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subselect.c
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1 /*-------------------------------------------------------------------------
2  *
3  * subselect.c
4  * Planning routines for subselects.
5  *
6  * This module deals with SubLinks and CTEs, but not subquery RTEs (i.e.,
7  * not sub-SELECT-in-FROM cases).
8  *
9  * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
10  * Portions Copyright (c) 1994, Regents of the University of California
11  *
12  * IDENTIFICATION
13  * src/backend/optimizer/plan/subselect.c
14  *
15  *-------------------------------------------------------------------------
16  */
17 #include "postgres.h"
18 
19 #include "access/htup_details.h"
20 #include "catalog/pg_operator.h"
21 #include "catalog/pg_type.h"
22 #include "executor/executor.h"
23 #include "miscadmin.h"
24 #include "nodes/makefuncs.h"
25 #include "nodes/nodeFuncs.h"
26 #include "optimizer/clauses.h"
27 #include "optimizer/cost.h"
28 #include "optimizer/optimizer.h"
29 #include "optimizer/paramassign.h"
30 #include "optimizer/pathnode.h"
31 #include "optimizer/planmain.h"
32 #include "optimizer/planner.h"
33 #include "optimizer/prep.h"
34 #include "optimizer/subselect.h"
35 #include "parser/parse_relation.h"
36 #include "rewrite/rewriteManip.h"
37 #include "utils/builtins.h"
38 #include "utils/lsyscache.h"
39 #include "utils/syscache.h"
40 
41 
43 {
45  List *subst_nodes; /* Nodes to substitute for Params */
47 
49 {
51  bool isTopQual;
53 
55 {
57  Bitmapset *paramids; /* Non-local PARAM_EXEC paramids found */
59 
61 {
62  const char *ctename; /* name and relative level of target CTE */
63  int levelsup;
64  int refcount; /* number of remaining references */
65  Query *ctequery; /* query to substitute */
67 
68 
69 static Node *build_subplan(PlannerInfo *root, Plan *plan, PlannerInfo *subroot,
70  List *plan_params,
71  SubLinkType subLinkType, int subLinkId,
72  Node *testexpr, bool adjust_testexpr,
73  bool unknownEqFalse);
75  List **paramIds);
77  Index varno);
79  Node *testexpr,
80  List *subst_nodes);
81 static Node *convert_testexpr_mutator(Node *node,
82  convert_testexpr_context *context);
83 static bool subplan_is_hashable(Plan *plan);
84 static bool testexpr_is_hashable(Node *testexpr);
85 static bool hash_ok_operator(OpExpr *expr);
86 static bool contain_dml(Node *node);
87 static bool contain_dml_walker(Node *node, void *context);
88 static bool contain_outer_selfref(Node *node);
89 static bool contain_outer_selfref_walker(Node *node, Index *depth);
90 static void inline_cte(PlannerInfo *root, CommonTableExpr *cte);
91 static bool inline_cte_walker(Node *node, inline_cte_walker_context *context);
92 static bool simplify_EXISTS_query(PlannerInfo *root, Query *query);
93 static Query *convert_EXISTS_to_ANY(PlannerInfo *root, Query *subselect,
94  Node **testexpr, List **paramIds);
96 static Node *process_sublinks_mutator(Node *node,
97  process_sublinks_context *context);
99  Plan *plan,
100  int gather_param,
101  Bitmapset *valid_params,
102  Bitmapset *scan_params);
103 static bool finalize_primnode(Node *node, finalize_primnode_context *context);
104 static bool finalize_agg_primnode(Node *node, finalize_primnode_context *context);
105 
106 
107 /*
108  * Get the datatype/typmod/collation of the first column of the plan's output.
109  *
110  * This information is stored for ARRAY_SUBLINK execution and for
111  * exprType()/exprTypmod()/exprCollation(), which have no way to get at the
112  * plan associated with a SubPlan node. We really only need the info for
113  * EXPR_SUBLINK and ARRAY_SUBLINK subplans, but for consistency we save it
114  * always.
115  */
116 static void
117 get_first_col_type(Plan *plan, Oid *coltype, int32 *coltypmod,
118  Oid *colcollation)
119 {
120  /* In cases such as EXISTS, tlist might be empty; arbitrarily use VOID */
121  if (plan->targetlist)
122  {
124 
125  if (!tent->resjunk)
126  {
127  *coltype = exprType((Node *) tent->expr);
128  *coltypmod = exprTypmod((Node *) tent->expr);
129  *colcollation = exprCollation((Node *) tent->expr);
130  return;
131  }
132  }
133  *coltype = VOIDOID;
134  *coltypmod = -1;
135  *colcollation = InvalidOid;
136 }
137 
138 /*
139  * Convert a SubLink (as created by the parser) into a SubPlan.
140  *
141  * We are given the SubLink's contained query, type, ID, and testexpr. We are
142  * also told if this expression appears at top level of a WHERE/HAVING qual.
143  *
144  * Note: we assume that the testexpr has been AND/OR flattened (actually,
145  * it's been through eval_const_expressions), but not converted to
146  * implicit-AND form; and any SubLinks in it should already have been
147  * converted to SubPlans. The subquery is as yet untouched, however.
148  *
149  * The result is whatever we need to substitute in place of the SubLink node
150  * in the executable expression. If we're going to do the subplan as a
151  * regular subplan, this will be the constructed SubPlan node. If we're going
152  * to do the subplan as an InitPlan, the SubPlan node instead goes into
153  * root->init_plans, and what we return here is an expression tree
154  * representing the InitPlan's result: usually just a Param node representing
155  * a single scalar result, but possibly a row comparison tree containing
156  * multiple Param nodes, or for a MULTIEXPR subquery a simple NULL constant
157  * (since the real output Params are elsewhere in the tree, and the MULTIEXPR
158  * subquery itself is in a resjunk tlist entry whose value is uninteresting).
159  */
160 static Node *
162  SubLinkType subLinkType, int subLinkId,
163  Node *testexpr, bool isTopQual)
164 {
165  Query *subquery;
166  bool simple_exists = false;
167  double tuple_fraction;
168  PlannerInfo *subroot;
169  RelOptInfo *final_rel;
170  Path *best_path;
171  Plan *plan;
172  List *plan_params;
173  Node *result;
174 
175  /*
176  * Copy the source Query node. This is a quick and dirty kluge to resolve
177  * the fact that the parser can generate trees with multiple links to the
178  * same sub-Query node, but the planner wants to scribble on the Query.
179  * Try to clean this up when we do querytree redesign...
180  */
181  subquery = copyObject(orig_subquery);
182 
183  /*
184  * If it's an EXISTS subplan, we might be able to simplify it.
185  */
186  if (subLinkType == EXISTS_SUBLINK)
187  simple_exists = simplify_EXISTS_query(root, subquery);
188 
189  /*
190  * For an EXISTS subplan, tell lower-level planner to expect that only the
191  * first tuple will be retrieved. For ALL and ANY subplans, we will be
192  * able to stop evaluating if the test condition fails or matches, so very
193  * often not all the tuples will be retrieved; for lack of a better idea,
194  * specify 50% retrieval. For EXPR, MULTIEXPR, and ROWCOMPARE subplans,
195  * use default behavior (we're only expecting one row out, anyway).
196  *
197  * NOTE: if you change these numbers, also change cost_subplan() in
198  * path/costsize.c.
199  *
200  * XXX If an ANY subplan is uncorrelated, build_subplan may decide to hash
201  * its output. In that case it would've been better to specify full
202  * retrieval. At present, however, we can only check hashability after
203  * we've made the subplan :-(. (Determining whether it'll fit in work_mem
204  * is the really hard part.) Therefore, we don't want to be too
205  * optimistic about the percentage of tuples retrieved, for fear of
206  * selecting a plan that's bad for the materialization case.
207  */
208  if (subLinkType == EXISTS_SUBLINK)
209  tuple_fraction = 1.0; /* just like a LIMIT 1 */
210  else if (subLinkType == ALL_SUBLINK ||
211  subLinkType == ANY_SUBLINK)
212  tuple_fraction = 0.5; /* 50% */
213  else
214  tuple_fraction = 0.0; /* default behavior */
215 
216  /* plan_params should not be in use in current query level */
217  Assert(root->plan_params == NIL);
218 
219  /* Generate Paths for the subquery */
220  subroot = subquery_planner(root->glob, subquery,
221  root,
222  false, tuple_fraction);
223 
224  /* Isolate the params needed by this specific subplan */
225  plan_params = root->plan_params;
226  root->plan_params = NIL;
227 
228  /*
229  * Select best Path and turn it into a Plan. At least for now, there
230  * seems no reason to postpone doing that.
231  */
232  final_rel = fetch_upper_rel(subroot, UPPERREL_FINAL, NULL);
233  best_path = get_cheapest_fractional_path(final_rel, tuple_fraction);
234 
235  plan = create_plan(subroot, best_path);
236 
237  /* And convert to SubPlan or InitPlan format. */
238  result = build_subplan(root, plan, subroot, plan_params,
239  subLinkType, subLinkId,
240  testexpr, true, isTopQual);
241 
242  /*
243  * If it's a correlated EXISTS with an unimportant targetlist, we might be
244  * able to transform it to the equivalent of an IN and then implement it
245  * by hashing. We don't have enough information yet to tell which way is
246  * likely to be better (it depends on the expected number of executions of
247  * the EXISTS qual, and we are much too early in planning the outer query
248  * to be able to guess that). So we generate both plans, if possible, and
249  * leave it to the executor to decide which to use.
250  */
251  if (simple_exists && IsA(result, SubPlan))
252  {
253  Node *newtestexpr;
254  List *paramIds;
255 
256  /* Make a second copy of the original subquery */
257  subquery = copyObject(orig_subquery);
258  /* and re-simplify */
259  simple_exists = simplify_EXISTS_query(root, subquery);
260  Assert(simple_exists);
261  /* See if it can be converted to an ANY query */
262  subquery = convert_EXISTS_to_ANY(root, subquery,
263  &newtestexpr, &paramIds);
264  if (subquery)
265  {
266  /* Generate Paths for the ANY subquery; we'll need all rows */
267  subroot = subquery_planner(root->glob, subquery,
268  root,
269  false, 0.0);
270 
271  /* Isolate the params needed by this specific subplan */
272  plan_params = root->plan_params;
273  root->plan_params = NIL;
274 
275  /* Select best Path and turn it into a Plan */
276  final_rel = fetch_upper_rel(subroot, UPPERREL_FINAL, NULL);
277  best_path = final_rel->cheapest_total_path;
278 
279  plan = create_plan(subroot, best_path);
280 
281  /* Now we can check if it'll fit in work_mem */
282  /* XXX can we check this at the Path stage? */
283  if (subplan_is_hashable(plan))
284  {
285  SubPlan *hashplan;
286  AlternativeSubPlan *asplan;
287 
288  /* OK, convert to SubPlan format. */
289  hashplan = castNode(SubPlan,
290  build_subplan(root, plan, subroot,
291  plan_params,
292  ANY_SUBLINK, 0,
293  newtestexpr,
294  false, true));
295  /* Check we got what we expected */
296  Assert(hashplan->parParam == NIL);
297  Assert(hashplan->useHashTable);
298  /* build_subplan won't have filled in paramIds */
299  hashplan->paramIds = paramIds;
300 
301  /* Leave it to the executor to decide which plan to use */
302  asplan = makeNode(AlternativeSubPlan);
303  asplan->subplans = list_make2(result, hashplan);
304  result = (Node *) asplan;
305  }
306  }
307  }
308 
309  return result;
310 }
311 
312 /*
313  * Build a SubPlan node given the raw inputs --- subroutine for make_subplan
314  *
315  * Returns either the SubPlan, or a replacement expression if we decide to
316  * make it an InitPlan, as explained in the comments for make_subplan.
317  */
318 static Node *
320  List *plan_params,
321  SubLinkType subLinkType, int subLinkId,
322  Node *testexpr, bool adjust_testexpr,
323  bool unknownEqFalse)
324 {
325  Node *result;
326  SubPlan *splan;
327  bool isInitPlan;
328  ListCell *lc;
329 
330  /*
331  * Initialize the SubPlan node. Note plan_id, plan_name, and cost fields
332  * are set further down.
333  */
334  splan = makeNode(SubPlan);
335  splan->subLinkType = subLinkType;
336  splan->testexpr = NULL;
337  splan->paramIds = NIL;
338  get_first_col_type(plan, &splan->firstColType, &splan->firstColTypmod,
339  &splan->firstColCollation);
340  splan->useHashTable = false;
341  splan->unknownEqFalse = unknownEqFalse;
342  splan->parallel_safe = plan->parallel_safe;
343  splan->setParam = NIL;
344  splan->parParam = NIL;
345  splan->args = NIL;
346 
347  /*
348  * Make parParam and args lists of param IDs and expressions that current
349  * query level will pass to this child plan.
350  */
351  foreach(lc, plan_params)
352  {
353  PlannerParamItem *pitem = (PlannerParamItem *) lfirst(lc);
354  Node *arg = pitem->item;
355 
356  /*
357  * The Var, PlaceHolderVar, or Aggref has already been adjusted to
358  * have the correct varlevelsup, phlevelsup, or agglevelsup.
359  *
360  * If it's a PlaceHolderVar or Aggref, its arguments might contain
361  * SubLinks, which have not yet been processed (see the comments for
362  * SS_replace_correlation_vars). Do that now.
363  */
364  if (IsA(arg, PlaceHolderVar) ||
365  IsA(arg, Aggref))
366  arg = SS_process_sublinks(root, arg, false);
367 
368  splan->parParam = lappend_int(splan->parParam, pitem->paramId);
369  splan->args = lappend(splan->args, arg);
370  }
371 
372  /*
373  * Un-correlated or undirect correlated plans of EXISTS, EXPR, ARRAY,
374  * ROWCOMPARE, or MULTIEXPR types can be used as initPlans. For EXISTS,
375  * EXPR, or ARRAY, we return a Param referring to the result of evaluating
376  * the initPlan. For ROWCOMPARE, we must modify the testexpr tree to
377  * contain PARAM_EXEC Params instead of the PARAM_SUBLINK Params emitted
378  * by the parser, and then return that tree. For MULTIEXPR, we return a
379  * null constant: the resjunk targetlist item containing the SubLink does
380  * not need to return anything useful, since the referencing Params are
381  * elsewhere.
382  */
383  if (splan->parParam == NIL && subLinkType == EXISTS_SUBLINK)
384  {
385  Param *prm;
386 
387  Assert(testexpr == NULL);
388  prm = generate_new_exec_param(root, BOOLOID, -1, InvalidOid);
389  splan->setParam = list_make1_int(prm->paramid);
390  isInitPlan = true;
391  result = (Node *) prm;
392  }
393  else if (splan->parParam == NIL && subLinkType == EXPR_SUBLINK)
394  {
395  TargetEntry *te = linitial(plan->targetlist);
396  Param *prm;
397 
398  Assert(!te->resjunk);
399  Assert(testexpr == NULL);
400  prm = generate_new_exec_param(root,
401  exprType((Node *) te->expr),
402  exprTypmod((Node *) te->expr),
403  exprCollation((Node *) te->expr));
404  splan->setParam = list_make1_int(prm->paramid);
405  isInitPlan = true;
406  result = (Node *) prm;
407  }
408  else if (splan->parParam == NIL && subLinkType == ARRAY_SUBLINK)
409  {
410  TargetEntry *te = linitial(plan->targetlist);
411  Oid arraytype;
412  Param *prm;
413 
414  Assert(!te->resjunk);
415  Assert(testexpr == NULL);
416  arraytype = get_promoted_array_type(exprType((Node *) te->expr));
417  if (!OidIsValid(arraytype))
418  elog(ERROR, "could not find array type for datatype %s",
419  format_type_be(exprType((Node *) te->expr)));
420  prm = generate_new_exec_param(root,
421  arraytype,
422  exprTypmod((Node *) te->expr),
423  exprCollation((Node *) te->expr));
424  splan->setParam = list_make1_int(prm->paramid);
425  isInitPlan = true;
426  result = (Node *) prm;
427  }
428  else if (splan->parParam == NIL && subLinkType == ROWCOMPARE_SUBLINK)
429  {
430  /* Adjust the Params */
431  List *params;
432 
433  Assert(testexpr != NULL);
434  params = generate_subquery_params(root,
435  plan->targetlist,
436  &splan->paramIds);
437  result = convert_testexpr(root,
438  testexpr,
439  params);
440  splan->setParam = list_copy(splan->paramIds);
441  isInitPlan = true;
442 
443  /*
444  * The executable expression is returned to become part of the outer
445  * plan's expression tree; it is not kept in the initplan node.
446  */
447  }
448  else if (subLinkType == MULTIEXPR_SUBLINK)
449  {
450  /*
451  * Whether it's an initplan or not, it needs to set a PARAM_EXEC Param
452  * for each output column.
453  */
454  List *params;
455 
456  Assert(testexpr == NULL);
457  params = generate_subquery_params(root,
458  plan->targetlist,
459  &splan->setParam);
460 
461  /*
462  * Save the list of replacement Params in the n'th cell of
463  * root->multiexpr_params; setrefs.c will use it to replace
464  * PARAM_MULTIEXPR Params.
465  */
466  while (list_length(root->multiexpr_params) < subLinkId)
468  lc = list_nth_cell(root->multiexpr_params, subLinkId - 1);
469  Assert(lfirst(lc) == NIL);
470  lfirst(lc) = params;
471 
472  /* It can be an initplan if there are no parParams. */
473  if (splan->parParam == NIL)
474  {
475  isInitPlan = true;
476  result = (Node *) makeNullConst(RECORDOID, -1, InvalidOid);
477  }
478  else
479  {
480  isInitPlan = false;
481  result = (Node *) splan;
482  }
483  }
484  else
485  {
486  /*
487  * Adjust the Params in the testexpr, unless caller said it's not
488  * needed.
489  */
490  if (testexpr && adjust_testexpr)
491  {
492  List *params;
493 
494  params = generate_subquery_params(root,
495  plan->targetlist,
496  &splan->paramIds);
497  splan->testexpr = convert_testexpr(root,
498  testexpr,
499  params);
500  }
501  else
502  splan->testexpr = testexpr;
503 
504  /*
505  * We can't convert subplans of ALL_SUBLINK or ANY_SUBLINK types to
506  * initPlans, even when they are uncorrelated or undirect correlated,
507  * because we need to scan the output of the subplan for each outer
508  * tuple. But if it's a not-direct-correlated IN (= ANY) test, we
509  * might be able to use a hashtable to avoid comparing all the tuples.
510  */
511  if (subLinkType == ANY_SUBLINK &&
512  splan->parParam == NIL &&
513  subplan_is_hashable(plan) &&
515  splan->useHashTable = true;
516 
517  /*
518  * Otherwise, we have the option to tack a Material node onto the top
519  * of the subplan, to reduce the cost of reading it repeatedly. This
520  * is pointless for a direct-correlated subplan, since we'd have to
521  * recompute its results each time anyway. For uncorrelated/undirect
522  * correlated subplans, we add Material unless the subplan's top plan
523  * node would materialize its output anyway. Also, if enable_material
524  * is false, then the user does not want us to materialize anything
525  * unnecessarily, so we don't.
526  */
527  else if (splan->parParam == NIL && enable_material &&
529  plan = materialize_finished_plan(plan);
530 
531  result = (Node *) splan;
532  isInitPlan = false;
533  }
534 
535  /*
536  * Add the subplan and its PlannerInfo to the global lists.
537  */
538  root->glob->subplans = lappend(root->glob->subplans, plan);
539  root->glob->subroots = lappend(root->glob->subroots, subroot);
540  splan->plan_id = list_length(root->glob->subplans);
541 
542  if (isInitPlan)
543  root->init_plans = lappend(root->init_plans, splan);
544 
545  /*
546  * A parameterless subplan (not initplan) should be prepared to handle
547  * REWIND efficiently. If it has direct parameters then there's no point
548  * since it'll be reset on each scan anyway; and if it's an initplan then
549  * there's no point since it won't get re-run without parameter changes
550  * anyway. The input of a hashed subplan doesn't need REWIND either.
551  */
552  if (splan->parParam == NIL && !isInitPlan && !splan->useHashTable)
554  splan->plan_id);
555 
556  /* Label the subplan for EXPLAIN purposes */
557  splan->plan_name = palloc(32 + 12 * list_length(splan->setParam));
558  sprintf(splan->plan_name, "%s %d",
559  isInitPlan ? "InitPlan" : "SubPlan",
560  splan->plan_id);
561  if (splan->setParam)
562  {
563  char *ptr = splan->plan_name + strlen(splan->plan_name);
564 
565  ptr += sprintf(ptr, " (returns ");
566  foreach(lc, splan->setParam)
567  {
568  ptr += sprintf(ptr, "$%d%s",
569  lfirst_int(lc),
570  lnext(splan->setParam, lc) ? "," : ")");
571  }
572  }
573 
574  /* Lastly, fill in the cost estimates for use later */
575  cost_subplan(root, splan, plan);
576 
577  return result;
578 }
579 
580 /*
581  * generate_subquery_params: build a list of Params representing the output
582  * columns of a sublink's sub-select, given the sub-select's targetlist.
583  *
584  * We also return an integer list of the paramids of the Params.
585  */
586 static List *
588 {
589  List *result;
590  List *ids;
591  ListCell *lc;
592 
593  result = ids = NIL;
594  foreach(lc, tlist)
595  {
596  TargetEntry *tent = (TargetEntry *) lfirst(lc);
597  Param *param;
598 
599  if (tent->resjunk)
600  continue;
601 
602  param = generate_new_exec_param(root,
603  exprType((Node *) tent->expr),
604  exprTypmod((Node *) tent->expr),
605  exprCollation((Node *) tent->expr));
606  result = lappend(result, param);
607  ids = lappend_int(ids, param->paramid);
608  }
609 
610  *paramIds = ids;
611  return result;
612 }
613 
614 /*
615  * generate_subquery_vars: build a list of Vars representing the output
616  * columns of a sublink's sub-select, given the sub-select's targetlist.
617  * The Vars have the specified varno (RTE index).
618  */
619 static List *
621 {
622  List *result;
623  ListCell *lc;
624 
625  result = NIL;
626  foreach(lc, tlist)
627  {
628  TargetEntry *tent = (TargetEntry *) lfirst(lc);
629  Var *var;
630 
631  if (tent->resjunk)
632  continue;
633 
634  var = makeVarFromTargetEntry(varno, tent);
635  result = lappend(result, var);
636  }
637 
638  return result;
639 }
640 
641 /*
642  * convert_testexpr: convert the testexpr given by the parser into
643  * actually executable form. This entails replacing PARAM_SUBLINK Params
644  * with Params or Vars representing the results of the sub-select. The
645  * nodes to be substituted are passed in as the List result from
646  * generate_subquery_params or generate_subquery_vars.
647  */
648 static Node *
650  Node *testexpr,
651  List *subst_nodes)
652 {
653  convert_testexpr_context context;
654 
655  context.root = root;
656  context.subst_nodes = subst_nodes;
657  return convert_testexpr_mutator(testexpr, &context);
658 }
659 
660 static Node *
662  convert_testexpr_context *context)
663 {
664  if (node == NULL)
665  return NULL;
666  if (IsA(node, Param))
667  {
668  Param *param = (Param *) node;
669 
670  if (param->paramkind == PARAM_SUBLINK)
671  {
672  if (param->paramid <= 0 ||
673  param->paramid > list_length(context->subst_nodes))
674  elog(ERROR, "unexpected PARAM_SUBLINK ID: %d", param->paramid);
675 
676  /*
677  * We copy the list item to avoid having doubly-linked
678  * substructure in the modified parse tree. This is probably
679  * unnecessary when it's a Param, but be safe.
680  */
681  return (Node *) copyObject(list_nth(context->subst_nodes,
682  param->paramid - 1));
683  }
684  }
685  if (IsA(node, SubLink))
686  {
687  /*
688  * If we come across a nested SubLink, it is neither necessary nor
689  * correct to recurse into it: any PARAM_SUBLINKs we might find inside
690  * belong to the inner SubLink not the outer. So just return it as-is.
691  *
692  * This reasoning depends on the assumption that nothing will pull
693  * subexpressions into or out of the testexpr field of a SubLink, at
694  * least not without replacing PARAM_SUBLINKs first. If we did want
695  * to do that we'd need to rethink the parser-output representation
696  * altogether, since currently PARAM_SUBLINKs are only unique per
697  * SubLink not globally across the query. The whole point of
698  * replacing them with Vars or PARAM_EXEC nodes is to make them
699  * globally unique before they escape from the SubLink's testexpr.
700  *
701  * Note: this can't happen when called during SS_process_sublinks,
702  * because that recursively processes inner SubLinks first. It can
703  * happen when called from convert_ANY_sublink_to_join, though.
704  */
705  return node;
706  }
707  return expression_tree_mutator(node,
709  (void *) context);
710 }
711 
712 /*
713  * subplan_is_hashable: can we implement an ANY subplan by hashing?
714  */
715 static bool
717 {
718  double subquery_size;
719 
720  /*
721  * The estimated size of the subquery result must fit in work_mem. (Note:
722  * we use heap tuple overhead here even though the tuples will actually be
723  * stored as MinimalTuples; this provides some fudge factor for hashtable
724  * overhead.)
725  */
726  subquery_size = plan->plan_rows *
728  if (subquery_size > work_mem * 1024L)
729  return false;
730 
731  return true;
732 }
733 
734 /*
735  * testexpr_is_hashable: is an ANY SubLink's test expression hashable?
736  */
737 static bool
739 {
740  /*
741  * The testexpr must be a single OpExpr, or an AND-clause containing only
742  * OpExprs.
743  *
744  * The combining operators must be hashable and strict. The need for
745  * hashability is obvious, since we want to use hashing. Without
746  * strictness, behavior in the presence of nulls is too unpredictable. We
747  * actually must assume even more than plain strictness: they can't yield
748  * NULL for non-null inputs, either (see nodeSubplan.c). However, hash
749  * indexes and hash joins assume that too.
750  */
751  if (testexpr && IsA(testexpr, OpExpr))
752  {
753  if (hash_ok_operator((OpExpr *) testexpr))
754  return true;
755  }
756  else if (is_andclause(testexpr))
757  {
758  ListCell *l;
759 
760  foreach(l, ((BoolExpr *) testexpr)->args)
761  {
762  Node *andarg = (Node *) lfirst(l);
763 
764  if (!IsA(andarg, OpExpr))
765  return false;
766  if (!hash_ok_operator((OpExpr *) andarg))
767  return false;
768  }
769  return true;
770  }
771 
772  return false;
773 }
774 
775 /*
776  * Check expression is hashable + strict
777  *
778  * We could use op_hashjoinable() and op_strict(), but do it like this to
779  * avoid a redundant cache lookup.
780  */
781 static bool
783 {
784  Oid opid = expr->opno;
785 
786  /* quick out if not a binary operator */
787  if (list_length(expr->args) != 2)
788  return false;
789  if (opid == ARRAY_EQ_OP)
790  {
791  /* array_eq is strict, but must check input type to ensure hashable */
792  /* XXX record_eq will need same treatment when it becomes hashable */
793  Node *leftarg = linitial(expr->args);
794 
795  return op_hashjoinable(opid, exprType(leftarg));
796  }
797  else
798  {
799  /* else must look up the operator properties */
800  HeapTuple tup;
801  Form_pg_operator optup;
802 
804  if (!HeapTupleIsValid(tup))
805  elog(ERROR, "cache lookup failed for operator %u", opid);
806  optup = (Form_pg_operator) GETSTRUCT(tup);
807  if (!optup->oprcanhash || !func_strict(optup->oprcode))
808  {
809  ReleaseSysCache(tup);
810  return false;
811  }
812  ReleaseSysCache(tup);
813  return true;
814  }
815 }
816 
817 
818 /*
819  * SS_process_ctes: process a query's WITH list
820  *
821  * Consider each CTE in the WITH list and either ignore it (if it's an
822  * unreferenced SELECT), "inline" it to create a regular sub-SELECT-in-FROM,
823  * or convert it to an initplan.
824  *
825  * A side effect is to fill in root->cte_plan_ids with a list that
826  * parallels root->parse->cteList and provides the subplan ID for
827  * each CTE's initplan, or a dummy ID (-1) if we didn't make an initplan.
828  */
829 void
831 {
832  ListCell *lc;
833 
834  Assert(root->cte_plan_ids == NIL);
835 
836  foreach(lc, root->parse->cteList)
837  {
838  CommonTableExpr *cte = (CommonTableExpr *) lfirst(lc);
839  CmdType cmdType = ((Query *) cte->ctequery)->commandType;
840  Query *subquery;
841  PlannerInfo *subroot;
842  RelOptInfo *final_rel;
843  Path *best_path;
844  Plan *plan;
845  SubPlan *splan;
846  int paramid;
847 
848  /*
849  * Ignore SELECT CTEs that are not actually referenced anywhere.
850  */
851  if (cte->cterefcount == 0 && cmdType == CMD_SELECT)
852  {
853  /* Make a dummy entry in cte_plan_ids */
854  root->cte_plan_ids = lappend_int(root->cte_plan_ids, -1);
855  continue;
856  }
857 
858  /*
859  * Consider inlining the CTE (creating RTE_SUBQUERY RTE(s)) instead of
860  * implementing it as a separately-planned CTE.
861  *
862  * We cannot inline if any of these conditions hold:
863  *
864  * 1. The user said not to (the CTEMaterializeAlways option).
865  *
866  * 2. The CTE is recursive.
867  *
868  * 3. The CTE has side-effects; this includes either not being a plain
869  * SELECT, or containing volatile functions. Inlining might change
870  * the side-effects, which would be bad.
871  *
872  * 4. The CTE is multiply-referenced and contains a self-reference to
873  * a recursive CTE outside itself. Inlining would result in multiple
874  * recursive self-references, which we don't support.
875  *
876  * Otherwise, we have an option whether to inline or not. That should
877  * always be a win if there's just a single reference, but if the CTE
878  * is multiply-referenced then it's unclear: inlining adds duplicate
879  * computations, but the ability to absorb restrictions from the outer
880  * query level could outweigh that. We do not have nearly enough
881  * information at this point to tell whether that's true, so we let
882  * the user express a preference. Our default behavior is to inline
883  * only singly-referenced CTEs, but a CTE marked CTEMaterializeNever
884  * will be inlined even if multiply referenced.
885  *
886  * Note: we check for volatile functions last, because that's more
887  * expensive than the other tests needed.
888  */
889  if ((cte->ctematerialized == CTEMaterializeNever ||
891  cte->cterefcount == 1)) &&
892  !cte->cterecursive &&
893  cmdType == CMD_SELECT &&
894  !contain_dml(cte->ctequery) &&
895  (cte->cterefcount <= 1 ||
898  {
899  inline_cte(root, cte);
900  /* Make a dummy entry in cte_plan_ids */
901  root->cte_plan_ids = lappend_int(root->cte_plan_ids, -1);
902  continue;
903  }
904 
905  /*
906  * Copy the source Query node. Probably not necessary, but let's keep
907  * this similar to make_subplan.
908  */
909  subquery = (Query *) copyObject(cte->ctequery);
910 
911  /* plan_params should not be in use in current query level */
912  Assert(root->plan_params == NIL);
913 
914  /*
915  * Generate Paths for the CTE query. Always plan for full retrieval
916  * --- we don't have enough info to predict otherwise.
917  */
918  subroot = subquery_planner(root->glob, subquery,
919  root,
920  cte->cterecursive, 0.0);
921 
922  /*
923  * Since the current query level doesn't yet contain any RTEs, it
924  * should not be possible for the CTE to have requested parameters of
925  * this level.
926  */
927  if (root->plan_params)
928  elog(ERROR, "unexpected outer reference in CTE query");
929 
930  /*
931  * Select best Path and turn it into a Plan. At least for now, there
932  * seems no reason to postpone doing that.
933  */
934  final_rel = fetch_upper_rel(subroot, UPPERREL_FINAL, NULL);
935  best_path = final_rel->cheapest_total_path;
936 
937  plan = create_plan(subroot, best_path);
938 
939  /*
940  * Make a SubPlan node for it. This is just enough unlike
941  * build_subplan that we can't share code.
942  *
943  * Note plan_id, plan_name, and cost fields are set further down.
944  */
945  splan = makeNode(SubPlan);
946  splan->subLinkType = CTE_SUBLINK;
947  splan->testexpr = NULL;
948  splan->paramIds = NIL;
949  get_first_col_type(plan, &splan->firstColType, &splan->firstColTypmod,
950  &splan->firstColCollation);
951  splan->useHashTable = false;
952  splan->unknownEqFalse = false;
953 
954  /*
955  * CTE scans are not considered for parallelism (cf
956  * set_rel_consider_parallel), and even if they were, initPlans aren't
957  * parallel-safe.
958  */
959  splan->parallel_safe = false;
960  splan->setParam = NIL;
961  splan->parParam = NIL;
962  splan->args = NIL;
963 
964  /*
965  * The node can't have any inputs (since it's an initplan), so the
966  * parParam and args lists remain empty. (It could contain references
967  * to earlier CTEs' output param IDs, but CTE outputs are not
968  * propagated via the args list.)
969  */
970 
971  /*
972  * Assign a param ID to represent the CTE's output. No ordinary
973  * "evaluation" of this param slot ever happens, but we use the param
974  * ID for setParam/chgParam signaling just as if the CTE plan were
975  * returning a simple scalar output. (Also, the executor abuses the
976  * ParamExecData slot for this param ID for communication among
977  * multiple CteScan nodes that might be scanning this CTE.)
978  */
979  paramid = assign_special_exec_param(root);
980  splan->setParam = list_make1_int(paramid);
981 
982  /*
983  * Add the subplan and its PlannerInfo to the global lists.
984  */
985  root->glob->subplans = lappend(root->glob->subplans, plan);
986  root->glob->subroots = lappend(root->glob->subroots, subroot);
987  splan->plan_id = list_length(root->glob->subplans);
988 
989  root->init_plans = lappend(root->init_plans, splan);
990 
991  root->cte_plan_ids = lappend_int(root->cte_plan_ids, splan->plan_id);
992 
993  /* Label the subplan for EXPLAIN purposes */
994  splan->plan_name = psprintf("CTE %s", cte->ctename);
995 
996  /* Lastly, fill in the cost estimates for use later */
997  cost_subplan(root, splan, plan);
998  }
999 }
1000 
1001 /*
1002  * contain_dml: is any subquery not a plain SELECT?
1003  *
1004  * We reject SELECT FOR UPDATE/SHARE as well as INSERT etc.
1005  */
1006 static bool
1008 {
1009  return contain_dml_walker(node, NULL);
1010 }
1011 
1012 static bool
1013 contain_dml_walker(Node *node, void *context)
1014 {
1015  if (node == NULL)
1016  return false;
1017  if (IsA(node, Query))
1018  {
1019  Query *query = (Query *) node;
1020 
1021  if (query->commandType != CMD_SELECT ||
1022  query->rowMarks != NIL)
1023  return true;
1024 
1025  return query_tree_walker(query, contain_dml_walker, context, 0);
1026  }
1027  return expression_tree_walker(node, contain_dml_walker, context);
1028 }
1029 
1030 /*
1031  * contain_outer_selfref: is there an external recursive self-reference?
1032  */
1033 static bool
1035 {
1036  Index depth = 0;
1037 
1038  /*
1039  * We should be starting with a Query, so that depth will be 1 while
1040  * examining its immediate contents.
1041  */
1042  Assert(IsA(node, Query));
1043 
1044  return contain_outer_selfref_walker(node, &depth);
1045 }
1046 
1047 static bool
1049 {
1050  if (node == NULL)
1051  return false;
1052  if (IsA(node, RangeTblEntry))
1053  {
1054  RangeTblEntry *rte = (RangeTblEntry *) node;
1055 
1056  /*
1057  * Check for a self-reference to a CTE that's above the Query that our
1058  * search started at.
1059  */
1060  if (rte->rtekind == RTE_CTE &&
1061  rte->self_reference &&
1062  rte->ctelevelsup >= *depth)
1063  return true;
1064  return false; /* allow range_table_walker to continue */
1065  }
1066  if (IsA(node, Query))
1067  {
1068  /* Recurse into subquery, tracking nesting depth properly */
1069  Query *query = (Query *) node;
1070  bool result;
1071 
1072  (*depth)++;
1073 
1075  (void *) depth, QTW_EXAMINE_RTES_BEFORE);
1076 
1077  (*depth)--;
1078 
1079  return result;
1080  }
1082  (void *) depth);
1083 }
1084 
1085 /*
1086  * inline_cte: convert RTE_CTE references to given CTE into RTE_SUBQUERYs
1087  */
1088 static void
1090 {
1091  struct inline_cte_walker_context context;
1092 
1093  context.ctename = cte->ctename;
1094  /* Start at levelsup = -1 because we'll immediately increment it */
1095  context.levelsup = -1;
1096  context.refcount = cte->cterefcount;
1097  context.ctequery = castNode(Query, cte->ctequery);
1098 
1099  (void) inline_cte_walker((Node *) root->parse, &context);
1100 
1101  /* Assert we replaced all references */
1102  Assert(context.refcount == 0);
1103 }
1104 
1105 static bool
1107 {
1108  if (node == NULL)
1109  return false;
1110  if (IsA(node, Query))
1111  {
1112  Query *query = (Query *) node;
1113 
1114  context->levelsup++;
1115 
1116  /*
1117  * Visit the query's RTE nodes after their contents; otherwise
1118  * query_tree_walker would descend into the newly inlined CTE query,
1119  * which we don't want.
1120  */
1121  (void) query_tree_walker(query, inline_cte_walker, context,
1123 
1124  context->levelsup--;
1125 
1126  return false;
1127  }
1128  else if (IsA(node, RangeTblEntry))
1129  {
1130  RangeTblEntry *rte = (RangeTblEntry *) node;
1131 
1132  if (rte->rtekind == RTE_CTE &&
1133  strcmp(rte->ctename, context->ctename) == 0 &&
1134  rte->ctelevelsup == context->levelsup)
1135  {
1136  /*
1137  * Found a reference to replace. Generate a copy of the CTE query
1138  * with appropriate level adjustment for outer references (e.g.,
1139  * to other CTEs).
1140  */
1141  Query *newquery = copyObject(context->ctequery);
1142 
1143  if (context->levelsup > 0)
1144  IncrementVarSublevelsUp((Node *) newquery, context->levelsup, 1);
1145 
1146  /*
1147  * Convert the RTE_CTE RTE into a RTE_SUBQUERY.
1148  *
1149  * Historically, a FOR UPDATE clause has been treated as extending
1150  * into views and subqueries, but not into CTEs. We preserve this
1151  * distinction by not trying to push rowmarks into the new
1152  * subquery.
1153  */
1154  rte->rtekind = RTE_SUBQUERY;
1155  rte->subquery = newquery;
1156  rte->security_barrier = false;
1157 
1158  /* Zero out CTE-specific fields */
1159  rte->ctename = NULL;
1160  rte->ctelevelsup = 0;
1161  rte->self_reference = false;
1162  rte->coltypes = NIL;
1163  rte->coltypmods = NIL;
1164  rte->colcollations = NIL;
1165 
1166  /* Count the number of replacements we've done */
1167  context->refcount--;
1168  }
1169 
1170  return false;
1171  }
1172 
1173  return expression_tree_walker(node, inline_cte_walker, context);
1174 }
1175 
1176 
1177 /*
1178  * convert_ANY_sublink_to_join: try to convert an ANY SubLink to a join
1179  *
1180  * The caller has found an ANY SubLink at the top level of one of the query's
1181  * qual clauses, but has not checked the properties of the SubLink further.
1182  * Decide whether it is appropriate to process this SubLink in join style.
1183  * If so, form a JoinExpr and return it. Return NULL if the SubLink cannot
1184  * be converted to a join.
1185  *
1186  * The only non-obvious input parameter is available_rels: this is the set
1187  * of query rels that can safely be referenced in the sublink expression.
1188  * (We must restrict this to avoid changing the semantics when a sublink
1189  * is present in an outer join's ON qual.) The conversion must fail if
1190  * the converted qual would reference any but these parent-query relids.
1191  *
1192  * On success, the returned JoinExpr has larg = NULL and rarg = the jointree
1193  * item representing the pulled-up subquery. The caller must set larg to
1194  * represent the relation(s) on the lefthand side of the new join, and insert
1195  * the JoinExpr into the upper query's jointree at an appropriate place
1196  * (typically, where the lefthand relation(s) had been). Note that the
1197  * passed-in SubLink must also be removed from its original position in the
1198  * query quals, since the quals of the returned JoinExpr replace it.
1199  * (Notionally, we replace the SubLink with a constant TRUE, then elide the
1200  * redundant constant from the qual.)
1201  *
1202  * On success, the caller is also responsible for recursively applying
1203  * pull_up_sublinks processing to the rarg and quals of the returned JoinExpr.
1204  * (On failure, there is no need to do anything, since pull_up_sublinks will
1205  * be applied when we recursively plan the sub-select.)
1206  *
1207  * Side effects of a successful conversion include adding the SubLink's
1208  * subselect to the query's rangetable, so that it can be referenced in
1209  * the JoinExpr's rarg.
1210  */
1211 JoinExpr *
1213  Relids available_rels)
1214 {
1215  JoinExpr *result;
1216  Query *parse = root->parse;
1217  Query *subselect = (Query *) sublink->subselect;
1218  Relids upper_varnos;
1219  int rtindex;
1220  ParseNamespaceItem *nsitem;
1221  RangeTblEntry *rte;
1222  RangeTblRef *rtr;
1223  List *subquery_vars;
1224  Node *quals;
1225  ParseState *pstate;
1226 
1227  Assert(sublink->subLinkType == ANY_SUBLINK);
1228 
1229  /*
1230  * The sub-select must not refer to any Vars of the parent query. (Vars of
1231  * higher levels should be okay, though.)
1232  */
1233  if (contain_vars_of_level((Node *) subselect, 1))
1234  return NULL;
1235 
1236  /*
1237  * The test expression must contain some Vars of the parent query, else
1238  * it's not gonna be a join. (Note that it won't have Vars referring to
1239  * the subquery, rather Params.)
1240  */
1241  upper_varnos = pull_varnos(sublink->testexpr);
1242  if (bms_is_empty(upper_varnos))
1243  return NULL;
1244 
1245  /*
1246  * However, it can't refer to anything outside available_rels.
1247  */
1248  if (!bms_is_subset(upper_varnos, available_rels))
1249  return NULL;
1250 
1251  /*
1252  * The combining operators and left-hand expressions mustn't be volatile.
1253  */
1254  if (contain_volatile_functions(sublink->testexpr))
1255  return NULL;
1256 
1257  /* Create a dummy ParseState for addRangeTableEntryForSubquery */
1258  pstate = make_parsestate(NULL);
1259 
1260  /*
1261  * Okay, pull up the sub-select into upper range table.
1262  *
1263  * We rely here on the assumption that the outer query has no references
1264  * to the inner (necessarily true, other than the Vars that we build
1265  * below). Therefore this is a lot easier than what pull_up_subqueries has
1266  * to go through.
1267  */
1268  nsitem = addRangeTableEntryForSubquery(pstate,
1269  subselect,
1270  makeAlias("ANY_subquery", NIL),
1271  false,
1272  false);
1273  rte = nsitem->p_rte;
1274  parse->rtable = lappend(parse->rtable, rte);
1275  rtindex = list_length(parse->rtable);
1276 
1277  /*
1278  * Form a RangeTblRef for the pulled-up sub-select.
1279  */
1280  rtr = makeNode(RangeTblRef);
1281  rtr->rtindex = rtindex;
1282 
1283  /*
1284  * Build a list of Vars representing the subselect outputs.
1285  */
1286  subquery_vars = generate_subquery_vars(root,
1287  subselect->targetList,
1288  rtindex);
1289 
1290  /*
1291  * Build the new join's qual expression, replacing Params with these Vars.
1292  */
1293  quals = convert_testexpr(root, sublink->testexpr, subquery_vars);
1294 
1295  /*
1296  * And finally, build the JoinExpr node.
1297  */
1298  result = makeNode(JoinExpr);
1299  result->jointype = JOIN_SEMI;
1300  result->isNatural = false;
1301  result->larg = NULL; /* caller must fill this in */
1302  result->rarg = (Node *) rtr;
1303  result->usingClause = NIL;
1304  result->quals = quals;
1305  result->alias = NULL;
1306  result->rtindex = 0; /* we don't need an RTE for it */
1307 
1308  return result;
1309 }
1310 
1311 /*
1312  * convert_EXISTS_sublink_to_join: try to convert an EXISTS SubLink to a join
1313  *
1314  * The API of this function is identical to convert_ANY_sublink_to_join's,
1315  * except that we also support the case where the caller has found NOT EXISTS,
1316  * so we need an additional input parameter "under_not".
1317  */
1318 JoinExpr *
1320  bool under_not, Relids available_rels)
1321 {
1322  JoinExpr *result;
1323  Query *parse = root->parse;
1324  Query *subselect = (Query *) sublink->subselect;
1325  Node *whereClause;
1326  int rtoffset;
1327  int varno;
1328  Relids clause_varnos;
1329  Relids upper_varnos;
1330 
1331  Assert(sublink->subLinkType == EXISTS_SUBLINK);
1332 
1333  /*
1334  * Can't flatten if it contains WITH. (We could arrange to pull up the
1335  * WITH into the parent query's cteList, but that risks changing the
1336  * semantics, since a WITH ought to be executed once per associated query
1337  * call.) Note that convert_ANY_sublink_to_join doesn't have to reject
1338  * this case, since it just produces a subquery RTE that doesn't have to
1339  * get flattened into the parent query.
1340  */
1341  if (subselect->cteList)
1342  return NULL;
1343 
1344  /*
1345  * Copy the subquery so we can modify it safely (see comments in
1346  * make_subplan).
1347  */
1348  subselect = copyObject(subselect);
1349 
1350  /*
1351  * See if the subquery can be simplified based on the knowledge that it's
1352  * being used in EXISTS(). If we aren't able to get rid of its
1353  * targetlist, we have to fail, because the pullup operation leaves us
1354  * with noplace to evaluate the targetlist.
1355  */
1356  if (!simplify_EXISTS_query(root, subselect))
1357  return NULL;
1358 
1359  /*
1360  * Separate out the WHERE clause. (We could theoretically also remove
1361  * top-level plain JOIN/ON clauses, but it's probably not worth the
1362  * trouble.)
1363  */
1364  whereClause = subselect->jointree->quals;
1365  subselect->jointree->quals = NULL;
1366 
1367  /*
1368  * The rest of the sub-select must not refer to any Vars of the parent
1369  * query. (Vars of higher levels should be okay, though.)
1370  */
1371  if (contain_vars_of_level((Node *) subselect, 1))
1372  return NULL;
1373 
1374  /*
1375  * On the other hand, the WHERE clause must contain some Vars of the
1376  * parent query, else it's not gonna be a join.
1377  */
1378  if (!contain_vars_of_level(whereClause, 1))
1379  return NULL;
1380 
1381  /*
1382  * We don't risk optimizing if the WHERE clause is volatile, either.
1383  */
1384  if (contain_volatile_functions(whereClause))
1385  return NULL;
1386 
1387  /*
1388  * The subquery must have a nonempty jointree, but we can make it so.
1389  */
1390  replace_empty_jointree(subselect);
1391 
1392  /*
1393  * Prepare to pull up the sub-select into top range table.
1394  *
1395  * We rely here on the assumption that the outer query has no references
1396  * to the inner (necessarily true). Therefore this is a lot easier than
1397  * what pull_up_subqueries has to go through.
1398  *
1399  * In fact, it's even easier than what convert_ANY_sublink_to_join has to
1400  * do. The machinations of simplify_EXISTS_query ensured that there is
1401  * nothing interesting in the subquery except an rtable and jointree, and
1402  * even the jointree FromExpr no longer has quals. So we can just append
1403  * the rtable to our own and use the FromExpr in our jointree. But first,
1404  * adjust all level-zero varnos in the subquery to account for the rtable
1405  * merger.
1406  */
1407  rtoffset = list_length(parse->rtable);
1408  OffsetVarNodes((Node *) subselect, rtoffset, 0);
1409  OffsetVarNodes(whereClause, rtoffset, 0);
1410 
1411  /*
1412  * Upper-level vars in subquery will now be one level closer to their
1413  * parent than before; in particular, anything that had been level 1
1414  * becomes level zero.
1415  */
1416  IncrementVarSublevelsUp((Node *) subselect, -1, 1);
1417  IncrementVarSublevelsUp(whereClause, -1, 1);
1418 
1419  /*
1420  * Now that the WHERE clause is adjusted to match the parent query
1421  * environment, we can easily identify all the level-zero rels it uses.
1422  * The ones <= rtoffset belong to the upper query; the ones > rtoffset do
1423  * not.
1424  */
1425  clause_varnos = pull_varnos(whereClause);
1426  upper_varnos = NULL;
1427  while ((varno = bms_first_member(clause_varnos)) >= 0)
1428  {
1429  if (varno <= rtoffset)
1430  upper_varnos = bms_add_member(upper_varnos, varno);
1431  }
1432  bms_free(clause_varnos);
1433  Assert(!bms_is_empty(upper_varnos));
1434 
1435  /*
1436  * Now that we've got the set of upper-level varnos, we can make the last
1437  * check: only available_rels can be referenced.
1438  */
1439  if (!bms_is_subset(upper_varnos, available_rels))
1440  return NULL;
1441 
1442  /* Now we can attach the modified subquery rtable to the parent */
1443  parse->rtable = list_concat(parse->rtable, subselect->rtable);
1444 
1445  /*
1446  * And finally, build the JoinExpr node.
1447  */
1448  result = makeNode(JoinExpr);
1449  result->jointype = under_not ? JOIN_ANTI : JOIN_SEMI;
1450  result->isNatural = false;
1451  result->larg = NULL; /* caller must fill this in */
1452  /* flatten out the FromExpr node if it's useless */
1453  if (list_length(subselect->jointree->fromlist) == 1)
1454  result->rarg = (Node *) linitial(subselect->jointree->fromlist);
1455  else
1456  result->rarg = (Node *) subselect->jointree;
1457  result->usingClause = NIL;
1458  result->quals = whereClause;
1459  result->alias = NULL;
1460  result->rtindex = 0; /* we don't need an RTE for it */
1461 
1462  return result;
1463 }
1464 
1465 /*
1466  * simplify_EXISTS_query: remove any useless stuff in an EXISTS's subquery
1467  *
1468  * The only thing that matters about an EXISTS query is whether it returns
1469  * zero or more than zero rows. Therefore, we can remove certain SQL features
1470  * that won't affect that. The only part that is really likely to matter in
1471  * typical usage is simplifying the targetlist: it's a common habit to write
1472  * "SELECT * FROM" even though there is no need to evaluate any columns.
1473  *
1474  * Note: by suppressing the targetlist we could cause an observable behavioral
1475  * change, namely that any errors that might occur in evaluating the tlist
1476  * won't occur, nor will other side-effects of volatile functions. This seems
1477  * unlikely to bother anyone in practice.
1478  *
1479  * Returns true if was able to discard the targetlist, else false.
1480  */
1481 static bool
1483 {
1484  /*
1485  * We don't try to simplify at all if the query uses set operations,
1486  * aggregates, grouping sets, SRFs, modifying CTEs, HAVING, OFFSET, or FOR
1487  * UPDATE/SHARE; none of these seem likely in normal usage and their
1488  * possible effects are complex. (Note: we could ignore an "OFFSET 0"
1489  * clause, but that traditionally is used as an optimization fence, so we
1490  * don't.)
1491  */
1492  if (query->commandType != CMD_SELECT ||
1493  query->setOperations ||
1494  query->hasAggs ||
1495  query->groupingSets ||
1496  query->hasWindowFuncs ||
1497  query->hasTargetSRFs ||
1498  query->hasModifyingCTE ||
1499  query->havingQual ||
1500  query->limitOffset ||
1501  query->rowMarks)
1502  return false;
1503 
1504  /*
1505  * LIMIT with a constant positive (or NULL) value doesn't affect the
1506  * semantics of EXISTS, so let's ignore such clauses. This is worth doing
1507  * because people accustomed to certain other DBMSes may be in the habit
1508  * of writing EXISTS(SELECT ... LIMIT 1) as an optimization. If there's a
1509  * LIMIT with anything else as argument, though, we can't simplify.
1510  */
1511  if (query->limitCount)
1512  {
1513  /*
1514  * The LIMIT clause has not yet been through eval_const_expressions,
1515  * so we have to apply that here. It might seem like this is a waste
1516  * of cycles, since the only case plausibly worth worrying about is
1517  * "LIMIT 1" ... but what we'll actually see is "LIMIT int8(1::int4)",
1518  * so we have to fold constants or we're not going to recognize it.
1519  */
1520  Node *node = eval_const_expressions(root, query->limitCount);
1521  Const *limit;
1522 
1523  /* Might as well update the query if we simplified the clause. */
1524  query->limitCount = node;
1525 
1526  if (!IsA(node, Const))
1527  return false;
1528 
1529  limit = (Const *) node;
1530  Assert(limit->consttype == INT8OID);
1531  if (!limit->constisnull && DatumGetInt64(limit->constvalue) <= 0)
1532  return false;
1533 
1534  /* Whether or not the targetlist is safe, we can drop the LIMIT. */
1535  query->limitCount = NULL;
1536  }
1537 
1538  /*
1539  * Otherwise, we can throw away the targetlist, as well as any GROUP,
1540  * WINDOW, DISTINCT, and ORDER BY clauses; none of those clauses will
1541  * change a nonzero-rows result to zero rows or vice versa. (Furthermore,
1542  * since our parsetree representation of these clauses depends on the
1543  * targetlist, we'd better throw them away if we drop the targetlist.)
1544  */
1545  query->targetList = NIL;
1546  query->groupClause = NIL;
1547  query->windowClause = NIL;
1548  query->distinctClause = NIL;
1549  query->sortClause = NIL;
1550  query->hasDistinctOn = false;
1551 
1552  return true;
1553 }
1554 
1555 /*
1556  * convert_EXISTS_to_ANY: try to convert EXISTS to a hashable ANY sublink
1557  *
1558  * The subselect is expected to be a fresh copy that we can munge up,
1559  * and to have been successfully passed through simplify_EXISTS_query.
1560  *
1561  * On success, the modified subselect is returned, and we store a suitable
1562  * upper-level test expression at *testexpr, plus a list of the subselect's
1563  * output Params at *paramIds. (The test expression is already Param-ified
1564  * and hence need not go through convert_testexpr, which is why we have to
1565  * deal with the Param IDs specially.)
1566  *
1567  * On failure, returns NULL.
1568  */
1569 static Query *
1571  Node **testexpr, List **paramIds)
1572 {
1573  Node *whereClause;
1574  List *leftargs,
1575  *rightargs,
1576  *opids,
1577  *opcollations,
1578  *newWhere,
1579  *tlist,
1580  *testlist,
1581  *paramids;
1582  ListCell *lc,
1583  *rc,
1584  *oc,
1585  *cc;
1586  AttrNumber resno;
1587 
1588  /*
1589  * Query must not require a targetlist, since we have to insert a new one.
1590  * Caller should have dealt with the case already.
1591  */
1592  Assert(subselect->targetList == NIL);
1593 
1594  /*
1595  * Separate out the WHERE clause. (We could theoretically also remove
1596  * top-level plain JOIN/ON clauses, but it's probably not worth the
1597  * trouble.)
1598  */
1599  whereClause = subselect->jointree->quals;
1600  subselect->jointree->quals = NULL;
1601 
1602  /*
1603  * The rest of the sub-select must not refer to any Vars of the parent
1604  * query. (Vars of higher levels should be okay, though.)
1605  *
1606  * Note: we need not check for Aggrefs separately because we know the
1607  * sub-select is as yet unoptimized; any uplevel Aggref must therefore
1608  * contain an uplevel Var reference. This is not the case below ...
1609  */
1610  if (contain_vars_of_level((Node *) subselect, 1))
1611  return NULL;
1612 
1613  /*
1614  * We don't risk optimizing if the WHERE clause is volatile, either.
1615  */
1616  if (contain_volatile_functions(whereClause))
1617  return NULL;
1618 
1619  /*
1620  * Clean up the WHERE clause by doing const-simplification etc on it.
1621  * Aside from simplifying the processing we're about to do, this is
1622  * important for being able to pull chunks of the WHERE clause up into the
1623  * parent query. Since we are invoked partway through the parent's
1624  * preprocess_expression() work, earlier steps of preprocess_expression()
1625  * wouldn't get applied to the pulled-up stuff unless we do them here. For
1626  * the parts of the WHERE clause that get put back into the child query,
1627  * this work is partially duplicative, but it shouldn't hurt.
1628  *
1629  * Note: we do not run flatten_join_alias_vars. This is OK because any
1630  * parent aliases were flattened already, and we're not going to pull any
1631  * child Vars (of any description) into the parent.
1632  *
1633  * Note: passing the parent's root to eval_const_expressions is
1634  * technically wrong, but we can get away with it since only the
1635  * boundParams (if any) are used, and those would be the same in a
1636  * subroot.
1637  */
1638  whereClause = eval_const_expressions(root, whereClause);
1639  whereClause = (Node *) canonicalize_qual((Expr *) whereClause, false);
1640  whereClause = (Node *) make_ands_implicit((Expr *) whereClause);
1641 
1642  /*
1643  * We now have a flattened implicit-AND list of clauses, which we try to
1644  * break apart into "outervar = innervar" hash clauses. Anything that
1645  * can't be broken apart just goes back into the newWhere list. Note that
1646  * we aren't trying hard yet to ensure that we have only outer or only
1647  * inner on each side; we'll check that if we get to the end.
1648  */
1649  leftargs = rightargs = opids = opcollations = newWhere = NIL;
1650  foreach(lc, (List *) whereClause)
1651  {
1652  OpExpr *expr = (OpExpr *) lfirst(lc);
1653 
1654  if (IsA(expr, OpExpr) &&
1655  hash_ok_operator(expr))
1656  {
1657  Node *leftarg = (Node *) linitial(expr->args);
1658  Node *rightarg = (Node *) lsecond(expr->args);
1659 
1660  if (contain_vars_of_level(leftarg, 1))
1661  {
1662  leftargs = lappend(leftargs, leftarg);
1663  rightargs = lappend(rightargs, rightarg);
1664  opids = lappend_oid(opids, expr->opno);
1665  opcollations = lappend_oid(opcollations, expr->inputcollid);
1666  continue;
1667  }
1668  if (contain_vars_of_level(rightarg, 1))
1669  {
1670  /*
1671  * We must commute the clause to put the outer var on the
1672  * left, because the hashing code in nodeSubplan.c expects
1673  * that. This probably shouldn't ever fail, since hashable
1674  * operators ought to have commutators, but be paranoid.
1675  */
1676  expr->opno = get_commutator(expr->opno);
1677  if (OidIsValid(expr->opno) && hash_ok_operator(expr))
1678  {
1679  leftargs = lappend(leftargs, rightarg);
1680  rightargs = lappend(rightargs, leftarg);
1681  opids = lappend_oid(opids, expr->opno);
1682  opcollations = lappend_oid(opcollations, expr->inputcollid);
1683  continue;
1684  }
1685  /* If no commutator, no chance to optimize the WHERE clause */
1686  return NULL;
1687  }
1688  }
1689  /* Couldn't handle it as a hash clause */
1690  newWhere = lappend(newWhere, expr);
1691  }
1692 
1693  /*
1694  * If we didn't find anything we could convert, fail.
1695  */
1696  if (leftargs == NIL)
1697  return NULL;
1698 
1699  /*
1700  * There mustn't be any parent Vars or Aggs in the stuff that we intend to
1701  * put back into the child query. Note: you might think we don't need to
1702  * check for Aggs separately, because an uplevel Agg must contain an
1703  * uplevel Var in its argument. But it is possible that the uplevel Var
1704  * got optimized away by eval_const_expressions. Consider
1705  *
1706  * SUM(CASE WHEN false THEN uplevelvar ELSE 0 END)
1707  */
1708  if (contain_vars_of_level((Node *) newWhere, 1) ||
1709  contain_vars_of_level((Node *) rightargs, 1))
1710  return NULL;
1711  if (root->parse->hasAggs &&
1712  (contain_aggs_of_level((Node *) newWhere, 1) ||
1713  contain_aggs_of_level((Node *) rightargs, 1)))
1714  return NULL;
1715 
1716  /*
1717  * And there can't be any child Vars in the stuff we intend to pull up.
1718  * (Note: we'd need to check for child Aggs too, except we know the child
1719  * has no aggs at all because of simplify_EXISTS_query's check. The same
1720  * goes for window functions.)
1721  */
1722  if (contain_vars_of_level((Node *) leftargs, 0))
1723  return NULL;
1724 
1725  /*
1726  * Also reject sublinks in the stuff we intend to pull up. (It might be
1727  * possible to support this, but doesn't seem worth the complication.)
1728  */
1729  if (contain_subplans((Node *) leftargs))
1730  return NULL;
1731 
1732  /*
1733  * Okay, adjust the sublevelsup in the stuff we're pulling up.
1734  */
1735  IncrementVarSublevelsUp((Node *) leftargs, -1, 1);
1736 
1737  /*
1738  * Put back any child-level-only WHERE clauses.
1739  */
1740  if (newWhere)
1741  subselect->jointree->quals = (Node *) make_ands_explicit(newWhere);
1742 
1743  /*
1744  * Build a new targetlist for the child that emits the expressions we
1745  * need. Concurrently, build a testexpr for the parent using Params to
1746  * reference the child outputs. (Since we generate Params directly here,
1747  * there will be no need to convert the testexpr in build_subplan.)
1748  */
1749  tlist = testlist = paramids = NIL;
1750  resno = 1;
1751  forfour(lc, leftargs, rc, rightargs, oc, opids, cc, opcollations)
1752  {
1753  Node *leftarg = (Node *) lfirst(lc);
1754  Node *rightarg = (Node *) lfirst(rc);
1755  Oid opid = lfirst_oid(oc);
1756  Oid opcollation = lfirst_oid(cc);
1757  Param *param;
1758 
1759  param = generate_new_exec_param(root,
1760  exprType(rightarg),
1761  exprTypmod(rightarg),
1762  exprCollation(rightarg));
1763  tlist = lappend(tlist,
1764  makeTargetEntry((Expr *) rightarg,
1765  resno++,
1766  NULL,
1767  false));
1768  testlist = lappend(testlist,
1769  make_opclause(opid, BOOLOID, false,
1770  (Expr *) leftarg, (Expr *) param,
1771  InvalidOid, opcollation));
1772  paramids = lappend_int(paramids, param->paramid);
1773  }
1774 
1775  /* Put everything where it should go, and we're done */
1776  subselect->targetList = tlist;
1777  *testexpr = (Node *) make_ands_explicit(testlist);
1778  *paramIds = paramids;
1779 
1780  return subselect;
1781 }
1782 
1783 
1784 /*
1785  * Replace correlation vars (uplevel vars) with Params.
1786  *
1787  * Uplevel PlaceHolderVars and aggregates are replaced, too.
1788  *
1789  * Note: it is critical that this runs immediately after SS_process_sublinks.
1790  * Since we do not recurse into the arguments of uplevel PHVs and aggregates,
1791  * they will get copied to the appropriate subplan args list in the parent
1792  * query with uplevel vars not replaced by Params, but only adjusted in level
1793  * (see replace_outer_placeholdervar and replace_outer_agg). That's exactly
1794  * what we want for the vars of the parent level --- but if a PHV's or
1795  * aggregate's argument contains any further-up variables, they have to be
1796  * replaced with Params in their turn. That will happen when the parent level
1797  * runs SS_replace_correlation_vars. Therefore it must do so after expanding
1798  * its sublinks to subplans. And we don't want any steps in between, else
1799  * those steps would never get applied to the argument expressions, either in
1800  * the parent or the child level.
1801  *
1802  * Another fairly tricky thing going on here is the handling of SubLinks in
1803  * the arguments of uplevel PHVs/aggregates. Those are not touched inside the
1804  * intermediate query level, either. Instead, SS_process_sublinks recurses on
1805  * them after copying the PHV or Aggref expression into the parent plan level
1806  * (this is actually taken care of in build_subplan).
1807  */
1808 Node *
1810 {
1811  /* No setup needed for tree walk, so away we go */
1812  return replace_correlation_vars_mutator(expr, root);
1813 }
1814 
1815 static Node *
1817 {
1818  if (node == NULL)
1819  return NULL;
1820  if (IsA(node, Var))
1821  {
1822  if (((Var *) node)->varlevelsup > 0)
1823  return (Node *) replace_outer_var(root, (Var *) node);
1824  }
1825  if (IsA(node, PlaceHolderVar))
1826  {
1827  if (((PlaceHolderVar *) node)->phlevelsup > 0)
1828  return (Node *) replace_outer_placeholdervar(root,
1829  (PlaceHolderVar *) node);
1830  }
1831  if (IsA(node, Aggref))
1832  {
1833  if (((Aggref *) node)->agglevelsup > 0)
1834  return (Node *) replace_outer_agg(root, (Aggref *) node);
1835  }
1836  if (IsA(node, GroupingFunc))
1837  {
1838  if (((GroupingFunc *) node)->agglevelsup > 0)
1839  return (Node *) replace_outer_grouping(root, (GroupingFunc *) node);
1840  }
1841  return expression_tree_mutator(node,
1843  (void *) root);
1844 }
1845 
1846 /*
1847  * Expand SubLinks to SubPlans in the given expression.
1848  *
1849  * The isQual argument tells whether or not this expression is a WHERE/HAVING
1850  * qualifier expression. If it is, any sublinks appearing at top level need
1851  * not distinguish FALSE from UNKNOWN return values.
1852  */
1853 Node *
1855 {
1856  process_sublinks_context context;
1857 
1858  context.root = root;
1859  context.isTopQual = isQual;
1860  return process_sublinks_mutator(expr, &context);
1861 }
1862 
1863 static Node *
1865 {
1866  process_sublinks_context locContext;
1867 
1868  locContext.root = context->root;
1869 
1870  if (node == NULL)
1871  return NULL;
1872  if (IsA(node, SubLink))
1873  {
1874  SubLink *sublink = (SubLink *) node;
1875  Node *testexpr;
1876 
1877  /*
1878  * First, recursively process the lefthand-side expressions, if any.
1879  * They're not top-level anymore.
1880  */
1881  locContext.isTopQual = false;
1882  testexpr = process_sublinks_mutator(sublink->testexpr, &locContext);
1883 
1884  /*
1885  * Now build the SubPlan node and make the expr to return.
1886  */
1887  return make_subplan(context->root,
1888  (Query *) sublink->subselect,
1889  sublink->subLinkType,
1890  sublink->subLinkId,
1891  testexpr,
1892  context->isTopQual);
1893  }
1894 
1895  /*
1896  * Don't recurse into the arguments of an outer PHV or aggregate here. Any
1897  * SubLinks in the arguments have to be dealt with at the outer query
1898  * level; they'll be handled when build_subplan collects the PHV or Aggref
1899  * into the arguments to be passed down to the current subplan.
1900  */
1901  if (IsA(node, PlaceHolderVar))
1902  {
1903  if (((PlaceHolderVar *) node)->phlevelsup > 0)
1904  return node;
1905  }
1906  else if (IsA(node, Aggref))
1907  {
1908  if (((Aggref *) node)->agglevelsup > 0)
1909  return node;
1910  }
1911 
1912  /*
1913  * We should never see a SubPlan expression in the input (since this is
1914  * the very routine that creates 'em to begin with). We shouldn't find
1915  * ourselves invoked directly on a Query, either.
1916  */
1917  Assert(!IsA(node, SubPlan));
1918  Assert(!IsA(node, AlternativeSubPlan));
1919  Assert(!IsA(node, Query));
1920 
1921  /*
1922  * Because make_subplan() could return an AND or OR clause, we have to
1923  * take steps to preserve AND/OR flatness of a qual. We assume the input
1924  * has been AND/OR flattened and so we need no recursion here.
1925  *
1926  * (Due to the coding here, we will not get called on the List subnodes of
1927  * an AND; and the input is *not* yet in implicit-AND format. So no check
1928  * is needed for a bare List.)
1929  *
1930  * Anywhere within the top-level AND/OR clause structure, we can tell
1931  * make_subplan() that NULL and FALSE are interchangeable. So isTopQual
1932  * propagates down in both cases. (Note that this is unlike the meaning
1933  * of "top level qual" used in most other places in Postgres.)
1934  */
1935  if (is_andclause(node))
1936  {
1937  List *newargs = NIL;
1938  ListCell *l;
1939 
1940  /* Still at qual top-level */
1941  locContext.isTopQual = context->isTopQual;
1942 
1943  foreach(l, ((BoolExpr *) node)->args)
1944  {
1945  Node *newarg;
1946 
1947  newarg = process_sublinks_mutator(lfirst(l), &locContext);
1948  if (is_andclause(newarg))
1949  newargs = list_concat(newargs, ((BoolExpr *) newarg)->args);
1950  else
1951  newargs = lappend(newargs, newarg);
1952  }
1953  return (Node *) make_andclause(newargs);
1954  }
1955 
1956  if (is_orclause(node))
1957  {
1958  List *newargs = NIL;
1959  ListCell *l;
1960 
1961  /* Still at qual top-level */
1962  locContext.isTopQual = context->isTopQual;
1963 
1964  foreach(l, ((BoolExpr *) node)->args)
1965  {
1966  Node *newarg;
1967 
1968  newarg = process_sublinks_mutator(lfirst(l), &locContext);
1969  if (is_orclause(newarg))
1970  newargs = list_concat(newargs, ((BoolExpr *) newarg)->args);
1971  else
1972  newargs = lappend(newargs, newarg);
1973  }
1974  return (Node *) make_orclause(newargs);
1975  }
1976 
1977  /*
1978  * If we recurse down through anything other than an AND or OR node, we
1979  * are definitely not at top qual level anymore.
1980  */
1981  locContext.isTopQual = false;
1982 
1983  return expression_tree_mutator(node,
1985  (void *) &locContext);
1986 }
1987 
1988 /*
1989  * SS_identify_outer_params - identify the Params available from outer levels
1990  *
1991  * This must be run after SS_replace_correlation_vars and SS_process_sublinks
1992  * processing is complete in a given query level as well as all of its
1993  * descendant levels (which means it's most practical to do it at the end of
1994  * processing the query level). We compute the set of paramIds that outer
1995  * levels will make available to this level+descendants, and record it in
1996  * root->outer_params for use while computing extParam/allParam sets in final
1997  * plan cleanup. (We can't just compute it then, because the upper levels'
1998  * plan_params lists are transient and will be gone by then.)
1999  */
2000 void
2002 {
2003  Bitmapset *outer_params;
2004  PlannerInfo *proot;
2005  ListCell *l;
2006 
2007  /*
2008  * If no parameters have been assigned anywhere in the tree, we certainly
2009  * don't need to do anything here.
2010  */
2011  if (root->glob->paramExecTypes == NIL)
2012  return;
2013 
2014  /*
2015  * Scan all query levels above this one to see which parameters are due to
2016  * be available from them, either because lower query levels have
2017  * requested them (via plan_params) or because they will be available from
2018  * initPlans of those levels.
2019  */
2020  outer_params = NULL;
2021  for (proot = root->parent_root; proot != NULL; proot = proot->parent_root)
2022  {
2023  /* Include ordinary Var/PHV/Aggref params */
2024  foreach(l, proot->plan_params)
2025  {
2026  PlannerParamItem *pitem = (PlannerParamItem *) lfirst(l);
2027 
2028  outer_params = bms_add_member(outer_params, pitem->paramId);
2029  }
2030  /* Include any outputs of outer-level initPlans */
2031  foreach(l, proot->init_plans)
2032  {
2033  SubPlan *initsubplan = (SubPlan *) lfirst(l);
2034  ListCell *l2;
2035 
2036  foreach(l2, initsubplan->setParam)
2037  {
2038  outer_params = bms_add_member(outer_params, lfirst_int(l2));
2039  }
2040  }
2041  /* Include worktable ID, if a recursive query is being planned */
2042  if (proot->wt_param_id >= 0)
2043  outer_params = bms_add_member(outer_params, proot->wt_param_id);
2044  }
2045  root->outer_params = outer_params;
2046 }
2047 
2048 /*
2049  * SS_charge_for_initplans - account for initplans in Path costs & parallelism
2050  *
2051  * If any initPlans have been created in the current query level, they will
2052  * get attached to the Plan tree created from whichever Path we select from
2053  * the given rel. Increment all that rel's Paths' costs to account for them,
2054  * and make sure the paths get marked as parallel-unsafe, since we can't
2055  * currently transmit initPlans to parallel workers.
2056  *
2057  * This is separate from SS_attach_initplans because we might conditionally
2058  * create more initPlans during create_plan(), depending on which Path we
2059  * select. However, Paths that would generate such initPlans are expected
2060  * to have included their cost already.
2061  */
2062 void
2064 {
2065  Cost initplan_cost;
2066  ListCell *lc;
2067 
2068  /* Nothing to do if no initPlans */
2069  if (root->init_plans == NIL)
2070  return;
2071 
2072  /*
2073  * Compute the cost increment just once, since it will be the same for all
2074  * Paths. We assume each initPlan gets run once during top plan startup.
2075  * This is a conservative overestimate, since in fact an initPlan might be
2076  * executed later than plan startup, or even not at all.
2077  */
2078  initplan_cost = 0;
2079  foreach(lc, root->init_plans)
2080  {
2081  SubPlan *initsubplan = (SubPlan *) lfirst(lc);
2082 
2083  initplan_cost += initsubplan->startup_cost + initsubplan->per_call_cost;
2084  }
2085 
2086  /*
2087  * Now adjust the costs and parallel_safe flags.
2088  */
2089  foreach(lc, final_rel->pathlist)
2090  {
2091  Path *path = (Path *) lfirst(lc);
2092 
2093  path->startup_cost += initplan_cost;
2094  path->total_cost += initplan_cost;
2095  path->parallel_safe = false;
2096  }
2097 
2098  /*
2099  * Forget about any partial paths and clear consider_parallel, too;
2100  * they're not usable if we attached an initPlan.
2101  */
2102  final_rel->partial_pathlist = NIL;
2103  final_rel->consider_parallel = false;
2104 
2105  /* We needn't do set_cheapest() here, caller will do it */
2106 }
2107 
2108 /*
2109  * SS_attach_initplans - attach initplans to topmost plan node
2110  *
2111  * Attach any initplans created in the current query level to the specified
2112  * plan node, which should normally be the topmost node for the query level.
2113  * (In principle the initPlans could go in any node at or above where they're
2114  * referenced; but there seems no reason to put them any lower than the
2115  * topmost node, so we don't bother to track exactly where they came from.)
2116  * We do not touch the plan node's cost; the initplans should have been
2117  * accounted for in path costing.
2118  */
2119 void
2121 {
2122  plan->initPlan = root->init_plans;
2123 }
2124 
2125 /*
2126  * SS_finalize_plan - do final parameter processing for a completed Plan.
2127  *
2128  * This recursively computes the extParam and allParam sets for every Plan
2129  * node in the given plan tree. (Oh, and RangeTblFunction.funcparams too.)
2130  *
2131  * We assume that SS_finalize_plan has already been run on any initplans or
2132  * subplans the plan tree could reference.
2133  */
2134 void
2136 {
2137  /* No setup needed, just recurse through plan tree. */
2138  (void) finalize_plan(root, plan, -1, root->outer_params, NULL);
2139 }
2140 
2141 /*
2142  * Recursive processing of all nodes in the plan tree
2143  *
2144  * gather_param is the rescan_param of an ancestral Gather/GatherMerge,
2145  * or -1 if there is none.
2146  *
2147  * valid_params is the set of param IDs supplied by outer plan levels
2148  * that are valid to reference in this plan node or its children.
2149  *
2150  * scan_params is a set of param IDs to force scan plan nodes to reference.
2151  * This is for EvalPlanQual support, and is always NULL at the top of the
2152  * recursion.
2153  *
2154  * The return value is the computed allParam set for the given Plan node.
2155  * This is just an internal notational convenience: we can add a child
2156  * plan's allParams to the set of param IDs of interest to this level
2157  * in the same statement that recurses to that child.
2158  *
2159  * Do not scribble on caller's values of valid_params or scan_params!
2160  *
2161  * Note: although we attempt to deal with initPlans anywhere in the tree, the
2162  * logic is not really right. The problem is that a plan node might return an
2163  * output Param of its initPlan as a targetlist item, in which case it's valid
2164  * for the parent plan level to reference that same Param; the parent's usage
2165  * will be converted into a Var referencing the child plan node by setrefs.c.
2166  * But this function would see the parent's reference as out of scope and
2167  * complain about it. For now, this does not matter because the planner only
2168  * attaches initPlans to the topmost plan node in a query level, so the case
2169  * doesn't arise. If we ever merge this processing into setrefs.c, maybe it
2170  * can be handled more cleanly.
2171  */
2172 static Bitmapset *
2174  int gather_param,
2175  Bitmapset *valid_params,
2176  Bitmapset *scan_params)
2177 {
2178  finalize_primnode_context context;
2179  int locally_added_param;
2180  Bitmapset *nestloop_params;
2181  Bitmapset *initExtParam;
2182  Bitmapset *initSetParam;
2183  Bitmapset *child_params;
2184  ListCell *l;
2185 
2186  if (plan == NULL)
2187  return NULL;
2188 
2189  context.root = root;
2190  context.paramids = NULL; /* initialize set to empty */
2191  locally_added_param = -1; /* there isn't one */
2192  nestloop_params = NULL; /* there aren't any */
2193 
2194  /*
2195  * Examine any initPlans to determine the set of external params they
2196  * reference and the set of output params they supply. (We assume
2197  * SS_finalize_plan was run on them already.)
2198  */
2199  initExtParam = initSetParam = NULL;
2200  foreach(l, plan->initPlan)
2201  {
2202  SubPlan *initsubplan = (SubPlan *) lfirst(l);
2203  Plan *initplan = planner_subplan_get_plan(root, initsubplan);
2204  ListCell *l2;
2205 
2206  initExtParam = bms_add_members(initExtParam, initplan->extParam);
2207  foreach(l2, initsubplan->setParam)
2208  {
2209  initSetParam = bms_add_member(initSetParam, lfirst_int(l2));
2210  }
2211  }
2212 
2213  /* Any setParams are validly referenceable in this node and children */
2214  if (initSetParam)
2215  valid_params = bms_union(valid_params, initSetParam);
2216 
2217  /*
2218  * When we call finalize_primnode, context.paramids sets are automatically
2219  * merged together. But when recursing to self, we have to do it the hard
2220  * way. We want the paramids set to include params in subplans as well as
2221  * at this level.
2222  */
2223 
2224  /* Find params in targetlist and qual */
2225  finalize_primnode((Node *) plan->targetlist, &context);
2226  finalize_primnode((Node *) plan->qual, &context);
2227 
2228  /*
2229  * If it's a parallel-aware scan node, mark it as dependent on the parent
2230  * Gather/GatherMerge's rescan Param.
2231  */
2232  if (plan->parallel_aware)
2233  {
2234  if (gather_param < 0)
2235  elog(ERROR, "parallel-aware plan node is not below a Gather");
2236  context.paramids =
2237  bms_add_member(context.paramids, gather_param);
2238  }
2239 
2240  /* Check additional node-type-specific fields */
2241  switch (nodeTag(plan))
2242  {
2243  case T_Result:
2244  finalize_primnode(((Result *) plan)->resconstantqual,
2245  &context);
2246  break;
2247 
2248  case T_SeqScan:
2249  context.paramids = bms_add_members(context.paramids, scan_params);
2250  break;
2251 
2252  case T_SampleScan:
2253  finalize_primnode((Node *) ((SampleScan *) plan)->tablesample,
2254  &context);
2255  context.paramids = bms_add_members(context.paramids, scan_params);
2256  break;
2257 
2258  case T_IndexScan:
2259  finalize_primnode((Node *) ((IndexScan *) plan)->indexqual,
2260  &context);
2261  finalize_primnode((Node *) ((IndexScan *) plan)->indexorderby,
2262  &context);
2263 
2264  /*
2265  * we need not look at indexqualorig, since it will have the same
2266  * param references as indexqual. Likewise, we can ignore
2267  * indexorderbyorig.
2268  */
2269  context.paramids = bms_add_members(context.paramids, scan_params);
2270  break;
2271 
2272  case T_IndexOnlyScan:
2273  finalize_primnode((Node *) ((IndexOnlyScan *) plan)->indexqual,
2274  &context);
2275  finalize_primnode((Node *) ((IndexOnlyScan *) plan)->indexorderby,
2276  &context);
2277 
2278  /*
2279  * we need not look at indextlist, since it cannot contain Params.
2280  */
2281  context.paramids = bms_add_members(context.paramids, scan_params);
2282  break;
2283 
2284  case T_BitmapIndexScan:
2285  finalize_primnode((Node *) ((BitmapIndexScan *) plan)->indexqual,
2286  &context);
2287 
2288  /*
2289  * we need not look at indexqualorig, since it will have the same
2290  * param references as indexqual.
2291  */
2292  break;
2293 
2294  case T_BitmapHeapScan:
2295  finalize_primnode((Node *) ((BitmapHeapScan *) plan)->bitmapqualorig,
2296  &context);
2297  context.paramids = bms_add_members(context.paramids, scan_params);
2298  break;
2299 
2300  case T_TidScan:
2301  finalize_primnode((Node *) ((TidScan *) plan)->tidquals,
2302  &context);
2303  context.paramids = bms_add_members(context.paramids, scan_params);
2304  break;
2305 
2306  case T_SubqueryScan:
2307  {
2308  SubqueryScan *sscan = (SubqueryScan *) plan;
2309  RelOptInfo *rel;
2310  Bitmapset *subquery_params;
2311 
2312  /* We must run finalize_plan on the subquery */
2313  rel = find_base_rel(root, sscan->scan.scanrelid);
2314  subquery_params = rel->subroot->outer_params;
2315  if (gather_param >= 0)
2316  subquery_params = bms_add_member(bms_copy(subquery_params),
2317  gather_param);
2318  finalize_plan(rel->subroot, sscan->subplan, gather_param,
2319  subquery_params, NULL);
2320 
2321  /* Now we can add its extParams to the parent's params */
2322  context.paramids = bms_add_members(context.paramids,
2323  sscan->subplan->extParam);
2324  /* We need scan_params too, though */
2325  context.paramids = bms_add_members(context.paramids,
2326  scan_params);
2327  }
2328  break;
2329 
2330  case T_FunctionScan:
2331  {
2332  FunctionScan *fscan = (FunctionScan *) plan;
2333  ListCell *lc;
2334 
2335  /*
2336  * Call finalize_primnode independently on each function
2337  * expression, so that we can record which params are
2338  * referenced in each, in order to decide which need
2339  * re-evaluating during rescan.
2340  */
2341  foreach(lc, fscan->functions)
2342  {
2343  RangeTblFunction *rtfunc = (RangeTblFunction *) lfirst(lc);
2344  finalize_primnode_context funccontext;
2345 
2346  funccontext = context;
2347  funccontext.paramids = NULL;
2348 
2349  finalize_primnode(rtfunc->funcexpr, &funccontext);
2350 
2351  /* remember results for execution */
2352  rtfunc->funcparams = funccontext.paramids;
2353 
2354  /* add the function's params to the overall set */
2355  context.paramids = bms_add_members(context.paramids,
2356  funccontext.paramids);
2357  }
2358 
2359  context.paramids = bms_add_members(context.paramids,
2360  scan_params);
2361  }
2362  break;
2363 
2364  case T_TableFuncScan:
2365  finalize_primnode((Node *) ((TableFuncScan *) plan)->tablefunc,
2366  &context);
2367  context.paramids = bms_add_members(context.paramids, scan_params);
2368  break;
2369 
2370  case T_ValuesScan:
2371  finalize_primnode((Node *) ((ValuesScan *) plan)->values_lists,
2372  &context);
2373  context.paramids = bms_add_members(context.paramids, scan_params);
2374  break;
2375 
2376  case T_CteScan:
2377  {
2378  /*
2379  * You might think we should add the node's cteParam to
2380  * paramids, but we shouldn't because that param is just a
2381  * linkage mechanism for multiple CteScan nodes for the same
2382  * CTE; it is never used for changed-param signaling. What we
2383  * have to do instead is to find the referenced CTE plan and
2384  * incorporate its external paramids, so that the correct
2385  * things will happen if the CTE references outer-level
2386  * variables. See test cases for bug #4902. (We assume
2387  * SS_finalize_plan was run on the CTE plan already.)
2388  */
2389  int plan_id = ((CteScan *) plan)->ctePlanId;
2390  Plan *cteplan;
2391 
2392  /* so, do this ... */
2393  if (plan_id < 1 || plan_id > list_length(root->glob->subplans))
2394  elog(ERROR, "could not find plan for CteScan referencing plan ID %d",
2395  plan_id);
2396  cteplan = (Plan *) list_nth(root->glob->subplans, plan_id - 1);
2397  context.paramids =
2398  bms_add_members(context.paramids, cteplan->extParam);
2399 
2400 #ifdef NOT_USED
2401  /* ... but not this */
2402  context.paramids =
2403  bms_add_member(context.paramids,
2404  ((CteScan *) plan)->cteParam);
2405 #endif
2406 
2407  context.paramids = bms_add_members(context.paramids,
2408  scan_params);
2409  }
2410  break;
2411 
2412  case T_WorkTableScan:
2413  context.paramids =
2414  bms_add_member(context.paramids,
2415  ((WorkTableScan *) plan)->wtParam);
2416  context.paramids = bms_add_members(context.paramids, scan_params);
2417  break;
2418 
2419  case T_NamedTuplestoreScan:
2420  context.paramids = bms_add_members(context.paramids, scan_params);
2421  break;
2422 
2423  case T_ForeignScan:
2424  {
2425  ForeignScan *fscan = (ForeignScan *) plan;
2426 
2427  finalize_primnode((Node *) fscan->fdw_exprs,
2428  &context);
2430  &context);
2431 
2432  /* We assume fdw_scan_tlist cannot contain Params */
2433  context.paramids = bms_add_members(context.paramids,
2434  scan_params);
2435  }
2436  break;
2437 
2438  case T_CustomScan:
2439  {
2440  CustomScan *cscan = (CustomScan *) plan;
2441  ListCell *lc;
2442 
2443  finalize_primnode((Node *) cscan->custom_exprs,
2444  &context);
2445  /* We assume custom_scan_tlist cannot contain Params */
2446  context.paramids =
2447  bms_add_members(context.paramids, scan_params);
2448 
2449  /* child nodes if any */
2450  foreach(lc, cscan->custom_plans)
2451  {
2452  context.paramids =
2453  bms_add_members(context.paramids,
2454  finalize_plan(root,
2455  (Plan *) lfirst(lc),
2456  gather_param,
2457  valid_params,
2458  scan_params));
2459  }
2460  }
2461  break;
2462 
2463  case T_ModifyTable:
2464  {
2465  ModifyTable *mtplan = (ModifyTable *) plan;
2466  ListCell *l;
2467 
2468  /* Force descendant scan nodes to reference epqParam */
2469  locally_added_param = mtplan->epqParam;
2470  valid_params = bms_add_member(bms_copy(valid_params),
2471  locally_added_param);
2472  scan_params = bms_add_member(bms_copy(scan_params),
2473  locally_added_param);
2475  &context);
2476  finalize_primnode((Node *) mtplan->onConflictSet,
2477  &context);
2479  &context);
2480  /* exclRelTlist contains only Vars, doesn't need examination */
2481  foreach(l, mtplan->plans)
2482  {
2483  context.paramids =
2484  bms_add_members(context.paramids,
2485  finalize_plan(root,
2486  (Plan *) lfirst(l),
2487  gather_param,
2488  valid_params,
2489  scan_params));
2490  }
2491  }
2492  break;
2493 
2494  case T_Append:
2495  {
2496  ListCell *l;
2497 
2498  foreach(l, ((Append *) plan)->appendplans)
2499  {
2500  context.paramids =
2501  bms_add_members(context.paramids,
2502  finalize_plan(root,
2503  (Plan *) lfirst(l),
2504  gather_param,
2505  valid_params,
2506  scan_params));
2507  }
2508  }
2509  break;
2510 
2511  case T_MergeAppend:
2512  {
2513  ListCell *l;
2514 
2515  foreach(l, ((MergeAppend *) plan)->mergeplans)
2516  {
2517  context.paramids =
2518  bms_add_members(context.paramids,
2519  finalize_plan(root,
2520  (Plan *) lfirst(l),
2521  gather_param,
2522  valid_params,
2523  scan_params));
2524  }
2525  }
2526  break;
2527 
2528  case T_BitmapAnd:
2529  {
2530  ListCell *l;
2531 
2532  foreach(l, ((BitmapAnd *) plan)->bitmapplans)
2533  {
2534  context.paramids =
2535  bms_add_members(context.paramids,
2536  finalize_plan(root,
2537  (Plan *) lfirst(l),
2538  gather_param,
2539  valid_params,
2540  scan_params));
2541  }
2542  }
2543  break;
2544 
2545  case T_BitmapOr:
2546  {
2547  ListCell *l;
2548 
2549  foreach(l, ((BitmapOr *) plan)->bitmapplans)
2550  {
2551  context.paramids =
2552  bms_add_members(context.paramids,
2553  finalize_plan(root,
2554  (Plan *) lfirst(l),
2555  gather_param,
2556  valid_params,
2557  scan_params));
2558  }
2559  }
2560  break;
2561 
2562  case T_NestLoop:
2563  {
2564  ListCell *l;
2565 
2566  finalize_primnode((Node *) ((Join *) plan)->joinqual,
2567  &context);
2568  /* collect set of params that will be passed to right child */
2569  foreach(l, ((NestLoop *) plan)->nestParams)
2570  {
2571  NestLoopParam *nlp = (NestLoopParam *) lfirst(l);
2572 
2573  nestloop_params = bms_add_member(nestloop_params,
2574  nlp->paramno);
2575  }
2576  }
2577  break;
2578 
2579  case T_MergeJoin:
2580  finalize_primnode((Node *) ((Join *) plan)->joinqual,
2581  &context);
2582  finalize_primnode((Node *) ((MergeJoin *) plan)->mergeclauses,
2583  &context);
2584  break;
2585 
2586  case T_HashJoin:
2587  finalize_primnode((Node *) ((Join *) plan)->joinqual,
2588  &context);
2589  finalize_primnode((Node *) ((HashJoin *) plan)->hashclauses,
2590  &context);
2591  break;
2592 
2593  case T_Limit:
2594  finalize_primnode(((Limit *) plan)->limitOffset,
2595  &context);
2596  finalize_primnode(((Limit *) plan)->limitCount,
2597  &context);
2598  break;
2599 
2600  case T_RecursiveUnion:
2601  /* child nodes are allowed to reference wtParam */
2602  locally_added_param = ((RecursiveUnion *) plan)->wtParam;
2603  valid_params = bms_add_member(bms_copy(valid_params),
2604  locally_added_param);
2605  /* wtParam does *not* get added to scan_params */
2606  break;
2607 
2608  case T_LockRows:
2609  /* Force descendant scan nodes to reference epqParam */
2610  locally_added_param = ((LockRows *) plan)->epqParam;
2611  valid_params = bms_add_member(bms_copy(valid_params),
2612  locally_added_param);
2613  scan_params = bms_add_member(bms_copy(scan_params),
2614  locally_added_param);
2615  break;
2616 
2617  case T_Agg:
2618  {
2619  Agg *agg = (Agg *) plan;
2620 
2621  /*
2622  * AGG_HASHED plans need to know which Params are referenced
2623  * in aggregate calls. Do a separate scan to identify them.
2624  */
2625  if (agg->aggstrategy == AGG_HASHED)
2626  {
2627  finalize_primnode_context aggcontext;
2628 
2629  aggcontext.root = root;
2630  aggcontext.paramids = NULL;
2632  &aggcontext);
2634  &aggcontext);
2635  agg->aggParams = aggcontext.paramids;
2636  }
2637  }
2638  break;
2639 
2640  case T_WindowAgg:
2641  finalize_primnode(((WindowAgg *) plan)->startOffset,
2642  &context);
2643  finalize_primnode(((WindowAgg *) plan)->endOffset,
2644  &context);
2645  break;
2646 
2647  case T_Gather:
2648  /* child nodes are allowed to reference rescan_param, if any */
2649  locally_added_param = ((Gather *) plan)->rescan_param;
2650  if (locally_added_param >= 0)
2651  {
2652  valid_params = bms_add_member(bms_copy(valid_params),
2653  locally_added_param);
2654 
2655  /*
2656  * We currently don't support nested Gathers. The issue so
2657  * far as this function is concerned would be how to identify
2658  * which child nodes depend on which Gather.
2659  */
2660  Assert(gather_param < 0);
2661  /* Pass down rescan_param to child parallel-aware nodes */
2662  gather_param = locally_added_param;
2663  }
2664  /* rescan_param does *not* get added to scan_params */
2665  break;
2666 
2667  case T_GatherMerge:
2668  /* child nodes are allowed to reference rescan_param, if any */
2669  locally_added_param = ((GatherMerge *) plan)->rescan_param;
2670  if (locally_added_param >= 0)
2671  {
2672  valid_params = bms_add_member(bms_copy(valid_params),
2673  locally_added_param);
2674 
2675  /*
2676  * We currently don't support nested Gathers. The issue so
2677  * far as this function is concerned would be how to identify
2678  * which child nodes depend on which Gather.
2679  */
2680  Assert(gather_param < 0);
2681  /* Pass down rescan_param to child parallel-aware nodes */
2682  gather_param = locally_added_param;
2683  }
2684  /* rescan_param does *not* get added to scan_params */
2685  break;
2686 
2687  case T_ProjectSet:
2688  case T_Hash:
2689  case T_Material:
2690  case T_Sort:
2691  case T_IncrementalSort:
2692  case T_Unique:
2693  case T_SetOp:
2694  case T_Group:
2695  /* no node-type-specific fields need fixing */
2696  break;
2697 
2698  default:
2699  elog(ERROR, "unrecognized node type: %d",
2700  (int) nodeTag(plan));
2701  }
2702 
2703  /* Process left and right child plans, if any */
2704  child_params = finalize_plan(root,
2705  plan->lefttree,
2706  gather_param,
2707  valid_params,
2708  scan_params);
2709  context.paramids = bms_add_members(context.paramids, child_params);
2710 
2711  if (nestloop_params)
2712  {
2713  /* right child can reference nestloop_params as well as valid_params */
2714  child_params = finalize_plan(root,
2715  plan->righttree,
2716  gather_param,
2717  bms_union(nestloop_params, valid_params),
2718  scan_params);
2719  /* ... and they don't count as parameters used at my level */
2720  child_params = bms_difference(child_params, nestloop_params);
2721  bms_free(nestloop_params);
2722  }
2723  else
2724  {
2725  /* easy case */
2726  child_params = finalize_plan(root,
2727  plan->righttree,
2728  gather_param,
2729  valid_params,
2730  scan_params);
2731  }
2732  context.paramids = bms_add_members(context.paramids, child_params);
2733 
2734  /*
2735  * Any locally generated parameter doesn't count towards its generating
2736  * plan node's external dependencies. (Note: if we changed valid_params
2737  * and/or scan_params, we leak those bitmapsets; not worth the notational
2738  * trouble to clean them up.)
2739  */
2740  if (locally_added_param >= 0)
2741  {
2742  context.paramids = bms_del_member(context.paramids,
2743  locally_added_param);
2744  }
2745 
2746  /* Now we have all the paramids referenced in this node and children */
2747 
2748  if (!bms_is_subset(context.paramids, valid_params))
2749  elog(ERROR, "plan should not reference subplan's variable");
2750 
2751  /*
2752  * The plan node's allParam and extParam fields should include all its
2753  * referenced paramids, plus contributions from any child initPlans.
2754  * However, any setParams of the initPlans should not be present in the
2755  * parent node's extParams, only in its allParams. (It's possible that
2756  * some initPlans have extParams that are setParams of other initPlans.)
2757  */
2758 
2759  /* allParam must include initplans' extParams and setParams */
2760  plan->allParam = bms_union(context.paramids, initExtParam);
2761  plan->allParam = bms_add_members(plan->allParam, initSetParam);
2762  /* extParam must include any initplan extParams */
2763  plan->extParam = bms_union(context.paramids, initExtParam);
2764  /* but not any initplan setParams */
2765  plan->extParam = bms_del_members(plan->extParam, initSetParam);
2766 
2767  /*
2768  * For speed at execution time, make sure extParam/allParam are actually
2769  * NULL if they are empty sets.
2770  */
2771  if (bms_is_empty(plan->extParam))
2772  plan->extParam = NULL;
2773  if (bms_is_empty(plan->allParam))
2774  plan->allParam = NULL;
2775 
2776  return plan->allParam;
2777 }
2778 
2779 /*
2780  * finalize_primnode: add IDs of all PARAM_EXEC params appearing in the given
2781  * expression tree to the result set.
2782  */
2783 static bool
2785 {
2786  if (node == NULL)
2787  return false;
2788  if (IsA(node, Param))
2789  {
2790  if (((Param *) node)->paramkind == PARAM_EXEC)
2791  {
2792  int paramid = ((Param *) node)->paramid;
2793 
2794  context->paramids = bms_add_member(context->paramids, paramid);
2795  }
2796  return false; /* no more to do here */
2797  }
2798  if (IsA(node, SubPlan))
2799  {
2800  SubPlan *subplan = (SubPlan *) node;
2801  Plan *plan = planner_subplan_get_plan(context->root, subplan);
2802  ListCell *lc;
2803  Bitmapset *subparamids;
2804 
2805  /* Recurse into the testexpr, but not into the Plan */
2806  finalize_primnode(subplan->testexpr, context);
2807 
2808  /*
2809  * Remove any param IDs of output parameters of the subplan that were
2810  * referenced in the testexpr. These are not interesting for
2811  * parameter change signaling since we always re-evaluate the subplan.
2812  * Note that this wouldn't work too well if there might be uses of the
2813  * same param IDs elsewhere in the plan, but that can't happen because
2814  * generate_new_exec_param never tries to merge params.
2815  */
2816  foreach(lc, subplan->paramIds)
2817  {
2818  context->paramids = bms_del_member(context->paramids,
2819  lfirst_int(lc));
2820  }
2821 
2822  /* Also examine args list */
2823  finalize_primnode((Node *) subplan->args, context);
2824 
2825  /*
2826  * Add params needed by the subplan to paramids, but excluding those
2827  * we will pass down to it. (We assume SS_finalize_plan was run on
2828  * the subplan already.)
2829  */
2830  subparamids = bms_copy(plan->extParam);
2831  foreach(lc, subplan->parParam)
2832  {
2833  subparamids = bms_del_member(subparamids, lfirst_int(lc));
2834  }
2835  context->paramids = bms_join(context->paramids, subparamids);
2836 
2837  return false; /* no more to do here */
2838  }
2840  (void *) context);
2841 }
2842 
2843 /*
2844  * finalize_agg_primnode: find all Aggref nodes in the given expression tree,
2845  * and add IDs of all PARAM_EXEC params appearing within their aggregated
2846  * arguments to the result set.
2847  */
2848 static bool
2850 {
2851  if (node == NULL)
2852  return false;
2853  if (IsA(node, Aggref))
2854  {
2855  Aggref *agg = (Aggref *) node;
2856 
2857  /* we should not consider the direct arguments, if any */
2858  finalize_primnode((Node *) agg->args, context);
2859  finalize_primnode((Node *) agg->aggfilter, context);
2860  return false; /* there can't be any Aggrefs below here */
2861  }
2863  (void *) context);
2864 }
2865 
2866 /*
2867  * SS_make_initplan_output_param - make a Param for an initPlan's output
2868  *
2869  * The plan is expected to return a scalar value of the given type/collation.
2870  *
2871  * Note that in some cases the initplan may not ever appear in the finished
2872  * plan tree. If that happens, we'll have wasted a PARAM_EXEC slot, which
2873  * is no big deal.
2874  */
2875 Param *
2877  Oid resulttype, int32 resulttypmod,
2878  Oid resultcollation)
2879 {
2880  return generate_new_exec_param(root, resulttype,
2881  resulttypmod, resultcollation);
2882 }
2883 
2884 /*
2885  * SS_make_initplan_from_plan - given a plan tree, make it an InitPlan
2886  *
2887  * We build an EXPR_SUBLINK SubPlan node and put it into the initplan
2888  * list for the outer query level. A Param that represents the initplan's
2889  * output has already been assigned using SS_make_initplan_output_param.
2890  */
2891 void
2893  PlannerInfo *subroot, Plan *plan,
2894  Param *prm)
2895 {
2896  SubPlan *node;
2897 
2898  /*
2899  * Add the subplan and its PlannerInfo to the global lists.
2900  */
2901  root->glob->subplans = lappend(root->glob->subplans, plan);
2902  root->glob->subroots = lappend(root->glob->subroots, subroot);
2903 
2904  /*
2905  * Create a SubPlan node and add it to the outer list of InitPlans. Note
2906  * it has to appear after any other InitPlans it might depend on (see
2907  * comments in ExecReScan).
2908  */
2909  node = makeNode(SubPlan);
2910  node->subLinkType = EXPR_SUBLINK;
2911  node->plan_id = list_length(root->glob->subplans);
2912  node->plan_name = psprintf("InitPlan %d (returns $%d)",
2913  node->plan_id, prm->paramid);
2914  get_first_col_type(plan, &node->firstColType, &node->firstColTypmod,
2915  &node->firstColCollation);
2916  node->setParam = list_make1_int(prm->paramid);
2917 
2918  root->init_plans = lappend(root->init_plans, node);
2919 
2920  /*
2921  * The node can't have any inputs (since it's an initplan), so the
2922  * parParam and args lists remain empty.
2923  */
2924 
2925  /* Set costs of SubPlan using info from the plan tree */
2926  cost_subplan(subroot, node, plan);
2927 }
Datum constvalue
Definition: primnodes.h:214
#define list_make2(x1, x2)
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Node * limitOffset
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static Node * convert_testexpr(PlannerInfo *root, Node *testexpr, List *subst_nodes)
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static Node * make_subplan(PlannerInfo *root, Query *orig_subquery, SubLinkType subLinkType, int subLinkId, Node *testexpr, bool isTopQual)
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Index scanrelid
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SubLinkType
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Definition: var.c:369
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int paramid
Definition: primnodes.h:263
void cost_subplan(PlannerInfo *root, SubPlan *subplan, Plan *plan)
Definition: costsize.c:3843
Bitmapset * outer_params
Definition: pathnodes.h:194
bool unknownEqFalse
Definition: primnodes.h:720
Bitmapset * bms_union(const Bitmapset *a, const Bitmapset *b)
Definition: bitmapset.c:225
Oid exprType(const Node *expr)
Definition: nodeFuncs.c:41
const char * ctename
Definition: subselect.c:62
bool expression_tree_walker(Node *node, bool(*walker)(), void *context)
Definition: nodeFuncs.c:1839
static int list_length(const List *l)
Definition: pg_list.h:169
Node * SS_replace_correlation_vars(PlannerInfo *root, Node *expr)
Definition: subselect.c:1809
Oid exprCollation(const Node *expr)
Definition: nodeFuncs.c:719
void SS_attach_initplans(PlannerInfo *root, Plan *plan)
Definition: subselect.c:2120
List * subroots
Definition: pathnodes.h:113
Expr * aggfilter
Definition: primnodes.h:322
Bitmapset * extParam
Definition: plannodes.h:160
Index ctelevelsup
Definition: parsenodes.h:1080
#define MAXALIGN(LEN)
Definition: c.h:691
Bitmapset * funcparams
Definition: parsenodes.h:1156
List * parParam
Definition: primnodes.h:729
Oid inputcollid
Definition: primnodes.h:521
bool consider_parallel
Definition: pathnodes.h:673
Bitmapset * bms_add_member(Bitmapset *a, int x)
Definition: bitmapset.c:736
void SS_make_initplan_from_plan(PlannerInfo *root, PlannerInfo *subroot, Plan *plan, Param *prm)
Definition: subselect.c:2892
struct Plan * lefttree
Definition: plannodes.h:144
FormData_pg_operator * Form_pg_operator
Definition: pg_operator.h:83
bool func_strict(Oid funcid)
Definition: lsyscache.c:1673
bool parallel_safe
Definition: primnodes.h:723
#define nodeTag(nodeptr)
Definition: nodes.h:534
List * targetlist
Definition: plannodes.h:142
bool contain_aggs_of_level(Node *node, int levelsup)
Definition: rewriteManip.c:67
#define forfour(cell1, list1, cell2, list2, cell3, list3, cell4, list4)
Definition: pg_list.h:476
Bitmapset * bms_del_members(Bitmapset *a, const Bitmapset *b)
Definition: bitmapset.c:928
RTEKind rtekind
Definition: parsenodes.h:976
Definition: nodes.h:85
char * ctename
Definition: parsenodes.h:1079
List * cteList
Definition: parsenodes.h:135
Node * setOperations
Definition: parsenodes.h:166
Query * subquery
Definition: parsenodes.h:1011
List * groupClause
Definition: parsenodes.h:148
void * palloc(Size size)
Definition: mcxt.c:949
List * initPlan
Definition: plannodes.h:146
Definition: nodes.h:82
#define elog(elevel,...)
Definition: elog.h:214
ParseNamespaceItem * addRangeTableEntryForSubquery(ParseState *pstate, Query *subquery, Alias *alias, bool lateral, bool inFromCl)
bool hasModifyingCTE
Definition: parsenodes.h:131
void * arg
bool ExecMaterializesOutput(NodeTag plantype)
Definition: execAmi.c:623
bool useHashTable
Definition: primnodes.h:718
List * returningLists
Definition: plannodes.h:231
bool parallel_safe
Definition: plannodes.h:136
Oid firstColCollation
Definition: primnodes.h:715
Cost startup_cost
Definition: primnodes.h:732
List * pathlist
Definition: pathnodes.h:679
Oid opno
Definition: primnodes.h:516
Definition: plannodes.h:816
RelOptInfo * find_base_rel(PlannerInfo *root, int relid)
Definition: relnode.c:374
#define copyObject(obj)
Definition: nodes.h:645
List * args
Definition: primnodes.h:522
Node * havingQual
Definition: parsenodes.h:152
List * coltypes
Definition: parsenodes.h:1101
void SS_finalize_plan(PlannerInfo *root, Plan *plan)
Definition: subselect.c:2135
Bitmapset * bms_del_member(Bitmapset *a, int x)
Definition: bitmapset.c:773
Param * replace_outer_grouping(PlannerInfo *root, GroupingFunc *grp)
Definition: paramassign.c:269
struct finalize_primnode_context finalize_primnode_context
int rtindex
Definition: primnodes.h:1495
Definition: pg_list.h:50
int16 AttrNumber
Definition: attnum.h:21
PlannerInfo * subquery_planner(PlannerGlobal *glob, Query *parse, PlannerInfo *parent_root, bool hasRecursion, double tuple_fraction)
Definition: planner.c:597
CmdType
Definition: nodes.h:672
static Node * replace_correlation_vars_mutator(Node *node, PlannerInfo *root)
Definition: subselect.c:1816
bool constisnull
Definition: primnodes.h:215
static bool inline_cte_walker(Node *node, inline_cte_walker_context *context)
Definition: subselect.c:1106
double Cost
Definition: nodes.h:663
Bitmapset * bms_add_members(Bitmapset *a, const Bitmapset *b)
Definition: bitmapset.c:793
Plan * subplan
Definition: plannodes.h:515
Path * get_cheapest_fractional_path(RelOptInfo *rel, double tuple_fraction)
Definition: planner.c:5998
#define lfirst_oid(lc)
Definition: pg_list.h:192
static bool contain_outer_selfref_walker(Node *node, Index *depth)
Definition: subselect.c:1048
static struct subre * parse(struct vars *, int, int, struct state *, struct state *)
Definition: regcomp.c:648
int epqParam
Definition: plannodes.h:235
Node * onConflictWhere
Definition: plannodes.h:239
bool enable_material
Definition: costsize.c:136
Param * replace_outer_agg(PlannerInfo *root, Aggref *agg)
Definition: paramassign.c:223
Definition: nodes.h:87
List * args
Definition: primnodes.h:730