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) 1996-2025, 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 : List *sub_states; /* List of states for subtree components */
92 : } reduce_outer_joins_pass1_state;
93 :
94 : typedef struct reduce_outer_joins_pass2_state
95 : {
96 : Relids inner_reduced; /* OJ relids reduced to plain inner joins */
97 : List *partial_reduced; /* List of partially reduced FULL joins */
98 : } reduce_outer_joins_pass2_state;
99 :
100 : typedef struct reduce_outer_joins_partial_state
101 : {
102 : int full_join_rti; /* RT index of a formerly-FULL join */
103 : Relids unreduced_side; /* relids in its still-nullable side */
104 : } reduce_outer_joins_partial_state;
105 :
106 : static Query *expand_virtual_generated_columns(PlannerInfo *root, Query *parse,
107 : RangeTblEntry *rte, int rt_index,
108 : Relation relation);
109 : static Node *pull_up_sublinks_jointree_recurse(PlannerInfo *root, Node *jtnode,
110 : Relids *relids);
111 : static Node *pull_up_sublinks_qual_recurse(PlannerInfo *root, Node *node,
112 : Node **jtlink1, Relids available_rels1,
113 : Node **jtlink2, Relids available_rels2);
114 : static Node *pull_up_subqueries_recurse(PlannerInfo *root, Node *jtnode,
115 : JoinExpr *lowest_outer_join,
116 : AppendRelInfo *containing_appendrel);
117 : static Node *pull_up_simple_subquery(PlannerInfo *root, Node *jtnode,
118 : RangeTblEntry *rte,
119 : JoinExpr *lowest_outer_join,
120 : AppendRelInfo *containing_appendrel);
121 : static Node *pull_up_simple_union_all(PlannerInfo *root, Node *jtnode,
122 : RangeTblEntry *rte);
123 : static void pull_up_union_leaf_queries(Node *setOp, PlannerInfo *root,
124 : int parentRTindex, Query *setOpQuery,
125 : int childRToffset);
126 : static void make_setop_translation_list(Query *query, int newvarno,
127 : AppendRelInfo *appinfo);
128 : static bool is_simple_subquery(PlannerInfo *root, Query *subquery,
129 : RangeTblEntry *rte,
130 : JoinExpr *lowest_outer_join);
131 : static Node *pull_up_simple_values(PlannerInfo *root, Node *jtnode,
132 : RangeTblEntry *rte);
133 : static bool is_simple_values(PlannerInfo *root, RangeTblEntry *rte);
134 : static Node *pull_up_constant_function(PlannerInfo *root, Node *jtnode,
135 : RangeTblEntry *rte,
136 : AppendRelInfo *containing_appendrel);
137 : static bool is_simple_union_all(Query *subquery);
138 : static bool is_simple_union_all_recurse(Node *setOp, Query *setOpQuery,
139 : List *colTypes);
140 : static bool is_safe_append_member(Query *subquery);
141 : static bool jointree_contains_lateral_outer_refs(PlannerInfo *root,
142 : Node *jtnode, bool restricted,
143 : Relids safe_upper_varnos);
144 : static void perform_pullup_replace_vars(PlannerInfo *root,
145 : pullup_replace_vars_context *rvcontext,
146 : AppendRelInfo *containing_appendrel);
147 : static void replace_vars_in_jointree(Node *jtnode,
148 : pullup_replace_vars_context *context);
149 : static Node *pullup_replace_vars(Node *expr,
150 : pullup_replace_vars_context *context);
151 : static Node *pullup_replace_vars_callback(Var *var,
152 : replace_rte_variables_context *context);
153 : static Query *pullup_replace_vars_subquery(Query *query,
154 : pullup_replace_vars_context *context);
155 : static reduce_outer_joins_pass1_state *reduce_outer_joins_pass1(Node *jtnode);
156 : static void reduce_outer_joins_pass2(Node *jtnode,
157 : reduce_outer_joins_pass1_state *state1,
158 : reduce_outer_joins_pass2_state *state2,
159 : PlannerInfo *root,
160 : Relids nonnullable_rels,
161 : List *forced_null_vars);
162 : static void report_reduced_full_join(reduce_outer_joins_pass2_state *state2,
163 : int rtindex, Relids relids);
164 : static Node *remove_useless_results_recurse(PlannerInfo *root, Node *jtnode,
165 : Node **parent_quals,
166 : Relids *dropped_outer_joins);
167 : static int get_result_relid(PlannerInfo *root, Node *jtnode);
168 : static void remove_result_refs(PlannerInfo *root, int varno, Node *newjtloc);
169 : static bool find_dependent_phvs(PlannerInfo *root, int varno);
170 : static bool find_dependent_phvs_in_jointree(PlannerInfo *root,
171 : Node *node, int varno);
172 : static void substitute_phv_relids(Node *node,
173 : int varno, Relids subrelids);
174 : static void fix_append_rel_relids(PlannerInfo *root, int varno,
175 : Relids subrelids);
176 : static Node *find_jointree_node_for_rel(Node *jtnode, int relid);
177 : static nullingrel_info *get_nullingrels(Query *parse);
178 : static void get_nullingrels_recurse(Node *jtnode, Relids upper_nullingrels,
179 : nullingrel_info *info);
180 :
181 :
182 : /*
183 : * transform_MERGE_to_join
184 : * Replace a MERGE's jointree to also include the target relation.
185 : */
186 : void
187 527244 : transform_MERGE_to_join(Query *parse)
188 : {
189 : RangeTblEntry *joinrte;
190 : JoinExpr *joinexpr;
191 : bool have_action[NUM_MERGE_MATCH_KINDS];
192 : JoinType jointype;
193 : int joinrti;
194 : List *vars;
195 : RangeTblRef *rtr;
196 : FromExpr *target;
197 : Node *source;
198 : int sourcerti;
199 :
200 527244 : if (parse->commandType != CMD_MERGE)
201 525372 : return;
202 :
203 : /* XXX probably bogus */
204 1872 : vars = NIL;
205 :
206 : /*
207 : * Work out what kind of join is required. If there any WHEN NOT MATCHED
208 : * BY SOURCE/TARGET actions, an outer join is required so that we process
209 : * all unmatched tuples from the source and/or target relations.
210 : * Otherwise, we can use an inner join.
211 : */
212 1872 : have_action[MERGE_WHEN_MATCHED] = false;
213 1872 : have_action[MERGE_WHEN_NOT_MATCHED_BY_SOURCE] = false;
214 1872 : have_action[MERGE_WHEN_NOT_MATCHED_BY_TARGET] = false;
215 :
216 6588 : foreach_node(MergeAction, action, parse->mergeActionList)
217 : {
218 2844 : if (action->commandType != CMD_NOTHING)
219 2772 : have_action[action->matchKind] = true;
220 : }
221 :
222 1872 : if (have_action[MERGE_WHEN_NOT_MATCHED_BY_SOURCE] &&
223 126 : have_action[MERGE_WHEN_NOT_MATCHED_BY_TARGET])
224 96 : jointype = JOIN_FULL;
225 1776 : else if (have_action[MERGE_WHEN_NOT_MATCHED_BY_SOURCE])
226 30 : jointype = JOIN_LEFT;
227 1746 : else if (have_action[MERGE_WHEN_NOT_MATCHED_BY_TARGET])
228 824 : jointype = JOIN_RIGHT;
229 : else
230 922 : jointype = JOIN_INNER;
231 :
232 : /* Manufacture a join RTE to use. */
233 1872 : joinrte = makeNode(RangeTblEntry);
234 1872 : joinrte->rtekind = RTE_JOIN;
235 1872 : joinrte->jointype = jointype;
236 1872 : joinrte->joinmergedcols = 0;
237 1872 : joinrte->joinaliasvars = vars;
238 1872 : joinrte->joinleftcols = NIL; /* MERGE does not allow JOIN USING */
239 1872 : joinrte->joinrightcols = NIL; /* ditto */
240 1872 : joinrte->join_using_alias = NULL;
241 :
242 1872 : joinrte->alias = NULL;
243 1872 : joinrte->eref = makeAlias("*MERGE*", NIL);
244 1872 : joinrte->lateral = false;
245 1872 : joinrte->inh = false;
246 1872 : joinrte->inFromCl = true;
247 :
248 : /*
249 : * Add completed RTE to pstate's range table list, so that we know its
250 : * index.
251 : */
252 1872 : parse->rtable = lappend(parse->rtable, joinrte);
253 1872 : joinrti = list_length(parse->rtable);
254 :
255 : /*
256 : * Create a JOIN between the target and the source relation.
257 : *
258 : * Here the target is identified by parse->mergeTargetRelation. For a
259 : * regular table, this will equal parse->resultRelation, but for a
260 : * trigger-updatable view, it will be the expanded view subquery that we
261 : * need to pull data from.
262 : *
263 : * The source relation is in parse->jointree->fromlist, but any quals in
264 : * parse->jointree->quals are restrictions on the target relation (if the
265 : * target relation is an auto-updatable view).
266 : */
267 : /* target rel, with any quals */
268 1872 : rtr = makeNode(RangeTblRef);
269 1872 : rtr->rtindex = parse->mergeTargetRelation;
270 1872 : target = makeFromExpr(list_make1(rtr), parse->jointree->quals);
271 :
272 : /* source rel (expect exactly one -- see transformMergeStmt()) */
273 : Assert(list_length(parse->jointree->fromlist) == 1);
274 1872 : source = linitial(parse->jointree->fromlist);
275 :
276 : /*
277 : * index of source rel (expect either a RangeTblRef or a JoinExpr -- see
278 : * transformFromClauseItem()).
279 : */
280 1872 : if (IsA(source, RangeTblRef))
281 1788 : sourcerti = ((RangeTblRef *) source)->rtindex;
282 84 : else if (IsA(source, JoinExpr))
283 84 : sourcerti = ((JoinExpr *) source)->rtindex;
284 : else
285 : {
286 0 : elog(ERROR, "unrecognized source node type: %d",
287 : (int) nodeTag(source));
288 : sourcerti = 0; /* keep compiler quiet */
289 : }
290 :
291 : /* Join the source and target */
292 1872 : joinexpr = makeNode(JoinExpr);
293 1872 : joinexpr->jointype = jointype;
294 1872 : joinexpr->isNatural = false;
295 1872 : joinexpr->larg = (Node *) target;
296 1872 : joinexpr->rarg = source;
297 1872 : joinexpr->usingClause = NIL;
298 1872 : joinexpr->join_using_alias = NULL;
299 1872 : joinexpr->quals = parse->mergeJoinCondition;
300 1872 : joinexpr->alias = NULL;
301 1872 : joinexpr->rtindex = joinrti;
302 :
303 : /* Make the new join be the sole entry in the query's jointree */
304 1872 : parse->jointree->fromlist = list_make1(joinexpr);
305 1872 : parse->jointree->quals = NULL;
306 :
307 : /*
308 : * If necessary, mark parse->targetlist entries that refer to the target
309 : * as nullable by the join. Normally the targetlist will be empty for a
310 : * MERGE, but if the target is a trigger-updatable view, it will contain a
311 : * whole-row Var referring to the expanded view query.
312 : */
313 1872 : if (parse->targetList != NIL &&
314 42 : (jointype == JOIN_RIGHT || jointype == JOIN_FULL))
315 42 : parse->targetList = (List *)
316 42 : add_nulling_relids((Node *) parse->targetList,
317 42 : bms_make_singleton(parse->mergeTargetRelation),
318 42 : bms_make_singleton(joinrti));
319 :
320 : /*
321 : * If the source relation is on the outer side of the join, mark any
322 : * source relation Vars in the join condition, actions, and RETURNING list
323 : * as nullable by the join. These Vars will be added to the targetlist by
324 : * preprocess_targetlist(), so it's important to mark them correctly here.
325 : *
326 : * It might seem that this is not necessary for Vars in the join
327 : * condition, since it is inside the join, but it is also needed above the
328 : * join (in the ModifyTable node) to distinguish between the MATCHED and
329 : * NOT MATCHED BY SOURCE cases -- see ExecMergeMatched(). Note that this
330 : * creates a modified copy of the join condition, for use above the join,
331 : * without modifying the original join condition, inside the join.
332 : */
333 1872 : if (jointype == JOIN_LEFT || jointype == JOIN_FULL)
334 : {
335 126 : parse->mergeJoinCondition =
336 126 : add_nulling_relids(parse->mergeJoinCondition,
337 126 : bms_make_singleton(sourcerti),
338 126 : bms_make_singleton(joinrti));
339 :
340 600 : foreach_node(MergeAction, action, parse->mergeActionList)
341 : {
342 348 : action->qual =
343 348 : add_nulling_relids(action->qual,
344 348 : bms_make_singleton(sourcerti),
345 348 : bms_make_singleton(joinrti));
346 :
347 348 : action->targetList = (List *)
348 348 : add_nulling_relids((Node *) action->targetList,
349 348 : bms_make_singleton(sourcerti),
350 348 : bms_make_singleton(joinrti));
351 : }
352 :
353 126 : parse->returningList = (List *)
354 126 : add_nulling_relids((Node *) parse->returningList,
355 126 : bms_make_singleton(sourcerti),
356 126 : bms_make_singleton(joinrti));
357 : }
358 :
359 : /*
360 : * If there are any WHEN NOT MATCHED BY SOURCE actions, the executor will
361 : * use the join condition to distinguish between MATCHED and NOT MATCHED
362 : * BY SOURCE cases. Otherwise, it's no longer needed, and we set it to
363 : * NULL, saving cycles during planning and execution.
364 : *
365 : * We need to be careful though: the executor evaluates this condition
366 : * using the output of the join subplan node, which nulls the output from
367 : * the source relation when the join condition doesn't match. That risks
368 : * producing incorrect results when rechecking using a "non-strict" join
369 : * condition, such as "src.col IS NOT DISTINCT FROM tgt.col". To guard
370 : * against that, we add an additional "src IS NOT NULL" check to the join
371 : * condition, so that it does the right thing when performing a recheck
372 : * based on the output of the join subplan.
373 : */
374 1872 : if (have_action[MERGE_WHEN_NOT_MATCHED_BY_SOURCE])
375 : {
376 : Var *var;
377 : NullTest *ntest;
378 :
379 : /* source wholerow Var (nullable by the new join) */
380 126 : var = makeWholeRowVar(rt_fetch(sourcerti, parse->rtable),
381 : sourcerti, 0, false);
382 126 : var->varnullingrels = bms_make_singleton(joinrti);
383 :
384 : /* "src IS NOT NULL" check */
385 126 : ntest = makeNode(NullTest);
386 126 : ntest->arg = (Expr *) var;
387 126 : ntest->nulltesttype = IS_NOT_NULL;
388 126 : ntest->argisrow = false;
389 126 : ntest->location = -1;
390 :
391 : /* combine it with the original join condition */
392 126 : parse->mergeJoinCondition =
393 126 : (Node *) make_and_qual((Node *) ntest, parse->mergeJoinCondition);
394 : }
395 : else
396 1746 : parse->mergeJoinCondition = NULL; /* join condition not needed */
397 : }
398 :
399 : /*
400 : * preprocess_relation_rtes
401 : * Do the preprocessing work for any relation RTEs in the FROM clause.
402 : *
403 : * This scans the rangetable for relation RTEs and retrieves the necessary
404 : * catalog information for each relation. Using this information, it clears
405 : * the inh flag for any relation that has no children, collects not-null
406 : * attribute numbers for any relation that has column not-null constraints, and
407 : * expands virtual generated columns for any relation that contains them.
408 : *
409 : * Note that expanding virtual generated columns may cause the query tree to
410 : * have new copies of rangetable entries. Therefore, we have to use list_nth
411 : * instead of foreach when iterating over the query's rangetable.
412 : *
413 : * Returns a modified copy of the query tree, if any relations with virtual
414 : * generated columns are present.
415 : */
416 : Query *
417 567814 : preprocess_relation_rtes(PlannerInfo *root)
418 : {
419 567814 : Query *parse = root->parse;
420 : int rtable_size;
421 : int rt_index;
422 :
423 567814 : rtable_size = list_length(parse->rtable);
424 :
425 1258860 : for (rt_index = 0; rt_index < rtable_size; rt_index++)
426 : {
427 691046 : RangeTblEntry *rte = rt_fetch(rt_index + 1, parse->rtable);
428 : Relation relation;
429 :
430 : /* We only care about relation RTEs. */
431 691046 : if (rte->rtekind != RTE_RELATION)
432 220222 : continue;
433 :
434 : /*
435 : * We need not lock the relation since it was already locked by the
436 : * rewriter.
437 : */
438 470824 : relation = table_open(rte->relid, NoLock);
439 :
440 : /*
441 : * Check to see if the relation actually has any children; if not,
442 : * clear the inh flag so we can treat it as a plain base relation.
443 : *
444 : * Note: this could give a false-positive result, if the rel once had
445 : * children but no longer does. We used to be able to clear rte->inh
446 : * later on when we discovered that, but no more; we have to handle
447 : * such cases as full-fledged inheritance.
448 : */
449 470824 : if (rte->inh)
450 390056 : rte->inh = relation->rd_rel->relhassubclass;
451 :
452 : /*
453 : * Check to see if the relation has any column not-null constraints;
454 : * if so, retrieve the constraint information and store it in a
455 : * relation OID based hash table.
456 : */
457 470824 : get_relation_notnullatts(root, relation);
458 :
459 : /*
460 : * Check to see if the relation has any virtual generated columns; if
461 : * so, replace all Var nodes in the query that reference these columns
462 : * with the generation expressions.
463 : */
464 470824 : parse = expand_virtual_generated_columns(root, parse,
465 : rte, rt_index + 1,
466 : relation);
467 :
468 470824 : table_close(relation, NoLock);
469 : }
470 :
471 567814 : return parse;
472 : }
473 :
474 : /*
475 : * expand_virtual_generated_columns
476 : * Expand virtual generated columns for the given relation.
477 : *
478 : * This checks whether the given relation has any virtual generated columns,
479 : * and if so, replaces all Var nodes in the query that reference those columns
480 : * with their generation expressions.
481 : *
482 : * Returns a modified copy of the query tree if the relation contains virtual
483 : * generated columns.
484 : */
485 : static Query *
486 470824 : expand_virtual_generated_columns(PlannerInfo *root, Query *parse,
487 : RangeTblEntry *rte, int rt_index,
488 : Relation relation)
489 : {
490 : TupleDesc tupdesc;
491 :
492 : /* Only normal relations can have virtual generated columns */
493 : Assert(rte->rtekind == RTE_RELATION);
494 :
495 470824 : tupdesc = RelationGetDescr(relation);
496 470824 : if (tupdesc->constr && tupdesc->constr->has_generated_virtual)
497 : {
498 1052 : List *tlist = NIL;
499 : pullup_replace_vars_context rvcontext;
500 :
501 4046 : for (int i = 0; i < tupdesc->natts; i++)
502 : {
503 2994 : Form_pg_attribute attr = TupleDescAttr(tupdesc, i);
504 : TargetEntry *tle;
505 :
506 2994 : if (attr->attgenerated == ATTRIBUTE_GENERATED_VIRTUAL)
507 : {
508 : Node *defexpr;
509 :
510 1394 : defexpr = build_generation_expression(relation, i + 1);
511 1394 : ChangeVarNodes(defexpr, 1, rt_index, 0);
512 :
513 1394 : tle = makeTargetEntry((Expr *) defexpr, i + 1, 0, false);
514 1394 : tlist = lappend(tlist, tle);
515 : }
516 : else
517 : {
518 : Var *var;
519 :
520 1600 : var = makeVar(rt_index,
521 1600 : i + 1,
522 : attr->atttypid,
523 : attr->atttypmod,
524 : attr->attcollation,
525 : 0);
526 :
527 1600 : tle = makeTargetEntry((Expr *) var, i + 1, 0, false);
528 1600 : tlist = lappend(tlist, tle);
529 : }
530 : }
531 :
532 : Assert(list_length(tlist) > 0);
533 : Assert(!rte->lateral);
534 :
535 : /*
536 : * The relation's targetlist items are now in the appropriate form to
537 : * insert into the query, except that we may need to wrap them in
538 : * PlaceHolderVars. Set up required context data for
539 : * pullup_replace_vars.
540 : */
541 1052 : rvcontext.root = root;
542 1052 : rvcontext.targetlist = tlist;
543 1052 : rvcontext.target_rte = rte;
544 1052 : rvcontext.result_relation = parse->resultRelation;
545 : /* won't need these values */
546 1052 : rvcontext.relids = NULL;
547 1052 : rvcontext.nullinfo = NULL;
548 : /* pass NULL for outer_hasSubLinks */
549 1052 : rvcontext.outer_hasSubLinks = NULL;
550 1052 : rvcontext.varno = rt_index;
551 : /* this flag will be set below, if needed */
552 1052 : rvcontext.wrap_option = REPLACE_WRAP_NONE;
553 : /* initialize cache array with indexes 0 .. length(tlist) */
554 1052 : rvcontext.rv_cache = palloc0((list_length(tlist) + 1) *
555 : sizeof(Node *));
556 :
557 : /*
558 : * If the query uses grouping sets, we need a PlaceHolderVar for each
559 : * expression of the relation's targetlist items. (See comments in
560 : * pull_up_simple_subquery().)
561 : */
562 1052 : if (parse->groupingSets)
563 12 : rvcontext.wrap_option = REPLACE_WRAP_ALL;
564 :
565 : /*
566 : * Apply pullup variable replacement throughout the query tree.
567 : */
568 1052 : parse = (Query *) pullup_replace_vars((Node *) parse, &rvcontext);
569 : }
570 :
571 470824 : return parse;
572 : }
573 :
574 : /*
575 : * replace_empty_jointree
576 : * If the Query's jointree is empty, replace it with a dummy RTE_RESULT
577 : * relation.
578 : *
579 : * By doing this, we can avoid a bunch of corner cases that formerly existed
580 : * for SELECTs with omitted FROM clauses. An example is that a subquery
581 : * with empty jointree previously could not be pulled up, because that would
582 : * have resulted in an empty relid set, making the subquery not uniquely
583 : * identifiable for join or PlaceHolderVar processing.
584 : *
585 : * Unlike most other functions in this file, this function doesn't recurse;
586 : * we rely on other processing to invoke it on sub-queries at suitable times.
587 : */
588 : void
589 567814 : replace_empty_jointree(Query *parse)
590 : {
591 : RangeTblEntry *rte;
592 : Index rti;
593 : RangeTblRef *rtr;
594 :
595 : /* Nothing to do if jointree is already nonempty */
596 567814 : if (parse->jointree->fromlist != NIL)
597 371958 : return;
598 :
599 : /* We mustn't change it in the top level of a setop tree, either */
600 202486 : if (parse->setOperations)
601 6630 : return;
602 :
603 : /* Create suitable RTE */
604 195856 : rte = makeNode(RangeTblEntry);
605 195856 : rte->rtekind = RTE_RESULT;
606 195856 : rte->eref = makeAlias("*RESULT*", NIL);
607 :
608 : /* Add it to rangetable */
609 195856 : parse->rtable = lappend(parse->rtable, rte);
610 195856 : rti = list_length(parse->rtable);
611 :
612 : /* And jam a reference into the jointree */
613 195856 : rtr = makeNode(RangeTblRef);
614 195856 : rtr->rtindex = rti;
615 195856 : parse->jointree->fromlist = list_make1(rtr);
616 : }
617 :
618 : /*
619 : * pull_up_sublinks
620 : * Attempt to pull up ANY and EXISTS SubLinks to be treated as
621 : * semijoins or anti-semijoins.
622 : *
623 : * A clause "foo op ANY (sub-SELECT)" can be processed by pulling the
624 : * sub-SELECT up to become a rangetable entry and treating the implied
625 : * comparisons as quals of a semijoin. However, this optimization *only*
626 : * works at the top level of WHERE or a JOIN/ON clause, because we cannot
627 : * distinguish whether the ANY ought to return FALSE or NULL in cases
628 : * involving NULL inputs. Also, in an outer join's ON clause we can only
629 : * do this if the sublink is degenerate (ie, references only the nullable
630 : * side of the join). In that case it is legal to push the semijoin
631 : * down into the nullable side of the join. If the sublink references any
632 : * nonnullable-side variables then it would have to be evaluated as part
633 : * of the outer join, which makes things way too complicated.
634 : *
635 : * Under similar conditions, EXISTS and NOT EXISTS clauses can be handled
636 : * by pulling up the sub-SELECT and creating a semijoin or anti-semijoin.
637 : *
638 : * This routine searches for such clauses and does the necessary parsetree
639 : * transformations if any are found.
640 : *
641 : * This routine has to run before preprocess_expression(), so the quals
642 : * clauses are not yet reduced to implicit-AND format, and are not guaranteed
643 : * to be AND/OR-flat either. That means we need to recursively search through
644 : * explicit AND clauses. We stop as soon as we hit a non-AND item.
645 : */
646 : void
647 40364 : pull_up_sublinks(PlannerInfo *root)
648 : {
649 : Node *jtnode;
650 : Relids relids;
651 :
652 : /* Begin recursion through the jointree */
653 40364 : jtnode = pull_up_sublinks_jointree_recurse(root,
654 40364 : (Node *) root->parse->jointree,
655 : &relids);
656 :
657 : /*
658 : * root->parse->jointree must always be a FromExpr, so insert a dummy one
659 : * if we got a bare RangeTblRef or JoinExpr out of the recursion.
660 : */
661 40364 : if (IsA(jtnode, FromExpr))
662 32580 : root->parse->jointree = (FromExpr *) jtnode;
663 : else
664 7784 : root->parse->jointree = makeFromExpr(list_make1(jtnode), NULL);
665 40364 : }
666 :
667 : /*
668 : * Recurse through jointree nodes for pull_up_sublinks()
669 : *
670 : * In addition to returning the possibly-modified jointree node, we return
671 : * a relids set of the contained rels into *relids.
672 : */
673 : static Node *
674 136184 : pull_up_sublinks_jointree_recurse(PlannerInfo *root, Node *jtnode,
675 : Relids *relids)
676 : {
677 : /* Since this function recurses, it could be driven to stack overflow. */
678 136184 : check_stack_depth();
679 :
680 136184 : if (jtnode == NULL)
681 : {
682 0 : *relids = NULL;
683 : }
684 136184 : else if (IsA(jtnode, RangeTblRef))
685 : {
686 73746 : int varno = ((RangeTblRef *) jtnode)->rtindex;
687 :
688 73746 : *relids = bms_make_singleton(varno);
689 : /* jtnode is returned unmodified */
690 : }
691 62438 : else if (IsA(jtnode, FromExpr))
692 : {
693 40592 : FromExpr *f = (FromExpr *) jtnode;
694 40592 : List *newfromlist = NIL;
695 40592 : Relids frelids = NULL;
696 : FromExpr *newf;
697 : Node *jtlink;
698 : ListCell *l;
699 :
700 : /* First, recurse to process children and collect their relids */
701 84712 : foreach(l, f->fromlist)
702 : {
703 : Node *newchild;
704 : Relids childrelids;
705 :
706 44120 : newchild = pull_up_sublinks_jointree_recurse(root,
707 44120 : lfirst(l),
708 : &childrelids);
709 44120 : newfromlist = lappend(newfromlist, newchild);
710 44120 : frelids = bms_join(frelids, childrelids);
711 : }
712 : /* Build the replacement FromExpr; no quals yet */
713 40592 : newf = makeFromExpr(newfromlist, NULL);
714 : /* Set up a link representing the rebuilt jointree */
715 40592 : jtlink = (Node *) newf;
716 : /* Now process qual --- all children are available for use */
717 40592 : newf->quals = pull_up_sublinks_qual_recurse(root, f->quals,
718 : &jtlink, frelids,
719 : NULL, NULL);
720 :
721 : /*
722 : * Note that the result will be either newf, or a stack of JoinExprs
723 : * with newf at the base. We rely on subsequent optimization steps to
724 : * flatten this and rearrange the joins as needed.
725 : *
726 : * Although we could include the pulled-up subqueries in the returned
727 : * relids, there's no need since upper quals couldn't refer to their
728 : * outputs anyway.
729 : */
730 40592 : *relids = frelids;
731 40592 : jtnode = jtlink;
732 : }
733 21846 : else if (IsA(jtnode, JoinExpr))
734 : {
735 : JoinExpr *j;
736 : Relids leftrelids;
737 : Relids rightrelids;
738 : Node *jtlink;
739 :
740 : /*
741 : * Make a modifiable copy of join node, but don't bother copying its
742 : * subnodes (yet).
743 : */
744 21846 : j = (JoinExpr *) palloc(sizeof(JoinExpr));
745 21846 : memcpy(j, jtnode, sizeof(JoinExpr));
746 21846 : jtlink = (Node *) j;
747 :
748 : /* Recurse to process children and collect their relids */
749 21846 : j->larg = pull_up_sublinks_jointree_recurse(root, j->larg,
750 : &leftrelids);
751 21846 : j->rarg = pull_up_sublinks_jointree_recurse(root, j->rarg,
752 : &rightrelids);
753 :
754 : /*
755 : * Now process qual, showing appropriate child relids as available,
756 : * and attach any pulled-up jointree items at the right place. In the
757 : * inner-join case we put new JoinExprs above the existing one (much
758 : * as for a FromExpr-style join). In outer-join cases the new
759 : * JoinExprs must go into the nullable side of the outer join. The
760 : * point of the available_rels machinations is to ensure that we only
761 : * pull up quals for which that's okay.
762 : *
763 : * We don't expect to see any pre-existing JOIN_SEMI, JOIN_ANTI,
764 : * JOIN_RIGHT_SEMI, or JOIN_RIGHT_ANTI jointypes here.
765 : */
766 21846 : switch (j->jointype)
767 : {
768 9616 : case JOIN_INNER:
769 9616 : j->quals = pull_up_sublinks_qual_recurse(root, j->quals,
770 : &jtlink,
771 : bms_union(leftrelids,
772 : rightrelids),
773 : NULL, NULL);
774 9616 : break;
775 12122 : case JOIN_LEFT:
776 12122 : j->quals = pull_up_sublinks_qual_recurse(root, j->quals,
777 : &j->rarg,
778 : rightrelids,
779 : NULL, NULL);
780 12122 : break;
781 12 : case JOIN_FULL:
782 : /* can't do anything with full-join quals */
783 12 : break;
784 96 : case JOIN_RIGHT:
785 96 : j->quals = pull_up_sublinks_qual_recurse(root, j->quals,
786 : &j->larg,
787 : leftrelids,
788 : NULL, NULL);
789 96 : break;
790 0 : default:
791 0 : elog(ERROR, "unrecognized join type: %d",
792 : (int) j->jointype);
793 : break;
794 : }
795 :
796 : /*
797 : * Although we could include the pulled-up subqueries in the returned
798 : * relids, there's no need since upper quals couldn't refer to their
799 : * outputs anyway. But we *do* need to include the join's own rtindex
800 : * because we haven't yet collapsed join alias variables, so upper
801 : * levels would mistakenly think they couldn't use references to this
802 : * join.
803 : */
804 21846 : *relids = bms_join(leftrelids, rightrelids);
805 21846 : if (j->rtindex)
806 21846 : *relids = bms_add_member(*relids, j->rtindex);
807 21846 : jtnode = jtlink;
808 : }
809 : else
810 0 : elog(ERROR, "unrecognized node type: %d",
811 : (int) nodeTag(jtnode));
812 136184 : return jtnode;
813 : }
814 :
815 : /*
816 : * Recurse through top-level qual nodes for pull_up_sublinks()
817 : *
818 : * jtlink1 points to the link in the jointree where any new JoinExprs should
819 : * be inserted if they reference available_rels1 (i.e., available_rels1
820 : * denotes the relations present underneath jtlink1). Optionally, jtlink2 can
821 : * point to a second link where new JoinExprs should be inserted if they
822 : * reference available_rels2 (pass NULL for both those arguments if not used).
823 : * Note that SubLinks referencing both sets of variables cannot be optimized.
824 : * If we find multiple pull-up-able SubLinks, they'll get stacked onto jtlink1
825 : * and/or jtlink2 in the order we encounter them. We rely on subsequent
826 : * optimization to rearrange the stack if appropriate.
827 : *
828 : * Returns the replacement qual node, or NULL if the qual should be removed.
829 : */
830 : static Node *
831 128450 : pull_up_sublinks_qual_recurse(PlannerInfo *root, Node *node,
832 : Node **jtlink1, Relids available_rels1,
833 : Node **jtlink2, Relids available_rels2)
834 : {
835 128450 : if (node == NULL)
836 7982 : return NULL;
837 120468 : if (IsA(node, SubLink))
838 : {
839 5458 : SubLink *sublink = (SubLink *) node;
840 : JoinExpr *j;
841 : Relids child_rels;
842 :
843 : /* Is it a convertible ANY or EXISTS clause? */
844 5458 : if (sublink->subLinkType == ANY_SUBLINK)
845 : {
846 : ScalarArrayOpExpr *saop;
847 :
848 4526 : if ((saop = convert_VALUES_to_ANY(root,
849 : sublink->testexpr,
850 4526 : (Query *) sublink->subselect)) != NULL)
851 :
852 : /*
853 : * The VALUES sequence was simplified. Nothing more to do
854 : * here.
855 : */
856 84 : return (Node *) saop;
857 :
858 4442 : if ((j = convert_ANY_sublink_to_join(root, sublink,
859 : available_rels1)) != NULL)
860 : {
861 : /* Yes; insert the new join node into the join tree */
862 4336 : j->larg = *jtlink1;
863 4336 : *jtlink1 = (Node *) j;
864 : /* Recursively process pulled-up jointree nodes */
865 4336 : j->rarg = pull_up_sublinks_jointree_recurse(root,
866 : j->rarg,
867 : &child_rels);
868 :
869 : /*
870 : * Now recursively process the pulled-up quals. Any inserted
871 : * joins can get stacked onto either j->larg or j->rarg,
872 : * depending on which rels they reference.
873 : */
874 4336 : j->quals = pull_up_sublinks_qual_recurse(root,
875 : j->quals,
876 : &j->larg,
877 : available_rels1,
878 : &j->rarg,
879 : child_rels);
880 : /* Return NULL representing constant TRUE */
881 4336 : return NULL;
882 : }
883 112 : if (available_rels2 != NULL &&
884 6 : (j = convert_ANY_sublink_to_join(root, sublink,
885 : available_rels2)) != NULL)
886 : {
887 : /* Yes; insert the new join node into the join tree */
888 0 : j->larg = *jtlink2;
889 0 : *jtlink2 = (Node *) j;
890 : /* Recursively process pulled-up jointree nodes */
891 0 : j->rarg = pull_up_sublinks_jointree_recurse(root,
892 : j->rarg,
893 : &child_rels);
894 :
895 : /*
896 : * Now recursively process the pulled-up quals. Any inserted
897 : * joins can get stacked onto either j->larg or j->rarg,
898 : * depending on which rels they reference.
899 : */
900 0 : j->quals = pull_up_sublinks_qual_recurse(root,
901 : j->quals,
902 : &j->larg,
903 : available_rels2,
904 : &j->rarg,
905 : child_rels);
906 : /* Return NULL representing constant TRUE */
907 0 : return NULL;
908 : }
909 : }
910 932 : else if (sublink->subLinkType == EXISTS_SUBLINK)
911 : {
912 872 : if ((j = convert_EXISTS_sublink_to_join(root, sublink, false,
913 : available_rels1)) != NULL)
914 : {
915 : /* Yes; insert the new join node into the join tree */
916 712 : j->larg = *jtlink1;
917 712 : *jtlink1 = (Node *) j;
918 : /* Recursively process pulled-up jointree nodes */
919 712 : j->rarg = pull_up_sublinks_jointree_recurse(root,
920 : j->rarg,
921 : &child_rels);
922 :
923 : /*
924 : * Now recursively process the pulled-up quals. Any inserted
925 : * joins can get stacked onto either j->larg or j->rarg,
926 : * depending on which rels they reference.
927 : */
928 712 : j->quals = pull_up_sublinks_qual_recurse(root,
929 : j->quals,
930 : &j->larg,
931 : available_rels1,
932 : &j->rarg,
933 : child_rels);
934 : /* Return NULL representing constant TRUE */
935 712 : return NULL;
936 : }
937 192 : if (available_rels2 != NULL &&
938 32 : (j = convert_EXISTS_sublink_to_join(root, sublink, false,
939 : available_rels2)) != NULL)
940 : {
941 : /* Yes; insert the new join node into the join tree */
942 32 : j->larg = *jtlink2;
943 32 : *jtlink2 = (Node *) j;
944 : /* Recursively process pulled-up jointree nodes */
945 32 : j->rarg = pull_up_sublinks_jointree_recurse(root,
946 : j->rarg,
947 : &child_rels);
948 :
949 : /*
950 : * Now recursively process the pulled-up quals. Any inserted
951 : * joins can get stacked onto either j->larg or j->rarg,
952 : * depending on which rels they reference.
953 : */
954 32 : j->quals = pull_up_sublinks_qual_recurse(root,
955 : j->quals,
956 : &j->larg,
957 : available_rels2,
958 : &j->rarg,
959 : child_rels);
960 : /* Return NULL representing constant TRUE */
961 32 : return NULL;
962 : }
963 : }
964 : /* Else return it unmodified */
965 294 : return node;
966 : }
967 115010 : if (is_notclause(node))
968 : {
969 : /* If the immediate argument of NOT is EXISTS, try to convert */
970 7568 : SubLink *sublink = (SubLink *) get_notclausearg((Expr *) node);
971 : JoinExpr *j;
972 : Relids child_rels;
973 :
974 7568 : if (sublink && IsA(sublink, SubLink))
975 : {
976 3038 : if (sublink->subLinkType == EXISTS_SUBLINK)
977 : {
978 2942 : if ((j = convert_EXISTS_sublink_to_join(root, sublink, true,
979 : available_rels1)) != NULL)
980 : {
981 : /* Yes; insert the new join node into the join tree */
982 2928 : j->larg = *jtlink1;
983 2928 : *jtlink1 = (Node *) j;
984 : /* Recursively process pulled-up jointree nodes */
985 2928 : j->rarg = pull_up_sublinks_jointree_recurse(root,
986 : j->rarg,
987 : &child_rels);
988 :
989 : /*
990 : * Now recursively process the pulled-up quals. Because
991 : * we are underneath a NOT, we can't pull up sublinks that
992 : * reference the left-hand stuff, but it's still okay to
993 : * pull up sublinks referencing j->rarg.
994 : */
995 2928 : j->quals = pull_up_sublinks_qual_recurse(root,
996 : j->quals,
997 : &j->rarg,
998 : child_rels,
999 : NULL, NULL);
1000 : /* Return NULL representing constant TRUE */
1001 2928 : return NULL;
1002 : }
1003 14 : if (available_rels2 != NULL &&
1004 0 : (j = convert_EXISTS_sublink_to_join(root, sublink, true,
1005 : available_rels2)) != NULL)
1006 : {
1007 : /* Yes; insert the new join node into the join tree */
1008 0 : j->larg = *jtlink2;
1009 0 : *jtlink2 = (Node *) j;
1010 : /* Recursively process pulled-up jointree nodes */
1011 0 : j->rarg = pull_up_sublinks_jointree_recurse(root,
1012 : j->rarg,
1013 : &child_rels);
1014 :
1015 : /*
1016 : * Now recursively process the pulled-up quals. Because
1017 : * we are underneath a NOT, we can't pull up sublinks that
1018 : * reference the left-hand stuff, but it's still okay to
1019 : * pull up sublinks referencing j->rarg.
1020 : */
1021 0 : j->quals = pull_up_sublinks_qual_recurse(root,
1022 : j->quals,
1023 : &j->rarg,
1024 : child_rels,
1025 : NULL, NULL);
1026 : /* Return NULL representing constant TRUE */
1027 0 : return NULL;
1028 : }
1029 : }
1030 : }
1031 : /* Else return it unmodified */
1032 4640 : return node;
1033 : }
1034 107442 : if (is_andclause(node))
1035 : {
1036 : /* Recurse into AND clause */
1037 20308 : List *newclauses = NIL;
1038 : ListCell *l;
1039 :
1040 78324 : foreach(l, ((BoolExpr *) node)->args)
1041 : {
1042 58016 : Node *oldclause = (Node *) lfirst(l);
1043 : Node *newclause;
1044 :
1045 58016 : newclause = pull_up_sublinks_qual_recurse(root,
1046 : oldclause,
1047 : jtlink1,
1048 : available_rels1,
1049 : jtlink2,
1050 : available_rels2);
1051 58016 : if (newclause)
1052 52336 : newclauses = lappend(newclauses, newclause);
1053 : }
1054 : /* We might have got back fewer clauses than we started with */
1055 20308 : if (newclauses == NIL)
1056 126 : return NULL;
1057 20182 : else if (list_length(newclauses) == 1)
1058 1140 : return (Node *) linitial(newclauses);
1059 : else
1060 19042 : return (Node *) make_andclause(newclauses);
1061 : }
1062 : /* Stop if not an AND */
1063 87134 : return node;
1064 : }
1065 :
1066 : /*
1067 : * preprocess_function_rtes
1068 : * Constant-simplify any FUNCTION RTEs in the FROM clause, and then
1069 : * attempt to "inline" any that are set-returning functions.
1070 : *
1071 : * If an RTE_FUNCTION rtable entry invokes a set-returning function that
1072 : * contains just a simple SELECT, we can convert the rtable entry to an
1073 : * RTE_SUBQUERY entry exposing the SELECT directly. This is especially
1074 : * useful if the subquery can then be "pulled up" for further optimization,
1075 : * but we do it even if not, to reduce executor overhead.
1076 : *
1077 : * This has to be done before we have started to do any optimization of
1078 : * subqueries, else any such steps wouldn't get applied to subqueries
1079 : * obtained via inlining. However, we do it after pull_up_sublinks
1080 : * so that we can inline any functions used in SubLink subselects.
1081 : *
1082 : * The reason for applying const-simplification at this stage is that
1083 : * (a) we'd need to do it anyway to inline a SRF, and (b) by doing it now,
1084 : * we can be sure that pull_up_constant_function() will see constants
1085 : * if there are constants to be seen. This approach also guarantees
1086 : * that every FUNCTION RTE has been const-simplified, allowing planner.c's
1087 : * preprocess_expression() to skip doing it again.
1088 : *
1089 : * Like most of the planner, this feels free to scribble on its input data
1090 : * structure.
1091 : */
1092 : void
1093 564098 : preprocess_function_rtes(PlannerInfo *root)
1094 : {
1095 : ListCell *rt;
1096 :
1097 1455250 : foreach(rt, root->parse->rtable)
1098 : {
1099 891158 : RangeTblEntry *rte = (RangeTblEntry *) lfirst(rt);
1100 :
1101 891158 : if (rte->rtekind == RTE_FUNCTION)
1102 : {
1103 : Query *funcquery;
1104 :
1105 : /* Apply const-simplification */
1106 52176 : rte->functions = (List *)
1107 52176 : eval_const_expressions(root, (Node *) rte->functions);
1108 :
1109 : /* Check safety of expansion, and expand if possible */
1110 52176 : funcquery = inline_set_returning_function(root, rte);
1111 52170 : if (funcquery)
1112 : {
1113 : /* Successful expansion, convert the RTE to a subquery */
1114 222 : rte->rtekind = RTE_SUBQUERY;
1115 222 : rte->subquery = funcquery;
1116 222 : rte->security_barrier = false;
1117 :
1118 : /*
1119 : * Clear fields that should not be set in a subquery RTE.
1120 : * However, we leave rte->functions filled in for the moment,
1121 : * in case makeWholeRowVar needs to consult it. We'll clear
1122 : * it in setrefs.c (see add_rte_to_flat_rtable) so that this
1123 : * abuse of the data structure doesn't escape the planner.
1124 : */
1125 222 : rte->funcordinality = false;
1126 : }
1127 : }
1128 : }
1129 564092 : }
1130 :
1131 : /*
1132 : * pull_up_subqueries
1133 : * Look for subqueries in the rangetable that can be pulled up into
1134 : * the parent query. If the subquery has no special features like
1135 : * grouping/aggregation then we can merge it into the parent's jointree.
1136 : * Also, subqueries that are simple UNION ALL structures can be
1137 : * converted into "append relations".
1138 : */
1139 : void
1140 564092 : pull_up_subqueries(PlannerInfo *root)
1141 : {
1142 : /* Top level of jointree must always be a FromExpr */
1143 : Assert(IsA(root->parse->jointree, FromExpr));
1144 : /* Recursion starts with no containing join nor appendrel */
1145 1128178 : root->parse->jointree = (FromExpr *)
1146 564092 : pull_up_subqueries_recurse(root, (Node *) root->parse->jointree,
1147 : NULL, NULL);
1148 : /* We should still have a FromExpr */
1149 : Assert(IsA(root->parse->jointree, FromExpr));
1150 564086 : }
1151 :
1152 : /*
1153 : * pull_up_subqueries_recurse
1154 : * Recursive guts of pull_up_subqueries.
1155 : *
1156 : * This recursively processes the jointree and returns a modified jointree.
1157 : *
1158 : * If this jointree node is within either side of an outer join, then
1159 : * lowest_outer_join references the lowest such JoinExpr node; otherwise
1160 : * it is NULL. We use this to constrain the effects of LATERAL subqueries.
1161 : *
1162 : * If we are looking at a member subquery of an append relation,
1163 : * containing_appendrel describes that relation; else it is NULL.
1164 : * This forces use of the PlaceHolderVar mechanism for all non-Var targetlist
1165 : * items, and puts some additional restrictions on what can be pulled up.
1166 : *
1167 : * A tricky aspect of this code is that if we pull up a subquery we have
1168 : * to replace Vars that reference the subquery's outputs throughout the
1169 : * parent query, including quals attached to jointree nodes above the one
1170 : * we are currently processing! We handle this by being careful to maintain
1171 : * validity of the jointree structure while recursing, in the following sense:
1172 : * whenever we recurse, all qual expressions in the tree must be reachable
1173 : * from the top level, in case the recursive call needs to modify them.
1174 : *
1175 : * Notice also that we can't turn pullup_replace_vars loose on the whole
1176 : * jointree, because it'd return a mutated copy of the tree; we have to
1177 : * invoke it just on the quals, instead. This behavior is what makes it
1178 : * reasonable to pass lowest_outer_join as a pointer rather than some
1179 : * more-indirect way of identifying the lowest OJ. Likewise, we don't
1180 : * replace append_rel_list members but only their substructure, so the
1181 : * containing_appendrel reference is safe to use.
1182 : */
1183 : static Node *
1184 1385840 : pull_up_subqueries_recurse(PlannerInfo *root, Node *jtnode,
1185 : JoinExpr *lowest_outer_join,
1186 : AppendRelInfo *containing_appendrel)
1187 : {
1188 : /* Since this function recurses, it could be driven to stack overflow. */
1189 1385840 : check_stack_depth();
1190 : /* Also, since it's a bit expensive, let's check for query cancel. */
1191 1385840 : CHECK_FOR_INTERRUPTS();
1192 :
1193 : Assert(jtnode != NULL);
1194 1385840 : if (IsA(jtnode, RangeTblRef))
1195 : {
1196 715222 : int varno = ((RangeTblRef *) jtnode)->rtindex;
1197 715222 : RangeTblEntry *rte = rt_fetch(varno, root->parse->rtable);
1198 :
1199 : /*
1200 : * Is this a subquery RTE, and if so, is the subquery simple enough to
1201 : * pull up?
1202 : *
1203 : * If we are looking at an append-relation member, we can't pull it up
1204 : * unless is_safe_append_member says so.
1205 : */
1206 767996 : if (rte->rtekind == RTE_SUBQUERY &&
1207 90676 : is_simple_subquery(root, rte->subquery, rte, lowest_outer_join) &&
1208 7332 : (containing_appendrel == NULL ||
1209 7332 : is_safe_append_member(rte->subquery)))
1210 36854 : return pull_up_simple_subquery(root, jtnode, rte,
1211 : lowest_outer_join,
1212 : containing_appendrel);
1213 :
1214 : /*
1215 : * Alternatively, is it a simple UNION ALL subquery? If so, flatten
1216 : * into an "append relation".
1217 : *
1218 : * It's safe to do this regardless of whether this query is itself an
1219 : * appendrel member. (If you're thinking we should try to flatten the
1220 : * two levels of appendrel together, you're right; but we handle that
1221 : * in set_append_rel_pathlist, not here.)
1222 : */
1223 694288 : if (rte->rtekind == RTE_SUBQUERY &&
1224 15920 : is_simple_union_all(rte->subquery))
1225 4368 : return pull_up_simple_union_all(root, jtnode, rte);
1226 :
1227 : /*
1228 : * Or perhaps it's a simple VALUES RTE?
1229 : *
1230 : * We don't allow VALUES pullup below an outer join nor into an
1231 : * appendrel (such cases are impossible anyway at the moment).
1232 : */
1233 674000 : if (rte->rtekind == RTE_VALUES &&
1234 12780 : lowest_outer_join == NULL &&
1235 12780 : containing_appendrel == NULL &&
1236 12780 : is_simple_values(root, rte))
1237 4512 : return pull_up_simple_values(root, jtnode, rte);
1238 :
1239 : /*
1240 : * Or perhaps it's a FUNCTION RTE that we could inline?
1241 : */
1242 669488 : if (rte->rtekind == RTE_FUNCTION)
1243 51948 : return pull_up_constant_function(root, jtnode, rte,
1244 : containing_appendrel);
1245 :
1246 : /* Otherwise, do nothing at this node. */
1247 : }
1248 670618 : else if (IsA(jtnode, FromExpr))
1249 : {
1250 573766 : FromExpr *f = (FromExpr *) jtnode;
1251 : ListCell *l;
1252 :
1253 : Assert(containing_appendrel == NULL);
1254 : /* Recursively transform all the child nodes */
1255 1191306 : foreach(l, f->fromlist)
1256 : {
1257 617546 : lfirst(l) = pull_up_subqueries_recurse(root, lfirst(l),
1258 : lowest_outer_join,
1259 : NULL);
1260 : }
1261 : }
1262 96852 : else if (IsA(jtnode, JoinExpr))
1263 : {
1264 96852 : JoinExpr *j = (JoinExpr *) jtnode;
1265 :
1266 : Assert(containing_appendrel == NULL);
1267 : /* Recurse, being careful to tell myself when inside outer join */
1268 96852 : switch (j->jointype)
1269 : {
1270 39430 : case JOIN_INNER:
1271 39430 : j->larg = pull_up_subqueries_recurse(root, j->larg,
1272 : lowest_outer_join,
1273 : NULL);
1274 39430 : j->rarg = pull_up_subqueries_recurse(root, j->rarg,
1275 : lowest_outer_join,
1276 : NULL);
1277 39430 : break;
1278 55148 : case JOIN_LEFT:
1279 : case JOIN_SEMI:
1280 : case JOIN_ANTI:
1281 55148 : j->larg = pull_up_subqueries_recurse(root, j->larg,
1282 : j,
1283 : NULL);
1284 55148 : j->rarg = pull_up_subqueries_recurse(root, j->rarg,
1285 : j,
1286 : NULL);
1287 55148 : break;
1288 1090 : case JOIN_FULL:
1289 1090 : j->larg = pull_up_subqueries_recurse(root, j->larg,
1290 : j,
1291 : NULL);
1292 1090 : j->rarg = pull_up_subqueries_recurse(root, j->rarg,
1293 : j,
1294 : NULL);
1295 1090 : break;
1296 1184 : case JOIN_RIGHT:
1297 1184 : j->larg = pull_up_subqueries_recurse(root, j->larg,
1298 : j,
1299 : NULL);
1300 1184 : j->rarg = pull_up_subqueries_recurse(root, j->rarg,
1301 : j,
1302 : NULL);
1303 1184 : break;
1304 0 : default:
1305 0 : elog(ERROR, "unrecognized join type: %d",
1306 : (int) j->jointype);
1307 : break;
1308 : }
1309 : }
1310 : else
1311 0 : elog(ERROR, "unrecognized node type: %d",
1312 : (int) nodeTag(jtnode));
1313 1288152 : return jtnode;
1314 : }
1315 :
1316 : /*
1317 : * pull_up_simple_subquery
1318 : * Attempt to pull up a single simple subquery.
1319 : *
1320 : * jtnode is a RangeTblRef that has been tentatively identified as a simple
1321 : * subquery by pull_up_subqueries. We return the replacement jointree node,
1322 : * or jtnode itself if we determine that the subquery can't be pulled up
1323 : * after all.
1324 : *
1325 : * rte is the RangeTblEntry referenced by jtnode. Remaining parameters are
1326 : * as for pull_up_subqueries_recurse.
1327 : */
1328 : static Node *
1329 36854 : pull_up_simple_subquery(PlannerInfo *root, Node *jtnode, RangeTblEntry *rte,
1330 : JoinExpr *lowest_outer_join,
1331 : AppendRelInfo *containing_appendrel)
1332 : {
1333 36854 : Query *parse = root->parse;
1334 36854 : int varno = ((RangeTblRef *) jtnode)->rtindex;
1335 : Query *subquery;
1336 : PlannerInfo *subroot;
1337 : int rtoffset;
1338 : pullup_replace_vars_context rvcontext;
1339 : ListCell *lc;
1340 :
1341 : /*
1342 : * Make a modifiable copy of the subquery to hack on, so that the RTE will
1343 : * be left unchanged in case we decide below that we can't pull it up
1344 : * after all.
1345 : */
1346 36854 : subquery = copyObject(rte->subquery);
1347 :
1348 : /*
1349 : * Create a PlannerInfo data structure for this subquery.
1350 : *
1351 : * NOTE: the next few steps should match the first processing in
1352 : * subquery_planner(). Can we refactor to avoid code duplication, or
1353 : * would that just make things uglier?
1354 : */
1355 36854 : subroot = makeNode(PlannerInfo);
1356 36854 : subroot->parse = subquery;
1357 36854 : subroot->glob = root->glob;
1358 36854 : subroot->query_level = root->query_level;
1359 36854 : subroot->parent_root = root->parent_root;
1360 36854 : subroot->plan_params = NIL;
1361 36854 : subroot->outer_params = NULL;
1362 36854 : subroot->planner_cxt = CurrentMemoryContext;
1363 36854 : subroot->init_plans = NIL;
1364 36854 : subroot->cte_plan_ids = NIL;
1365 36854 : subroot->multiexpr_params = NIL;
1366 36854 : subroot->join_domains = NIL;
1367 36854 : subroot->eq_classes = NIL;
1368 36854 : subroot->ec_merging_done = false;
1369 36854 : subroot->last_rinfo_serial = 0;
1370 36854 : subroot->all_result_relids = NULL;
1371 36854 : subroot->leaf_result_relids = NULL;
1372 36854 : subroot->append_rel_list = NIL;
1373 36854 : subroot->row_identity_vars = NIL;
1374 36854 : subroot->rowMarks = NIL;
1375 36854 : memset(subroot->upper_rels, 0, sizeof(subroot->upper_rels));
1376 36854 : memset(subroot->upper_targets, 0, sizeof(subroot->upper_targets));
1377 36854 : subroot->processed_groupClause = NIL;
1378 36854 : subroot->processed_distinctClause = NIL;
1379 36854 : subroot->processed_tlist = NIL;
1380 36854 : subroot->update_colnos = NIL;
1381 36854 : subroot->grouping_map = NULL;
1382 36854 : subroot->minmax_aggs = NIL;
1383 36854 : subroot->qual_security_level = 0;
1384 36854 : subroot->placeholdersFrozen = false;
1385 36854 : subroot->hasRecursion = false;
1386 36854 : subroot->wt_param_id = -1;
1387 36854 : subroot->non_recursive_path = NULL;
1388 : /* We don't currently need a top JoinDomain for the subroot */
1389 :
1390 : /* No CTEs to worry about */
1391 : Assert(subquery->cteList == NIL);
1392 :
1393 : /*
1394 : * Scan the rangetable for relation RTEs and retrieve the necessary
1395 : * catalog information for each relation. Using this information, clear
1396 : * the inh flag for any relation that has no children, collect not-null
1397 : * attribute numbers for any relation that has column not-null
1398 : * constraints, and expand virtual generated columns for any relation that
1399 : * contains them.
1400 : */
1401 36854 : subquery = subroot->parse = preprocess_relation_rtes(subroot);
1402 :
1403 : /*
1404 : * If the FROM clause is empty, replace it with a dummy RTE_RESULT RTE, so
1405 : * that we don't need so many special cases to deal with that situation.
1406 : */
1407 36854 : replace_empty_jointree(subquery);
1408 :
1409 : /*
1410 : * Pull up any SubLinks within the subquery's quals, so that we don't
1411 : * leave unoptimized SubLinks behind.
1412 : */
1413 36854 : if (subquery->hasSubLinks)
1414 2382 : pull_up_sublinks(subroot);
1415 :
1416 : /*
1417 : * Similarly, preprocess its function RTEs to inline any set-returning
1418 : * functions in its rangetable.
1419 : */
1420 36854 : preprocess_function_rtes(subroot);
1421 :
1422 : /*
1423 : * Recursively pull up the subquery's subqueries, so that
1424 : * pull_up_subqueries' processing is complete for its jointree and
1425 : * rangetable.
1426 : *
1427 : * Note: it's okay that the subquery's recursion starts with NULL for
1428 : * containing-join info, even if we are within an outer join in the upper
1429 : * query; the lower query starts with a clean slate for outer-join
1430 : * semantics. Likewise, we needn't pass down appendrel state.
1431 : */
1432 36854 : pull_up_subqueries(subroot);
1433 :
1434 : /*
1435 : * Now we must recheck whether the subquery is still simple enough to pull
1436 : * up. If not, abandon processing it.
1437 : *
1438 : * We don't really need to recheck all the conditions involved, but it's
1439 : * easier just to keep this "if" looking the same as the one in
1440 : * pull_up_subqueries_recurse.
1441 : */
1442 36854 : if (is_simple_subquery(root, subquery, rte, lowest_outer_join) &&
1443 6284 : (containing_appendrel == NULL || is_safe_append_member(subquery)))
1444 : {
1445 : /* good to go */
1446 : }
1447 : else
1448 : {
1449 : /*
1450 : * Give up, return unmodified RangeTblRef.
1451 : *
1452 : * Note: The work we just did will be redone when the subquery gets
1453 : * planned on its own. Perhaps we could avoid that by storing the
1454 : * modified subquery back into the rangetable, but I'm not gonna risk
1455 : * it now.
1456 : */
1457 210 : return jtnode;
1458 : }
1459 :
1460 : /*
1461 : * We must flatten any join alias Vars in the subquery's targetlist,
1462 : * because pulling up the subquery's subqueries might have changed their
1463 : * expansions into arbitrary expressions, which could affect
1464 : * pullup_replace_vars' decisions about whether PlaceHolderVar wrappers
1465 : * are needed for tlist entries. (Likely it'd be better to do
1466 : * flatten_join_alias_vars on the whole query tree at some earlier stage,
1467 : * maybe even in the rewriter; but for now let's just fix this case here.)
1468 : */
1469 36644 : subquery->targetList = (List *)
1470 36644 : flatten_join_alias_vars(subroot, subroot->parse,
1471 36644 : (Node *) subquery->targetList);
1472 :
1473 : /*
1474 : * Adjust level-0 varnos in subquery so that we can append its rangetable
1475 : * to upper query's. We have to fix the subquery's append_rel_list as
1476 : * well.
1477 : */
1478 36644 : rtoffset = list_length(parse->rtable);
1479 36644 : OffsetVarNodes((Node *) subquery, rtoffset, 0);
1480 36644 : OffsetVarNodes((Node *) subroot->append_rel_list, rtoffset, 0);
1481 :
1482 : /*
1483 : * Upper-level vars in subquery are now one level closer to their parent
1484 : * than before.
1485 : */
1486 36644 : IncrementVarSublevelsUp((Node *) subquery, -1, 1);
1487 36644 : IncrementVarSublevelsUp((Node *) subroot->append_rel_list, -1, 1);
1488 :
1489 : /*
1490 : * The subquery's targetlist items are now in the appropriate form to
1491 : * insert into the top query, except that we may need to wrap them in
1492 : * PlaceHolderVars. Set up required context data for pullup_replace_vars.
1493 : * (Note that we should include the subquery's inner joins in relids,
1494 : * since it may include join alias vars referencing them.)
1495 : */
1496 36644 : rvcontext.root = root;
1497 36644 : rvcontext.targetlist = subquery->targetList;
1498 36644 : rvcontext.target_rte = rte;
1499 36644 : rvcontext.result_relation = 0;
1500 36644 : if (rte->lateral)
1501 : {
1502 1148 : rvcontext.relids = get_relids_in_jointree((Node *) subquery->jointree,
1503 : true, true);
1504 1148 : rvcontext.nullinfo = get_nullingrels(parse);
1505 : }
1506 : else /* won't need these values */
1507 : {
1508 35496 : rvcontext.relids = NULL;
1509 35496 : rvcontext.nullinfo = NULL;
1510 : }
1511 36644 : rvcontext.outer_hasSubLinks = &parse->hasSubLinks;
1512 36644 : rvcontext.varno = varno;
1513 : /* this flag will be set below, if needed */
1514 36644 : rvcontext.wrap_option = REPLACE_WRAP_NONE;
1515 : /* initialize cache array with indexes 0 .. length(tlist) */
1516 36644 : rvcontext.rv_cache = palloc0((list_length(subquery->targetList) + 1) *
1517 : sizeof(Node *));
1518 :
1519 : /*
1520 : * If the parent query uses grouping sets, we need a PlaceHolderVar for
1521 : * each expression of the subquery's targetlist items. This ensures that
1522 : * expressions retain their separate identity so that they will match
1523 : * grouping set columns when appropriate. (It'd be sufficient to wrap
1524 : * values used in grouping set columns, and do so only in non-aggregated
1525 : * portions of the tlist and havingQual, but that would require a lot of
1526 : * infrastructure that pullup_replace_vars hasn't currently got.)
1527 : */
1528 36644 : if (parse->groupingSets)
1529 332 : rvcontext.wrap_option = REPLACE_WRAP_ALL;
1530 :
1531 : /*
1532 : * Replace all of the top query's references to the subquery's outputs
1533 : * with copies of the adjusted subtlist items, being careful not to
1534 : * replace any of the jointree structure.
1535 : */
1536 36644 : perform_pullup_replace_vars(root, &rvcontext,
1537 : containing_appendrel);
1538 :
1539 : /*
1540 : * If the subquery had a LATERAL marker, propagate that to any of its
1541 : * child RTEs that could possibly now contain lateral cross-references.
1542 : * The children might or might not contain any actual lateral
1543 : * cross-references, but we have to mark the pulled-up child RTEs so that
1544 : * later planner stages will check for such.
1545 : */
1546 36638 : if (rte->lateral)
1547 : {
1548 2692 : foreach(lc, subquery->rtable)
1549 : {
1550 1544 : RangeTblEntry *child_rte = (RangeTblEntry *) lfirst(lc);
1551 :
1552 1544 : switch (child_rte->rtekind)
1553 : {
1554 696 : case RTE_RELATION:
1555 696 : if (child_rte->tablesample)
1556 36 : child_rte->lateral = true;
1557 696 : break;
1558 280 : case RTE_SUBQUERY:
1559 : case RTE_FUNCTION:
1560 : case RTE_VALUES:
1561 : case RTE_TABLEFUNC:
1562 280 : child_rte->lateral = true;
1563 280 : break;
1564 568 : case RTE_JOIN:
1565 : case RTE_CTE:
1566 : case RTE_NAMEDTUPLESTORE:
1567 : case RTE_RESULT:
1568 : case RTE_GROUP:
1569 : /* these can't contain any lateral references */
1570 568 : break;
1571 : }
1572 : }
1573 : }
1574 :
1575 : /*
1576 : * Now append the adjusted rtable entries and their perminfos to upper
1577 : * query. (We hold off until after fixing the upper rtable entries; no
1578 : * point in running that code on the subquery ones too.)
1579 : */
1580 36638 : CombineRangeTables(&parse->rtable, &parse->rteperminfos,
1581 : subquery->rtable, subquery->rteperminfos);
1582 :
1583 : /*
1584 : * Pull up any FOR UPDATE/SHARE markers, too. (OffsetVarNodes already
1585 : * adjusted the marker rtindexes, so just concat the lists.)
1586 : */
1587 36638 : parse->rowMarks = list_concat(parse->rowMarks, subquery->rowMarks);
1588 :
1589 : /*
1590 : * We also have to fix the relid sets of any PlaceHolderVar nodes in the
1591 : * parent query. (This could perhaps be done by pullup_replace_vars(),
1592 : * but it seems cleaner to use two passes.) Note in particular that any
1593 : * PlaceHolderVar nodes just created by pullup_replace_vars() will be
1594 : * adjusted, so having created them with the subquery's varno is correct.
1595 : *
1596 : * Likewise, relids appearing in AppendRelInfo nodes have to be fixed. We
1597 : * already checked that this won't require introducing multiple subrelids
1598 : * into the single-slot AppendRelInfo structs.
1599 : */
1600 36638 : if (root->glob->lastPHId != 0 || root->append_rel_list)
1601 : {
1602 : Relids subrelids;
1603 :
1604 8002 : subrelids = get_relids_in_jointree((Node *) subquery->jointree,
1605 : true, false);
1606 8002 : if (root->glob->lastPHId != 0)
1607 1970 : substitute_phv_relids((Node *) parse, varno, subrelids);
1608 8002 : fix_append_rel_relids(root, varno, subrelids);
1609 : }
1610 :
1611 : /*
1612 : * And now add subquery's AppendRelInfos to our list.
1613 : */
1614 73276 : root->append_rel_list = list_concat(root->append_rel_list,
1615 36638 : subroot->append_rel_list);
1616 :
1617 : /*
1618 : * We don't have to do the equivalent bookkeeping for outer-join info,
1619 : * because that hasn't been set up yet. placeholder_list likewise.
1620 : */
1621 : Assert(root->join_info_list == NIL);
1622 : Assert(subroot->join_info_list == NIL);
1623 : Assert(root->placeholder_list == NIL);
1624 : Assert(subroot->placeholder_list == NIL);
1625 :
1626 : /*
1627 : * We no longer need the RTE's copy of the subquery's query tree. Getting
1628 : * rid of it saves nothing in particular so far as this level of query is
1629 : * concerned; but if this query level is in turn pulled up into a parent,
1630 : * we'd waste cycles copying the now-unused query tree.
1631 : */
1632 36638 : rte->subquery = NULL;
1633 :
1634 : /*
1635 : * Miscellaneous housekeeping.
1636 : *
1637 : * Although replace_rte_variables() faithfully updated parse->hasSubLinks
1638 : * if it copied any SubLinks out of the subquery's targetlist, we still
1639 : * could have SubLinks added to the query in the expressions of FUNCTION
1640 : * and VALUES RTEs copied up from the subquery. So it's necessary to copy
1641 : * subquery->hasSubLinks anyway. Perhaps this can be improved someday.
1642 : */
1643 36638 : parse->hasSubLinks |= subquery->hasSubLinks;
1644 :
1645 : /* If subquery had any RLS conditions, now main query does too */
1646 36638 : parse->hasRowSecurity |= subquery->hasRowSecurity;
1647 :
1648 : /*
1649 : * subquery won't be pulled up if it hasAggs, hasWindowFuncs, or
1650 : * hasTargetSRFs, so no work needed on those flags
1651 : */
1652 :
1653 : /*
1654 : * Return the adjusted subquery jointree to replace the RangeTblRef entry
1655 : * in parent's jointree; or, if the FromExpr is degenerate, just return
1656 : * its single member.
1657 : */
1658 : Assert(IsA(subquery->jointree, FromExpr));
1659 : Assert(subquery->jointree->fromlist != NIL);
1660 68268 : if (subquery->jointree->quals == NULL &&
1661 31630 : list_length(subquery->jointree->fromlist) == 1)
1662 31314 : return (Node *) linitial(subquery->jointree->fromlist);
1663 :
1664 5324 : return (Node *) subquery->jointree;
1665 : }
1666 :
1667 : /*
1668 : * pull_up_simple_union_all
1669 : * Pull up a single simple UNION ALL subquery.
1670 : *
1671 : * jtnode is a RangeTblRef that has been identified as a simple UNION ALL
1672 : * subquery by pull_up_subqueries. We pull up the leaf subqueries and
1673 : * build an "append relation" for the union set. The result value is just
1674 : * jtnode, since we don't actually need to change the query jointree.
1675 : */
1676 : static Node *
1677 4368 : pull_up_simple_union_all(PlannerInfo *root, Node *jtnode, RangeTblEntry *rte)
1678 : {
1679 4368 : int varno = ((RangeTblRef *) jtnode)->rtindex;
1680 4368 : Query *subquery = rte->subquery;
1681 4368 : int rtoffset = list_length(root->parse->rtable);
1682 : List *rtable;
1683 :
1684 : /*
1685 : * Make a modifiable copy of the subquery's rtable, so we can adjust
1686 : * upper-level Vars in it. There are no such Vars in the setOperations
1687 : * tree proper, so fixing the rtable should be sufficient.
1688 : */
1689 4368 : rtable = copyObject(subquery->rtable);
1690 :
1691 : /*
1692 : * Upper-level vars in subquery are now one level closer to their parent
1693 : * than before. We don't have to worry about offsetting varnos, though,
1694 : * because the UNION leaf queries can't cross-reference each other.
1695 : */
1696 4368 : IncrementVarSublevelsUp_rtable(rtable, -1, 1);
1697 :
1698 : /*
1699 : * If the UNION ALL subquery had a LATERAL marker, propagate that to all
1700 : * its children. The individual children might or might not contain any
1701 : * actual lateral cross-references, but we have to mark the pulled-up
1702 : * child RTEs so that later planner stages will check for such.
1703 : */
1704 4368 : if (rte->lateral)
1705 : {
1706 : ListCell *rt;
1707 :
1708 198 : foreach(rt, rtable)
1709 : {
1710 132 : RangeTblEntry *child_rte = (RangeTblEntry *) lfirst(rt);
1711 :
1712 : Assert(child_rte->rtekind == RTE_SUBQUERY);
1713 132 : child_rte->lateral = true;
1714 : }
1715 : }
1716 :
1717 : /*
1718 : * Append child RTEs (and their perminfos) to parent rtable.
1719 : */
1720 4368 : CombineRangeTables(&root->parse->rtable, &root->parse->rteperminfos,
1721 : rtable, subquery->rteperminfos);
1722 :
1723 : /*
1724 : * Recursively scan the subquery's setOperations tree and add
1725 : * AppendRelInfo nodes for leaf subqueries to the parent's
1726 : * append_rel_list. Also apply pull_up_subqueries to the leaf subqueries.
1727 : */
1728 : Assert(subquery->setOperations);
1729 4368 : pull_up_union_leaf_queries(subquery->setOperations, root, varno, subquery,
1730 : rtoffset);
1731 :
1732 : /*
1733 : * Mark the parent as an append relation.
1734 : */
1735 4368 : rte->inh = true;
1736 :
1737 4368 : return jtnode;
1738 : }
1739 :
1740 : /*
1741 : * pull_up_union_leaf_queries -- recursive guts of pull_up_simple_union_all
1742 : *
1743 : * Build an AppendRelInfo for each leaf query in the setop tree, and then
1744 : * apply pull_up_subqueries to the leaf query.
1745 : *
1746 : * Note that setOpQuery is the Query containing the setOp node, whose tlist
1747 : * contains references to all the setop output columns. When called from
1748 : * pull_up_simple_union_all, this is *not* the same as root->parse, which is
1749 : * the parent Query we are pulling up into.
1750 : *
1751 : * parentRTindex is the appendrel parent's index in root->parse->rtable.
1752 : *
1753 : * The child RTEs have already been copied to the parent. childRToffset
1754 : * tells us where in the parent's range table they were copied. When called
1755 : * from flatten_simple_union_all, childRToffset is 0 since the child RTEs
1756 : * were already in root->parse->rtable and no RT index adjustment is needed.
1757 : */
1758 : static void
1759 16178 : pull_up_union_leaf_queries(Node *setOp, PlannerInfo *root, int parentRTindex,
1760 : Query *setOpQuery, int childRToffset)
1761 : {
1762 16178 : if (IsA(setOp, RangeTblRef))
1763 : {
1764 10498 : RangeTblRef *rtr = (RangeTblRef *) setOp;
1765 : int childRTindex;
1766 : AppendRelInfo *appinfo;
1767 :
1768 : /*
1769 : * Calculate the index in the parent's range table
1770 : */
1771 10498 : childRTindex = childRToffset + rtr->rtindex;
1772 :
1773 : /*
1774 : * Build a suitable AppendRelInfo, and attach to parent's list.
1775 : */
1776 10498 : appinfo = makeNode(AppendRelInfo);
1777 10498 : appinfo->parent_relid = parentRTindex;
1778 10498 : appinfo->child_relid = childRTindex;
1779 10498 : appinfo->parent_reltype = InvalidOid;
1780 10498 : appinfo->child_reltype = InvalidOid;
1781 10498 : make_setop_translation_list(setOpQuery, childRTindex, appinfo);
1782 10498 : appinfo->parent_reloid = InvalidOid;
1783 10498 : root->append_rel_list = lappend(root->append_rel_list, appinfo);
1784 :
1785 : /*
1786 : * Recursively apply pull_up_subqueries to the new child RTE. (We
1787 : * must build the AppendRelInfo first, because this will modify it;
1788 : * indeed, that's the only part of the upper query where Vars
1789 : * referencing childRTindex can exist at this point.)
1790 : *
1791 : * Note that we can pass NULL for containing-join info even if we're
1792 : * actually under an outer join, because the child's expressions
1793 : * aren't going to propagate up to the join. Also, we ignore the
1794 : * possibility that pull_up_subqueries_recurse() returns a different
1795 : * jointree node than what we pass it; if it does, the important thing
1796 : * is that it replaced the child relid in the AppendRelInfo node.
1797 : */
1798 10498 : rtr = makeNode(RangeTblRef);
1799 10498 : rtr->rtindex = childRTindex;
1800 10498 : (void) pull_up_subqueries_recurse(root, (Node *) rtr,
1801 : NULL, appinfo);
1802 : }
1803 5680 : else if (IsA(setOp, SetOperationStmt))
1804 : {
1805 5680 : SetOperationStmt *op = (SetOperationStmt *) setOp;
1806 :
1807 : /* Recurse to reach leaf queries */
1808 5680 : pull_up_union_leaf_queries(op->larg, root, parentRTindex, setOpQuery,
1809 : childRToffset);
1810 5680 : pull_up_union_leaf_queries(op->rarg, root, parentRTindex, setOpQuery,
1811 : childRToffset);
1812 : }
1813 : else
1814 : {
1815 0 : elog(ERROR, "unrecognized node type: %d",
1816 : (int) nodeTag(setOp));
1817 : }
1818 16178 : }
1819 :
1820 : /*
1821 : * make_setop_translation_list
1822 : * Build the list of translations from parent Vars to child Vars for
1823 : * a UNION ALL member. (At this point it's just a simple list of
1824 : * referencing Vars, but if we succeed in pulling up the member
1825 : * subquery, the Vars will get replaced by pulled-up expressions.)
1826 : * Also create the rather trivial reverse-translation array.
1827 : */
1828 : static void
1829 10498 : make_setop_translation_list(Query *query, int newvarno,
1830 : AppendRelInfo *appinfo)
1831 : {
1832 10498 : List *vars = NIL;
1833 : AttrNumber *pcolnos;
1834 : ListCell *l;
1835 :
1836 : /* Initialize reverse-translation array with all entries zero */
1837 : /* (entries for resjunk columns will stay that way) */
1838 10498 : appinfo->num_child_cols = list_length(query->targetList);
1839 10498 : appinfo->parent_colnos = pcolnos =
1840 10498 : (AttrNumber *) palloc0(appinfo->num_child_cols * sizeof(AttrNumber));
1841 :
1842 26826 : foreach(l, query->targetList)
1843 : {
1844 16328 : TargetEntry *tle = (TargetEntry *) lfirst(l);
1845 :
1846 16328 : if (tle->resjunk)
1847 0 : continue;
1848 :
1849 16328 : vars = lappend(vars, makeVarFromTargetEntry(newvarno, tle));
1850 16328 : pcolnos[tle->resno - 1] = tle->resno;
1851 : }
1852 :
1853 10498 : appinfo->translated_vars = vars;
1854 10498 : }
1855 :
1856 : /*
1857 : * is_simple_subquery
1858 : * Check a subquery in the range table to see if it's simple enough
1859 : * to pull up into the parent query.
1860 : *
1861 : * rte is the RTE_SUBQUERY RangeTblEntry that contained the subquery.
1862 : * (Note subquery is not necessarily equal to rte->subquery; it could be a
1863 : * processed copy of that.)
1864 : * lowest_outer_join is the lowest outer join above the subquery, or NULL.
1865 : */
1866 : static bool
1867 89628 : is_simple_subquery(PlannerInfo *root, Query *subquery, RangeTblEntry *rte,
1868 : JoinExpr *lowest_outer_join)
1869 : {
1870 : /*
1871 : * Let's just make sure it's a valid subselect ...
1872 : */
1873 89628 : if (!IsA(subquery, Query) ||
1874 89628 : subquery->commandType != CMD_SELECT)
1875 0 : elog(ERROR, "subquery is bogus");
1876 :
1877 : /*
1878 : * Can't currently pull up a query with setops (unless it's simple UNION
1879 : * ALL, which is handled by a different code path). Maybe after querytree
1880 : * redesign...
1881 : */
1882 89628 : if (subquery->setOperations)
1883 5118 : return false;
1884 :
1885 : /*
1886 : * Can't pull up a subquery involving grouping, aggregation, SRFs,
1887 : * sorting, limiting, or WITH. (XXX WITH could possibly be allowed later)
1888 : *
1889 : * We also don't pull up a subquery that has explicit FOR UPDATE/SHARE
1890 : * clauses, because pullup would cause the locking to occur semantically
1891 : * higher than it should. Implicit FOR UPDATE/SHARE is okay because in
1892 : * that case the locking was originally declared in the upper query
1893 : * anyway.
1894 : */
1895 84510 : if (subquery->hasAggs ||
1896 82982 : subquery->hasWindowFuncs ||
1897 82596 : subquery->hasTargetSRFs ||
1898 78392 : subquery->groupClause ||
1899 78312 : subquery->groupingSets ||
1900 78312 : subquery->havingQual ||
1901 78312 : subquery->sortClause ||
1902 77434 : subquery->distinctClause ||
1903 77164 : subquery->limitOffset ||
1904 76714 : subquery->limitCount ||
1905 76404 : subquery->hasForUpdate ||
1906 75874 : subquery->cteList)
1907 8804 : return false;
1908 :
1909 : /*
1910 : * Don't pull up if the RTE represents a security-barrier view; we
1911 : * couldn't prevent information leakage once the RTE's Vars are scattered
1912 : * about in the upper query.
1913 : */
1914 75706 : if (rte->security_barrier)
1915 672 : return false;
1916 :
1917 : /*
1918 : * If the subquery is LATERAL, check for pullup restrictions from that.
1919 : */
1920 75034 : if (rte->lateral)
1921 : {
1922 : bool restricted;
1923 : Relids safe_upper_varnos;
1924 :
1925 : /*
1926 : * The subquery's WHERE and JOIN/ON quals mustn't contain any lateral
1927 : * references to rels outside a higher outer join (including the case
1928 : * where the outer join is within the subquery itself). In such a
1929 : * case, pulling up would result in a situation where we need to
1930 : * postpone quals from below an outer join to above it, which is
1931 : * probably completely wrong and in any case is a complication that
1932 : * doesn't seem worth addressing at the moment.
1933 : */
1934 2392 : if (lowest_outer_join != NULL)
1935 : {
1936 1344 : restricted = true;
1937 1344 : safe_upper_varnos = get_relids_in_jointree((Node *) lowest_outer_join,
1938 : true, true);
1939 : }
1940 : else
1941 : {
1942 1048 : restricted = false;
1943 1048 : safe_upper_varnos = NULL; /* doesn't matter */
1944 : }
1945 :
1946 2392 : if (jointree_contains_lateral_outer_refs(root,
1947 2392 : (Node *) subquery->jointree,
1948 : restricted, safe_upper_varnos))
1949 24 : return false;
1950 :
1951 : /*
1952 : * If there's an outer join above the LATERAL subquery, also disallow
1953 : * pullup if the subquery's targetlist has any references to rels
1954 : * outside the outer join, since these might get pulled into quals
1955 : * above the subquery (but in or below the outer join) and then lead
1956 : * to qual-postponement issues similar to the case checked for above.
1957 : * (We wouldn't need to prevent pullup if no such references appear in
1958 : * outer-query quals, but we don't have enough info here to check
1959 : * that. Also, maybe this restriction could be removed if we forced
1960 : * such refs to be wrapped in PlaceHolderVars, even when they're below
1961 : * the nearest outer join? But it's a pretty hokey usage, so not
1962 : * clear this is worth sweating over.)
1963 : *
1964 : * If you change this, see also the comments about lateral references
1965 : * in pullup_replace_vars_callback().
1966 : */
1967 2368 : if (lowest_outer_join != NULL)
1968 : {
1969 1344 : Relids lvarnos = pull_varnos_of_level(root,
1970 1344 : (Node *) subquery->targetList,
1971 : 1);
1972 :
1973 1344 : if (!bms_is_subset(lvarnos, safe_upper_varnos))
1974 12 : return false;
1975 : }
1976 : }
1977 :
1978 : /*
1979 : * Don't pull up a subquery that has any volatile functions in its
1980 : * targetlist. Otherwise we might introduce multiple evaluations of these
1981 : * functions, if they get copied to multiple places in the upper query,
1982 : * leading to surprising results. (Note: the PlaceHolderVar mechanism
1983 : * doesn't quite guarantee single evaluation; else we could pull up anyway
1984 : * and just wrap such items in PlaceHolderVars ...)
1985 : */
1986 74998 : if (contain_volatile_functions((Node *) subquery->targetList))
1987 254 : return false;
1988 :
1989 74744 : return true;
1990 : }
1991 :
1992 : /*
1993 : * pull_up_simple_values
1994 : * Pull up a single simple VALUES RTE.
1995 : *
1996 : * jtnode is a RangeTblRef that has been identified as a simple VALUES RTE
1997 : * by pull_up_subqueries. We always return a RangeTblRef representing a
1998 : * RESULT RTE to replace it (all failure cases should have been detected by
1999 : * is_simple_values()). Actually, what we return is just jtnode, because
2000 : * we replace the VALUES RTE in the rangetable with the RESULT RTE.
2001 : *
2002 : * rte is the RangeTblEntry referenced by jtnode. Because of the limited
2003 : * possible usage of VALUES RTEs, we do not need the remaining parameters
2004 : * of pull_up_subqueries_recurse.
2005 : */
2006 : static Node *
2007 4512 : pull_up_simple_values(PlannerInfo *root, Node *jtnode, RangeTblEntry *rte)
2008 : {
2009 4512 : Query *parse = root->parse;
2010 4512 : int varno = ((RangeTblRef *) jtnode)->rtindex;
2011 : List *values_list;
2012 : List *tlist;
2013 : AttrNumber attrno;
2014 : pullup_replace_vars_context rvcontext;
2015 : ListCell *lc;
2016 :
2017 : Assert(rte->rtekind == RTE_VALUES);
2018 : Assert(list_length(rte->values_lists) == 1);
2019 :
2020 : /*
2021 : * Need a modifiable copy of the VALUES list to hack on, just in case it's
2022 : * multiply referenced.
2023 : */
2024 4512 : values_list = copyObject(linitial(rte->values_lists));
2025 :
2026 : /*
2027 : * The VALUES RTE can't contain any Vars of level zero, let alone any that
2028 : * are join aliases, so no need to flatten join alias Vars.
2029 : */
2030 : Assert(!contain_vars_of_level((Node *) values_list, 0));
2031 :
2032 : /*
2033 : * Set up required context data for pullup_replace_vars. In particular,
2034 : * we have to make the VALUES list look like a subquery targetlist.
2035 : */
2036 4512 : tlist = NIL;
2037 4512 : attrno = 1;
2038 9728 : foreach(lc, values_list)
2039 : {
2040 5216 : tlist = lappend(tlist,
2041 5216 : makeTargetEntry((Expr *) lfirst(lc),
2042 : attrno,
2043 : NULL,
2044 : false));
2045 5216 : attrno++;
2046 : }
2047 4512 : rvcontext.root = root;
2048 4512 : rvcontext.targetlist = tlist;
2049 4512 : rvcontext.target_rte = rte;
2050 4512 : rvcontext.result_relation = 0;
2051 4512 : rvcontext.relids = NULL; /* can't be any lateral references here */
2052 4512 : rvcontext.nullinfo = NULL;
2053 4512 : rvcontext.outer_hasSubLinks = &parse->hasSubLinks;
2054 4512 : rvcontext.varno = varno;
2055 4512 : rvcontext.wrap_option = REPLACE_WRAP_NONE;
2056 : /* initialize cache array with indexes 0 .. length(tlist) */
2057 4512 : rvcontext.rv_cache = palloc0((list_length(tlist) + 1) *
2058 : sizeof(Node *));
2059 :
2060 : /*
2061 : * Replace all of the top query's references to the RTE's outputs with
2062 : * copies of the adjusted VALUES expressions, being careful not to replace
2063 : * any of the jointree structure. We can assume there's no outer joins or
2064 : * appendrels in the dummy Query that surrounds a VALUES RTE.
2065 : */
2066 4512 : perform_pullup_replace_vars(root, &rvcontext, NULL);
2067 :
2068 : /*
2069 : * There should be no appendrels to fix, nor any outer joins and hence no
2070 : * PlaceHolderVars.
2071 : */
2072 : Assert(root->append_rel_list == NIL);
2073 : Assert(root->join_info_list == NIL);
2074 : Assert(root->placeholder_list == NIL);
2075 :
2076 : /*
2077 : * Replace the VALUES RTE with a RESULT RTE. The VALUES RTE is the only
2078 : * rtable entry in the current query level, so this is easy.
2079 : */
2080 : Assert(list_length(parse->rtable) == 1);
2081 :
2082 : /* Create suitable RTE */
2083 4512 : rte = makeNode(RangeTblEntry);
2084 4512 : rte->rtekind = RTE_RESULT;
2085 4512 : rte->eref = makeAlias("*RESULT*", NIL);
2086 :
2087 : /* Replace rangetable */
2088 4512 : parse->rtable = list_make1(rte);
2089 :
2090 : /* We could manufacture a new RangeTblRef, but the one we have is fine */
2091 : Assert(varno == 1);
2092 :
2093 4512 : return jtnode;
2094 : }
2095 :
2096 : /*
2097 : * is_simple_values
2098 : * Check a VALUES RTE in the range table to see if it's simple enough
2099 : * to pull up into the parent query.
2100 : *
2101 : * rte is the RTE_VALUES RangeTblEntry to check.
2102 : */
2103 : static bool
2104 12780 : is_simple_values(PlannerInfo *root, RangeTblEntry *rte)
2105 : {
2106 : Assert(rte->rtekind == RTE_VALUES);
2107 :
2108 : /*
2109 : * There must be exactly one VALUES list, else it's not semantically
2110 : * correct to replace the VALUES RTE with a RESULT RTE, nor would we have
2111 : * a unique set of expressions to substitute into the parent query.
2112 : */
2113 12780 : if (list_length(rte->values_lists) != 1)
2114 8268 : return false;
2115 :
2116 : /*
2117 : * Because VALUES can't appear under an outer join (or at least, we won't
2118 : * try to pull it up if it does), we need not worry about LATERAL, nor
2119 : * about validity of PHVs for the VALUES' outputs.
2120 : */
2121 :
2122 : /*
2123 : * Don't pull up a VALUES that contains any set-returning or volatile
2124 : * functions. The considerations here are basically identical to the
2125 : * restrictions on a pull-able subquery's targetlist.
2126 : */
2127 9024 : if (expression_returns_set((Node *) rte->values_lists) ||
2128 4512 : contain_volatile_functions((Node *) rte->values_lists))
2129 0 : return false;
2130 :
2131 : /*
2132 : * Do not pull up a VALUES that's not the only RTE in its parent query.
2133 : * This is actually the only case that the parser will generate at the
2134 : * moment, and assuming this is true greatly simplifies
2135 : * pull_up_simple_values().
2136 : */
2137 4512 : if (list_length(root->parse->rtable) != 1 ||
2138 4512 : rte != (RangeTblEntry *) linitial(root->parse->rtable))
2139 0 : return false;
2140 :
2141 4512 : return true;
2142 : }
2143 :
2144 : /*
2145 : * pull_up_constant_function
2146 : * Pull up an RTE_FUNCTION expression that was simplified to a constant.
2147 : *
2148 : * jtnode is a RangeTblRef that has been identified as a FUNCTION RTE by
2149 : * pull_up_subqueries. If its expression is just a Const, hoist that value
2150 : * up into the parent query, and replace the RTE_FUNCTION with RTE_RESULT.
2151 : *
2152 : * In principle we could pull up any immutable expression, but we don't.
2153 : * That might result in multiple evaluations of the expression, which could
2154 : * be costly if it's not just a Const. Also, the main value of this is
2155 : * to let the constant participate in further const-folding, and of course
2156 : * that won't happen for a non-Const.
2157 : *
2158 : * The pulled-up value might need to be wrapped in a PlaceHolderVar if the
2159 : * RTE is below an outer join or is part of an appendrel; the extra
2160 : * parameters show whether that's needed.
2161 : */
2162 : static Node *
2163 51948 : pull_up_constant_function(PlannerInfo *root, Node *jtnode,
2164 : RangeTblEntry *rte,
2165 : AppendRelInfo *containing_appendrel)
2166 : {
2167 51948 : Query *parse = root->parse;
2168 : RangeTblFunction *rtf;
2169 : TypeFuncClass functypclass;
2170 : Oid funcrettype;
2171 : TupleDesc tupdesc;
2172 : pullup_replace_vars_context rvcontext;
2173 :
2174 : /* Fail if the RTE has ORDINALITY - we don't implement that here. */
2175 51948 : if (rte->funcordinality)
2176 914 : return jtnode;
2177 :
2178 : /* Fail if RTE isn't a single, simple Const expr */
2179 51034 : if (list_length(rte->functions) != 1)
2180 72 : return jtnode;
2181 50962 : rtf = linitial_node(RangeTblFunction, rte->functions);
2182 50962 : if (!IsA(rtf->funcexpr, Const))
2183 50590 : return jtnode;
2184 :
2185 : /*
2186 : * If the function's result is not a scalar, we punt. In principle we
2187 : * could break the composite constant value apart into per-column
2188 : * constants, but for now it seems not worth the work.
2189 : */
2190 372 : if (rtf->funccolcount != 1)
2191 30 : return jtnode; /* definitely composite */
2192 :
2193 : /* If it has a coldeflist, it certainly returns RECORD */
2194 342 : if (rtf->funccolnames != NIL)
2195 0 : return jtnode; /* must be a one-column RECORD type */
2196 :
2197 342 : functypclass = get_expr_result_type(rtf->funcexpr,
2198 : &funcrettype,
2199 : &tupdesc);
2200 342 : if (functypclass != TYPEFUNC_SCALAR)
2201 12 : return jtnode; /* must be a one-column composite type */
2202 :
2203 : /* Create context for applying pullup_replace_vars */
2204 330 : rvcontext.root = root;
2205 330 : rvcontext.targetlist = list_make1(makeTargetEntry((Expr *) rtf->funcexpr,
2206 : 1, /* resno */
2207 : NULL, /* resname */
2208 : false)); /* resjunk */
2209 330 : rvcontext.target_rte = rte;
2210 330 : rvcontext.result_relation = 0;
2211 :
2212 : /*
2213 : * Since this function was reduced to a Const, it doesn't contain any
2214 : * lateral references, even if it's marked as LATERAL. This means we
2215 : * don't need to fill relids or nullinfo.
2216 : */
2217 330 : rvcontext.relids = NULL;
2218 330 : rvcontext.nullinfo = NULL;
2219 :
2220 330 : rvcontext.outer_hasSubLinks = &parse->hasSubLinks;
2221 330 : rvcontext.varno = ((RangeTblRef *) jtnode)->rtindex;
2222 : /* this flag will be set below, if needed */
2223 330 : rvcontext.wrap_option = REPLACE_WRAP_NONE;
2224 : /* initialize cache array with indexes 0 .. length(tlist) */
2225 330 : rvcontext.rv_cache = palloc0((list_length(rvcontext.targetlist) + 1) *
2226 : sizeof(Node *));
2227 :
2228 : /*
2229 : * If the parent query uses grouping sets, we need a PlaceHolderVar for
2230 : * each expression of the subquery's targetlist items. (See comments in
2231 : * pull_up_simple_subquery().)
2232 : */
2233 330 : if (parse->groupingSets)
2234 0 : rvcontext.wrap_option = REPLACE_WRAP_ALL;
2235 :
2236 : /*
2237 : * Replace all of the top query's references to the RTE's output with
2238 : * copies of the funcexpr, being careful not to replace any of the
2239 : * jointree structure.
2240 : */
2241 330 : perform_pullup_replace_vars(root, &rvcontext,
2242 : containing_appendrel);
2243 :
2244 : /*
2245 : * We don't need to bother with changing PlaceHolderVars in the parent
2246 : * query. Their references to the RT index are still good for now, and
2247 : * will get removed later if we're able to drop the RTE_RESULT.
2248 : */
2249 :
2250 : /*
2251 : * Convert the RTE to be RTE_RESULT type, signifying that we don't need to
2252 : * scan it anymore, and zero out RTE_FUNCTION-specific fields. Also make
2253 : * sure the RTE is not marked LATERAL, since elsewhere we don't expect
2254 : * RTE_RESULTs to be LATERAL.
2255 : */
2256 330 : rte->rtekind = RTE_RESULT;
2257 330 : rte->functions = NIL;
2258 330 : rte->lateral = false;
2259 :
2260 : /*
2261 : * We can reuse the RangeTblRef node.
2262 : */
2263 330 : return jtnode;
2264 : }
2265 :
2266 : /*
2267 : * is_simple_union_all
2268 : * Check a subquery to see if it's a simple UNION ALL.
2269 : *
2270 : * We require all the setops to be UNION ALL (no mixing) and there can't be
2271 : * any datatype coercions involved, ie, all the leaf queries must emit the
2272 : * same datatypes.
2273 : */
2274 : static bool
2275 15920 : is_simple_union_all(Query *subquery)
2276 : {
2277 : SetOperationStmt *topop;
2278 :
2279 : /* Let's just make sure it's a valid subselect ... */
2280 15920 : if (!IsA(subquery, Query) ||
2281 15920 : subquery->commandType != CMD_SELECT)
2282 0 : elog(ERROR, "subquery is bogus");
2283 :
2284 : /* Is it a set-operation query at all? */
2285 15920 : topop = castNode(SetOperationStmt, subquery->setOperations);
2286 15920 : if (!topop)
2287 10802 : return false;
2288 :
2289 : /* Can't handle ORDER BY, LIMIT/OFFSET, locking, or WITH */
2290 5118 : if (subquery->sortClause ||
2291 5054 : subquery->limitOffset ||
2292 5054 : subquery->limitCount ||
2293 5054 : subquery->rowMarks ||
2294 5054 : subquery->cteList)
2295 232 : return false;
2296 :
2297 : /* Recursively check the tree of set operations */
2298 4886 : return is_simple_union_all_recurse((Node *) topop, subquery,
2299 : topop->colTypes);
2300 : }
2301 :
2302 : static bool
2303 23908 : is_simple_union_all_recurse(Node *setOp, Query *setOpQuery, List *colTypes)
2304 : {
2305 : /* Since this function recurses, it could be driven to stack overflow. */
2306 23908 : check_stack_depth();
2307 :
2308 23908 : if (IsA(setOp, RangeTblRef))
2309 : {
2310 11986 : RangeTblRef *rtr = (RangeTblRef *) setOp;
2311 11986 : RangeTblEntry *rte = rt_fetch(rtr->rtindex, setOpQuery->rtable);
2312 11986 : Query *subquery = rte->subquery;
2313 :
2314 : Assert(subquery != NULL);
2315 :
2316 : /* Leaf nodes are OK if they match the toplevel column types */
2317 : /* We don't have to compare typmods or collations here */
2318 11986 : return tlist_same_datatypes(subquery->targetList, colTypes, true);
2319 : }
2320 11922 : else if (IsA(setOp, SetOperationStmt))
2321 : {
2322 11922 : SetOperationStmt *op = (SetOperationStmt *) setOp;
2323 :
2324 : /* Must be UNION ALL */
2325 11922 : if (op->op != SETOP_UNION || !op->all)
2326 4826 : return false;
2327 :
2328 : /* Recurse to check inputs */
2329 13410 : return is_simple_union_all_recurse(op->larg, setOpQuery, colTypes) &&
2330 6314 : is_simple_union_all_recurse(op->rarg, setOpQuery, colTypes);
2331 : }
2332 : else
2333 : {
2334 0 : elog(ERROR, "unrecognized node type: %d",
2335 : (int) nodeTag(setOp));
2336 : return false; /* keep compiler quiet */
2337 : }
2338 : }
2339 :
2340 : /*
2341 : * is_safe_append_member
2342 : * Check a subquery that is a leaf of a UNION ALL appendrel to see if it's
2343 : * safe to pull up.
2344 : */
2345 : static bool
2346 13616 : is_safe_append_member(Query *subquery)
2347 : {
2348 : FromExpr *jtnode;
2349 :
2350 : /*
2351 : * It's only safe to pull up the child if its jointree contains exactly
2352 : * one RTE, else the AppendRelInfo data structure breaks. The one base RTE
2353 : * could be buried in several levels of FromExpr, however. Also, if the
2354 : * child's jointree is completely empty, we can pull up because
2355 : * pull_up_simple_subquery will insert a single RTE_RESULT RTE instead.
2356 : *
2357 : * Also, the child can't have any WHERE quals because there's no place to
2358 : * put them in an appendrel. (This is a bit annoying...) If we didn't
2359 : * need to check this, we'd just test whether get_relids_in_jointree()
2360 : * yields a singleton set, to be more consistent with the coding of
2361 : * fix_append_rel_relids().
2362 : */
2363 13616 : jtnode = subquery->jointree;
2364 : Assert(IsA(jtnode, FromExpr));
2365 : /* Check the completely-empty case */
2366 13616 : if (jtnode->fromlist == NIL && jtnode->quals == NULL)
2367 584 : return true;
2368 : /* Check the more general case */
2369 25066 : while (IsA(jtnode, FromExpr))
2370 : {
2371 13044 : if (jtnode->quals != NULL)
2372 1010 : return false;
2373 12034 : if (list_length(jtnode->fromlist) != 1)
2374 0 : return false;
2375 12034 : jtnode = linitial(jtnode->fromlist);
2376 : }
2377 12022 : if (!IsA(jtnode, RangeTblRef))
2378 236 : return false;
2379 :
2380 11786 : return true;
2381 : }
2382 :
2383 : /*
2384 : * jointree_contains_lateral_outer_refs
2385 : * Check for disallowed lateral references in a jointree's quals
2386 : *
2387 : * If restricted is false, all level-1 Vars are allowed (but we still must
2388 : * search the jointree, since it might contain outer joins below which there
2389 : * will be restrictions). If restricted is true, return true when any qual
2390 : * in the jointree contains level-1 Vars coming from outside the rels listed
2391 : * in safe_upper_varnos.
2392 : */
2393 : static bool
2394 5154 : jointree_contains_lateral_outer_refs(PlannerInfo *root, Node *jtnode,
2395 : bool restricted,
2396 : Relids safe_upper_varnos)
2397 : {
2398 5154 : if (jtnode == NULL)
2399 0 : return false;
2400 5154 : if (IsA(jtnode, RangeTblRef))
2401 2400 : return false;
2402 2754 : else if (IsA(jtnode, FromExpr))
2403 : {
2404 2440 : FromExpr *f = (FromExpr *) jtnode;
2405 : ListCell *l;
2406 :
2407 : /* First, recurse to check child joins */
2408 4550 : foreach(l, f->fromlist)
2409 : {
2410 2134 : if (jointree_contains_lateral_outer_refs(root,
2411 2134 : lfirst(l),
2412 : restricted,
2413 : safe_upper_varnos))
2414 24 : return true;
2415 : }
2416 :
2417 : /* Then check the top-level quals */
2418 2416 : if (restricted &&
2419 1392 : !bms_is_subset(pull_varnos_of_level(root, f->quals, 1),
2420 : safe_upper_varnos))
2421 0 : return true;
2422 : }
2423 314 : else if (IsA(jtnode, JoinExpr))
2424 : {
2425 314 : JoinExpr *j = (JoinExpr *) jtnode;
2426 :
2427 : /*
2428 : * If this is an outer join, we mustn't allow any upper lateral
2429 : * references in or below it.
2430 : */
2431 314 : if (j->jointype != JOIN_INNER)
2432 : {
2433 158 : restricted = true;
2434 158 : safe_upper_varnos = NULL;
2435 : }
2436 :
2437 : /* Check the child joins */
2438 314 : if (jointree_contains_lateral_outer_refs(root,
2439 : j->larg,
2440 : restricted,
2441 : safe_upper_varnos))
2442 0 : return true;
2443 314 : if (jointree_contains_lateral_outer_refs(root,
2444 : j->rarg,
2445 : restricted,
2446 : safe_upper_varnos))
2447 0 : return true;
2448 :
2449 : /* Check the JOIN's qual clauses */
2450 314 : if (restricted &&
2451 290 : !bms_is_subset(pull_varnos_of_level(root, j->quals, 1),
2452 : safe_upper_varnos))
2453 24 : return true;
2454 : }
2455 : else
2456 0 : elog(ERROR, "unrecognized node type: %d",
2457 : (int) nodeTag(jtnode));
2458 2706 : return false;
2459 : }
2460 :
2461 : /*
2462 : * Perform pullup_replace_vars everyplace it's needed in the query tree.
2463 : *
2464 : * Caller has already filled *rvcontext with data describing what to
2465 : * substitute for Vars referencing the target subquery. In addition
2466 : * we need the identity of the containing appendrel if any.
2467 : */
2468 : static void
2469 41486 : perform_pullup_replace_vars(PlannerInfo *root,
2470 : pullup_replace_vars_context *rvcontext,
2471 : AppendRelInfo *containing_appendrel)
2472 : {
2473 41486 : Query *parse = root->parse;
2474 : ListCell *lc;
2475 :
2476 : /*
2477 : * If we are considering an appendrel child subquery (that is, a UNION ALL
2478 : * member query that we're pulling up), then the only part of the upper
2479 : * query that could reference the child yet is the translated_vars list of
2480 : * the associated AppendRelInfo. Furthermore, we do not want to force use
2481 : * of PHVs in the AppendRelInfo --- there isn't any outer join between.
2482 : */
2483 41486 : if (containing_appendrel)
2484 : {
2485 6086 : ReplaceWrapOption save_wrap_option = rvcontext->wrap_option;
2486 :
2487 6086 : rvcontext->wrap_option = REPLACE_WRAP_NONE;
2488 6086 : containing_appendrel->translated_vars = (List *)
2489 6086 : pullup_replace_vars((Node *) containing_appendrel->translated_vars,
2490 : rvcontext);
2491 6086 : rvcontext->wrap_option = save_wrap_option;
2492 6086 : return;
2493 : }
2494 :
2495 : /*
2496 : * Replace all of the top query's references to the subquery's outputs
2497 : * with copies of the adjusted subtlist items, being careful not to
2498 : * replace any of the jointree structure. (This'd be a lot cleaner if we
2499 : * could use query_tree_mutator.) We have to use PHVs in the targetList,
2500 : * returningList, and havingQual, since those are certainly above any
2501 : * outer join. replace_vars_in_jointree tracks its location in the
2502 : * jointree and uses PHVs or not appropriately.
2503 : */
2504 35400 : parse->targetList = (List *)
2505 35400 : pullup_replace_vars((Node *) parse->targetList, rvcontext);
2506 35400 : parse->returningList = (List *)
2507 35400 : pullup_replace_vars((Node *) parse->returningList, rvcontext);
2508 :
2509 35400 : if (parse->onConflict)
2510 : {
2511 44 : parse->onConflict->onConflictSet = (List *)
2512 22 : pullup_replace_vars((Node *) parse->onConflict->onConflictSet,
2513 : rvcontext);
2514 22 : parse->onConflict->onConflictWhere =
2515 22 : pullup_replace_vars(parse->onConflict->onConflictWhere,
2516 : rvcontext);
2517 :
2518 : /*
2519 : * We assume ON CONFLICT's arbiterElems, arbiterWhere, exclRelTlist
2520 : * can't contain any references to a subquery.
2521 : */
2522 : }
2523 35400 : if (parse->mergeActionList)
2524 : {
2525 2948 : foreach(lc, parse->mergeActionList)
2526 : {
2527 1748 : MergeAction *action = lfirst(lc);
2528 :
2529 1748 : action->qual = pullup_replace_vars(action->qual, rvcontext);
2530 1748 : action->targetList = (List *)
2531 1748 : pullup_replace_vars((Node *) action->targetList, rvcontext);
2532 : }
2533 : }
2534 35400 : parse->mergeJoinCondition = pullup_replace_vars(parse->mergeJoinCondition,
2535 : rvcontext);
2536 35400 : replace_vars_in_jointree((Node *) parse->jointree, rvcontext);
2537 : Assert(parse->setOperations == NULL);
2538 35394 : parse->havingQual = pullup_replace_vars(parse->havingQual, rvcontext);
2539 :
2540 : /*
2541 : * Replace references in the translated_vars lists of appendrels.
2542 : */
2543 35430 : foreach(lc, root->append_rel_list)
2544 : {
2545 36 : AppendRelInfo *appinfo = (AppendRelInfo *) lfirst(lc);
2546 :
2547 36 : appinfo->translated_vars = (List *)
2548 36 : pullup_replace_vars((Node *) appinfo->translated_vars, rvcontext);
2549 : }
2550 :
2551 : /*
2552 : * Replace references in the joinaliasvars lists of join RTEs and the
2553 : * groupexprs list of group RTE.
2554 : */
2555 98944 : foreach(lc, parse->rtable)
2556 : {
2557 63550 : RangeTblEntry *otherrte = (RangeTblEntry *) lfirst(lc);
2558 :
2559 63550 : if (otherrte->rtekind == RTE_JOIN)
2560 6704 : otherrte->joinaliasvars = (List *)
2561 6704 : pullup_replace_vars((Node *) otherrte->joinaliasvars,
2562 : rvcontext);
2563 56846 : else if (otherrte->rtekind == RTE_GROUP)
2564 736 : otherrte->groupexprs = (List *)
2565 736 : pullup_replace_vars((Node *) otherrte->groupexprs,
2566 : rvcontext);
2567 : }
2568 : }
2569 :
2570 : /*
2571 : * Helper routine for perform_pullup_replace_vars: do pullup_replace_vars on
2572 : * every expression in the jointree, without changing the jointree structure
2573 : * itself. Ugly, but there's no other way...
2574 : */
2575 : static void
2576 92320 : replace_vars_in_jointree(Node *jtnode,
2577 : pullup_replace_vars_context *context)
2578 : {
2579 92320 : if (jtnode == NULL)
2580 0 : return;
2581 92320 : if (IsA(jtnode, RangeTblRef))
2582 : {
2583 : /*
2584 : * If the RangeTblRef refers to a LATERAL subquery (that isn't the
2585 : * same subquery we're pulling up), it might contain references to the
2586 : * target subquery, which we must replace. We drive this from the
2587 : * jointree scan, rather than a scan of the rtable, so that we can
2588 : * avoid processing no-longer-referenced RTEs.
2589 : */
2590 46390 : int varno = ((RangeTblRef *) jtnode)->rtindex;
2591 :
2592 46390 : if (varno != context->varno) /* ignore target subquery itself */
2593 : {
2594 10990 : RangeTblEntry *rte = rt_fetch(varno, context->root->parse->rtable);
2595 :
2596 : Assert(rte != context->target_rte);
2597 10990 : if (rte->lateral)
2598 : {
2599 908 : switch (rte->rtekind)
2600 : {
2601 0 : case RTE_RELATION:
2602 : /* shouldn't be marked LATERAL unless tablesample */
2603 : Assert(rte->tablesample);
2604 0 : rte->tablesample = (TableSampleClause *)
2605 0 : pullup_replace_vars((Node *) rte->tablesample,
2606 : context);
2607 0 : break;
2608 450 : case RTE_SUBQUERY:
2609 450 : rte->subquery =
2610 450 : pullup_replace_vars_subquery(rte->subquery,
2611 : context);
2612 450 : break;
2613 350 : case RTE_FUNCTION:
2614 350 : rte->functions = (List *)
2615 350 : pullup_replace_vars((Node *) rte->functions,
2616 : context);
2617 350 : break;
2618 108 : case RTE_TABLEFUNC:
2619 108 : rte->tablefunc = (TableFunc *)
2620 108 : pullup_replace_vars((Node *) rte->tablefunc,
2621 : context);
2622 108 : break;
2623 0 : case RTE_VALUES:
2624 0 : rte->values_lists = (List *)
2625 0 : pullup_replace_vars((Node *) rte->values_lists,
2626 : context);
2627 0 : break;
2628 0 : case RTE_JOIN:
2629 : case RTE_CTE:
2630 : case RTE_NAMEDTUPLESTORE:
2631 : case RTE_RESULT:
2632 : case RTE_GROUP:
2633 : /* these shouldn't be marked LATERAL */
2634 : Assert(false);
2635 0 : break;
2636 : }
2637 : }
2638 : }
2639 : }
2640 45930 : else if (IsA(jtnode, FromExpr))
2641 : {
2642 38050 : FromExpr *f = (FromExpr *) jtnode;
2643 : ListCell *l;
2644 :
2645 79210 : foreach(l, f->fromlist)
2646 41160 : replace_vars_in_jointree(lfirst(l), context);
2647 38050 : f->quals = pullup_replace_vars(f->quals, context);
2648 : }
2649 7880 : else if (IsA(jtnode, JoinExpr))
2650 : {
2651 7880 : JoinExpr *j = (JoinExpr *) jtnode;
2652 7880 : ReplaceWrapOption save_wrap_option = context->wrap_option;
2653 :
2654 7880 : replace_vars_in_jointree(j->larg, context);
2655 7880 : replace_vars_in_jointree(j->rarg, context);
2656 :
2657 : /*
2658 : * Use PHVs within the join quals of a full join for variable-free
2659 : * expressions. Otherwise, we cannot identify which side of the join
2660 : * a pulled-up variable-free expression came from, which can lead to
2661 : * failure to make a plan at all because none of the quals appear to
2662 : * be mergeable or hashable conditions.
2663 : */
2664 7880 : if (j->jointype == JOIN_FULL)
2665 622 : context->wrap_option = REPLACE_WRAP_VARFREE;
2666 :
2667 7880 : j->quals = pullup_replace_vars(j->quals, context);
2668 :
2669 7880 : context->wrap_option = save_wrap_option;
2670 : }
2671 : else
2672 0 : elog(ERROR, "unrecognized node type: %d",
2673 : (int) nodeTag(jtnode));
2674 : }
2675 :
2676 : /*
2677 : * Apply pullup variable replacement throughout an expression tree
2678 : *
2679 : * Returns a modified copy of the tree, so this can't be used where we
2680 : * need to do in-place replacement.
2681 : */
2682 : static Node *
2683 206136 : pullup_replace_vars(Node *expr, pullup_replace_vars_context *context)
2684 : {
2685 206136 : return replace_rte_variables(expr,
2686 : context->varno, 0,
2687 : pullup_replace_vars_callback,
2688 : context,
2689 : context->outer_hasSubLinks);
2690 : }
2691 :
2692 : static Node *
2693 114408 : pullup_replace_vars_callback(Var *var,
2694 : replace_rte_variables_context *context)
2695 : {
2696 114408 : pullup_replace_vars_context *rcon = (pullup_replace_vars_context *) context->callback_arg;
2697 114408 : int varattno = var->varattno;
2698 : bool need_phv;
2699 : Node *newnode;
2700 :
2701 : /* System columns are not replaced. */
2702 114408 : if (varattno < InvalidAttrNumber)
2703 42 : return (Node *) copyObject(var);
2704 :
2705 : /*
2706 : * We need a PlaceHolderVar if the Var-to-be-replaced has nonempty
2707 : * varnullingrels (unless we find below that the replacement expression is
2708 : * a Var or PlaceHolderVar that we can just add the nullingrels to). We
2709 : * also need one if the caller has instructed us that certain expression
2710 : * replacements need to be wrapped for identification purposes.
2711 : */
2712 216994 : need_phv = (var->varnullingrels != NULL) ||
2713 102628 : (rcon->wrap_option != REPLACE_WRAP_NONE);
2714 :
2715 : /*
2716 : * If PlaceHolderVars are needed, we cache the modified expressions in
2717 : * rcon->rv_cache[]. This is not in hopes of any material speed gain
2718 : * within this function, but to avoid generating identical PHVs with
2719 : * different IDs. That would result in duplicate evaluations at runtime,
2720 : * and possibly prevent optimizations that rely on recognizing different
2721 : * references to the same subquery output as being equal(). So it's worth
2722 : * a bit of extra effort to avoid it.
2723 : *
2724 : * The cached items have phlevelsup = 0 and phnullingrels = NULL; we'll
2725 : * copy them and adjust those values for this reference site below.
2726 : */
2727 114366 : if (need_phv &&
2728 13698 : varattno >= InvalidAttrNumber &&
2729 13698 : varattno <= list_length(rcon->targetlist) &&
2730 13698 : rcon->rv_cache[varattno] != NULL)
2731 : {
2732 : /* Just copy the entry and fall through to adjust phlevelsup etc */
2733 2794 : newnode = copyObject(rcon->rv_cache[varattno]);
2734 : }
2735 : else
2736 : {
2737 : /*
2738 : * Generate the replacement expression. This takes care of expanding
2739 : * wholerow references and dealing with non-default varreturningtype.
2740 : */
2741 111572 : newnode = ReplaceVarFromTargetList(var,
2742 : rcon->target_rte,
2743 : rcon->targetlist,
2744 : rcon->result_relation,
2745 : REPLACEVARS_REPORT_ERROR,
2746 : 0);
2747 :
2748 : /* Insert PlaceHolderVar if needed */
2749 111572 : if (need_phv)
2750 : {
2751 : bool wrap;
2752 :
2753 10904 : if (rcon->wrap_option == REPLACE_WRAP_ALL)
2754 : {
2755 : /* Caller told us to wrap all expressions in a PlaceHolderVar */
2756 800 : wrap = true;
2757 : }
2758 10104 : else if (varattno == InvalidAttrNumber)
2759 : {
2760 : /*
2761 : * Insert PlaceHolderVar for whole-tuple reference. Notice
2762 : * that we are wrapping one PlaceHolderVar around the whole
2763 : * RowExpr, rather than putting one around each element of the
2764 : * row. This is because we need the expression to yield NULL,
2765 : * not ROW(NULL,NULL,...) when it is forced to null by an
2766 : * outer join.
2767 : */
2768 66 : wrap = true;
2769 : }
2770 10038 : else if (newnode && IsA(newnode, Var) &&
2771 8040 : ((Var *) newnode)->varlevelsup == 0)
2772 : {
2773 : /*
2774 : * Simple Vars always escape being wrapped, unless they are
2775 : * lateral references to something outside the subquery being
2776 : * pulled up and the referenced rel is not under the same
2777 : * lowest nulling outer join.
2778 : */
2779 8024 : wrap = false;
2780 8024 : if (rcon->target_rte->lateral &&
2781 1410 : !bms_is_member(((Var *) newnode)->varno, rcon->relids))
2782 : {
2783 132 : nullingrel_info *nullinfo = rcon->nullinfo;
2784 132 : int lvarno = ((Var *) newnode)->varno;
2785 :
2786 : Assert(lvarno > 0 && lvarno <= nullinfo->rtlength);
2787 132 : if (!bms_is_subset(nullinfo->nullingrels[rcon->varno],
2788 132 : nullinfo->nullingrels[lvarno]))
2789 108 : wrap = true;
2790 : }
2791 : }
2792 2014 : else if (newnode && IsA(newnode, PlaceHolderVar) &&
2793 180 : ((PlaceHolderVar *) newnode)->phlevelsup == 0)
2794 : {
2795 : /* The same rules apply for a PlaceHolderVar */
2796 180 : wrap = false;
2797 180 : if (rcon->target_rte->lateral &&
2798 48 : !bms_is_subset(((PlaceHolderVar *) newnode)->phrels,
2799 48 : rcon->relids))
2800 : {
2801 48 : nullingrel_info *nullinfo = rcon->nullinfo;
2802 48 : Relids lvarnos = ((PlaceHolderVar *) newnode)->phrels;
2803 : int lvarno;
2804 :
2805 48 : lvarno = -1;
2806 72 : while ((lvarno = bms_next_member(lvarnos, lvarno)) >= 0)
2807 : {
2808 : Assert(lvarno > 0 && lvarno <= nullinfo->rtlength);
2809 48 : if (!bms_is_subset(nullinfo->nullingrels[rcon->varno],
2810 48 : nullinfo->nullingrels[lvarno]))
2811 : {
2812 24 : wrap = true;
2813 24 : break;
2814 : }
2815 : }
2816 : }
2817 : }
2818 : else
2819 : {
2820 : /*
2821 : * If the node contains Var(s) or PlaceHolderVar(s) of the
2822 : * subquery being pulled up, or of rels that are under the
2823 : * same lowest nulling outer join as the subquery, and does
2824 : * not contain any non-strict constructs, then instead of
2825 : * adding a PHV on top we can add the required nullingrels to
2826 : * those Vars/PHVs. (This is fundamentally a generalization
2827 : * of the above cases for bare Vars and PHVs.)
2828 : *
2829 : * This test is somewhat expensive, but it avoids pessimizing
2830 : * the plan in cases where the nullingrels get removed again
2831 : * later by outer join reduction.
2832 : *
2833 : * Note that we don't force wrapping of expressions containing
2834 : * lateral references, so long as they also contain Vars/PHVs
2835 : * of the subquery, or of rels that are under the same lowest
2836 : * nulling outer join as the subquery. This is okay because
2837 : * of the restriction to strict constructs: if those Vars/PHVs
2838 : * have been forced to NULL by an outer join then the end
2839 : * result of the expression will be NULL too, regardless of
2840 : * the lateral references. So it's not necessary to force the
2841 : * expression to be evaluated below the outer join. This can
2842 : * be a very valuable optimization, because it may allow us to
2843 : * avoid using a nested loop to pass the lateral reference
2844 : * down.
2845 : *
2846 : * This analysis could be tighter: in particular, a non-strict
2847 : * construct hidden within a lower-level PlaceHolderVar is not
2848 : * reason to add another PHV. But for now it doesn't seem
2849 : * worth the code to be more exact. This is also why it's
2850 : * preferable to handle bare PHVs in the above branch, rather
2851 : * than this branch. We also prefer to handle bare Vars in a
2852 : * separate branch, as it's cheaper this way and parallels the
2853 : * handling of PHVs.
2854 : *
2855 : * For a LATERAL subquery, we have to check the actual var
2856 : * membership of the node, but if it's non-lateral then any
2857 : * level-zero var must belong to the subquery.
2858 : */
2859 1834 : bool contain_nullable_vars = false;
2860 :
2861 1834 : if (!rcon->target_rte->lateral)
2862 : {
2863 1606 : if (contain_vars_of_level(newnode, 0))
2864 522 : contain_nullable_vars = true;
2865 : }
2866 : else
2867 : {
2868 : Relids all_varnos;
2869 :
2870 228 : all_varnos = pull_varnos(rcon->root, newnode);
2871 228 : if (bms_overlap(all_varnos, rcon->relids))
2872 132 : contain_nullable_vars = true;
2873 : else
2874 : {
2875 96 : nullingrel_info *nullinfo = rcon->nullinfo;
2876 : int varno;
2877 :
2878 96 : varno = -1;
2879 180 : while ((varno = bms_next_member(all_varnos, varno)) >= 0)
2880 : {
2881 : Assert(varno > 0 && varno <= nullinfo->rtlength);
2882 108 : if (bms_is_subset(nullinfo->nullingrels[rcon->varno],
2883 108 : nullinfo->nullingrels[varno]))
2884 : {
2885 24 : contain_nullable_vars = true;
2886 24 : break;
2887 : }
2888 : }
2889 : }
2890 : }
2891 :
2892 1834 : if (contain_nullable_vars &&
2893 678 : !contain_nonstrict_functions(newnode))
2894 : {
2895 : /* No wrap needed */
2896 288 : wrap = false;
2897 : }
2898 : else
2899 : {
2900 : /* Else wrap it in a PlaceHolderVar */
2901 1546 : wrap = true;
2902 : }
2903 : }
2904 :
2905 10904 : if (wrap)
2906 : {
2907 : newnode = (Node *)
2908 2544 : make_placeholder_expr(rcon->root,
2909 : (Expr *) newnode,
2910 : bms_make_singleton(rcon->varno));
2911 :
2912 : /*
2913 : * Cache it if possible (ie, if the attno is in range, which
2914 : * it probably always should be).
2915 : */
2916 5088 : if (varattno >= InvalidAttrNumber &&
2917 2544 : varattno <= list_length(rcon->targetlist))
2918 2544 : rcon->rv_cache[varattno] = copyObject(newnode);
2919 : }
2920 : }
2921 : }
2922 :
2923 : /* Propagate any varnullingrels into the replacement expression */
2924 114366 : if (var->varnullingrels != NULL)
2925 : {
2926 11738 : if (IsA(newnode, Var))
2927 : {
2928 7426 : Var *newvar = (Var *) newnode;
2929 :
2930 : Assert(newvar->varlevelsup == 0);
2931 7426 : newvar->varnullingrels = bms_add_members(newvar->varnullingrels,
2932 7426 : var->varnullingrels);
2933 : }
2934 4312 : else if (IsA(newnode, PlaceHolderVar))
2935 : {
2936 4024 : PlaceHolderVar *newphv = (PlaceHolderVar *) newnode;
2937 :
2938 : Assert(newphv->phlevelsup == 0);
2939 4024 : newphv->phnullingrels = bms_add_members(newphv->phnullingrels,
2940 4024 : var->varnullingrels);
2941 : }
2942 : else
2943 : {
2944 : /*
2945 : * There should be Vars/PHVs within the expression that we can
2946 : * modify. Vars/PHVs of the subquery should have the full
2947 : * var->varnullingrels added to them, but if there are lateral
2948 : * references within the expression, those must be marked with
2949 : * only the nullingrels that potentially apply to them. (This
2950 : * corresponds to the fact that the expression will now be
2951 : * evaluated at the join level of the Var that we are replacing:
2952 : * the lateral references may have bubbled up through fewer outer
2953 : * joins than the subquery's Vars have. Per the discussion above,
2954 : * we'll still get the right answers.) That relid set could be
2955 : * different for different lateral relations, so we have to do
2956 : * this work for each one.
2957 : *
2958 : * (Currently, the restrictions in is_simple_subquery() mean that
2959 : * at most we have to remove the lowest outer join's relid from
2960 : * the nullingrels of a lateral reference. However, we might
2961 : * relax those restrictions someday, so let's do this right.)
2962 : */
2963 288 : if (rcon->target_rte->lateral)
2964 : {
2965 84 : nullingrel_info *nullinfo = rcon->nullinfo;
2966 : Relids lvarnos;
2967 : int lvarno;
2968 :
2969 : /*
2970 : * Identify lateral varnos used within newnode. We must do
2971 : * this before injecting var->varnullingrels into the tree.
2972 : */
2973 84 : lvarnos = pull_varnos(rcon->root, newnode);
2974 84 : lvarnos = bms_del_members(lvarnos, rcon->relids);
2975 : /* For each one, add relevant nullingrels if any */
2976 84 : lvarno = -1;
2977 168 : while ((lvarno = bms_next_member(lvarnos, lvarno)) >= 0)
2978 : {
2979 : Relids lnullingrels;
2980 :
2981 : Assert(lvarno > 0 && lvarno <= nullinfo->rtlength);
2982 84 : lnullingrels = bms_intersect(var->varnullingrels,
2983 84 : nullinfo->nullingrels[lvarno]);
2984 84 : if (!bms_is_empty(lnullingrels))
2985 48 : newnode = add_nulling_relids(newnode,
2986 48 : bms_make_singleton(lvarno),
2987 : lnullingrels);
2988 : }
2989 : }
2990 :
2991 : /* Finally, deal with Vars/PHVs of the subquery itself */
2992 288 : newnode = add_nulling_relids(newnode,
2993 288 : rcon->relids,
2994 288 : var->varnullingrels);
2995 : /* Assert we did put the varnullingrels into the expression */
2996 : Assert(bms_is_subset(var->varnullingrels,
2997 : pull_varnos(rcon->root, newnode)));
2998 : }
2999 : }
3000 :
3001 : /* Must adjust varlevelsup if replaced Var is within a subquery */
3002 114366 : if (var->varlevelsup > 0)
3003 1206 : IncrementVarSublevelsUp(newnode, var->varlevelsup, 0);
3004 :
3005 114366 : return newnode;
3006 : }
3007 :
3008 : /*
3009 : * Apply pullup variable replacement to a subquery
3010 : *
3011 : * This needs to be different from pullup_replace_vars() because
3012 : * replace_rte_variables will think that it shouldn't increment sublevels_up
3013 : * before entering the Query; so we need to call it with sublevels_up == 1.
3014 : */
3015 : static Query *
3016 450 : pullup_replace_vars_subquery(Query *query,
3017 : pullup_replace_vars_context *context)
3018 : {
3019 : Assert(IsA(query, Query));
3020 450 : return (Query *) replace_rte_variables((Node *) query,
3021 : context->varno, 1,
3022 : pullup_replace_vars_callback,
3023 : context,
3024 : NULL);
3025 : }
3026 :
3027 :
3028 : /*
3029 : * flatten_simple_union_all
3030 : * Try to optimize top-level UNION ALL structure into an appendrel
3031 : *
3032 : * If a query's setOperations tree consists entirely of simple UNION ALL
3033 : * operations, flatten it into an append relation, which we can process more
3034 : * intelligently than the general setops case. Otherwise, do nothing.
3035 : *
3036 : * In most cases, this can succeed only for a top-level query, because for a
3037 : * subquery in FROM, the parent query's invocation of pull_up_subqueries would
3038 : * already have flattened the UNION via pull_up_simple_union_all. But there
3039 : * are a few cases we can support here but not in that code path, for example
3040 : * when the subquery also contains ORDER BY.
3041 : */
3042 : void
3043 6630 : flatten_simple_union_all(PlannerInfo *root)
3044 : {
3045 6630 : Query *parse = root->parse;
3046 : SetOperationStmt *topop;
3047 : Node *leftmostjtnode;
3048 : int leftmostRTI;
3049 : RangeTblEntry *leftmostRTE;
3050 : int childRTI;
3051 : RangeTblEntry *childRTE;
3052 : RangeTblRef *rtr;
3053 :
3054 : /* Shouldn't be called unless query has setops */
3055 6630 : topop = castNode(SetOperationStmt, parse->setOperations);
3056 : Assert(topop);
3057 :
3058 : /* Can't optimize away a recursive UNION */
3059 6630 : if (root->hasRecursion)
3060 6180 : return;
3061 :
3062 : /*
3063 : * Recursively check the tree of set operations. If not all UNION ALL
3064 : * with identical column types, punt.
3065 : */
3066 5612 : if (!is_simple_union_all_recurse((Node *) topop, parse, topop->colTypes))
3067 5162 : return;
3068 :
3069 : /*
3070 : * Locate the leftmost leaf query in the setops tree. The upper query's
3071 : * Vars all refer to this RTE (see transformSetOperationStmt).
3072 : */
3073 450 : leftmostjtnode = topop->larg;
3074 810 : while (leftmostjtnode && IsA(leftmostjtnode, SetOperationStmt))
3075 360 : leftmostjtnode = ((SetOperationStmt *) leftmostjtnode)->larg;
3076 : Assert(leftmostjtnode && IsA(leftmostjtnode, RangeTblRef));
3077 450 : leftmostRTI = ((RangeTblRef *) leftmostjtnode)->rtindex;
3078 450 : leftmostRTE = rt_fetch(leftmostRTI, parse->rtable);
3079 : Assert(leftmostRTE->rtekind == RTE_SUBQUERY);
3080 :
3081 : /*
3082 : * Make a copy of the leftmost RTE and add it to the rtable. This copy
3083 : * will represent the leftmost leaf query in its capacity as a member of
3084 : * the appendrel. The original will represent the appendrel as a whole.
3085 : * (We must do things this way because the upper query's Vars have to be
3086 : * seen as referring to the whole appendrel.)
3087 : */
3088 450 : childRTE = copyObject(leftmostRTE);
3089 450 : parse->rtable = lappend(parse->rtable, childRTE);
3090 450 : childRTI = list_length(parse->rtable);
3091 :
3092 : /* Modify the setops tree to reference the child copy */
3093 450 : ((RangeTblRef *) leftmostjtnode)->rtindex = childRTI;
3094 :
3095 : /* Modify the formerly-leftmost RTE to mark it as an appendrel parent */
3096 450 : leftmostRTE->inh = true;
3097 :
3098 : /*
3099 : * Form a RangeTblRef for the appendrel, and insert it into FROM. The top
3100 : * Query of a setops tree should have had an empty FromClause initially.
3101 : */
3102 450 : rtr = makeNode(RangeTblRef);
3103 450 : rtr->rtindex = leftmostRTI;
3104 : Assert(parse->jointree->fromlist == NIL);
3105 450 : parse->jointree->fromlist = list_make1(rtr);
3106 :
3107 : /*
3108 : * Now pretend the query has no setops. We must do this before trying to
3109 : * do subquery pullup, because of Assert in pull_up_simple_subquery.
3110 : */
3111 450 : parse->setOperations = NULL;
3112 :
3113 : /*
3114 : * Build AppendRelInfo information, and apply pull_up_subqueries to the
3115 : * leaf queries of the UNION ALL. (We must do that now because they
3116 : * weren't previously referenced by the jointree, and so were missed by
3117 : * the main invocation of pull_up_subqueries.)
3118 : */
3119 450 : pull_up_union_leaf_queries((Node *) topop, root, leftmostRTI, parse, 0);
3120 : }
3121 :
3122 :
3123 : /*
3124 : * reduce_outer_joins
3125 : * Attempt to reduce outer joins to plain inner joins.
3126 : *
3127 : * The idea here is that given a query like
3128 : * SELECT ... FROM a LEFT JOIN b ON (...) WHERE b.y = 42;
3129 : * we can reduce the LEFT JOIN to a plain JOIN if the "=" operator in WHERE
3130 : * is strict. The strict operator will always return NULL, causing the outer
3131 : * WHERE to fail, on any row where the LEFT JOIN filled in NULLs for b's
3132 : * columns. Therefore, there's no need for the join to produce null-extended
3133 : * rows in the first place --- which makes it a plain join not an outer join.
3134 : * (This scenario may not be very likely in a query written out by hand, but
3135 : * it's reasonably likely when pushing quals down into complex views.)
3136 : *
3137 : * More generally, an outer join can be reduced in strength if there is a
3138 : * strict qual above it in the qual tree that constrains a Var from the
3139 : * nullable side of the join to be non-null. (For FULL joins this applies
3140 : * to each side separately.)
3141 : *
3142 : * Another transformation we apply here is to recognize cases like
3143 : * SELECT ... FROM a LEFT JOIN b ON (a.x = b.y) WHERE b.y IS NULL;
3144 : * If the join clause is strict for b.y, then only null-extended rows could
3145 : * pass the upper WHERE, and we can conclude that what the query is really
3146 : * specifying is an anti-semijoin. We change the join type from JOIN_LEFT
3147 : * to JOIN_ANTI. The IS NULL clause then becomes redundant, and must be
3148 : * removed to prevent bogus selectivity calculations, but we leave it to
3149 : * distribute_qual_to_rels to get rid of such clauses.
3150 : *
3151 : * Also, we get rid of JOIN_RIGHT cases by flipping them around to become
3152 : * JOIN_LEFT. This saves some code here and in some later planner routines;
3153 : * the main benefit is to reduce the number of jointypes that can appear in
3154 : * SpecialJoinInfo nodes. Note that we can still generate Paths and Plans
3155 : * that use JOIN_RIGHT (or JOIN_RIGHT_ANTI) by switching the inputs again.
3156 : *
3157 : * To ease recognition of strict qual clauses, we require this routine to be
3158 : * run after expression preprocessing (i.e., qual canonicalization and JOIN
3159 : * alias-var expansion).
3160 : */
3161 : void
3162 34598 : reduce_outer_joins(PlannerInfo *root)
3163 : {
3164 : reduce_outer_joins_pass1_state *state1;
3165 : reduce_outer_joins_pass2_state state2;
3166 : ListCell *lc;
3167 :
3168 : /*
3169 : * To avoid doing strictness checks on more quals than necessary, we want
3170 : * to stop descending the jointree as soon as there are no outer joins
3171 : * below our current point. This consideration forces a two-pass process.
3172 : * The first pass gathers information about which base rels appear below
3173 : * each side of each join clause, and about whether there are outer
3174 : * join(s) below each side of each join clause. The second pass examines
3175 : * qual clauses and changes join types as it descends the tree.
3176 : */
3177 34598 : state1 = reduce_outer_joins_pass1((Node *) root->parse->jointree);
3178 :
3179 : /* planner.c shouldn't have called me if no outer joins */
3180 34598 : if (state1 == NULL || !state1->contains_outer)
3181 0 : elog(ERROR, "so where are the outer joins?");
3182 :
3183 34598 : state2.inner_reduced = NULL;
3184 34598 : state2.partial_reduced = NIL;
3185 :
3186 34598 : reduce_outer_joins_pass2((Node *) root->parse->jointree,
3187 : state1, &state2,
3188 : root, NULL, NIL);
3189 :
3190 : /*
3191 : * If we successfully reduced the strength of any outer joins, we must
3192 : * remove references to those joins as nulling rels. This is handled as
3193 : * an additional pass, for simplicity and because we can handle all
3194 : * fully-reduced joins in a single pass over the parse tree.
3195 : */
3196 34598 : if (!bms_is_empty(state2.inner_reduced))
3197 : {
3198 1854 : root->parse = (Query *)
3199 1854 : remove_nulling_relids((Node *) root->parse,
3200 1854 : state2.inner_reduced,
3201 : NULL);
3202 : /* There could be references in the append_rel_list, too */
3203 1854 : root->append_rel_list = (List *)
3204 1854 : remove_nulling_relids((Node *) root->append_rel_list,
3205 1854 : state2.inner_reduced,
3206 : NULL);
3207 : }
3208 :
3209 : /*
3210 : * Partially-reduced full joins have to be done one at a time, since
3211 : * they'll each need a different setting of except_relids.
3212 : */
3213 34648 : foreach(lc, state2.partial_reduced)
3214 : {
3215 50 : reduce_outer_joins_partial_state *statep = lfirst(lc);
3216 50 : Relids full_join_relids = bms_make_singleton(statep->full_join_rti);
3217 :
3218 50 : root->parse = (Query *)
3219 50 : remove_nulling_relids((Node *) root->parse,
3220 : full_join_relids,
3221 50 : statep->unreduced_side);
3222 50 : root->append_rel_list = (List *)
3223 50 : remove_nulling_relids((Node *) root->append_rel_list,
3224 : full_join_relids,
3225 50 : statep->unreduced_side);
3226 : }
3227 34598 : }
3228 :
3229 : /*
3230 : * reduce_outer_joins_pass1 - phase 1 data collection
3231 : *
3232 : * Returns a state node describing the given jointree node.
3233 : */
3234 : static reduce_outer_joins_pass1_state *
3235 197294 : reduce_outer_joins_pass1(Node *jtnode)
3236 : {
3237 : reduce_outer_joins_pass1_state *result;
3238 :
3239 : result = (reduce_outer_joins_pass1_state *)
3240 197294 : palloc(sizeof(reduce_outer_joins_pass1_state));
3241 197294 : result->relids = NULL;
3242 197294 : result->contains_outer = false;
3243 197294 : result->sub_states = NIL;
3244 :
3245 197294 : if (jtnode == NULL)
3246 0 : return result;
3247 197294 : if (IsA(jtnode, RangeTblRef))
3248 : {
3249 98458 : int varno = ((RangeTblRef *) jtnode)->rtindex;
3250 :
3251 98458 : result->relids = bms_make_singleton(varno);
3252 : }
3253 98836 : else if (IsA(jtnode, FromExpr))
3254 : {
3255 37860 : FromExpr *f = (FromExpr *) jtnode;
3256 : ListCell *l;
3257 :
3258 78604 : foreach(l, f->fromlist)
3259 : {
3260 : reduce_outer_joins_pass1_state *sub_state;
3261 :
3262 40744 : sub_state = reduce_outer_joins_pass1(lfirst(l));
3263 81488 : result->relids = bms_add_members(result->relids,
3264 40744 : sub_state->relids);
3265 40744 : result->contains_outer |= sub_state->contains_outer;
3266 40744 : result->sub_states = lappend(result->sub_states, sub_state);
3267 : }
3268 : }
3269 60976 : else if (IsA(jtnode, JoinExpr))
3270 : {
3271 60976 : JoinExpr *j = (JoinExpr *) jtnode;
3272 : reduce_outer_joins_pass1_state *sub_state;
3273 :
3274 : /* join's own RT index is not wanted in result->relids */
3275 60976 : if (IS_OUTER_JOIN(j->jointype))
3276 49936 : result->contains_outer = true;
3277 :
3278 60976 : sub_state = reduce_outer_joins_pass1(j->larg);
3279 121952 : result->relids = bms_add_members(result->relids,
3280 60976 : sub_state->relids);
3281 60976 : result->contains_outer |= sub_state->contains_outer;
3282 60976 : result->sub_states = lappend(result->sub_states, sub_state);
3283 :
3284 60976 : sub_state = reduce_outer_joins_pass1(j->rarg);
3285 121952 : result->relids = bms_add_members(result->relids,
3286 60976 : sub_state->relids);
3287 60976 : result->contains_outer |= sub_state->contains_outer;
3288 60976 : result->sub_states = lappend(result->sub_states, sub_state);
3289 : }
3290 : else
3291 0 : elog(ERROR, "unrecognized node type: %d",
3292 : (int) nodeTag(jtnode));
3293 197294 : return result;
3294 : }
3295 :
3296 : /*
3297 : * reduce_outer_joins_pass2 - phase 2 processing
3298 : *
3299 : * jtnode: current jointree node
3300 : * state1: state data collected by phase 1 for this node
3301 : * state2: where to accumulate info about successfully-reduced joins
3302 : * root: toplevel planner state
3303 : * nonnullable_rels: set of base relids forced non-null by upper quals
3304 : * forced_null_vars: multibitmapset of Vars forced null by upper quals
3305 : *
3306 : * Returns info in state2 about outer joins that were successfully simplified.
3307 : * Joins that were fully reduced to inner joins are all added to
3308 : * state2->inner_reduced. If a full join is reduced to a left join,
3309 : * it needs its own entry in state2->partial_reduced, since that will
3310 : * require custom processing to remove only the correct nullingrel markers.
3311 : */
3312 : static void
3313 86554 : reduce_outer_joins_pass2(Node *jtnode,
3314 : reduce_outer_joins_pass1_state *state1,
3315 : reduce_outer_joins_pass2_state *state2,
3316 : PlannerInfo *root,
3317 : Relids nonnullable_rels,
3318 : List *forced_null_vars)
3319 : {
3320 : /*
3321 : * pass 2 should never descend as far as an empty subnode or base rel,
3322 : * because it's only called on subtrees marked as contains_outer.
3323 : */
3324 86554 : if (jtnode == NULL)
3325 0 : elog(ERROR, "reached empty jointree");
3326 86554 : if (IsA(jtnode, RangeTblRef))
3327 0 : elog(ERROR, "reached base rel");
3328 86554 : else if (IsA(jtnode, FromExpr))
3329 : {
3330 36024 : FromExpr *f = (FromExpr *) jtnode;
3331 : ListCell *l;
3332 : ListCell *s;
3333 : Relids pass_nonnullable_rels;
3334 : List *pass_forced_null_vars;
3335 :
3336 : /* Scan quals to see if we can add any constraints */
3337 36024 : pass_nonnullable_rels = find_nonnullable_rels(f->quals);
3338 36024 : pass_nonnullable_rels = bms_add_members(pass_nonnullable_rels,
3339 : nonnullable_rels);
3340 36024 : pass_forced_null_vars = find_forced_null_vars(f->quals);
3341 36024 : pass_forced_null_vars = mbms_add_members(pass_forced_null_vars,
3342 : forced_null_vars);
3343 : /* And recurse --- but only into interesting subtrees */
3344 : Assert(list_length(f->fromlist) == list_length(state1->sub_states));
3345 74770 : forboth(l, f->fromlist, s, state1->sub_states)
3346 : {
3347 38746 : reduce_outer_joins_pass1_state *sub_state = lfirst(s);
3348 :
3349 38746 : if (sub_state->contains_outer)
3350 36054 : reduce_outer_joins_pass2(lfirst(l), sub_state,
3351 : state2, root,
3352 : pass_nonnullable_rels,
3353 : pass_forced_null_vars);
3354 : }
3355 36024 : bms_free(pass_nonnullable_rels);
3356 : /* can't so easily clean up var lists, unfortunately */
3357 : }
3358 50530 : else if (IsA(jtnode, JoinExpr))
3359 : {
3360 50530 : JoinExpr *j = (JoinExpr *) jtnode;
3361 50530 : int rtindex = j->rtindex;
3362 50530 : JoinType jointype = j->jointype;
3363 50530 : reduce_outer_joins_pass1_state *left_state = linitial(state1->sub_states);
3364 50530 : reduce_outer_joins_pass1_state *right_state = lsecond(state1->sub_states);
3365 :
3366 : /* Can we simplify this join? */
3367 50530 : switch (jointype)
3368 : {
3369 544 : case JOIN_INNER:
3370 544 : break;
3371 47140 : case JOIN_LEFT:
3372 47140 : if (bms_overlap(nonnullable_rels, right_state->relids))
3373 1912 : jointype = JOIN_INNER;
3374 47140 : break;
3375 1184 : case JOIN_RIGHT:
3376 1184 : if (bms_overlap(nonnullable_rels, left_state->relids))
3377 80 : jointype = JOIN_INNER;
3378 1184 : break;
3379 1090 : case JOIN_FULL:
3380 1090 : if (bms_overlap(nonnullable_rels, left_state->relids))
3381 : {
3382 24 : if (bms_overlap(nonnullable_rels, right_state->relids))
3383 12 : jointype = JOIN_INNER;
3384 : else
3385 : {
3386 12 : jointype = JOIN_LEFT;
3387 : /* Also report partial reduction in state2 */
3388 12 : report_reduced_full_join(state2, rtindex,
3389 : right_state->relids);
3390 : }
3391 : }
3392 : else
3393 : {
3394 1066 : if (bms_overlap(nonnullable_rels, right_state->relids))
3395 : {
3396 38 : jointype = JOIN_RIGHT;
3397 : /* Also report partial reduction in state2 */
3398 38 : report_reduced_full_join(state2, rtindex,
3399 : left_state->relids);
3400 : }
3401 : }
3402 1090 : break;
3403 572 : case JOIN_SEMI:
3404 : case JOIN_ANTI:
3405 :
3406 : /*
3407 : * These could only have been introduced by pull_up_sublinks,
3408 : * so there's no way that upper quals could refer to their
3409 : * righthand sides, and no point in checking. We don't expect
3410 : * to see JOIN_RIGHT_SEMI or JOIN_RIGHT_ANTI yet.
3411 : */
3412 572 : break;
3413 0 : default:
3414 0 : elog(ERROR, "unrecognized join type: %d",
3415 : (int) jointype);
3416 : break;
3417 : }
3418 :
3419 : /*
3420 : * Convert JOIN_RIGHT to JOIN_LEFT. Note that in the case where we
3421 : * reduced JOIN_FULL to JOIN_RIGHT, this will mean the JoinExpr no
3422 : * longer matches the internal ordering of any CoalesceExpr's built to
3423 : * represent merged join variables. We don't care about that at
3424 : * present, but be wary of it ...
3425 : */
3426 50530 : if (jointype == JOIN_RIGHT)
3427 : {
3428 : Node *tmparg;
3429 :
3430 1142 : tmparg = j->larg;
3431 1142 : j->larg = j->rarg;
3432 1142 : j->rarg = tmparg;
3433 1142 : jointype = JOIN_LEFT;
3434 1142 : right_state = linitial(state1->sub_states);
3435 1142 : left_state = lsecond(state1->sub_states);
3436 : }
3437 :
3438 : /*
3439 : * See if we can reduce JOIN_LEFT to JOIN_ANTI. This is the case if
3440 : * the join's own quals are strict for any var that was forced null by
3441 : * higher qual levels. NOTE: there are other ways that we could
3442 : * detect an anti-join, in particular if we were to check whether Vars
3443 : * coming from the RHS must be non-null because of table constraints.
3444 : * That seems complicated and expensive though (in particular, one
3445 : * would have to be wary of lower outer joins). For the moment this
3446 : * seems sufficient.
3447 : */
3448 50530 : if (jointype == JOIN_LEFT)
3449 : {
3450 : List *nonnullable_vars;
3451 : Bitmapset *overlap;
3452 :
3453 : /* Find Vars in j->quals that must be non-null in joined rows */
3454 46382 : nonnullable_vars = find_nonnullable_vars(j->quals);
3455 :
3456 : /*
3457 : * It's not sufficient to check whether nonnullable_vars and
3458 : * forced_null_vars overlap: we need to know if the overlap
3459 : * includes any RHS variables.
3460 : */
3461 46382 : overlap = mbms_overlap_sets(nonnullable_vars, forced_null_vars);
3462 46382 : if (bms_overlap(overlap, right_state->relids))
3463 1212 : jointype = JOIN_ANTI;
3464 : }
3465 :
3466 : /*
3467 : * Apply the jointype change, if any, to both jointree node and RTE.
3468 : * Also, if we changed an RTE to INNER, add its RTI to inner_reduced.
3469 : */
3470 50530 : if (rtindex && jointype != j->jointype)
3471 : {
3472 4370 : RangeTblEntry *rte = rt_fetch(rtindex, root->parse->rtable);
3473 :
3474 : Assert(rte->rtekind == RTE_JOIN);
3475 : Assert(rte->jointype == j->jointype);
3476 4370 : rte->jointype = jointype;
3477 4370 : if (jointype == JOIN_INNER)
3478 2004 : state2->inner_reduced = bms_add_member(state2->inner_reduced,
3479 : rtindex);
3480 : }
3481 50530 : j->jointype = jointype;
3482 :
3483 : /* Only recurse if there's more to do below here */
3484 50530 : if (left_state->contains_outer || right_state->contains_outer)
3485 : {
3486 : Relids local_nonnullable_rels;
3487 : List *local_forced_null_vars;
3488 : Relids pass_nonnullable_rels;
3489 : List *pass_forced_null_vars;
3490 :
3491 : /*
3492 : * If this join is (now) inner, we can add any constraints its
3493 : * quals provide to those we got from above. But if it is outer,
3494 : * we can pass down the local constraints only into the nullable
3495 : * side, because an outer join never eliminates any rows from its
3496 : * non-nullable side. Also, there is no point in passing upper
3497 : * constraints into the nullable side, since if there were any
3498 : * we'd have been able to reduce the join. (In the case of upper
3499 : * forced-null constraints, we *must not* pass them into the
3500 : * nullable side --- they either applied here, or not.) The upshot
3501 : * is that we pass either the local or the upper constraints,
3502 : * never both, to the children of an outer join.
3503 : *
3504 : * Note that a SEMI join works like an inner join here: it's okay
3505 : * to pass down both local and upper constraints. (There can't be
3506 : * any upper constraints affecting its inner side, but it's not
3507 : * worth having a separate code path to avoid passing them.)
3508 : *
3509 : * At a FULL join we just punt and pass nothing down --- is it
3510 : * possible to be smarter?
3511 : */
3512 15834 : if (jointype != JOIN_FULL)
3513 : {
3514 15698 : local_nonnullable_rels = find_nonnullable_rels(j->quals);
3515 15698 : local_forced_null_vars = find_forced_null_vars(j->quals);
3516 15698 : if (jointype == JOIN_INNER || jointype == JOIN_SEMI)
3517 : {
3518 : /* OK to merge upper and local constraints */
3519 984 : local_nonnullable_rels = bms_add_members(local_nonnullable_rels,
3520 : nonnullable_rels);
3521 984 : local_forced_null_vars = mbms_add_members(local_forced_null_vars,
3522 : forced_null_vars);
3523 : }
3524 : }
3525 : else
3526 : {
3527 : /* no use in calculating these */
3528 136 : local_nonnullable_rels = NULL;
3529 136 : local_forced_null_vars = NIL;
3530 : }
3531 :
3532 15834 : if (left_state->contains_outer)
3533 : {
3534 15092 : if (jointype == JOIN_INNER || jointype == JOIN_SEMI)
3535 : {
3536 : /* pass union of local and upper constraints */
3537 772 : pass_nonnullable_rels = local_nonnullable_rels;
3538 772 : pass_forced_null_vars = local_forced_null_vars;
3539 : }
3540 14320 : else if (jointype != JOIN_FULL) /* ie, LEFT or ANTI */
3541 : {
3542 : /* can't pass local constraints to non-nullable side */
3543 14212 : pass_nonnullable_rels = nonnullable_rels;
3544 14212 : pass_forced_null_vars = forced_null_vars;
3545 : }
3546 : else
3547 : {
3548 : /* no constraints pass through JOIN_FULL */
3549 108 : pass_nonnullable_rels = NULL;
3550 108 : pass_forced_null_vars = NIL;
3551 : }
3552 15092 : reduce_outer_joins_pass2(j->larg, left_state,
3553 : state2, root,
3554 : pass_nonnullable_rels,
3555 : pass_forced_null_vars);
3556 : }
3557 :
3558 15834 : if (right_state->contains_outer)
3559 : {
3560 810 : if (jointype != JOIN_FULL) /* ie, INNER/LEFT/SEMI/ANTI */
3561 : {
3562 : /* pass appropriate constraints, per comment above */
3563 782 : pass_nonnullable_rels = local_nonnullable_rels;
3564 782 : pass_forced_null_vars = local_forced_null_vars;
3565 : }
3566 : else
3567 : {
3568 : /* no constraints pass through JOIN_FULL */
3569 28 : pass_nonnullable_rels = NULL;
3570 28 : pass_forced_null_vars = NIL;
3571 : }
3572 810 : reduce_outer_joins_pass2(j->rarg, right_state,
3573 : state2, root,
3574 : pass_nonnullable_rels,
3575 : pass_forced_null_vars);
3576 : }
3577 15834 : bms_free(local_nonnullable_rels);
3578 : }
3579 : }
3580 : else
3581 0 : elog(ERROR, "unrecognized node type: %d",
3582 : (int) nodeTag(jtnode));
3583 86554 : }
3584 :
3585 : /* Helper for reduce_outer_joins_pass2 */
3586 : static void
3587 50 : report_reduced_full_join(reduce_outer_joins_pass2_state *state2,
3588 : int rtindex, Relids relids)
3589 : {
3590 : reduce_outer_joins_partial_state *statep;
3591 :
3592 50 : statep = palloc(sizeof(reduce_outer_joins_partial_state));
3593 50 : statep->full_join_rti = rtindex;
3594 50 : statep->unreduced_side = relids;
3595 50 : state2->partial_reduced = lappend(state2->partial_reduced, statep);
3596 50 : }
3597 :
3598 :
3599 : /*
3600 : * remove_useless_result_rtes
3601 : * Attempt to remove RTE_RESULT RTEs from the join tree.
3602 : * Also, elide single-child FromExprs where possible.
3603 : *
3604 : * We can remove RTE_RESULT entries from the join tree using the knowledge
3605 : * that RTE_RESULT returns exactly one row and has no output columns. Hence,
3606 : * if one is inner-joined to anything else, we can delete it. Optimizations
3607 : * are also possible for some outer-join cases, as detailed below.
3608 : *
3609 : * This pass also replaces single-child FromExprs with their child node
3610 : * where possible. It's appropriate to do that here and not earlier because
3611 : * RTE_RESULT removal might reduce a multiple-child FromExpr to have only one
3612 : * child. We can remove such a FromExpr if its quals are empty, or if it's
3613 : * semantically valid to merge the quals into those of the parent node.
3614 : * While removing unnecessary join tree nodes has some micro-efficiency value,
3615 : * the real reason to do this is to eliminate cases where the nullable side of
3616 : * an outer join node is a FromExpr whose single child is another outer join.
3617 : * To correctly determine whether the two outer joins can commute,
3618 : * deconstruct_jointree() must treat any quals of such a FromExpr as being
3619 : * degenerate quals of the upper outer join. The best way to do that is to
3620 : * make them actually *be* quals of the upper join, by dropping the FromExpr
3621 : * and hoisting the quals up into the upper join's quals. (Note that there is
3622 : * no hazard when the intermediate FromExpr has multiple children, since then
3623 : * it represents an inner join that cannot commute with the upper outer join.)
3624 : * As long as we have to do that, we might as well elide such FromExprs
3625 : * everywhere.
3626 : *
3627 : * Some of these optimizations depend on recognizing empty (constant-true)
3628 : * quals for FromExprs and JoinExprs. That makes it useful to apply this
3629 : * optimization pass after expression preprocessing, since that will have
3630 : * eliminated constant-true quals, allowing more cases to be recognized as
3631 : * optimizable. What's more, the usual reason for an RTE_RESULT to be present
3632 : * is that we pulled up a subquery or VALUES clause, thus very possibly
3633 : * replacing Vars with constants, making it more likely that a qual can be
3634 : * reduced to constant true. Also, because some optimizations depend on
3635 : * the outer-join type, it's best to have done reduce_outer_joins() first.
3636 : *
3637 : * A PlaceHolderVar referencing an RTE_RESULT RTE poses an obstacle to this
3638 : * process: we must remove the RTE_RESULT's relid from the PHV's phrels, but
3639 : * we must not reduce the phrels set to empty. If that would happen, and
3640 : * the RTE_RESULT is an immediate child of an outer join, we have to give up
3641 : * and not remove the RTE_RESULT: there is noplace else to evaluate the
3642 : * PlaceHolderVar. (That is, in such cases the RTE_RESULT *does* have output
3643 : * columns.) But if the RTE_RESULT is an immediate child of an inner join,
3644 : * we can usually change the PlaceHolderVar's phrels so as to evaluate it at
3645 : * the inner join instead. This is OK because we really only care that PHVs
3646 : * are evaluated above or below the correct outer joins. We can't, however,
3647 : * postpone the evaluation of a PHV to above where it is used; so there are
3648 : * some checks below on whether output PHVs are laterally referenced in the
3649 : * other join input rel(s).
3650 : *
3651 : * We used to try to do this work as part of pull_up_subqueries() where the
3652 : * potentially-optimizable cases get introduced; but it's way simpler, and
3653 : * more effective, to do it separately.
3654 : */
3655 : void
3656 230084 : remove_useless_result_rtes(PlannerInfo *root)
3657 : {
3658 230084 : Relids dropped_outer_joins = NULL;
3659 : ListCell *cell;
3660 :
3661 : /* Top level of jointree must always be a FromExpr */
3662 : Assert(IsA(root->parse->jointree, FromExpr));
3663 : /* Recurse ... */
3664 460168 : root->parse->jointree = (FromExpr *)
3665 230084 : remove_useless_results_recurse(root,
3666 230084 : (Node *) root->parse->jointree,
3667 : NULL,
3668 : &dropped_outer_joins);
3669 : /* We should still have a FromExpr */
3670 : Assert(IsA(root->parse->jointree, FromExpr));
3671 :
3672 : /*
3673 : * If we removed any outer-join nodes from the jointree, run around and
3674 : * remove references to those joins as nulling rels. (There could be such
3675 : * references in PHVs that we pulled up out of the original subquery that
3676 : * the RESULT rel replaced. This is kosher on the grounds that we now
3677 : * know that such an outer join wouldn't really have nulled anything.) We
3678 : * don't do this during the main recursion, for simplicity and because we
3679 : * can handle all such joins in a single pass over the parse tree.
3680 : */
3681 230084 : if (!bms_is_empty(dropped_outer_joins))
3682 : {
3683 60 : root->parse = (Query *)
3684 60 : remove_nulling_relids((Node *) root->parse,
3685 : dropped_outer_joins,
3686 : NULL);
3687 : /* There could be references in the append_rel_list, too */
3688 60 : root->append_rel_list = (List *)
3689 60 : remove_nulling_relids((Node *) root->append_rel_list,
3690 : dropped_outer_joins,
3691 : NULL);
3692 : }
3693 :
3694 : /*
3695 : * Remove any PlanRowMark referencing an RTE_RESULT RTE. We obviously
3696 : * must do that for any RTE_RESULT that we just removed. But one for a
3697 : * RTE that we did not remove can be dropped anyway: since the RTE has
3698 : * only one possible output row, there is no need for EPQ to mark and
3699 : * restore that row.
3700 : *
3701 : * It's necessary, not optional, to remove the PlanRowMark for a surviving
3702 : * RTE_RESULT RTE; otherwise we'll generate a whole-row Var for the
3703 : * RTE_RESULT, which the executor has no support for.
3704 : */
3705 232140 : foreach(cell, root->rowMarks)
3706 : {
3707 2056 : PlanRowMark *rc = (PlanRowMark *) lfirst(cell);
3708 :
3709 2056 : if (rt_fetch(rc->rti, root->parse->rtable)->rtekind == RTE_RESULT)
3710 936 : root->rowMarks = foreach_delete_current(root->rowMarks, cell);
3711 : }
3712 230084 : }
3713 :
3714 : /*
3715 : * remove_useless_results_recurse
3716 : * Recursive guts of remove_useless_result_rtes.
3717 : *
3718 : * This recursively processes the jointree and returns a modified jointree.
3719 : * In addition, the RT indexes of any removed outer-join nodes are added to
3720 : * *dropped_outer_joins.
3721 : *
3722 : * jtnode is the current jointree node. If it could be valid to merge
3723 : * its quals into those of the parent node, parent_quals should point to
3724 : * the parent's quals list; otherwise, pass NULL for parent_quals.
3725 : * (Note that in some cases, parent_quals points to the quals of a parent
3726 : * more than one level up in the tree.)
3727 : */
3728 : static Node *
3729 600096 : remove_useless_results_recurse(PlannerInfo *root, Node *jtnode,
3730 : Node **parent_quals,
3731 : Relids *dropped_outer_joins)
3732 : {
3733 : Assert(jtnode != NULL);
3734 600096 : if (IsA(jtnode, RangeTblRef))
3735 : {
3736 : /* Can't immediately do anything with a RangeTblRef */
3737 : }
3738 301742 : else if (IsA(jtnode, FromExpr))
3739 : {
3740 237002 : FromExpr *f = (FromExpr *) jtnode;
3741 237002 : Relids result_relids = NULL;
3742 : ListCell *cell;
3743 :
3744 : /*
3745 : * We can drop RTE_RESULT rels from the fromlist so long as at least
3746 : * one child remains, since joining to a one-row table changes
3747 : * nothing. (But we can't drop a RTE_RESULT that computes PHV(s) that
3748 : * are needed by some sibling. The cleanup transformation below would
3749 : * reassign the PHVs to be computed at the join, which is too late for
3750 : * the sibling's use.) The easiest way to mechanize this rule is to
3751 : * modify the list in-place.
3752 : */
3753 477534 : foreach(cell, f->fromlist)
3754 : {
3755 240532 : Node *child = (Node *) lfirst(cell);
3756 : int varno;
3757 :
3758 : /* Recursively transform child, allowing it to push up quals ... */
3759 240532 : child = remove_useless_results_recurse(root, child,
3760 : &f->quals,
3761 : dropped_outer_joins);
3762 : /* ... and stick it back into the tree */
3763 240532 : lfirst(cell) = child;
3764 :
3765 : /*
3766 : * If it's an RTE_RESULT with at least one sibling, and no sibling
3767 : * references dependent PHVs, we can drop it. We don't yet know
3768 : * what the inner join's final relid set will be, so postpone
3769 : * cleanup of PHVs etc till after this loop.
3770 : */
3771 246250 : if (list_length(f->fromlist) > 1 &&
3772 5718 : (varno = get_result_relid(root, child)) != 0 &&
3773 346 : !find_dependent_phvs_in_jointree(root, (Node *) f, varno))
3774 : {
3775 322 : f->fromlist = foreach_delete_current(f->fromlist, cell);
3776 322 : result_relids = bms_add_member(result_relids, varno);
3777 : }
3778 : }
3779 :
3780 : /*
3781 : * Clean up if we dropped any RTE_RESULT RTEs. This is a bit
3782 : * inefficient if there's more than one, but it seems better to
3783 : * optimize the support code for the single-relid case.
3784 : */
3785 237002 : if (result_relids)
3786 : {
3787 310 : int varno = -1;
3788 :
3789 632 : while ((varno = bms_next_member(result_relids, varno)) >= 0)
3790 322 : remove_result_refs(root, varno, (Node *) f);
3791 : }
3792 :
3793 : /*
3794 : * If the FromExpr now has only one child, see if we can elide it.
3795 : * This is always valid if there are no quals, except at the top of
3796 : * the jointree (since Query.jointree is required to point to a
3797 : * FromExpr). Otherwise, we can do it if we can push the quals up to
3798 : * the parent node.
3799 : *
3800 : * Note: while it would not be terribly hard to generalize this
3801 : * transformation to merge multi-child FromExprs into their parent
3802 : * FromExpr, that risks making the parent join too expensive to plan.
3803 : * We leave it to later processing to decide heuristically whether
3804 : * that's a good idea. Pulling up a single child is always OK,
3805 : * however.
3806 : */
3807 237002 : if (list_length(f->fromlist) == 1 &&
3808 235022 : f != root->parse->jointree &&
3809 6688 : (f->quals == NULL || parent_quals != NULL))
3810 : {
3811 : /*
3812 : * Merge any quals up to parent. They should be in implicit-AND
3813 : * format by now, so we just need to concatenate lists. Put the
3814 : * child quals at the front, on the grounds that they should
3815 : * nominally be evaluated earlier.
3816 : */
3817 2746 : if (f->quals != NULL)
3818 1308 : *parent_quals = (Node *)
3819 1308 : list_concat(castNode(List, f->quals),
3820 : castNode(List, *parent_quals));
3821 2746 : return (Node *) linitial(f->fromlist);
3822 : }
3823 : }
3824 64740 : else if (IsA(jtnode, JoinExpr))
3825 : {
3826 64740 : JoinExpr *j = (JoinExpr *) jtnode;
3827 : int varno;
3828 :
3829 : /*
3830 : * First, recurse. We can absorb pushed-up FromExpr quals from either
3831 : * child into this node if the jointype is INNER, since then this is
3832 : * equivalent to a FromExpr. When the jointype is LEFT, we can absorb
3833 : * quals from the RHS child into the current node, as they're
3834 : * essentially degenerate quals of the outer join. Moreover, if we've
3835 : * been passed down a parent_quals pointer then we can allow quals of
3836 : * the LHS child to be absorbed into the parent. (This is important
3837 : * to ensure we remove single-child FromExprs immediately below
3838 : * commutable left joins.) For other jointypes, we can't move child
3839 : * quals up, or at least there's no particular reason to.
3840 : */
3841 64740 : j->larg = remove_useless_results_recurse(root, j->larg,
3842 64740 : (j->jointype == JOIN_INNER) ?
3843 : &j->quals :
3844 51128 : (j->jointype == JOIN_LEFT) ?
3845 51128 : parent_quals : NULL,
3846 : dropped_outer_joins);
3847 64740 : j->rarg = remove_useless_results_recurse(root, j->rarg,
3848 64740 : (j->jointype == JOIN_INNER ||
3849 51128 : j->jointype == JOIN_LEFT) ?
3850 : &j->quals : NULL,
3851 : dropped_outer_joins);
3852 :
3853 : /* Apply join-type-specific optimization rules */
3854 64740 : switch (j->jointype)
3855 : {
3856 13612 : case JOIN_INNER:
3857 :
3858 : /*
3859 : * An inner join is equivalent to a FromExpr, so if either
3860 : * side was simplified to an RTE_RESULT rel, we can replace
3861 : * the join with a FromExpr with just the other side.
3862 : * Furthermore, we can elide that FromExpr according to the
3863 : * same rules as above.
3864 : *
3865 : * Just as in the FromExpr case, we can't simplify if the
3866 : * other input rel references any PHVs that are marked as to
3867 : * be evaluated at the RTE_RESULT rel, because we can't
3868 : * postpone their evaluation in that case. But we only have
3869 : * to check this in cases where it's syntactically legal for
3870 : * the other input to have a LATERAL reference to the
3871 : * RTE_RESULT rel. Only RHSes of inner and left joins are
3872 : * allowed to have such refs.
3873 : */
3874 13612 : if ((varno = get_result_relid(root, j->larg)) != 0 &&
3875 96 : !find_dependent_phvs_in_jointree(root, j->rarg, varno))
3876 : {
3877 96 : remove_result_refs(root, varno, j->rarg);
3878 96 : if (j->quals != NULL && parent_quals == NULL)
3879 12 : jtnode = (Node *)
3880 12 : makeFromExpr(list_make1(j->rarg), j->quals);
3881 : else
3882 : {
3883 : /* Merge any quals up to parent */
3884 84 : if (j->quals != NULL)
3885 60 : *parent_quals = (Node *)
3886 60 : list_concat(castNode(List, j->quals),
3887 : castNode(List, *parent_quals));
3888 84 : jtnode = j->rarg;
3889 : }
3890 : }
3891 13516 : else if ((varno = get_result_relid(root, j->rarg)) != 0)
3892 : {
3893 872 : remove_result_refs(root, varno, j->larg);
3894 872 : if (j->quals != NULL && parent_quals == NULL)
3895 12 : jtnode = (Node *)
3896 12 : makeFromExpr(list_make1(j->larg), j->quals);
3897 : else
3898 : {
3899 : /* Merge any quals up to parent */
3900 860 : if (j->quals != NULL)
3901 606 : *parent_quals = (Node *)
3902 606 : list_concat(castNode(List, j->quals),
3903 : castNode(List, *parent_quals));
3904 860 : jtnode = j->larg;
3905 : }
3906 : }
3907 13612 : break;
3908 45170 : case JOIN_LEFT:
3909 :
3910 : /*
3911 : * We can simplify this case if the RHS is an RTE_RESULT, with
3912 : * two different possibilities:
3913 : *
3914 : * If the qual is empty (JOIN ON TRUE), then the join can be
3915 : * strength-reduced to a plain inner join, since each LHS row
3916 : * necessarily has exactly one join partner. So we can always
3917 : * discard the RHS, much as in the JOIN_INNER case above.
3918 : * (Again, the LHS could not contain a lateral reference to
3919 : * the RHS.)
3920 : *
3921 : * Otherwise, it's still true that each LHS row should be
3922 : * returned exactly once, and since the RHS returns no columns
3923 : * (unless there are PHVs that have to be evaluated there), we
3924 : * don't much care if it's null-extended or not. So in this
3925 : * case also, we can just ignore the qual and discard the left
3926 : * join.
3927 : */
3928 45170 : if ((varno = get_result_relid(root, j->rarg)) != 0 &&
3929 150 : (j->quals == NULL ||
3930 90 : !find_dependent_phvs(root, varno)))
3931 : {
3932 60 : remove_result_refs(root, varno, j->larg);
3933 60 : *dropped_outer_joins = bms_add_member(*dropped_outer_joins,
3934 : j->rtindex);
3935 60 : jtnode = j->larg;
3936 : }
3937 45170 : break;
3938 3196 : case JOIN_SEMI:
3939 :
3940 : /*
3941 : * We may simplify this case if the RHS is an RTE_RESULT; the
3942 : * join qual becomes effectively just a filter qual for the
3943 : * LHS, since we should either return the LHS row or not. The
3944 : * filter clause must go into a new FromExpr if we can't push
3945 : * it up to the parent.
3946 : *
3947 : * There is a fine point about PHVs that are supposed to be
3948 : * evaluated at the RHS. Such PHVs could only appear in the
3949 : * semijoin's qual, since the rest of the query cannot
3950 : * reference any outputs of the semijoin's RHS. Therefore,
3951 : * they can't actually go to null before being examined, and
3952 : * it'd be OK to just remove the PHV wrapping. We don't have
3953 : * infrastructure for that, but remove_result_refs() will
3954 : * relabel them as to be evaluated at the LHS, which is fine.
3955 : *
3956 : * Also, we don't need to worry about removing traces of the
3957 : * join's rtindex, since it hasn't got one.
3958 : */
3959 3196 : if ((varno = get_result_relid(root, j->rarg)) != 0)
3960 : {
3961 : Assert(j->rtindex == 0);
3962 36 : remove_result_refs(root, varno, j->larg);
3963 36 : if (j->quals != NULL && parent_quals == NULL)
3964 0 : jtnode = (Node *)
3965 0 : makeFromExpr(list_make1(j->larg), j->quals);
3966 : else
3967 : {
3968 : /* Merge any quals up to parent */
3969 36 : if (j->quals != NULL)
3970 36 : *parent_quals = (Node *)
3971 36 : list_concat(castNode(List, j->quals),
3972 : castNode(List, *parent_quals));
3973 36 : jtnode = j->larg;
3974 : }
3975 : }
3976 3196 : break;
3977 2762 : case JOIN_FULL:
3978 : case JOIN_ANTI:
3979 : /* We have no special smarts for these cases */
3980 2762 : break;
3981 0 : default:
3982 : /* Note: JOIN_RIGHT should be gone at this point */
3983 0 : elog(ERROR, "unrecognized join type: %d",
3984 : (int) j->jointype);
3985 : break;
3986 : }
3987 : }
3988 : else
3989 0 : elog(ERROR, "unrecognized node type: %d",
3990 : (int) nodeTag(jtnode));
3991 597350 : return jtnode;
3992 : }
3993 :
3994 : /*
3995 : * get_result_relid
3996 : * If jtnode is a RangeTblRef for an RTE_RESULT RTE, return its relid;
3997 : * otherwise return 0.
3998 : */
3999 : static int
4000 81212 : get_result_relid(PlannerInfo *root, Node *jtnode)
4001 : {
4002 : int varno;
4003 :
4004 81212 : if (!IsA(jtnode, RangeTblRef))
4005 6768 : return 0;
4006 74444 : varno = ((RangeTblRef *) jtnode)->rtindex;
4007 74444 : if (rt_fetch(varno, root->parse->rtable)->rtekind != RTE_RESULT)
4008 72944 : return 0;
4009 1500 : return varno;
4010 : }
4011 :
4012 : /*
4013 : * remove_result_refs
4014 : * Helper routine for dropping an unneeded RTE_RESULT RTE.
4015 : *
4016 : * This doesn't physically remove the RTE from the jointree, because that's
4017 : * more easily handled in remove_useless_results_recurse. What it does do
4018 : * is the necessary cleanup in the rest of the tree: we must adjust any PHVs
4019 : * that may reference the RTE. Be sure to call this at a point where the
4020 : * jointree is valid (no disconnected nodes).
4021 : *
4022 : * Note that we don't need to process the append_rel_list, since RTEs
4023 : * referenced directly in the jointree won't be appendrel members.
4024 : *
4025 : * varno is the RTE_RESULT's relid.
4026 : * newjtloc is the jointree location at which any PHVs referencing the
4027 : * RTE_RESULT should be evaluated instead.
4028 : */
4029 : static void
4030 1386 : remove_result_refs(PlannerInfo *root, int varno, Node *newjtloc)
4031 : {
4032 : /* Fix up PlaceHolderVars as needed */
4033 : /* If there are no PHVs anywhere, we can skip this bit */
4034 1386 : if (root->glob->lastPHId != 0)
4035 : {
4036 : Relids subrelids;
4037 :
4038 268 : subrelids = get_relids_in_jointree(newjtloc, true, false);
4039 : Assert(!bms_is_empty(subrelids));
4040 268 : substitute_phv_relids((Node *) root->parse, varno, subrelids);
4041 268 : fix_append_rel_relids(root, varno, subrelids);
4042 : }
4043 :
4044 : /*
4045 : * We also need to remove any PlanRowMark referencing the RTE, but we
4046 : * postpone that work until we return to remove_useless_result_rtes.
4047 : */
4048 1386 : }
4049 :
4050 :
4051 : /*
4052 : * find_dependent_phvs - are there any PlaceHolderVars whose relids are
4053 : * exactly the given varno?
4054 : *
4055 : * find_dependent_phvs should be used when we want to see if there are
4056 : * any such PHVs anywhere in the Query. Another use-case is to see if
4057 : * a subtree of the join tree contains such PHVs; but for that, we have
4058 : * to look not only at the join tree nodes themselves but at the
4059 : * referenced RTEs. For that, use find_dependent_phvs_in_jointree.
4060 : */
4061 :
4062 : typedef struct
4063 : {
4064 : Relids relids;
4065 : int sublevels_up;
4066 : } find_dependent_phvs_context;
4067 :
4068 : static bool
4069 2400 : find_dependent_phvs_walker(Node *node,
4070 : find_dependent_phvs_context *context)
4071 : {
4072 2400 : if (node == NULL)
4073 564 : return false;
4074 1836 : if (IsA(node, PlaceHolderVar))
4075 : {
4076 156 : PlaceHolderVar *phv = (PlaceHolderVar *) node;
4077 :
4078 312 : if (phv->phlevelsup == context->sublevels_up &&
4079 156 : bms_equal(context->relids, phv->phrels))
4080 114 : return true;
4081 : /* fall through to examine children */
4082 : }
4083 1722 : if (IsA(node, Query))
4084 : {
4085 : /* Recurse into subselects */
4086 : bool result;
4087 :
4088 48 : context->sublevels_up++;
4089 48 : result = query_tree_walker((Query *) node,
4090 : find_dependent_phvs_walker,
4091 : context, 0);
4092 48 : context->sublevels_up--;
4093 48 : return result;
4094 : }
4095 : /* Shouldn't need to handle most planner auxiliary nodes here */
4096 : Assert(!IsA(node, SpecialJoinInfo));
4097 : Assert(!IsA(node, PlaceHolderInfo));
4098 : Assert(!IsA(node, MinMaxAggInfo));
4099 :
4100 1674 : return expression_tree_walker(node, find_dependent_phvs_walker, context);
4101 : }
4102 :
4103 : static bool
4104 90 : find_dependent_phvs(PlannerInfo *root, int varno)
4105 : {
4106 : find_dependent_phvs_context context;
4107 :
4108 : /* If there are no PHVs anywhere, we needn't work hard */
4109 90 : if (root->glob->lastPHId == 0)
4110 0 : return false;
4111 :
4112 90 : context.relids = bms_make_singleton(varno);
4113 90 : context.sublevels_up = 0;
4114 :
4115 90 : if (query_tree_walker(root->parse, find_dependent_phvs_walker, &context, 0))
4116 90 : return true;
4117 : /* The append_rel_list could be populated already, so check it too */
4118 0 : if (expression_tree_walker((Node *) root->append_rel_list,
4119 : find_dependent_phvs_walker,
4120 : &context))
4121 0 : return true;
4122 0 : return false;
4123 : }
4124 :
4125 : static bool
4126 442 : find_dependent_phvs_in_jointree(PlannerInfo *root, Node *node, int varno)
4127 : {
4128 : find_dependent_phvs_context context;
4129 : Relids subrelids;
4130 : int relid;
4131 :
4132 : /* If there are no PHVs anywhere, we needn't work hard */
4133 442 : if (root->glob->lastPHId == 0)
4134 376 : return false;
4135 :
4136 66 : context.relids = bms_make_singleton(varno);
4137 66 : context.sublevels_up = 0;
4138 :
4139 : /*
4140 : * See if the jointree fragment itself contains references (in join quals)
4141 : */
4142 66 : if (find_dependent_phvs_walker(node, &context))
4143 0 : return true;
4144 :
4145 : /*
4146 : * Otherwise, identify the set of referenced RTEs (we can ignore joins,
4147 : * since they should be flattened already, so their join alias lists no
4148 : * longer matter), and tediously check each RTE. We can ignore RTEs that
4149 : * are not marked LATERAL, though, since they couldn't possibly contain
4150 : * any cross-references to other RTEs.
4151 : */
4152 66 : subrelids = get_relids_in_jointree(node, false, false);
4153 66 : relid = -1;
4154 144 : while ((relid = bms_next_member(subrelids, relid)) >= 0)
4155 : {
4156 102 : RangeTblEntry *rte = rt_fetch(relid, root->parse->rtable);
4157 :
4158 126 : if (rte->lateral &&
4159 24 : range_table_entry_walker(rte, find_dependent_phvs_walker, &context, 0))
4160 24 : return true;
4161 : }
4162 :
4163 42 : return false;
4164 : }
4165 :
4166 : /*
4167 : * substitute_phv_relids - adjust PlaceHolderVar relid sets after pulling up
4168 : * a subquery or removing an RTE_RESULT jointree item
4169 : *
4170 : * Find any PlaceHolderVar nodes in the given tree that reference the
4171 : * pulled-up relid, and change them to reference the replacement relid(s).
4172 : *
4173 : * NOTE: although this has the form of a walker, we cheat and modify the
4174 : * nodes in-place. This should be OK since the tree was copied by
4175 : * pullup_replace_vars earlier. Avoid scribbling on the original values of
4176 : * the bitmapsets, though, because expression_tree_mutator doesn't copy those.
4177 : */
4178 :
4179 : typedef struct
4180 : {
4181 : int varno;
4182 : int sublevels_up;
4183 : Relids subrelids;
4184 : } substitute_phv_relids_context;
4185 :
4186 : static bool
4187 265862 : substitute_phv_relids_walker(Node *node,
4188 : substitute_phv_relids_context *context)
4189 : {
4190 265862 : if (node == NULL)
4191 101398 : return false;
4192 164464 : if (IsA(node, PlaceHolderVar))
4193 : {
4194 7584 : PlaceHolderVar *phv = (PlaceHolderVar *) node;
4195 :
4196 15136 : if (phv->phlevelsup == context->sublevels_up &&
4197 7552 : bms_is_member(context->varno, phv->phrels))
4198 : {
4199 10792 : phv->phrels = bms_union(phv->phrels,
4200 5396 : context->subrelids);
4201 5396 : phv->phrels = bms_del_member(phv->phrels,
4202 : context->varno);
4203 : /* Assert we haven't broken the PHV */
4204 : Assert(!bms_is_empty(phv->phrels));
4205 : }
4206 : /* fall through to examine children */
4207 : }
4208 164464 : if (IsA(node, Query))
4209 : {
4210 : /* Recurse into subselects */
4211 : bool result;
4212 :
4213 4378 : context->sublevels_up++;
4214 4378 : result = query_tree_walker((Query *) node,
4215 : substitute_phv_relids_walker,
4216 : context, 0);
4217 4378 : context->sublevels_up--;
4218 4378 : return result;
4219 : }
4220 : /* Shouldn't need to handle planner auxiliary nodes here */
4221 : Assert(!IsA(node, SpecialJoinInfo));
4222 : Assert(!IsA(node, AppendRelInfo));
4223 : Assert(!IsA(node, PlaceHolderInfo));
4224 : Assert(!IsA(node, MinMaxAggInfo));
4225 :
4226 160086 : return expression_tree_walker(node, substitute_phv_relids_walker, context);
4227 : }
4228 :
4229 : static void
4230 2400 : substitute_phv_relids(Node *node, int varno, Relids subrelids)
4231 : {
4232 : substitute_phv_relids_context context;
4233 :
4234 2400 : context.varno = varno;
4235 2400 : context.sublevels_up = 0;
4236 2400 : context.subrelids = subrelids;
4237 :
4238 : /*
4239 : * Must be prepared to start with a Query or a bare expression tree.
4240 : */
4241 2400 : query_or_expression_tree_walker(node,
4242 : substitute_phv_relids_walker,
4243 : &context,
4244 : 0);
4245 2400 : }
4246 :
4247 : /*
4248 : * fix_append_rel_relids: update RT-index fields of AppendRelInfo nodes
4249 : *
4250 : * When we pull up a subquery, any AppendRelInfo references to the subquery's
4251 : * RT index have to be replaced by the substituted relid (and there had better
4252 : * be only one). We also need to apply substitute_phv_relids to their
4253 : * translated_vars lists, since those might contain PlaceHolderVars.
4254 : *
4255 : * We assume we may modify the AppendRelInfo nodes in-place.
4256 : */
4257 : static void
4258 8270 : fix_append_rel_relids(PlannerInfo *root, int varno, Relids subrelids)
4259 : {
4260 : ListCell *l;
4261 8270 : int subvarno = -1;
4262 :
4263 : /*
4264 : * We only want to extract the member relid once, but we mustn't fail
4265 : * immediately if there are multiple members; it could be that none of the
4266 : * AppendRelInfo nodes refer to it. So compute it on first use. Note that
4267 : * bms_singleton_member will complain if set is not singleton.
4268 : */
4269 19584 : foreach(l, root->append_rel_list)
4270 : {
4271 11314 : AppendRelInfo *appinfo = (AppendRelInfo *) lfirst(l);
4272 :
4273 : /* The parent_relid shouldn't ever be a pullup target */
4274 : Assert(appinfo->parent_relid != varno);
4275 :
4276 11314 : if (appinfo->child_relid == varno)
4277 : {
4278 6086 : if (subvarno < 0)
4279 6086 : subvarno = bms_singleton_member(subrelids);
4280 6086 : appinfo->child_relid = subvarno;
4281 : }
4282 :
4283 : /* Also fix up any PHVs in its translated vars */
4284 11314 : if (root->glob->lastPHId != 0)
4285 162 : substitute_phv_relids((Node *) appinfo->translated_vars,
4286 : varno, subrelids);
4287 : }
4288 8270 : }
4289 :
4290 : /*
4291 : * get_relids_in_jointree: get set of RT indexes present in a jointree
4292 : *
4293 : * Base-relation relids are always included in the result.
4294 : * If include_outer_joins is true, outer-join RT indexes are included.
4295 : * If include_inner_joins is true, inner-join RT indexes are included.
4296 : *
4297 : * Note that for most purposes in the planner, outer joins are included
4298 : * in standard relid sets. Setting include_inner_joins true is only
4299 : * appropriate for special purposes during subquery flattening.
4300 : */
4301 : Relids
4302 92452 : get_relids_in_jointree(Node *jtnode, bool include_outer_joins,
4303 : bool include_inner_joins)
4304 : {
4305 92452 : Relids result = NULL;
4306 :
4307 92452 : if (jtnode == NULL)
4308 0 : return result;
4309 92452 : if (IsA(jtnode, RangeTblRef))
4310 : {
4311 46588 : int varno = ((RangeTblRef *) jtnode)->rtindex;
4312 :
4313 46588 : result = bms_make_singleton(varno);
4314 : }
4315 45864 : else if (IsA(jtnode, FromExpr))
4316 : {
4317 39582 : FromExpr *f = (FromExpr *) jtnode;
4318 : ListCell *l;
4319 :
4320 80420 : foreach(l, f->fromlist)
4321 : {
4322 40838 : result = bms_join(result,
4323 40838 : get_relids_in_jointree(lfirst(l),
4324 : include_outer_joins,
4325 : include_inner_joins));
4326 : }
4327 : }
4328 6282 : else if (IsA(jtnode, JoinExpr))
4329 : {
4330 6282 : JoinExpr *j = (JoinExpr *) jtnode;
4331 :
4332 6282 : result = get_relids_in_jointree(j->larg,
4333 : include_outer_joins,
4334 : include_inner_joins);
4335 6282 : result = bms_join(result,
4336 : get_relids_in_jointree(j->rarg,
4337 : include_outer_joins,
4338 : include_inner_joins));
4339 6282 : if (j->rtindex)
4340 : {
4341 5956 : if (j->jointype == JOIN_INNER)
4342 : {
4343 2674 : if (include_inner_joins)
4344 1002 : result = bms_add_member(result, j->rtindex);
4345 : }
4346 : else
4347 : {
4348 3282 : if (include_outer_joins)
4349 2136 : result = bms_add_member(result, j->rtindex);
4350 : }
4351 : }
4352 : }
4353 : else
4354 0 : elog(ERROR, "unrecognized node type: %d",
4355 : (int) nodeTag(jtnode));
4356 92452 : return result;
4357 : }
4358 :
4359 : /*
4360 : * get_relids_for_join: get set of base+OJ RT indexes making up a join
4361 : */
4362 : Relids
4363 358 : get_relids_for_join(Query *query, int joinrelid)
4364 : {
4365 : Node *jtnode;
4366 :
4367 358 : jtnode = find_jointree_node_for_rel((Node *) query->jointree,
4368 : joinrelid);
4369 358 : if (!jtnode)
4370 0 : elog(ERROR, "could not find join node %d", joinrelid);
4371 358 : return get_relids_in_jointree(jtnode, true, false);
4372 : }
4373 :
4374 : /*
4375 : * find_jointree_node_for_rel: locate jointree node for a base or join RT index
4376 : *
4377 : * Returns NULL if not found
4378 : */
4379 : static Node *
4380 1730 : find_jointree_node_for_rel(Node *jtnode, int relid)
4381 : {
4382 1730 : if (jtnode == NULL)
4383 0 : return NULL;
4384 1730 : if (IsA(jtnode, RangeTblRef))
4385 : {
4386 454 : int varno = ((RangeTblRef *) jtnode)->rtindex;
4387 :
4388 454 : if (relid == varno)
4389 0 : return jtnode;
4390 : }
4391 1276 : else if (IsA(jtnode, FromExpr))
4392 : {
4393 368 : FromExpr *f = (FromExpr *) jtnode;
4394 : ListCell *l;
4395 :
4396 386 : foreach(l, f->fromlist)
4397 : {
4398 386 : jtnode = find_jointree_node_for_rel(lfirst(l), relid);
4399 386 : if (jtnode)
4400 368 : return jtnode;
4401 : }
4402 : }
4403 908 : else if (IsA(jtnode, JoinExpr))
4404 : {
4405 908 : JoinExpr *j = (JoinExpr *) jtnode;
4406 :
4407 908 : if (relid == j->rtindex)
4408 358 : return jtnode;
4409 550 : jtnode = find_jointree_node_for_rel(j->larg, relid);
4410 550 : if (jtnode)
4411 114 : return jtnode;
4412 436 : jtnode = find_jointree_node_for_rel(j->rarg, relid);
4413 436 : if (jtnode)
4414 436 : return jtnode;
4415 : }
4416 : else
4417 0 : elog(ERROR, "unrecognized node type: %d",
4418 : (int) nodeTag(jtnode));
4419 454 : return NULL;
4420 : }
4421 :
4422 : /*
4423 : * get_nullingrels: collect info about which outer joins null which relations
4424 : *
4425 : * The result struct contains, for each leaf relation used in the query,
4426 : * the set of relids of outer joins that potentially null that rel.
4427 : */
4428 : static nullingrel_info *
4429 1148 : get_nullingrels(Query *parse)
4430 : {
4431 1148 : nullingrel_info *result = palloc_object(nullingrel_info);
4432 :
4433 1148 : result->rtlength = list_length(parse->rtable);
4434 1148 : result->nullingrels = palloc0_array(Relids, result->rtlength + 1);
4435 1148 : get_nullingrels_recurse((Node *) parse->jointree, NULL, result);
4436 1148 : return result;
4437 : }
4438 :
4439 : /*
4440 : * Recursive guts of get_nullingrels().
4441 : *
4442 : * Note: at any recursion level, the passed-down upper_nullingrels must be
4443 : * treated as a constant, but it can be stored directly into *info
4444 : * if we're at leaf level. Upper recursion levels do not free their mutated
4445 : * copies of the nullingrels, because those are probably referenced by
4446 : * at least one leaf rel.
4447 : */
4448 : static void
4449 6036 : get_nullingrels_recurse(Node *jtnode, Relids upper_nullingrels,
4450 : nullingrel_info *info)
4451 : {
4452 6036 : if (jtnode == NULL)
4453 0 : return;
4454 6036 : if (IsA(jtnode, RangeTblRef))
4455 : {
4456 3196 : int varno = ((RangeTblRef *) jtnode)->rtindex;
4457 :
4458 : Assert(varno > 0 && varno <= info->rtlength);
4459 3196 : info->nullingrels[varno] = upper_nullingrels;
4460 : }
4461 2840 : else if (IsA(jtnode, FromExpr))
4462 : {
4463 1232 : FromExpr *f = (FromExpr *) jtnode;
4464 : ListCell *l;
4465 :
4466 2904 : foreach(l, f->fromlist)
4467 : {
4468 1672 : get_nullingrels_recurse(lfirst(l), upper_nullingrels, info);
4469 : }
4470 : }
4471 1608 : else if (IsA(jtnode, JoinExpr))
4472 : {
4473 1608 : JoinExpr *j = (JoinExpr *) jtnode;
4474 : Relids local_nullingrels;
4475 :
4476 1608 : switch (j->jointype)
4477 : {
4478 570 : case JOIN_INNER:
4479 570 : get_nullingrels_recurse(j->larg, upper_nullingrels, info);
4480 570 : get_nullingrels_recurse(j->rarg, upper_nullingrels, info);
4481 570 : break;
4482 1032 : case JOIN_LEFT:
4483 : case JOIN_SEMI:
4484 : case JOIN_ANTI:
4485 1032 : local_nullingrels = bms_add_member(bms_copy(upper_nullingrels),
4486 : j->rtindex);
4487 1032 : get_nullingrels_recurse(j->larg, upper_nullingrels, info);
4488 1032 : get_nullingrels_recurse(j->rarg, local_nullingrels, info);
4489 1032 : break;
4490 6 : case JOIN_FULL:
4491 6 : local_nullingrels = bms_add_member(bms_copy(upper_nullingrels),
4492 : j->rtindex);
4493 6 : get_nullingrels_recurse(j->larg, local_nullingrels, info);
4494 6 : get_nullingrels_recurse(j->rarg, local_nullingrels, info);
4495 6 : break;
4496 0 : case JOIN_RIGHT:
4497 0 : local_nullingrels = bms_add_member(bms_copy(upper_nullingrels),
4498 : j->rtindex);
4499 0 : get_nullingrels_recurse(j->larg, local_nullingrels, info);
4500 0 : get_nullingrels_recurse(j->rarg, upper_nullingrels, info);
4501 0 : break;
4502 0 : default:
4503 0 : elog(ERROR, "unrecognized join type: %d",
4504 : (int) j->jointype);
4505 : break;
4506 : }
4507 : }
4508 : else
4509 0 : elog(ERROR, "unrecognized node type: %d",
4510 : (int) nodeTag(jtnode));
4511 : }
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