quals down into complex views.)
3144 : *
3145 : * More generally, an outer join can be reduced in strength if there is a
3146 : * strict qual above it in the qual tree that constrains a Var from the
3147 : * nullable side of the join to be non-null. (For FULL joins this applies
3148 : * to each side separately.)
3149 : *
3150 : * Another transformation we apply here is to recognize cases like
3151 : * SELECT ... FROM a LEFT JOIN b ON (a.x = b.y) WHERE b.z IS NULL;
3152 : * If we can prove that b.z must be non-null for any matching row, either
3153 : * because the join clause is strict for b.z and b.z happens to be the join
3154 : * key b.y, or because b.z is defined NOT NULL by table constraints and is
3155 : * not nullable due to lower-level outer joins, then only null-extended rows
3156 : * could pass the upper WHERE, and we can conclude that what the query is
3157 : * really specifying is an anti-semijoin. We change the join type from
3158 : * JOIN_LEFT to JOIN_ANTI. The IS NULL clause then becomes redundant, and
3159 : * must be removed to prevent bogus selectivity calculations, but we leave
3160 : * it to distribute_qual_to_rels to get rid of such clauses.
3161 : *
3162 : * Also, we get rid of JOIN_RIGHT cases by flipping them around to become
3163 : * JOIN_LEFT. This saves some code here and in some later planner routines;
3164 : * the main benefit is to reduce the number of jointypes that can appear in
3165 : * SpecialJoinInfo nodes. Note that we can still generate Paths and Plans
3166 : * that use JOIN_RIGHT (or JOIN_RIGHT_ANTI) by switching the inputs again.
3167 : *
3168 : * To ease recognition of strict qual clauses, we require this routine to be
3169 : * run after expression preprocessing (i.e., qual canonicalization and JOIN
3170 : * alias-var expansion).
3171 : */
3172 : void
3173 18241 : reduce_outer_joins(PlannerInfo *root)
3174 : {
3175 : reduce_outer_joins_pass1_state *state1;
3176 : reduce_outer_joins_pass2_state state2;
3177 : ListCell *lc;
3178 :
3179 : /*
3180 : * To avoid doing strictness checks on more quals than necessary, we want
3181 : * to stop descending the jointree as soon as there are no outer joins
3182 : * below our current point. This consideration forces a two-pass process.
3183 : * The first pass gathers information about which base rels appear below
3184 : * each side of each join clause, about whether there are outer join(s)
3185 : * below each side of each join clause, and about which base rels are from
3186 : * the nullable side of those outer join(s). The second pass examines
3187 : * qual clauses and changes join types as it descends the tree.
3188 : */
3189 18241 : state1 = reduce_outer_joins_pass1((Node *) root->parse->jointree);
3190 :
3191 : /* planner.c shouldn't have called me if no outer joins */
3192 18241 : if (state1 == NULL || !state1->contains_outer)
3193 0 : elog(ERROR, "so where are the outer joins?");
3194 :
3195 18241 : state2.inner_reduced = NULL;
3196 18241 : state2.partial_reduced = NIL;
3197 :
3198 18241 : reduce_outer_joins_pass2((Node *) root->parse->jointree,
3199 : state1, &state2,
3200 : root, NULL, NIL);
3201 :
3202 : /*
3203 : * If we successfully reduced the strength of any outer joins, we must
3204 : * remove references to those joins as nulling rels. This is handled as
3205 : * an additional pass, for simplicity and because we can handle all
3206 : * fully-reduced joins in a single pass over the parse tree.
3207 : */
3208 18241 : if (!bms_is_empty(state2.inner_reduced))
3209 : {
3210 1212 : root->parse = (Query *)
3211 1212 : remove_nulling_relids((Node *) root->parse,
3212 1212 : state2.inner_reduced,
3213 : NULL);
3214 : /* There could be references in the append_rel_list, too */
3215 1212 : root->append_rel_list = (List *)
3216 1212 : remove_nulling_relids((Node *) root->append_rel_list,
3217 1212 : state2.inner_reduced,
3218 : NULL);
3219 : }
3220 :
3221 : /*
3222 : * Partially-reduced full joins have to be done one at a time, since
3223 : * they'll each need a different setting of except_relids.
3224 : */
3225 18266 : foreach(lc, state2.partial_reduced)
3226 : {
3227 25 : reduce_outer_joins_partial_state *statep = lfirst(lc);
3228 25 : Relids full_join_relids = bms_make_singleton(statep->full_join_rti);
3229 :
3230 25 : root->parse = (Query *)
3231 25 : remove_nulling_relids((Node *) root->parse,
3232 : full_join_relids,
3233 25 : statep->unreduced_side);
3234 25 : root->append_rel_list = (List *)
3235 25 : remove_nulling_relids((Node *) root->append_rel_list,
3236 : full_join_relids,
3237 25 : statep->unreduced_side);
3238 : }
3239 18241 : }
3240 :
3241 : /*
3242 : * reduce_outer_joins_pass1 - phase 1 data collection
3243 : *
3244 : * Returns a state node describing the given jointree node.
3245 : */
3246 : static reduce_outer_joins_pass1_state *
3247 105478 : reduce_outer_joins_pass1(Node *jtnode)
3248 : {
3249 : reduce_outer_joins_pass1_state *result;
3250 :
3251 105478 : result = palloc_object(reduce_outer_joins_pass1_state);
3252 105478 : result->relids = NULL;
3253 105478 : result->contains_outer = false;
3254 105478 : result->nullable_rels = NULL;
3255 105478 : result->sub_states = NIL;
3256 :
3257 105478 : if (jtnode == NULL)
3258 0 : return result;
3259 105478 : if (IsA(jtnode, RangeTblRef))
3260 : {
3261 52648 : int varno = ((RangeTblRef *) jtnode)->rtindex;
3262 :
3263 52648 : result->relids = bms_make_singleton(varno);
3264 : }
3265 52830 : else if (IsA(jtnode, FromExpr))
3266 : {
3267 19975 : FromExpr *f = (FromExpr *) jtnode;
3268 : ListCell *l;
3269 :
3270 41502 : foreach(l, f->fromlist)
3271 : {
3272 : reduce_outer_joins_pass1_state *sub_state;
3273 :
3274 21527 : sub_state = reduce_outer_joins_pass1(lfirst(l));
3275 43054 : result->relids = bms_add_members(result->relids,
3276 21527 : sub_state->relids);
3277 21527 : result->contains_outer |= sub_state->contains_outer;
3278 43054 : result->nullable_rels = bms_add_members(result->nullable_rels,
3279 21527 : sub_state->nullable_rels);
3280 21527 : result->sub_states = lappend(result->sub_states, sub_state);
3281 : }
3282 : }
3283 32855 : else if (IsA(jtnode, JoinExpr))
3284 : {
3285 32855 : JoinExpr *j = (JoinExpr *) jtnode;
3286 : reduce_outer_joins_pass1_state *left_state;
3287 : reduce_outer_joins_pass1_state *right_state;
3288 :
3289 : /* Recurse to children */
3290 32855 : left_state = reduce_outer_joins_pass1(j->larg);
3291 32855 : right_state = reduce_outer_joins_pass1(j->rarg);
3292 :
3293 : /* join's own RT index is not wanted in result->relids */
3294 32855 : result->relids = bms_union(left_state->relids, right_state->relids);
3295 :
3296 : /* Store children's states for pass 2 */
3297 32855 : result->sub_states = list_make2(left_state, right_state);
3298 :
3299 : /* Collect outer join information */
3300 32855 : switch (j->jointype)
3301 : {
3302 6161 : case JOIN_INNER:
3303 : case JOIN_SEMI:
3304 : /* No new nullability; propagate state from children */
3305 12069 : result->contains_outer = left_state->contains_outer ||
3306 5908 : right_state->contains_outer;
3307 12322 : result->nullable_rels = bms_union(left_state->nullable_rels,
3308 6161 : right_state->nullable_rels);
3309 6161 : break;
3310 25538 : case JOIN_LEFT:
3311 : case JOIN_ANTI:
3312 : /* RHS is nullable; LHS keeps existing status */
3313 25538 : result->contains_outer = true;
3314 51076 : result->nullable_rels = bms_union(left_state->nullable_rels,
3315 25538 : right_state->relids);
3316 25538 : break;
3317 608 : case JOIN_RIGHT:
3318 : /* LHS is nullable; RHS keeps existing status */
3319 608 : result->contains_outer = true;
3320 1216 : result->nullable_rels = bms_union(left_state->relids,
3321 608 : right_state->nullable_rels);
3322 608 : break;
3323 548 : case JOIN_FULL:
3324 : /* Both sides are nullable */
3325 548 : result->contains_outer = true;
3326 1096 : result->nullable_rels = bms_union(left_state->relids,
3327 548 : right_state->relids);
3328 548 : break;
3329 0 : default:
3330 0 : elog(ERROR, "unrecognized join type: %d",
3331 : (int) j->jointype);
3332 : break;
3333 : }
3334 : }
3335 : else
3336 0 : elog(ERROR, "unrecognized node type: %d",
3337 : (int) nodeTag(jtnode));
3338 105478 : return result;
3339 : }
3340 :
3341 : /*
3342 : * reduce_outer_joins_pass2 - phase 2 processing
3343 : *
3344 : * jtnode: current jointree node
3345 : * state1: state data collected by phase 1 for this node
3346 : * state2: where to accumulate info about successfully-reduced joins
3347 : * root: toplevel planner state
3348 : * nonnullable_rels: set of base relids forced non-null by upper quals
3349 : * forced_null_vars: multibitmapset of Vars forced null by upper quals
3350 : *
3351 : * Returns info in state2 about outer joins that were successfully simplified.
3352 : * Joins that were fully reduced to inner joins are all added to
3353 : * state2->inner_reduced. If a full join is reduced to a left join,
3354 : * it needs its own entry in state2->partial_reduced, since that will
3355 : * require custom processing to remove only the correct nullingrel markers.
3356 : */
3357 : static void
3358 46062 : reduce_outer_joins_pass2(Node *jtnode,
3359 : reduce_outer_joins_pass1_state *state1,
3360 : reduce_outer_joins_pass2_state *state2,
3361 : PlannerInfo *root,
3362 : Relids nonnullable_rels,
3363 : List *forced_null_vars)
3364 : {
3365 : /*
3366 : * pass 2 should never descend as far as an empty subnode or base rel,
3367 : * because it's only called on subtrees marked as contains_outer.
3368 : */
3369 46062 : if (jtnode == NULL)
3370 0 : elog(ERROR, "reached empty jointree");
3371 46062 : if (IsA(jtnode, RangeTblRef))
3372 0 : elog(ERROR, "reached base rel");
3373 46062 : else if (IsA(jtnode, FromExpr))
3374 : {
3375 19043 : FromExpr *f = (FromExpr *) jtnode;
3376 : ListCell *l;
3377 : ListCell *s;
3378 : Relids pass_nonnullable_rels;
3379 : List *pass_forced_null_vars;
3380 :
3381 : /* Scan quals to see if we can add any constraints */
3382 19043 : pass_nonnullable_rels = find_nonnullable_rels(f->quals);
3383 19043 : pass_nonnullable_rels = bms_add_members(pass_nonnullable_rels,
3384 : nonnullable_rels);
3385 19043 : pass_forced_null_vars = find_forced_null_vars(f->quals);
3386 19043 : pass_forced_null_vars = mbms_add_members(pass_forced_null_vars,
3387 : forced_null_vars);
3388 : /* And recurse --- but only into interesting subtrees */
3389 : Assert(list_length(f->fromlist) == list_length(state1->sub_states));
3390 39557 : forboth(l, f->fromlist, s, state1->sub_states)
3391 : {
3392 20514 : reduce_outer_joins_pass1_state *sub_state = lfirst(s);
3393 :
3394 20514 : if (sub_state->contains_outer)
3395 19058 : reduce_outer_joins_pass2(lfirst(l), sub_state,
3396 : state2, root,
3397 : pass_nonnullable_rels,
3398 : pass_forced_null_vars);
3399 : }
3400 19043 : bms_free(pass_nonnullable_rels);
3401 : /* can't so easily clean up var lists, unfortunately */
3402 : }
3403 27019 : else if (IsA(jtnode, JoinExpr))
3404 : {
3405 27019 : JoinExpr *j = (JoinExpr *) jtnode;
3406 27019 : int rtindex = j->rtindex;
3407 27019 : JoinType jointype = j->jointype;
3408 27019 : reduce_outer_joins_pass1_state *left_state = linitial(state1->sub_states);
3409 27019 : reduce_outer_joins_pass1_state *right_state = lsecond(state1->sub_states);
3410 :
3411 : /* Can we simplify this join? */
3412 27019 : switch (jointype)
3413 : {
3414 294 : case JOIN_INNER:
3415 294 : break;
3416 25262 : case JOIN_LEFT:
3417 25262 : if (bms_overlap(nonnullable_rels, right_state->relids))
3418 1241 : jointype = JOIN_INNER;
3419 25262 : break;
3420 608 : case JOIN_RIGHT:
3421 608 : if (bms_overlap(nonnullable_rels, left_state->relids))
3422 40 : jointype = JOIN_INNER;
3423 608 : break;
3424 548 : case JOIN_FULL:
3425 548 : if (bms_overlap(nonnullable_rels, left_state->relids))
3426 : {
3427 12 : if (bms_overlap(nonnullable_rels, right_state->relids))
3428 6 : jointype = JOIN_INNER;
3429 : else
3430 : {
3431 6 : jointype = JOIN_LEFT;
3432 : /* Also report partial reduction in state2 */
3433 6 : report_reduced_full_join(state2, rtindex,
3434 : right_state->relids);
3435 : }
3436 : }
3437 : else
3438 : {
3439 536 : if (bms_overlap(nonnullable_rels, right_state->relids))
3440 : {
3441 19 : jointype = JOIN_RIGHT;
3442 : /* Also report partial reduction in state2 */
3443 19 : report_reduced_full_join(state2, rtindex,
3444 : left_state->relids);
3445 : }
3446 : }
3447 548 : break;
3448 307 : case JOIN_SEMI:
3449 : case JOIN_ANTI:
3450 :
3451 : /*
3452 : * These could only have been introduced by pull_up_sublinks,
3453 : * so there's no way that upper quals could refer to their
3454 : * righthand sides, and no point in checking. We don't expect
3455 : * to see JOIN_RIGHT_SEMI or JOIN_RIGHT_ANTI yet.
3456 : */
3457 307 : break;
3458 0 : default:
3459 0 : elog(ERROR, "unrecognized join type: %d",
3460 : (int) jointype);
3461 : break;
3462 : }
3463 :
3464 : /*
3465 : * Convert JOIN_RIGHT to JOIN_LEFT. Note that in the case where we
3466 : * reduced JOIN_FULL to JOIN_RIGHT, this will mean the JoinExpr no
3467 : * longer matches the internal ordering of any CoalesceExpr's built to
3468 : * represent merged join variables. We don't care about that at
3469 : * present, but be wary of it ...
3470 : */
3471 27019 : if (jointype == JOIN_RIGHT)
3472 : {
3473 : Node *tmparg;
3474 :
3475 587 : tmparg = j->larg;
3476 587 : j->larg = j->rarg;
3477 587 : j->rarg = tmparg;
3478 587 : jointype = JOIN_LEFT;
3479 587 : right_state = linitial(state1->sub_states);
3480 587 : left_state = lsecond(state1->sub_states);
3481 : }
3482 :
3483 : /*
3484 : * See if we can reduce JOIN_LEFT to JOIN_ANTI. This is the case if
3485 : * any var from the RHS was forced null by higher qual levels, but is
3486 : * known to be non-nullable. We detect this either by seeing if the
3487 : * join's own quals are strict for the var, or by checking if the var
3488 : * is defined NOT NULL by table constraints (being careful to exclude
3489 : * vars that are nullable due to lower-level outer joins). In either
3490 : * case, the only way the higher qual clause's requirement for NULL
3491 : * can be met is if the join fails to match, producing a null-extended
3492 : * row. Thus, we can treat this as an anti-join.
3493 : */
3494 27019 : if (jointype == JOIN_LEFT && forced_null_vars != NIL)
3495 : {
3496 : List *nonnullable_vars;
3497 : Bitmapset *overlap;
3498 :
3499 : /* Find Vars in j->quals that must be non-null in joined rows */
3500 690 : nonnullable_vars = find_nonnullable_vars(j->quals);
3501 :
3502 : /*
3503 : * It's not sufficient to check whether nonnullable_vars and
3504 : * forced_null_vars overlap: we need to know if the overlap
3505 : * includes any RHS variables.
3506 : *
3507 : * Also check if any forced-null var is defined NOT NULL by table
3508 : * constraints.
3509 : */
3510 690 : overlap = mbms_overlap_sets(nonnullable_vars, forced_null_vars);
3511 796 : if (bms_overlap(overlap, right_state->relids) ||
3512 106 : has_notnull_forced_var(root, forced_null_vars, right_state))
3513 596 : jointype = JOIN_ANTI;
3514 : }
3515 :
3516 : /*
3517 : * Apply the jointype change, if any, to both jointree node and RTE.
3518 : * Also, if we changed an RTE to INNER, add its RTI to inner_reduced.
3519 : */
3520 27019 : if (rtindex && jointype != j->jointype)
3521 : {
3522 2476 : RangeTblEntry *rte = rt_fetch(rtindex, root->parse->rtable);
3523 :
3524 : Assert(rte->rtekind == RTE_JOIN);
3525 : Assert(rte->jointype == j->jointype);
3526 2476 : rte->jointype = jointype;
3527 2476 : if (jointype == JOIN_INNER)
3528 1287 : state2->inner_reduced = bms_add_member(state2->inner_reduced,
3529 : rtindex);
3530 : }
3531 27019 : j->jointype = jointype;
3532 :
3533 : /* Only recurse if there's more to do below here */
3534 27019 : if (left_state->contains_outer || right_state->contains_outer)
3535 : {
3536 : Relids local_nonnullable_rels;
3537 : List *local_forced_null_vars;
3538 : Relids pass_nonnullable_rels;
3539 : List *pass_forced_null_vars;
3540 :
3541 : /*
3542 : * If this join is (now) inner, we can add any constraints its
3543 : * quals provide to those we got from above. But if it is outer,
3544 : * we can pass down the local constraints only into the nullable
3545 : * side, because an outer join never eliminates any rows from its
3546 : * non-nullable side. Also, there is no point in passing upper
3547 : * constraints into the nullable side, since if there were any
3548 : * we'd have been able to reduce the join. (In the case of upper
3549 : * forced-null constraints, we *must not* pass them into the
3550 : * nullable side --- they either applied here, or not.) The upshot
3551 : * is that we pass either the local or the upper constraints,
3552 : * never both, to the children of an outer join.
3553 : *
3554 : * Note that a SEMI join works like an inner join here: it's okay
3555 : * to pass down both local and upper constraints. (There can't be
3556 : * any upper constraints affecting its inner side, but it's not
3557 : * worth having a separate code path to avoid passing them.)
3558 : *
3559 : * At a FULL join we just punt and pass nothing down --- is it
3560 : * possible to be smarter?
3561 : */
3562 8729 : if (jointype != JOIN_FULL)
3563 : {
3564 8661 : local_nonnullable_rels = find_nonnullable_rels(j->quals);
3565 8661 : local_forced_null_vars = find_forced_null_vars(j->quals);
3566 8661 : if (jointype == JOIN_INNER || jointype == JOIN_SEMI)
3567 : {
3568 : /* OK to merge upper and local constraints */
3569 711 : local_nonnullable_rels = bms_add_members(local_nonnullable_rels,
3570 : nonnullable_rels);
3571 711 : local_forced_null_vars = mbms_add_members(local_forced_null_vars,
3572 : forced_null_vars);
3573 : }
3574 : }
3575 : else
3576 : {
3577 : /* no use in calculating these */
3578 68 : local_nonnullable_rels = NULL;
3579 68 : local_forced_null_vars = NIL;
3580 : }
3581 :
3582 8729 : if (left_state->contains_outer)
3583 : {
3584 8352 : if (jointype == JOIN_INNER || jointype == JOIN_SEMI)
3585 : {
3586 : /* pass union of local and upper constraints */
3587 605 : pass_nonnullable_rels = local_nonnullable_rels;
3588 605 : pass_forced_null_vars = local_forced_null_vars;
3589 : }
3590 7747 : else if (jointype != JOIN_FULL) /* ie, LEFT or ANTI */
3591 : {
3592 : /* can't pass local constraints to non-nullable side */
3593 7693 : pass_nonnullable_rels = nonnullable_rels;
3594 7693 : pass_forced_null_vars = forced_null_vars;
3595 : }
3596 : else
3597 : {
3598 : /* no constraints pass through JOIN_FULL */
3599 54 : pass_nonnullable_rels = NULL;
3600 54 : pass_forced_null_vars = NIL;
3601 : }
3602 8352 : reduce_outer_joins_pass2(j->larg, left_state,
3603 : state2, root,
3604 : pass_nonnullable_rels,
3605 : pass_forced_null_vars);
3606 : }
3607 :
3608 8729 : if (right_state->contains_outer)
3609 : {
3610 411 : if (jointype != JOIN_FULL) /* ie, INNER/LEFT/SEMI/ANTI */
3611 : {
3612 : /* pass appropriate constraints, per comment above */
3613 397 : pass_nonnullable_rels = local_nonnullable_rels;
3614 397 : pass_forced_null_vars = local_forced_null_vars;
3615 : }
3616 : else
3617 : {
3618 : /* no constraints pass through JOIN_FULL */
3619 14 : pass_nonnullable_rels = NULL;
3620 14 : pass_forced_null_vars = NIL;
3621 : }
3622 411 : reduce_outer_joins_pass2(j->rarg, right_state,
3623 : state2, root,
3624 : pass_nonnullable_rels,
3625 : pass_forced_null_vars);
3626 : }
3627 8729 : bms_free(local_nonnullable_rels);
3628 : }
3629 : }
3630 : else
3631 0 : elog(ERROR, "unrecognized node type: %d",
3632 : (int) nodeTag(jtnode));
3633 46062 : }
3634 :
3635 : /* Helper for reduce_outer_joins_pass2 */
3636 : static void
3637 25 : report_reduced_full_join(reduce_outer_joins_pass2_state *state2,
3638 : int rtindex, Relids relids)
3639 : {
3640 : reduce_outer_joins_partial_state *statep;
3641 :
3642 25 : statep = palloc_object(reduce_outer_joins_partial_state);
3643 25 : statep->full_join_rti = rtindex;
3644 25 : statep->unreduced_side = relids;
3645 25 : state2->partial_reduced = lappend(state2->partial_reduced, statep);
3646 25 : }
3647 :
3648 : /*
3649 : * has_notnull_forced_var
3650 : * Check if "forced_null_vars" contains any Vars belonging to the subtree
3651 : * indicated by "right_state" that are known to be non-nullable due to
3652 : * table constraints.
3653 : *
3654 : * Note that we must also consider the situation where a NOT NULL Var can be
3655 : * nulled by lower-level outer joins.
3656 : *
3657 : * Helper for reduce_outer_joins_pass2.
3658 : */
3659 : static bool
3660 106 : has_notnull_forced_var(PlannerInfo *root, List *forced_null_vars,
3661 : reduce_outer_joins_pass1_state *right_state)
3662 : {
3663 106 : int varno = -1;
3664 :
3665 864 : foreach_node(Bitmapset, attrs, forced_null_vars)
3666 : {
3667 : RangeTblEntry *rte;
3668 : Bitmapset *notnullattnums;
3669 676 : Bitmapset *forcednullattnums = NULL;
3670 : int attno;
3671 :
3672 676 : varno++;
3673 :
3674 : /* Skip empty bitmaps */
3675 676 : if (bms_is_empty(attrs))
3676 570 : continue;
3677 :
3678 : /* Skip Vars that do not belong to the target relations */
3679 106 : if (!bms_is_member(varno, right_state->relids))
3680 41 : continue;
3681 :
3682 : /*
3683 : * Skip Vars that can be nulled by lower-level outer joins within the
3684 : * given subtree. These Vars might be NULL even if the schema defines
3685 : * them as NOT NULL.
3686 : */
3687 65 : if (bms_is_member(varno, right_state->nullable_rels))
3688 3 : continue;
3689 :
3690 : /*
3691 : * Iterate over attributes and adjust the bitmap indexes by
3692 : * FirstLowInvalidHeapAttributeNumber to get the actual attribute
3693 : * numbers.
3694 : */
3695 62 : attno = -1;
3696 124 : while ((attno = bms_next_member(attrs, attno)) >= 0)
3697 : {
3698 62 : AttrNumber real_attno = attno + FirstLowInvalidHeapAttributeNumber;
3699 :
3700 : /* system columns cannot be NULL */
3701 62 : if (real_attno < 0)
3702 12 : return true;
3703 :
3704 62 : forcednullattnums = bms_add_member(forcednullattnums, real_attno);
3705 : }
3706 :
3707 62 : rte = rt_fetch(varno, root->parse->rtable);
3708 :
3709 : /*
3710 : * We must skip inheritance parent tables, as some child tables may
3711 : * have a NOT NULL constraint for a column while others may not. This
3712 : * cannot happen with partitioned tables, though.
3713 : */
3714 62 : if (rte->inh && rte->relkind != RELKIND_PARTITIONED_TABLE)
3715 : {
3716 3 : bms_free(forcednullattnums);
3717 3 : continue;
3718 : }
3719 :
3720 : /* Get the column not-null constraint information for this relation */
3721 59 : notnullattnums = find_relation_notnullatts(root, rte->relid);
3722 :
3723 : /*
3724 : * Check if any forced-null attributes are defined as NOT NULL by
3725 : * table constraints.
3726 : */
3727 59 : if (bms_overlap(notnullattnums, forcednullattnums))
3728 : {
3729 12 : bms_free(forcednullattnums);
3730 12 : return true;
3731 : }
3732 :
3733 47 : bms_free(forcednullattnums);
3734 : }
3735 :
3736 94 : return false;
3737 : }
3738 :
3739 :
3740 : /*
3741 : * remove_useless_result_rtes
3742 : * Attempt to remove RTE_RESULT RTEs from the join tree.
3743 : * Also, elide single-child FromExprs where possible.
3744 : *
3745 : * We can remove RTE_RESULT entries from the join tree using the knowledge
3746 : * that RTE_RESULT returns exactly one row and has no output columns. Hence,
3747 : * if one is inner-joined to anything else, we can delete it. Optimizations
3748 : * are also possible for some outer-join cases, as detailed below.
3749 : *
3750 : * This pass also replaces single-child FromExprs with their child node
3751 : * where possible. It's appropriate to do that here and not earlier because
3752 : * RTE_RESULT removal might reduce a multiple-child FromExpr to have only one
3753 : * child. We can remove such a FromExpr if its quals are empty, or if it's
3754 : * semantically valid to merge the quals into those of the parent node.
3755 : * While removing unnecessary join tree nodes has some micro-efficiency value,
3756 : * the real reason to do this is to eliminate cases where the nullable side of
3757 : * an outer join node is a FromExpr whose single child is another outer join.
3758 : * To correctly determine whether the two outer joins can commute,
3759 : * deconstruct_jointree() must treat any quals of such a FromExpr as being
3760 : * degenerate quals of the upper outer join. The best way to do that is to
3761 : * make them actually *be* quals of the upper join, by dropping the FromExpr
3762 : * and hoisting the quals up into the upper join's quals. (Note that there is
3763 : * no hazard when the intermediate FromExpr has multiple children, since then
3764 : * it represents an inner join that cannot commute with the upper outer join.)
3765 : * As long as we have to do that, we might as well elide such FromExprs
3766 : * everywhere.
3767 : *
3768 : * Some of these optimizations depend on recognizing empty (constant-true)
3769 : * quals for FromExprs and JoinExprs. That makes it useful to apply this
3770 : * optimization pass after expression preprocessing, since that will have
3771 : * eliminated constant-true quals, allowing more cases to be recognized as
3772 : * optimizable. What's more, the usual reason for an RTE_RESULT to be present
3773 : * is that we pulled up a subquery or VALUES clause, thus very possibly
3774 : * replacing Vars with constants, making it more likely that a qual can be
3775 : * reduced to constant true. Also, because some optimizations depend on
3776 : * the outer-join type, it's best to have done reduce_outer_joins() first.
3777 : *
3778 : * A PlaceHolderVar referencing an RTE_RESULT RTE poses an obstacle to this
3779 : * process: we must remove the RTE_RESULT's relid from the PHV's phrels, but
3780 : * we must not reduce the phrels set to empty. If that would happen, and
3781 : * the RTE_RESULT is an immediate child of an outer join, we have to give up
3782 : * and not remove the RTE_RESULT: there is noplace else to evaluate the
3783 : * PlaceHolderVar. (That is, in such cases the RTE_RESULT *does* have output
3784 : * columns.) But if the RTE_RESULT is an immediate child of an inner join,
3785 : * we can usually change the PlaceHolderVar's phrels so as to evaluate it at
3786 : * the inner join instead. This is OK because we really only care that PHVs
3787 : * are evaluated above or below the correct outer joins. We can't, however,
3788 : * postpone the evaluation of a PHV to above where it is used; so there are
3789 : * some checks below on whether output PHVs are laterally referenced in the
3790 : * other join input rel(s).
3791 : *
3792 : * We used to try to do this work as part of pull_up_subqueries() where the
3793 : * potentially-optimizable cases get introduced; but it's way simpler, and
3794 : * more effective, to do it separately.
3795 : */
3796 : void
3797 118739 : remove_useless_result_rtes(PlannerInfo *root)
3798 : {
3799 118739 : Relids dropped_outer_joins = NULL;
3800 : ListCell *cell;
3801 :
3802 : /* Top level of jointree must always be a FromExpr */
3803 : Assert(IsA(root->parse->jointree, FromExpr));
3804 : /* Recurse ... */
3805 237478 : root->parse->jointree = (FromExpr *)
3806 118739 : remove_useless_results_recurse(root,
3807 118739 : (Node *) root->parse->jointree,
3808 : NULL,
3809 : &dropped_outer_joins);
3810 : /* We should still have a FromExpr */
3811 : Assert(IsA(root->parse->jointree, FromExpr));
3812 :
3813 : /*
3814 : * If we removed any outer-join nodes from the jointree, run around and
3815 : * remove references to those joins as nulling rels. (There could be such
3816 : * references in PHVs that we pulled up out of the original subquery that
3817 : * the RESULT rel replaced. This is kosher on the grounds that we now
3818 : * know that such an outer join wouldn't really have nulled anything.) We
3819 : * don't do this during the main recursion, for simplicity and because we
3820 : * can handle all such joins in a single pass over the parse tree.
3821 : */
3822 118739 : if (!bms_is_empty(dropped_outer_joins))
3823 : {
3824 30 : root->parse = (Query *)
3825 30 : remove_nulling_relids((Node *) root->parse,
3826 : dropped_outer_joins,
3827 : NULL);
3828 : /* There could be references in the append_rel_list, too */
3829 30 : root->append_rel_list = (List *)
3830 30 : remove_nulling_relids((Node *) root->append_rel_list,
3831 : dropped_outer_joins,
3832 : NULL);
3833 : }
3834 :
3835 : /*
3836 : * Remove any PlanRowMark referencing an RTE_RESULT RTE. We obviously
3837 : * must do that for any RTE_RESULT that we just removed. But one for a
3838 : * RTE that we did not remove can be dropped anyway: since the RTE has
3839 : * only one possible output row, there is no need for EPQ to mark and
3840 : * restore that row.
3841 : *
3842 : * It's necessary, not optional, to remove the PlanRowMark for a surviving
3843 : * RTE_RESULT RTE; otherwise we'll generate a whole-row Var for the
3844 : * RTE_RESULT, which the executor has no support for.
3845 : */
3846 119734 : foreach(cell, root->rowMarks)
3847 : {
3848 995 : PlanRowMark *rc = (PlanRowMark *) lfirst(cell);
3849 :
3850 995 : if (rt_fetch(rc->rti, root->parse->rtable)->rtekind == RTE_RESULT)
3851 425 : root->rowMarks = foreach_delete_current(root->rowMarks, cell);
3852 : }
3853 118739 : }
3854 :
3855 : /*
3856 : * remove_useless_results_recurse
3857 : * Recursive guts of remove_useless_result_rtes.
3858 : *
3859 : * This recursively processes the jointree and returns a modified jointree.
3860 : * In addition, the RT indexes of any removed outer-join nodes are added to
3861 : * *dropped_outer_joins.
3862 : *
3863 : * jtnode is the current jointree node. If it could be valid to merge
3864 : * its quals into those of the parent node, parent_quals should point to
3865 : * the parent's quals list; otherwise, pass NULL for parent_quals.
3866 : * (Note that in some cases, parent_quals points to the quals of a parent
3867 : * more than one level up in the tree.)
3868 : */
3869 : static Node *
3870 312405 : remove_useless_results_recurse(PlannerInfo *root, Node *jtnode,
3871 : Node **parent_quals,
3872 : Relids *dropped_outer_joins)
3873 : {
3874 : Assert(jtnode != NULL);
3875 312405 : if (IsA(jtnode, RangeTblRef))
3876 : {
3877 : /* Can't immediately do anything with a RangeTblRef */
3878 : }
3879 157041 : else if (IsA(jtnode, FromExpr))
3880 : {
3881 122291 : FromExpr *f = (FromExpr *) jtnode;
3882 122291 : Relids result_relids = NULL;
3883 : ListCell *cell;
3884 :
3885 : /*
3886 : * We can drop RTE_RESULT rels from the fromlist so long as at least
3887 : * one child remains, since joining to a one-row table changes
3888 : * nothing. (But we can't drop a RTE_RESULT that computes PHV(s) that
3889 : * are needed by some sibling. The cleanup transformation below would
3890 : * reassign the PHVs to be computed at the join, which is too late for
3891 : * the sibling's use.) The easiest way to mechanize this rule is to
3892 : * modify the list in-place.
3893 : */
3894 246457 : foreach(cell, f->fromlist)
3895 : {
3896 124166 : Node *child = (Node *) lfirst(cell);
3897 : int varno;
3898 :
3899 : /* Recursively transform child, allowing it to push up quals ... */
3900 124166 : child = remove_useless_results_recurse(root, child,
3901 : &f->quals,
3902 : dropped_outer_joins);
3903 : /* ... and stick it back into the tree */
3904 124166 : lfirst(cell) = child;
3905 :
3906 : /*
3907 : * If it's an RTE_RESULT with at least one sibling, and no sibling
3908 : * references dependent PHVs, we can drop it. We don't yet know
3909 : * what the inner join's final relid set will be, so postpone
3910 : * cleanup of PHVs etc till after this loop.
3911 : */
3912 127233 : if (list_length(f->fromlist) > 1 &&
3913 3067 : (varno = get_result_relid(root, child)) != 0 &&
3914 173 : !find_dependent_phvs_in_jointree(root, (Node *) f, varno))
3915 : {
3916 161 : f->fromlist = foreach_delete_current(f->fromlist, cell);
3917 161 : result_relids = bms_add_member(result_relids, varno);
3918 : }
3919 : }
3920 :
3921 : /*
3922 : * Clean up if we dropped any RTE_RESULT RTEs. This is a bit
3923 : * inefficient if there's more than one, but it seems better to
3924 : * optimize the support code for the single-relid case.
3925 : */
3926 122291 : if (result_relids)
3927 : {
3928 155 : int varno = -1;
3929 :
3930 316 : while ((varno = bms_next_member(result_relids, varno)) >= 0)
3931 161 : remove_result_refs(root, varno, (Node *) f);
3932 : }
3933 :
3934 : /*
3935 : * If the FromExpr now has only one child, see if we can elide it.
3936 : * This is always valid if there are no quals, except at the top of
3937 : * the jointree (since Query.jointree is required to point to a
3938 : * FromExpr). Otherwise, we can do it if we can push the quals up to
3939 : * the parent node.
3940 : *
3941 : * Note: while it would not be terribly hard to generalize this
3942 : * transformation to merge multi-child FromExprs into their parent
3943 : * FromExpr, that risks making the parent join too expensive to plan.
3944 : * We leave it to later processing to decide heuristically whether
3945 : * that's a good idea. Pulling up a single child is always OK,
3946 : * however.
3947 : */
3948 122291 : if (list_length(f->fromlist) == 1 &&
3949 121203 : f != root->parse->jointree &&
3950 3436 : (f->quals == NULL || parent_quals != NULL))
3951 : {
3952 : /*
3953 : * Merge any quals up to parent. They should be in implicit-AND
3954 : * format by now, so we just need to concatenate lists. Put the
3955 : * child quals at the front, on the grounds that they should
3956 : * nominally be evaluated earlier.
3957 : */
3958 1414 : if (f->quals != NULL)
3959 719 : *parent_quals = (Node *)
3960 719 : list_concat(castNode(List, f->quals),
3961 : castNode(List, *parent_quals));
3962 1414 : return (Node *) linitial(f->fromlist);
3963 : }
3964 : }
3965 34750 : else if (IsA(jtnode, JoinExpr))
3966 : {
3967 34750 : JoinExpr *j = (JoinExpr *) jtnode;
3968 : int varno;
3969 :
3970 : /*
3971 : * First, recurse. We can absorb pushed-up FromExpr quals from either
3972 : * child into this node if the jointype is INNER, since then this is
3973 : * equivalent to a FromExpr. When the jointype is LEFT, we can absorb
3974 : * quals from the RHS child into the current node, as they're
3975 : * essentially degenerate quals of the outer join. Moreover, if we've
3976 : * been passed down a parent_quals pointer then we can allow quals of
3977 : * the LHS child to be absorbed into the parent. (This is important
3978 : * to ensure we remove single-child FromExprs immediately below
3979 : * commutable left joins.) For other jointypes, we can't move child
3980 : * quals up, or at least there's no particular reason to.
3981 : */
3982 34750 : j->larg = remove_useless_results_recurse(root, j->larg,
3983 34750 : (j->jointype == JOIN_INNER) ?
3984 : &j->quals :
3985 27050 : (j->jointype == JOIN_LEFT) ?
3986 27050 : parent_quals : NULL,
3987 : dropped_outer_joins);
3988 34750 : j->rarg = remove_useless_results_recurse(root, j->rarg,
3989 34750 : (j->jointype == JOIN_INNER ||
3990 27050 : j->jointype == JOIN_LEFT) ?
3991 : &j->quals : NULL,
3992 : dropped_outer_joins);
3993 :
3994 : /* Apply join-type-specific optimization rules */
3995 34750 : switch (j->jointype)
3996 : {
3997 7700 : case JOIN_INNER:
3998 :
3999 : /*
4000 : * An inner join is equivalent to a FromExpr, so if either
4001 : * side was simplified to an RTE_RESULT rel, we can replace
4002 : * the join with a FromExpr with just the other side.
4003 : * Furthermore, we can elide that FromExpr according to the
4004 : * same rules as above.
4005 : *
4006 : * Just as in the FromExpr case, we can't simplify if the
4007 : * other input rel references any PHVs that are marked as to
4008 : * be evaluated at the RTE_RESULT rel, because we can't
4009 : * postpone their evaluation in that case. But we only have
4010 : * to check this in cases where it's syntactically legal for
4011 : * the other input to have a LATERAL reference to the
4012 : * RTE_RESULT rel. Only RHSes of inner and left joins are
4013 : * allowed to have such refs.
4014 : */
4015 7700 : if ((varno = get_result_relid(root, j->larg)) != 0 &&
4016 53 : !find_dependent_phvs_in_jointree(root, j->rarg, varno))
4017 : {
4018 53 : remove_result_refs(root, varno, j->rarg);
4019 53 : if (j->quals != NULL && parent_quals == NULL)
4020 6 : jtnode = (Node *)
4021 6 : makeFromExpr(list_make1(j->rarg), j->quals);
4022 : else
4023 : {
4024 : /* Merge any quals up to parent */
4025 47 : if (j->quals != NULL)
4026 35 : *parent_quals = (Node *)
4027 35 : list_concat(castNode(List, j->quals),
4028 : castNode(List, *parent_quals));
4029 47 : jtnode = j->rarg;
4030 : }
4031 : }
4032 7647 : else if ((varno = get_result_relid(root, j->rarg)) != 0)
4033 : {
4034 404 : remove_result_refs(root, varno, j->larg);
4035 404 : if (j->quals != NULL && parent_quals == NULL)
4036 6 : jtnode = (Node *)
4037 6 : makeFromExpr(list_make1(j->larg), j->quals);
4038 : else
4039 : {
4040 : /* Merge any quals up to parent */
4041 398 : if (j->quals != NULL)
4042 260 : *parent_quals = (Node *)
4043 260 : list_concat(castNode(List, j->quals),
4044 : castNode(List, *parent_quals));
4045 398 : jtnode = j->larg;
4046 : }
4047 : }
4048 7700 : break;
4049 24018 : case JOIN_LEFT:
4050 :
4051 : /*
4052 : * We can simplify this case if the RHS is an RTE_RESULT, with
4053 : * two different possibilities:
4054 : *
4055 : * If the qual is empty (JOIN ON TRUE), then the join can be
4056 : * strength-reduced to a plain inner join, since each LHS row
4057 : * necessarily has exactly one join partner. So we can always
4058 : * discard the RHS, much as in the JOIN_INNER case above.
4059 : * (Again, the LHS could not contain a lateral reference to
4060 : * the RHS.)
4061 : *
4062 : * Otherwise, it's still true that each LHS row should be
4063 : * returned exactly once, and since the RHS returns no columns
4064 : * (unless there are PHVs that have to be evaluated there), we
4065 : * don't much care if it's null-extended or not. So in this
4066 : * case also, we can just ignore the qual and discard the left
4067 : * join.
4068 : */
4069 24018 : if ((varno = get_result_relid(root, j->rarg)) != 0 &&
4070 75 : (j->quals == NULL ||
4071 45 : !find_dependent_phvs(root, varno)))
4072 : {
4073 30 : remove_result_refs(root, varno, j->larg);
4074 30 : *dropped_outer_joins = bms_add_member(*dropped_outer_joins,
4075 : j->rtindex);
4076 30 : jtnode = j->larg;
4077 : }
4078 24018 : break;
4079 1643 : case JOIN_SEMI:
4080 :
4081 : /*
4082 : * We may simplify this case if the RHS is an RTE_RESULT; the
4083 : * join qual becomes effectively just a filter qual for the
4084 : * LHS, since we should either return the LHS row or not. The
4085 : * filter clause must go into a new FromExpr if we can't push
4086 : * it up to the parent.
4087 : *
4088 : * There is a fine point about PHVs that are supposed to be
4089 : * evaluated at the RHS. Such PHVs could only appear in the
4090 : * semijoin's qual, since the rest of the query cannot
4091 : * reference any outputs of the semijoin's RHS. Therefore,
4092 : * they can't actually go to null before being examined, and
4093 : * it'd be OK to just remove the PHV wrapping. We don't have
4094 : * infrastructure for that, but remove_result_refs() will
4095 : * relabel them as to be evaluated at the LHS, which is fine.
4096 : *
4097 : * Also, we don't need to worry about removing traces of the
4098 : * join's rtindex, since it hasn't got one.
4099 : */
4100 1643 : if ((varno = get_result_relid(root, j->rarg)) != 0)
4101 : {
4102 : Assert(j->rtindex == 0);
4103 18 : remove_result_refs(root, varno, j->larg);
4104 18 : if (j->quals != NULL && parent_quals == NULL)
4105 0 : jtnode = (Node *)
4106 0 : makeFromExpr(list_make1(j->larg), j->quals);
4107 : else
4108 : {
4109 : /* Merge any quals up to parent */
4110 18 : if (j->quals != NULL)
4111 18 : *parent_quals = (Node *)
4112 18 : list_concat(castNode(List, j->quals),
4113 : castNode(List, *parent_quals));
4114 18 : jtnode = j->larg;
4115 : }
4116 : }
4117 1643 : break;
4118 1389 : case JOIN_FULL:
4119 : case JOIN_ANTI:
4120 : /* We have no special smarts for these cases */
4121 1389 : break;
4122 0 : default:
4123 : /* Note: JOIN_RIGHT should be gone at this point */
4124 0 : elog(ERROR, "unrecognized join type: %d",
4125 : (int) j->jointype);
4126 : break;
4127 : }
4128 : }
4129 : else
4130 0 : elog(ERROR, "unrecognized node type: %d",
4131 : (int) nodeTag(jtnode));
4132 310991 : return jtnode;
4133 : }
4134 :
4135 : /*
4136 : * get_result_relid
4137 : * If jtnode is a RangeTblRef for an RTE_RESULT RTE, return its relid;
4138 : * otherwise return 0.
4139 : */
4140 : static int
4141 44075 : get_result_relid(PlannerInfo *root, Node *jtnode)
4142 : {
4143 : int varno;
4144 :
4145 44075 : if (!IsA(jtnode, RangeTblRef))
4146 4005 : return 0;
4147 40070 : varno = ((RangeTblRef *) jtnode)->rtindex;
4148 40070 : if (rt_fetch(varno, root->parse->rtable)->rtekind != RTE_RESULT)
4149 39347 : return 0;
4150 723 : return varno;
4151 : }
4152 :
4153 : /*
4154 : * remove_result_refs
4155 : * Helper routine for dropping an unneeded RTE_RESULT RTE.
4156 : *
4157 : * This doesn't physically remove the RTE from the jointree, because that's
4158 : * more easily handled in remove_useless_results_recurse. What it does do
4159 : * is the necessary cleanup in the rest of the tree: we must adjust any PHVs
4160 : * that may reference the RTE. Be sure to call this at a point where the
4161 : * jointree is valid (no disconnected nodes).
4162 : *
4163 : * Note that we don't need to process the append_rel_list, since RTEs
4164 : * referenced directly in the jointree won't be appendrel members.
4165 : *
4166 : * varno is the RTE_RESULT's relid.
4167 : * newjtloc is the jointree location at which any PHVs referencing the
4168 : * RTE_RESULT should be evaluated instead.
4169 : */
4170 : static void
4171 666 : remove_result_refs(PlannerInfo *root, int varno, Node *newjtloc)
4172 : {
4173 : /* Fix up PlaceHolderVars as needed */
4174 : /* If there are no PHVs anywhere, we can skip this bit */
4175 666 : if (root->glob->lastPHId != 0)
4176 : {
4177 : Relids subrelids;
4178 :
4179 140 : subrelids = get_relids_in_jointree(newjtloc, true, false);
4180 : Assert(!bms_is_empty(subrelids));
4181 140 : substitute_phv_relids((Node *) root->parse, varno, subrelids);
4182 140 : fix_append_rel_relids(root, varno, subrelids);
4183 : }
4184 :
4185 : /*
4186 : * We also need to remove any PlanRowMark referencing the RTE, but we
4187 : * postpone that work until we return to remove_useless_result_rtes.
4188 : */
4189 666 : }
4190 :
4191 :
4192 : /*
4193 : * find_dependent_phvs - are there any PlaceHolderVars whose relids are
4194 : * exactly the given varno?
4195 : *
4196 : * find_dependent_phvs should be used when we want to see if there are
4197 : * any such PHVs anywhere in the Query. Another use-case is to see if
4198 : * a subtree of the join tree contains such PHVs; but for that, we have
4199 : * to look not only at the join tree nodes themselves but at the
4200 : * referenced RTEs. For that, use find_dependent_phvs_in_jointree.
4201 : */
4202 :
4203 : typedef struct
4204 : {
4205 : Relids relids;
4206 : int sublevels_up;
4207 : } find_dependent_phvs_context;
4208 :
4209 : static bool
4210 1200 : find_dependent_phvs_walker(Node *node,
4211 : find_dependent_phvs_context *context)
4212 : {
4213 1200 : if (node == NULL)
4214 282 : return false;
4215 918 : if (IsA(node, PlaceHolderVar))
4216 : {
4217 78 : PlaceHolderVar *phv = (PlaceHolderVar *) node;
4218 :
4219 156 : if (phv->phlevelsup == context->sublevels_up &&
4220 78 : bms_equal(context->relids, phv->phrels))
4221 57 : return true;
4222 : /* fall through to examine children */
4223 : }
4224 861 : if (IsA(node, Query))
4225 : {
4226 : /* Recurse into subselects */
4227 : bool result;
4228 :
4229 24 : context->sublevels_up++;
4230 24 : result = query_tree_walker((Query *) node,
4231 : find_dependent_phvs_walker,
4232 : context, 0);
4233 24 : context->sublevels_up--;
4234 24 : return result;
4235 : }
4236 : /* Shouldn't need to handle most planner auxiliary nodes here */
4237 : Assert(!IsA(node, SpecialJoinInfo));
4238 : Assert(!IsA(node, PlaceHolderInfo));
4239 : Assert(!IsA(node, MinMaxAggInfo));
4240 :
4241 837 : return expression_tree_walker(node, find_dependent_phvs_walker, context);
4242 : }
4243 :
4244 : static bool
4245 45 : find_dependent_phvs(PlannerInfo *root, int varno)
4246 : {
4247 : find_dependent_phvs_context context;
4248 :
4249 : /* If there are no PHVs anywhere, we needn't work hard */
4250 45 : if (root->glob->lastPHId == 0)
4251 0 : return false;
4252 :
4253 45 : context.relids = bms_make_singleton(varno);
4254 45 : context.sublevels_up = 0;
4255 :
4256 45 : if (query_tree_walker(root->parse, find_dependent_phvs_walker, &context, 0))
4257 45 : return true;
4258 : /* The append_rel_list could be populated already, so check it too */
4259 0 : if (expression_tree_walker((Node *) root->append_rel_list,
4260 : find_dependent_phvs_walker,
4261 : &context))
4262 0 : return true;
4263 0 : return false;
4264 : }
4265 :
4266 : static bool
4267 226 : find_dependent_phvs_in_jointree(PlannerInfo *root, Node *node, int varno)
4268 : {
4269 : find_dependent_phvs_context context;
4270 : Relids subrelids;
4271 : int relid;
4272 :
4273 : /* If there are no PHVs anywhere, we needn't work hard */
4274 226 : if (root->glob->lastPHId == 0)
4275 193 : return false;
4276 :
4277 33 : context.relids = bms_make_singleton(varno);
4278 33 : context.sublevels_up = 0;
4279 :
4280 : /*
4281 : * See if the jointree fragment itself contains references (in join quals)
4282 : */
4283 33 : if (find_dependent_phvs_walker(node, &context))
4284 0 : return true;
4285 :
4286 : /*
4287 : * Otherwise, identify the set of referenced RTEs (we can ignore joins,
4288 : * since they should be flattened already, so their join alias lists no
4289 : * longer matter), and tediously check each RTE. We can ignore RTEs that
4290 : * are not marked LATERAL, though, since they couldn't possibly contain
4291 : * any cross-references to other RTEs.
4292 : */
4293 33 : subrelids = get_relids_in_jointree(node, false, false);
4294 33 : relid = -1;
4295 72 : while ((relid = bms_next_member(subrelids, relid)) >= 0)
4296 : {
4297 51 : RangeTblEntry *rte = rt_fetch(relid, root->parse->rtable);
4298 :
4299 63 : if (rte->lateral &&
4300 12 : range_table_entry_walker(rte, find_dependent_phvs_walker, &context, 0))
4301 12 : return true;
4302 : }
4303 :
4304 21 : return false;
4305 : }
4306 :
4307 : /*
4308 : * substitute_phv_relids - adjust PlaceHolderVar relid sets after pulling up
4309 : * a subquery or removing an RTE_RESULT jointree item
4310 : *
4311 : * Find any PlaceHolderVar nodes in the given tree that reference the
4312 : * pulled-up relid, and change them to reference the replacement relid(s).
4313 : *
4314 : * NOTE: although this has the form of a walker, we cheat and modify the
4315 : * nodes in-place. This should be OK since the tree was copied by
4316 : * pullup_replace_vars earlier. Avoid scribbling on the original values of
4317 : * the bitmapsets, though, because expression_tree_mutator doesn't copy those.
4318 : */
4319 :
4320 : typedef struct
4321 : {
4322 : int varno;
4323 : int sublevels_up;
4324 : Relids subrelids;
4325 : } substitute_phv_relids_context;
4326 :
4327 : static bool
4328 138887 : substitute_phv_relids_walker(Node *node,
4329 : substitute_phv_relids_context *context)
4330 : {
4331 138887 : if (node == NULL)
4332 52809 : return false;
4333 86078 : if (IsA(node, PlaceHolderVar))
4334 : {
4335 3938 : PlaceHolderVar *phv = (PlaceHolderVar *) node;
4336 :
4337 7860 : if (phv->phlevelsup == context->sublevels_up &&
4338 3922 : bms_is_member(context->varno, phv->phrels))
4339 : {
4340 5676 : phv->phrels = bms_union(phv->phrels,
4341 2838 : context->subrelids);
4342 2838 : phv->phrels = bms_del_member(phv->phrels,
4343 : context->varno);
4344 : /* Assert we haven't broken the PHV */
4345 : Assert(!bms_is_empty(phv->phrels));
4346 : }
4347 : /* fall through to examine children */
4348 : }
4349 86078 : if (IsA(node, Query))
4350 : {
4351 : /* Recurse into subselects */
4352 : bool result;
4353 :
4354 2272 : context->sublevels_up++;
4355 2272 : result = query_tree_walker((Query *) node,
4356 : substitute_phv_relids_walker,
4357 : context, 0);
4358 2272 : context->sublevels_up--;
4359 2272 : return result;
4360 : }
4361 : /* Shouldn't need to handle planner auxiliary nodes here */
4362 : Assert(!IsA(node, SpecialJoinInfo));
4363 : Assert(!IsA(node, AppendRelInfo));
4364 : Assert(!IsA(node, PlaceHolderInfo));
4365 : Assert(!IsA(node, MinMaxAggInfo));
4366 :
4367 83806 : return expression_tree_walker(node, substitute_phv_relids_walker, context);
4368 : }
4369 :
4370 : static void
4371 1256 : substitute_phv_relids(Node *node, int varno, Relids subrelids)
4372 : {
4373 : substitute_phv_relids_context context;
4374 :
4375 1256 : context.varno = varno;
4376 1256 : context.sublevels_up = 0;
4377 1256 : context.subrelids = subrelids;
4378 :
4379 : /*
4380 : * Must be prepared to start with a Query or a bare expression tree.
4381 : */
4382 1256 : query_or_expression_tree_walker(node,
4383 : substitute_phv_relids_walker,
4384 : &context,
4385 : 0);
4386 1256 : }
4387 :
4388 : /*
4389 : * fix_append_rel_relids: update RT-index fields of AppendRelInfo nodes
4390 : *
4391 : * When we pull up a subquery, any AppendRelInfo references to the subquery's
4392 : * RT index have to be replaced by the substituted relid (and there had better
4393 : * be only one). We also need to apply substitute_phv_relids to their
4394 : * translated_vars lists, since those might contain PlaceHolderVars.
4395 : *
4396 : * We assume we may modify the AppendRelInfo nodes in-place.
4397 : */
4398 : static void
4399 4353 : fix_append_rel_relids(PlannerInfo *root, int varno, Relids subrelids)
4400 : {
4401 : ListCell *l;
4402 4353 : int subvarno = -1;
4403 :
4404 : /*
4405 : * We only want to extract the member relid once, but we mustn't fail
4406 : * immediately if there are multiple members; it could be that none of the
4407 : * AppendRelInfo nodes refer to it. So compute it on first use. Note that
4408 : * bms_singleton_member will complain if set is not singleton.
4409 : */
4410 10271 : foreach(l, root->append_rel_list)
4411 : {
4412 5918 : AppendRelInfo *appinfo = (AppendRelInfo *) lfirst(l);
4413 :
4414 : /* The parent_relid shouldn't ever be a pullup target */
4415 : Assert(appinfo->parent_relid != varno);
4416 :
4417 5918 : if (appinfo->child_relid == varno)
4418 : {
4419 3205 : if (subvarno < 0)
4420 3205 : subvarno = bms_singleton_member(subrelids);
4421 3205 : appinfo->child_relid = subvarno;
4422 : }
4423 :
4424 : /* Also fix up any PHVs in its translated vars */
4425 5918 : if (root->glob->lastPHId != 0)
4426 81 : substitute_phv_relids((Node *) appinfo->translated_vars,
4427 : varno, subrelids);
4428 : }
4429 4353 : }
4430 :
4431 : /*
4432 : * get_relids_in_jointree: get set of RT indexes present in a jointree
4433 : *
4434 : * Base-relation relids are always included in the result.
4435 : * If include_outer_joins is true, outer-join RT indexes are included.
4436 : * If include_inner_joins is true, inner-join RT indexes are included.
4437 : *
4438 : * Note that for most purposes in the planner, outer joins are included
4439 : * in standard relid sets. Setting include_inner_joins true is only
4440 : * appropriate for special purposes during subquery flattening.
4441 : */
4442 : Relids
4443 53642 : get_relids_in_jointree(Node *jtnode, bool include_outer_joins,
4444 : bool include_inner_joins)
4445 : {
4446 53642 : Relids result = NULL;
4447 :
4448 53642 : if (jtnode == NULL)
4449 0 : return result;
4450 53642 : if (IsA(jtnode, RangeTblRef))
4451 : {
4452 27030 : int varno = ((RangeTblRef *) jtnode)->rtindex;
4453 :
4454 27030 : result = bms_make_singleton(varno);
4455 : }
4456 26612 : else if (IsA(jtnode, FromExpr))
4457 : {
4458 23405 : FromExpr *f = (FromExpr *) jtnode;
4459 : ListCell *l;
4460 :
4461 47457 : foreach(l, f->fromlist)
4462 : {
4463 24052 : result = bms_join(result,
4464 24052 : get_relids_in_jointree(lfirst(l),
4465 : include_outer_joins,
4466 : include_inner_joins));
4467 : }
4468 : }
4469 3207 : else if (IsA(jtnode, JoinExpr))
4470 : {
4471 3207 : JoinExpr *j = (JoinExpr *) jtnode;
4472 :
4473 3207 : result = get_relids_in_jointree(j->larg,
4474 : include_outer_joins,
4475 : include_inner_joins);
4476 3207 : result = bms_join(result,
4477 : get_relids_in_jointree(j->rarg,
4478 : include_outer_joins,
4479 : include_inner_joins));
4480 3207 : if (j->rtindex)
4481 : {
4482 3044 : if (j->jointype == JOIN_INNER)
4483 : {
4484 1365 : if (include_inner_joins)
4485 545 : result = bms_add_member(result, j->rtindex);
4486 : }
4487 : else
4488 : {
4489 1679 : if (include_outer_joins)
4490 1093 : result = bms_add_member(result, j->rtindex);
4491 : }
4492 : }
4493 : }
4494 : else
4495 0 : elog(ERROR, "unrecognized node type: %d",
4496 : (int) nodeTag(jtnode));
4497 53642 : return result;
4498 : }
4499 :
4500 : /*
4501 : * get_relids_for_join: get set of base+OJ RT indexes making up a join
4502 : */
4503 : Relids
4504 179 : get_relids_for_join(Query *query, int joinrelid)
4505 : {
4506 : Node *jtnode;
4507 :
4508 179 : jtnode = find_jointree_node_for_rel((Node *) query->jointree,
4509 : joinrelid);
4510 179 : if (!jtnode)
4511 0 : elog(ERROR, "could not find join node %d", joinrelid);
4512 179 : return get_relids_in_jointree(jtnode, true, false);
4513 : }
4514 :
4515 : /*
4516 : * find_jointree_node_for_rel: locate jointree node for a base or join RT index
4517 : *
4518 : * Returns NULL if not found
4519 : */
4520 : static Node *
4521 865 : find_jointree_node_for_rel(Node *jtnode, int relid)
4522 : {
4523 865 : if (jtnode == NULL)
4524 0 : return NULL;
4525 865 : if (IsA(jtnode, RangeTblRef))
4526 : {
4527 227 : int varno = ((RangeTblRef *) jtnode)->rtindex;
4528 :
4529 227 : if (relid == varno)
4530 0 : return jtnode;
4531 : }
4532 638 : else if (IsA(jtnode, FromExpr))
4533 : {
4534 184 : FromExpr *f = (FromExpr *) jtnode;
4535 : ListCell *l;
4536 :
4537 193 : foreach(l, f->fromlist)
4538 : {
4539 193 : jtnode = find_jointree_node_for_rel(lfirst(l), relid);
4540 193 : if (jtnode)
4541 184 : return jtnode;
4542 : }
4543 : }
4544 454 : else if (IsA(jtnode, JoinExpr))
4545 : {
4546 454 : JoinExpr *j = (JoinExpr *) jtnode;
4547 :
4548 454 : if (relid == j->rtindex)
4549 179 : return jtnode;
4550 275 : jtnode = find_jointree_node_for_rel(j->larg, relid);
4551 275 : if (jtnode)
4552 57 : return jtnode;
4553 218 : jtnode = find_jointree_node_for_rel(j->rarg, relid);
4554 218 : if (jtnode)
4555 218 : return jtnode;
4556 : }
4557 : else
4558 0 : elog(ERROR, "unrecognized node type: %d",
4559 : (int) nodeTag(jtnode));
4560 227 : return NULL;
4561 : }
4562 :
4563 : /*
4564 : * get_nullingrels: collect info about which outer joins null which relations
4565 : *
4566 : * The result struct contains, for each leaf relation used in the query,
4567 : * the set of relids of outer joins that potentially null that rel.
4568 : */
4569 : static nullingrel_info *
4570 597 : get_nullingrels(Query *parse)
4571 : {
4572 597 : nullingrel_info *result = palloc_object(nullingrel_info);
4573 :
4574 597 : result->rtlength = list_length(parse->rtable);
4575 597 : result->nullingrels = palloc0_array(Relids, result->rtlength + 1);
4576 597 : get_nullingrels_recurse((Node *) parse->jointree, NULL, result);
4577 597 : return result;
4578 : }
4579 :
4580 : /*
4581 : * Recursive guts of get_nullingrels().
4582 : *
4583 : * Note: at any recursion level, the passed-down upper_nullingrels must be
4584 : * treated as a constant, but it can be stored directly into *info
4585 : * if we're at leaf level. Upper recursion levels do not free their mutated
4586 : * copies of the nullingrels, because those are probably referenced by
4587 : * at least one leaf rel.
4588 : */
4589 : static void
4590 3184 : get_nullingrels_recurse(Node *jtnode, Relids upper_nullingrels,
4591 : nullingrel_info *info)
4592 : {
4593 3184 : if (jtnode == NULL)
4594 0 : return;
4595 3184 : if (IsA(jtnode, RangeTblRef))
4596 : {
4597 1681 : int varno = ((RangeTblRef *) jtnode)->rtindex;
4598 :
4599 : Assert(varno > 0 && varno <= info->rtlength);
4600 1681 : info->nullingrels[varno] = upper_nullingrels;
4601 : }
4602 1503 : else if (IsA(jtnode, FromExpr))
4603 : {
4604 639 : FromExpr *f = (FromExpr *) jtnode;
4605 : ListCell *l;
4606 :
4607 1498 : foreach(l, f->fromlist)
4608 : {
4609 859 : get_nullingrels_recurse(lfirst(l), upper_nullingrels, info);
4610 : }
4611 : }
4612 864 : else if (IsA(jtnode, JoinExpr))
4613 : {
4614 864 : JoinExpr *j = (JoinExpr *) jtnode;
4615 : Relids local_nullingrels;
4616 :
4617 864 : switch (j->jointype)
4618 : {
4619 319 : case JOIN_INNER:
4620 319 : get_nullingrels_recurse(j->larg, upper_nullingrels, info);
4621 319 : get_nullingrels_recurse(j->rarg, upper_nullingrels, info);
4622 319 : break;
4623 542 : case JOIN_LEFT:
4624 : case JOIN_SEMI:
4625 : case JOIN_ANTI:
4626 542 : local_nullingrels = bms_add_member(bms_copy(upper_nullingrels),
4627 : j->rtindex);
4628 542 : get_nullingrels_recurse(j->larg, upper_nullingrels, info);
4629 542 : get_nullingrels_recurse(j->rarg, local_nullingrels, info);
4630 542 : break;
4631 3 : case JOIN_FULL:
4632 3 : local_nullingrels = bms_add_member(bms_copy(upper_nullingrels),
4633 : j->rtindex);
4634 3 : get_nullingrels_recurse(j->larg, local_nullingrels, info);
4635 3 : get_nullingrels_recurse(j->rarg, local_nullingrels, info);
4636 3 : break;
4637 0 : case JOIN_RIGHT:
4638 0 : local_nullingrels = bms_add_member(bms_copy(upper_nullingrels),
4639 : j->rtindex);
4640 0 : get_nullingrels_recurse(j->larg, local_nullingrels, info);
4641 0 : get_nullingrels_recurse(j->rarg, upper_nullingrels, info);
4642 0 : break;
4643 0 : default:
4644 0 : elog(ERROR, "unrecognized join type: %d",
4645 : (int) j->jointype);
4646 : break;
4647 : }
4648 : }
4649 : else
4650 0 : elog(ERROR, "unrecognized node type: %d",
4651 : (int) nodeTag(jtnode));
4652 : }
|
