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equivclass.c
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1/*-------------------------------------------------------------------------
2 *
3 * equivclass.c
4 * Routines for managing EquivalenceClasses
5 *
6 * See src/backend/optimizer/README for discussion of EquivalenceClasses.
7 *
8 *
9 * Portions Copyright (c) 1996-2025, PostgreSQL Global Development Group
10 * Portions Copyright (c) 1994, Regents of the University of California
11 *
12 * IDENTIFICATION
13 * src/backend/optimizer/path/equivclass.c
14 *
15 *-------------------------------------------------------------------------
16 */
17#include "postgres.h"
18
19#include <limits.h>
20
21#include "access/stratnum.h"
22#include "catalog/pg_type.h"
23#include "common/hashfn.h"
24#include "nodes/makefuncs.h"
25#include "nodes/nodeFuncs.h"
26#include "optimizer/appendinfo.h"
27#include "optimizer/clauses.h"
28#include "optimizer/optimizer.h"
29#include "optimizer/pathnode.h"
30#include "optimizer/paths.h"
31#include "optimizer/planmain.h"
32#include "optimizer/restrictinfo.h"
33#include "rewrite/rewriteManip.h"
34#include "utils/lsyscache.h"
35
36
37static EquivalenceMember *make_eq_member(EquivalenceClass *ec,
38 Expr *expr, Relids relids,
39 JoinDomain *jdomain,
40 EquivalenceMember *parent,
41 Oid datatype);
42static EquivalenceMember *add_eq_member(EquivalenceClass *ec,
43 Expr *expr, Relids relids,
44 JoinDomain *jdomain,
45 Oid datatype);
46static EquivalenceMember *add_child_eq_member(PlannerInfo *root,
47 EquivalenceClass *ec,
48 int ec_index, Expr *expr,
49 Relids relids,
50 JoinDomain *jdomain,
51 EquivalenceMember *parent_em,
52 Oid datatype,
53 Index child_relid);
54static void generate_base_implied_equalities_const(PlannerInfo *root,
55 EquivalenceClass *ec);
56static void generate_base_implied_equalities_no_const(PlannerInfo *root,
57 EquivalenceClass *ec);
58static void generate_base_implied_equalities_broken(PlannerInfo *root,
59 EquivalenceClass *ec);
60static List *generate_join_implied_equalities_normal(PlannerInfo *root,
61 EquivalenceClass *ec,
62 Relids join_relids,
63 Relids outer_relids,
64 Relids inner_relids);
65static List *generate_join_implied_equalities_broken(PlannerInfo *root,
66 EquivalenceClass *ec,
67 Relids nominal_join_relids,
68 Relids outer_relids,
69 Relids nominal_inner_relids,
70 RelOptInfo *inner_rel);
71static Oid select_equality_operator(EquivalenceClass *ec,
72 Oid lefttype, Oid righttype);
73static RestrictInfo *create_join_clause(PlannerInfo *root,
74 EquivalenceClass *ec, Oid opno,
75 EquivalenceMember *leftem,
76 EquivalenceMember *rightem,
77 EquivalenceClass *parent_ec);
78static bool reconsider_outer_join_clause(PlannerInfo *root,
79 OuterJoinClauseInfo *ojcinfo,
80 bool outer_on_left);
81static bool reconsider_full_join_clause(PlannerInfo *root,
82 OuterJoinClauseInfo *ojcinfo);
83static JoinDomain *find_join_domain(PlannerInfo *root, Relids relids);
84static Bitmapset *get_eclass_indexes_for_relids(PlannerInfo *root,
85 Relids relids);
86static Bitmapset *get_common_eclass_indexes(PlannerInfo *root, Relids relids1,
87 Relids relids2);
88static void ec_build_derives_hash(PlannerInfo *root, EquivalenceClass *ec);
89static void ec_add_derived_clauses(EquivalenceClass *ec, List *clauses);
90static void ec_add_derived_clause(EquivalenceClass *ec, RestrictInfo *clause);
91static void ec_add_clause_to_derives_hash(EquivalenceClass *ec, RestrictInfo *rinfo);
92static RestrictInfo *ec_search_clause_for_ems(PlannerInfo *root, EquivalenceClass *ec,
93 EquivalenceMember *leftem,
94 EquivalenceMember *rightem,
95 EquivalenceClass *parent_ec);
96static RestrictInfo *ec_search_derived_clause_for_ems(PlannerInfo *root,
97 EquivalenceClass *ec,
98 EquivalenceMember *leftem,
99 EquivalenceMember *rightem,
100 EquivalenceClass *parent_ec);
101
102/*
103 * Hash key identifying a derived clause.
104 *
105 * This structure should not be filled manually. Use fill_ec_derives_key() to
106 * set it up in canonical form.
107 */
108typedef struct
109{
110 EquivalenceMember *em1;
111 EquivalenceMember *em2;
112 EquivalenceClass *parent_ec;
113} ECDerivesKey;
114
115/* Hash table entry in ec_derives_hash. */
116typedef struct
117{
118 uint32 status;
119 ECDerivesKey key;
120 RestrictInfo *rinfo;
121} ECDerivesEntry;
122
123/* Threshold for switching from list to hash table */
124#define EC_DERIVES_HASH_THRESHOLD 32
125
126#define SH_PREFIX derives
127#define SH_ELEMENT_TYPE ECDerivesEntry
128#define SH_KEY_TYPE ECDerivesKey
129#define SH_KEY key
130#define SH_HASH_KEY(tb, key) \
131 hash_bytes((const unsigned char *) &(key), sizeof(ECDerivesKey))
132#define SH_EQUAL(tb, a, b) \
133 ((a).em1 == (b).em1 && (a).em2 == (b).em2 && (a).parent_ec == (b).parent_ec)
134#define SH_SCOPE static inline
135#define SH_DECLARE
136#define SH_DEFINE
137#include "lib/simplehash.h"
138
139/*
140 * process_equivalence
141 * The given clause has a mergejoinable operator and is not an outer-join
142 * qualification, so its two sides can be considered equal
143 * anywhere they are both computable; moreover that equality can be
144 * extended transitively. Record this knowledge in the EquivalenceClass
145 * data structure, if applicable. Returns true if successful, false if not
146 * (in which case caller should treat the clause as ordinary, not an
147 * equivalence).
148 *
149 * In some cases, although we cannot convert a clause into EquivalenceClass
150 * knowledge, we can still modify it to a more useful form than the original.
151 * Then, *p_restrictinfo will be replaced by a new RestrictInfo, which is what
152 * the caller should use for further processing.
153 *
154 * jdomain is the join domain within which the given clause was found.
155 * This limits the applicability of deductions from the EquivalenceClass,
156 * as described in optimizer/README.
157 *
158 * We reject proposed equivalence clauses if they contain leaky functions
159 * and have security_level above zero. The EC evaluation rules require us to
160 * apply certain tests at certain joining levels, and we can't tolerate
161 * delaying any test on security_level grounds. By rejecting candidate clauses
162 * that might require security delays, we ensure it's safe to apply an EC
163 * clause as soon as it's supposed to be applied.
164 *
165 * On success return, we have also initialized the clause's left_ec/right_ec
166 * fields to point to the EquivalenceClass representing it. This saves lookup
167 * effort later.
168 *
169 * Note: constructing merged EquivalenceClasses is a standard UNION-FIND
170 * problem, for which there exist better data structures than simple lists.
171 * If this code ever proves to be a bottleneck then it could be sped up ---
172 * but for now, simple is beautiful.
173 *
174 * Note: this is only called during planner startup, not during GEQO
175 * exploration, so we need not worry about whether we're in the right
176 * memory context.
177 */
178bool
179process_equivalence(PlannerInfo *root,
180 RestrictInfo **p_restrictinfo,
181 JoinDomain *jdomain)
182{
183 RestrictInfo *restrictinfo = *p_restrictinfo;
184 Expr *clause = restrictinfo->clause;
185 Oid opno,
186 collation,
187 item1_type,
188 item2_type;
189 Expr *item1;
190 Expr *item2;
191 Relids item1_relids,
192 item2_relids;
193 List *opfamilies;
194 EquivalenceClass *ec1,
195 *ec2;
196 EquivalenceMember *em1,
197 *em2;
198 ListCell *lc1;
199 int ec2_idx;
200
201 /* Should not already be marked as having generated an eclass */
202 Assert(restrictinfo->left_ec == NULL);
203 Assert(restrictinfo->right_ec == NULL);
204
205 /* Reject if it is potentially postponable by security considerations */
206 if (restrictinfo->security_level > 0 && !restrictinfo->leakproof)
207 return false;
208
209 /* Extract info from given clause */
210 Assert(is_opclause(clause));
211 opno = ((OpExpr *) clause)->opno;
212 collation = ((OpExpr *) clause)->inputcollid;
213 item1 = (Expr *) get_leftop(clause);
214 item2 = (Expr *) get_rightop(clause);
215 item1_relids = restrictinfo->left_relids;
216 item2_relids = restrictinfo->right_relids;
217
218 /*
219 * Ensure both input expressions expose the desired collation (their types
220 * should be OK already); see comments for canonicalize_ec_expression.
221 */
222 item1 = canonicalize_ec_expression(item1,
223 exprType((Node *) item1),
224 collation);
225 item2 = canonicalize_ec_expression(item2,
226 exprType((Node *) item2),
227 collation);
228
229 /*
230 * Clauses of the form X=X cannot be translated into EquivalenceClasses.
231 * We'd either end up with a single-entry EC, losing the knowledge that
232 * the clause was present at all, or else make an EC with duplicate
233 * entries, causing other issues.
234 */
235 if (equal(item1, item2))
236 {
237 /*
238 * If the operator is strict, then the clause can be treated as just
239 * "X IS NOT NULL". (Since we know we are considering a top-level
240 * qual, we can ignore the difference between FALSE and NULL results.)
241 * It's worth making the conversion because we'll typically get a much
242 * better selectivity estimate than we would for X=X.
243 *
244 * If the operator is not strict, we can't be sure what it will do
245 * with NULLs, so don't attempt to optimize it.
246 */
247 set_opfuncid((OpExpr *) clause);
248 if (func_strict(((OpExpr *) clause)->opfuncid))
249 {
250 NullTest *ntest = makeNode(NullTest);
251
252 ntest->arg = item1;
253 ntest->nulltesttype = IS_NOT_NULL;
254 ntest->argisrow = false; /* correct even if composite arg */
255 ntest->location = -1;
256
257 *p_restrictinfo =
258 make_restrictinfo(root,
259 (Expr *) ntest,
260 restrictinfo->is_pushed_down,
261 restrictinfo->has_clone,
262 restrictinfo->is_clone,
263 restrictinfo->pseudoconstant,
264 restrictinfo->security_level,
265 NULL,
266 restrictinfo->incompatible_relids,
267 restrictinfo->outer_relids);
268 }
269 return false;
270 }
271
272 /*
273 * We use the declared input types of the operator, not exprType() of the
274 * inputs, as the nominal datatypes for opfamily lookup. This presumes
275 * that btree operators are always registered with amoplefttype and
276 * amoprighttype equal to their declared input types. We will need this
277 * info anyway to build EquivalenceMember nodes, and by extracting it now
278 * we can use type comparisons to short-circuit some equal() tests.
279 */
280 op_input_types(opno, &item1_type, &item2_type);
281
282 opfamilies = restrictinfo->mergeopfamilies;
283
284 /*
285 * Sweep through the existing EquivalenceClasses looking for matches to
286 * item1 and item2. These are the possible outcomes:
287 *
288 * 1. We find both in the same EC. The equivalence is already known, so
289 * there's nothing to do.
290 *
291 * 2. We find both in different ECs. Merge the two ECs together.
292 *
293 * 3. We find just one. Add the other to its EC.
294 *
295 * 4. We find neither. Make a new, two-entry EC.
296 *
297 * Note: since all ECs are built through this process or the similar
298 * search in get_eclass_for_sort_expr(), it's impossible that we'd match
299 * an item in more than one existing nonvolatile EC. So it's okay to stop
300 * at the first match.
301 */
302 ec1 = ec2 = NULL;
303 em1 = em2 = NULL;
304 ec2_idx = -1;
305 foreach(lc1, root->eq_classes)
306 {
307 EquivalenceClass *cur_ec = (EquivalenceClass *) lfirst(lc1);
308 ListCell *lc2;
309
310 /* Never match to a volatile EC */
311 if (cur_ec->ec_has_volatile)
312 continue;
313
314 /*
315 * The collation has to match; check this first since it's cheaper
316 * than the opfamily comparison.
317 */
318 if (collation != cur_ec->ec_collation)
319 continue;
320
321 /*
322 * A "match" requires matching sets of btree opfamilies. Use of
323 * equal() for this test has implications discussed in the comments
324 * for get_mergejoin_opfamilies().
325 */
326 if (!equal(opfamilies, cur_ec->ec_opfamilies))
327 continue;
328
329 /* We don't expect any children yet */
330 Assert(cur_ec->ec_childmembers == NULL);
331
332 foreach(lc2, cur_ec->ec_members)
333 {
334 EquivalenceMember *cur_em = (EquivalenceMember *) lfirst(lc2);
335
336 /* Child members should not exist in ec_members */
337 Assert(!cur_em->em_is_child);
338
339 /*
340 * Match constants only within the same JoinDomain (see
341 * optimizer/README).
342 */
343 if (cur_em->em_is_const && cur_em->em_jdomain != jdomain)
344 continue;
345
346 if (!ec1 &&
347 item1_type == cur_em->em_datatype &&
348 equal(item1, cur_em->em_expr))
349 {
350 ec1 = cur_ec;
351 em1 = cur_em;
352 if (ec2)
353 break;
354 }
355
356 if (!ec2 &&
357 item2_type == cur_em->em_datatype &&
358 equal(item2, cur_em->em_expr))
359 {
360 ec2 = cur_ec;
361 ec2_idx = foreach_current_index(lc1);
362 em2 = cur_em;
363 if (ec1)
364 break;
365 }
366 }
367
368 if (ec1 && ec2)
369 break;
370 }
371
372 /* Sweep finished, what did we find? */
373
374 if (ec1 && ec2)
375 {
376 /* If case 1, nothing to do, except add to sources */
377 if (ec1 == ec2)
378 {
379 ec1->ec_sources = lappend(ec1->ec_sources, restrictinfo);
380 ec1->ec_min_security = Min(ec1->ec_min_security,
381 restrictinfo->security_level);
382 ec1->ec_max_security = Max(ec1->ec_max_security,
383 restrictinfo->security_level);
384 /* mark the RI as associated with this eclass */
385 restrictinfo->left_ec = ec1;
386 restrictinfo->right_ec = ec1;
387 /* mark the RI as usable with this pair of EMs */
388 restrictinfo->left_em = em1;
389 restrictinfo->right_em = em2;
390 return true;
391 }
392
393 /*
394 * Case 2: need to merge ec1 and ec2. This should never happen after
395 * the ECs have reached canonical state; otherwise, pathkeys could be
396 * rendered non-canonical by the merge, and relation eclass indexes
397 * would get broken by removal of an eq_classes list entry.
398 */
399 if (root->ec_merging_done)
400 elog(ERROR, "too late to merge equivalence classes");
401
402 /*
403 * We add ec2's items to ec1, then set ec2's ec_merged link to point
404 * to ec1 and remove ec2 from the eq_classes list. We cannot simply
405 * delete ec2 because that could leave dangling pointers in existing
406 * PathKeys. We leave it behind with a link so that the merged EC can
407 * be found.
408 */
409 ec1->ec_members = list_concat(ec1->ec_members, ec2->ec_members);
410 ec1->ec_sources = list_concat(ec1->ec_sources, ec2->ec_sources);
411
412 /*
413 * Appends ec2's derived clauses to ec1->ec_derives_list and adds them
414 * to ec1->ec_derives_hash if present.
415 */
416 ec_add_derived_clauses(ec1, ec2->ec_derives_list);
417 ec1->ec_relids = bms_join(ec1->ec_relids, ec2->ec_relids);
418 ec1->ec_has_const |= ec2->ec_has_const;
419 /* can't need to set has_volatile */
420 ec1->ec_min_security = Min(ec1->ec_min_security,
421 ec2->ec_min_security);
422 ec1->ec_max_security = Max(ec1->ec_max_security,
423 ec2->ec_max_security);
424 ec2->ec_merged = ec1;
425 root->eq_classes = list_delete_nth_cell(root->eq_classes, ec2_idx);
426 /* just to avoid debugging confusion w/ dangling pointers: */
427 ec2->ec_members = NIL;
428 ec2->ec_sources = NIL;
429 ec_clear_derived_clauses(ec2);
430 ec2->ec_relids = NULL;
431 ec1->ec_sources = lappend(ec1->ec_sources, restrictinfo);
432 ec1->ec_min_security = Min(ec1->ec_min_security,
433 restrictinfo->security_level);
434 ec1->ec_max_security = Max(ec1->ec_max_security,
435 restrictinfo->security_level);
436 /* mark the RI as associated with this eclass */
437 restrictinfo->left_ec = ec1;
438 restrictinfo->right_ec = ec1;
439 /* mark the RI as usable with this pair of EMs */
440 restrictinfo->left_em = em1;
441 restrictinfo->right_em = em2;
442 }
443 else if (ec1)
444 {
445 /* Case 3: add item2 to ec1 */
446 em2 = add_eq_member(ec1, item2, item2_relids,
447 jdomain, item2_type);
448 ec1->ec_sources = lappend(ec1->ec_sources, restrictinfo);
449 ec1->ec_min_security = Min(ec1->ec_min_security,
450 restrictinfo->security_level);
451 ec1->ec_max_security = Max(ec1->ec_max_security,
452 restrictinfo->security_level);
453 /* mark the RI as associated with this eclass */
454 restrictinfo->left_ec = ec1;
455 restrictinfo->right_ec = ec1;
456 /* mark the RI as usable with this pair of EMs */
457 restrictinfo->left_em = em1;
458 restrictinfo->right_em = em2;
459 }
460 else if (ec2)
461 {
462 /* Case 3: add item1 to ec2 */
463 em1 = add_eq_member(ec2, item1, item1_relids,
464 jdomain, item1_type);
465 ec2->ec_sources = lappend(ec2->ec_sources, restrictinfo);
466 ec2->ec_min_security = Min(ec2->ec_min_security,
467 restrictinfo->security_level);
468 ec2->ec_max_security = Max(ec2->ec_max_security,
469 restrictinfo->security_level);
470 /* mark the RI as associated with this eclass */
471 restrictinfo->left_ec = ec2;
472 restrictinfo->right_ec = ec2;
473 /* mark the RI as usable with this pair of EMs */
474 restrictinfo->left_em = em1;
475 restrictinfo->right_em = em2;
476 }
477 else
478 {
479 /* Case 4: make a new, two-entry EC */
480 EquivalenceClass *ec = makeNode(EquivalenceClass);
481
482 ec->ec_opfamilies = opfamilies;
483 ec->ec_collation = collation;
484 ec->ec_childmembers_size = 0;
485 ec->ec_members = NIL;
486 ec->ec_childmembers = NULL;
487 ec->ec_sources = list_make1(restrictinfo);
488 ec->ec_derives_list = NIL;
489 ec->ec_derives_hash = NULL;
490 ec->ec_relids = NULL;
491 ec->ec_has_const = false;
492 ec->ec_has_volatile = false;
493 ec->ec_broken = false;
494 ec->ec_sortref = 0;
495 ec->ec_min_security = restrictinfo->security_level;
496 ec->ec_max_security = restrictinfo->security_level;
497 ec->ec_merged = NULL;
498 em1 = add_eq_member(ec, item1, item1_relids,
499 jdomain, item1_type);
500 em2 = add_eq_member(ec, item2, item2_relids,
501 jdomain, item2_type);
502
503 root->eq_classes = lappend(root->eq_classes, ec);
504
505 /* mark the RI as associated with this eclass */
506 restrictinfo->left_ec = ec;
507 restrictinfo->right_ec = ec;
508 /* mark the RI as usable with this pair of EMs */
509 restrictinfo->left_em = em1;
510 restrictinfo->right_em = em2;
511 }
512
513 return true;
514}
515
516/*
517 * canonicalize_ec_expression
518 *
519 * This function ensures that the expression exposes the expected type and
520 * collation, so that it will be equal() to other equivalence-class expressions
521 * that it ought to be equal() to.
522 *
523 * The rule for datatypes is that the exposed type should match what it would
524 * be for an input to an operator of the EC's opfamilies; which is usually
525 * the declared input type of the operator, but in the case of polymorphic
526 * operators no relabeling is wanted (compare the behavior of parse_coerce.c).
527 * Expressions coming in from quals will generally have the right type
528 * already, but expressions coming from indexkeys may not (because they are
529 * represented without any explicit relabel in pg_index), and the same problem
530 * occurs for sort expressions (because the parser is likewise cavalier about
531 * putting relabels on them). Such cases will be binary-compatible with the
532 * real operators, so adding a RelabelType is sufficient.
533 *
534 * Also, the expression's exposed collation must match the EC's collation.
535 * This is important because in comparisons like "foo < bar COLLATE baz",
536 * only one of the expressions has the correct exposed collation as we receive
537 * it from the parser. Forcing both of them to have it ensures that all
538 * variant spellings of such a construct behave the same. Again, we can
539 * stick on a RelabelType to force the right exposed collation. (It might
540 * work to not label the collation at all in EC members, but this is risky
541 * since some parts of the system expect exprCollation() to deliver the
542 * right answer for a sort key.)
543 */
544Expr *
545canonicalize_ec_expression(Expr *expr, Oid req_type, Oid req_collation)
546{
547 Oid expr_type = exprType((Node *) expr);
548
549 /*
550 * For a polymorphic-input-type opclass, just keep the same exposed type.
551 * RECORD opclasses work like polymorphic-type ones for this purpose.
552 */
553 if (IsPolymorphicType(req_type) || req_type == RECORDOID)
554 req_type = expr_type;
555
556 /*
557 * No work if the expression exposes the right type/collation already.
558 */
559 if (expr_type != req_type ||
560 exprCollation((Node *) expr) != req_collation)
561 {
562 /*
563 * If we have to change the type of the expression, set typmod to -1,
564 * since the new type may not have the same typmod interpretation.
565 * When we only have to change collation, preserve the exposed typmod.
566 */
567 int32 req_typmod;
568
569 if (expr_type != req_type)
570 req_typmod = -1;
571 else
572 req_typmod = exprTypmod((Node *) expr);
573
574 /*
575 * Use applyRelabelType so that we preserve const-flatness. This is
576 * important since eval_const_expressions has already been applied.
577 */
578 expr = (Expr *) applyRelabelType((Node *) expr,
579 req_type, req_typmod, req_collation,
580 COERCE_IMPLICIT_CAST, -1, false);
581 }
582
583 return expr;
584}
585
586/*
587 * make_eq_member
588 * Build a new EquivalenceMember without adding it to an EC. If 'parent'
589 * is NULL, the result will be a parent member, otherwise a child member.
590 */
591static EquivalenceMember *
592make_eq_member(EquivalenceClass *ec, Expr *expr, Relids relids,
593 JoinDomain *jdomain, EquivalenceMember *parent, Oid datatype)
594{
595 EquivalenceMember *em = makeNode(EquivalenceMember);
596
597 em->em_expr = expr;
598 em->em_relids = relids;
599 em->em_is_const = false;
600 em->em_is_child = (parent != NULL);
601 em->em_datatype = datatype;
602 em->em_jdomain = jdomain;
603 em->em_parent = parent;
604
605 if (bms_is_empty(relids))
606 {
607 /*
608 * No Vars, assume it's a pseudoconstant. This is correct for entries
609 * generated from process_equivalence(), because a WHERE clause can't
610 * contain aggregates or SRFs, and non-volatility was checked before
611 * process_equivalence() ever got called. But
612 * get_eclass_for_sort_expr() has to work harder. We put the tests
613 * there not here to save cycles in the equivalence case.
614 */
615 Assert(!parent);
616 em->em_is_const = true;
617 ec->ec_has_const = true;
618 /* it can't affect ec_relids */
619 }
620
621 return em;
622}
623
624/*
625 * add_eq_member - build a new non-child EquivalenceMember and add it to 'ec'.
626 */
627static EquivalenceMember *
628add_eq_member(EquivalenceClass *ec, Expr *expr, Relids relids,
629 JoinDomain *jdomain, Oid datatype)
630{
631 EquivalenceMember *em = make_eq_member(ec, expr, relids, jdomain,
632 NULL, datatype);
633
634 /* add to the members list */
635 ec->ec_members = lappend(ec->ec_members, em);
636
637 /* record the relids for parent members */
638 ec->ec_relids = bms_add_members(ec->ec_relids, relids);
639
640 return em;
641}
642
643/*
644 * add_child_eq_member
645 * Create an em_is_child=true EquivalenceMember and add it to 'ec'.
646 *
647 * 'root' is the PlannerInfo that 'ec' belongs to.
648 * 'ec' is the EquivalenceClass to add the child member to.
649 * 'ec_index' the index of 'ec' within root->eq_classes, or -1 if maintaining
650 * the RelOptInfo.eclass_indexes isn't needed.
651 * 'expr' is the em_expr for the new member.
652 * 'relids' is the 'em_relids' for the new member.
653 * 'jdomain' is the 'em_jdomain' for the new member.
654 * 'parent_em' is the parent member of the child to create.
655 * 'datatype' is the em_datatype of the new member.
656 * 'child_relid' defines which element of ec_childmembers to add this member
657 * to. This is generally a RELOPT_OTHER_MEMBER_REL, but for set operations
658 * can be a RELOPT_BASEREL representing the set-op children.
659 */
660static EquivalenceMember *
661add_child_eq_member(PlannerInfo *root, EquivalenceClass *ec, int ec_index,
662 Expr *expr, Relids relids, JoinDomain *jdomain,
663 EquivalenceMember *parent_em, Oid datatype,
664 Index child_relid)
665{
666 EquivalenceMember *em;
667
668 Assert(parent_em != NULL);
669
670 /*
671 * Allocate the array to store child members; an array of Lists indexed by
672 * relid, or expand the existing one, if necessary.
673 */
674 if (unlikely(ec->ec_childmembers_size < root->simple_rel_array_size))
675 {
676 if (ec->ec_childmembers == NULL)
677 ec->ec_childmembers = palloc0_array(List *, root->simple_rel_array_size);
678 else
679 ec->ec_childmembers = repalloc0_array(ec->ec_childmembers, List *,
680 ec->ec_childmembers_size,
681 root->simple_rel_array_size);
682
683 ec->ec_childmembers_size = root->simple_rel_array_size;
684 }
685
686 em = make_eq_member(ec, expr, relids, jdomain, parent_em, datatype);
687
688 /* add member to the ec_childmembers List for the given child_relid */
689 ec->ec_childmembers[child_relid] = lappend(ec->ec_childmembers[child_relid], em);
690
691 /* Record this EC index for the child rel */
692 if (ec_index >= 0)
693 {
694 RelOptInfo *child_rel = root->simple_rel_array[child_relid];
695
696 child_rel->eclass_indexes =
697 bms_add_member(child_rel->eclass_indexes, ec_index);
698 }
699
700 return em;
701}
702
703
704/*
705 * get_eclass_for_sort_expr
706 * Given an expression and opfamily/collation info, find an existing
707 * equivalence class it is a member of; if none, optionally build a new
708 * single-member EquivalenceClass for it.
709 *
710 * sortref is the SortGroupRef of the originating SortGroupClause, if any,
711 * or zero if not. (It should never be zero if the expression is volatile!)
712 *
713 * If rel is not NULL, it identifies a specific relation we're considering
714 * a path for, and indicates that child EC members for that relation can be
715 * considered. Otherwise child members are ignored. (Note: since child EC
716 * members aren't guaranteed unique, a non-NULL value means that there could
717 * be more than one EC that matches the expression; if so it's order-dependent
718 * which one you get. This is annoying but it only happens in corner cases,
719 * so for now we live with just reporting the first match. See also
720 * generate_implied_equalities_for_column and match_pathkeys_to_index.)
721 *
722 * If create_it is true, we'll build a new EquivalenceClass when there is no
723 * match. If create_it is false, we just return NULL when no match.
724 *
725 * This can be used safely both before and after EquivalenceClass merging;
726 * since it never causes merging it does not invalidate any existing ECs
727 * or PathKeys. However, ECs added after path generation has begun are
728 * of limited usefulness, so usually it's best to create them beforehand.
729 *
730 * Note: opfamilies must be chosen consistently with the way
731 * process_equivalence() would do; that is, generated from a mergejoinable
732 * equality operator. Else we might fail to detect valid equivalences,
733 * generating poor (but not incorrect) plans.
734 */
735EquivalenceClass *
736get_eclass_for_sort_expr(PlannerInfo *root,
737 Expr *expr,
738 List *opfamilies,
739 Oid opcintype,
740 Oid collation,
741 Index sortref,
742 Relids rel,
743 bool create_it)
744{
745 JoinDomain *jdomain;
746 Relids expr_relids;
747 EquivalenceClass *newec;
748 EquivalenceMember *newem;
749 ListCell *lc1;
750 MemoryContext oldcontext;
751
752 /*
753 * Ensure the expression exposes the correct type and collation.
754 */
755 expr = canonicalize_ec_expression(expr, opcintype, collation);
756
757 /*
758 * Since SortGroupClause nodes are top-level expressions (GROUP BY, ORDER
759 * BY, etc), they can be presumed to belong to the top JoinDomain.
760 */
761 jdomain = linitial_node(JoinDomain, root->join_domains);
762
763 /*
764 * Scan through the existing EquivalenceClasses for a match
765 */
766 foreach(lc1, root->eq_classes)
767 {
768 EquivalenceClass *cur_ec = (EquivalenceClass *) lfirst(lc1);
769 EquivalenceMemberIterator it;
770 EquivalenceMember *cur_em;
771
772 /*
773 * Never match to a volatile EC, except when we are looking at another
774 * reference to the same volatile SortGroupClause.
775 */
776 if (cur_ec->ec_has_volatile &&
777 (sortref == 0 || sortref != cur_ec->ec_sortref))
778 continue;
779
780 if (collation != cur_ec->ec_collation)
781 continue;
782 if (!equal(opfamilies, cur_ec->ec_opfamilies))
783 continue;
784
785 setup_eclass_member_iterator(&it, cur_ec, rel);
786 while ((cur_em = eclass_member_iterator_next(&it)) != NULL)
787 {
788 /*
789 * Ignore child members unless they match the request.
790 */
791 if (cur_em->em_is_child &&
792 !bms_equal(cur_em->em_relids, rel))
793 continue;
794
795 /*
796 * Match constants only within the same JoinDomain (see
797 * optimizer/README).
798 */
799 if (cur_em->em_is_const && cur_em->em_jdomain != jdomain)
800 continue;
801
802 if (opcintype == cur_em->em_datatype &&
803 equal(expr, cur_em->em_expr))
804 return cur_ec; /* Match! */
805 }
806 }
807
808 /* No match; does caller want a NULL result? */
809 if (!create_it)
810 return NULL;
811
812 /*
813 * OK, build a new single-member EC
814 *
815 * Here, we must be sure that we construct the EC in the right context.
816 */
817 oldcontext = MemoryContextSwitchTo(root->planner_cxt);
818
819 newec = makeNode(EquivalenceClass);
820 newec->ec_opfamilies = list_copy(opfamilies);
821 newec->ec_collation = collation;
822 newec->ec_childmembers_size = 0;
823 newec->ec_members = NIL;
824 newec->ec_childmembers = NULL;
825 newec->ec_sources = NIL;
826 newec->ec_derives_list = NIL;
827 newec->ec_derives_hash = NULL;
828 newec->ec_relids = NULL;
829 newec->ec_has_const = false;
830 newec->ec_has_volatile = contain_volatile_functions((Node *) expr);
831 newec->ec_broken = false;
832 newec->ec_sortref = sortref;
833 newec->ec_min_security = UINT_MAX;
834 newec->ec_max_security = 0;
835 newec->ec_merged = NULL;
836
837 if (newec->ec_has_volatile && sortref == 0) /* should not happen */
838 elog(ERROR, "volatile EquivalenceClass has no sortref");
839
840 /*
841 * Get the precise set of relids appearing in the expression.
842 */
843 expr_relids = pull_varnos(root, (Node *) expr);
844
845 newem = add_eq_member(newec, copyObject(expr), expr_relids,
846 jdomain, opcintype);
847
848 /*
849 * add_eq_member doesn't check for volatile functions, set-returning
850 * functions, aggregates, or window functions, but such could appear in
851 * sort expressions; so we have to check whether its const-marking was
852 * correct.
853 */
854 if (newec->ec_has_const)
855 {
856 if (newec->ec_has_volatile ||
857 expression_returns_set((Node *) expr) ||
858 contain_agg_clause((Node *) expr) ||
859 contain_window_function((Node *) expr))
860 {
861 newec->ec_has_const = false;
862 newem->em_is_const = false;
863 }
864 }
865
866 root->eq_classes = lappend(root->eq_classes, newec);
867
868 /*
869 * If EC merging is already complete, we have to mop up by adding the new
870 * EC to the eclass_indexes of the relation(s) mentioned in it.
871 */
872 if (root->ec_merging_done)
873 {
874 int ec_index = list_length(root->eq_classes) - 1;
875 int i = -1;
876
877 while ((i = bms_next_member(newec->ec_relids, i)) > 0)
878 {
879 RelOptInfo *rel = root->simple_rel_array[i];
880
881 /* ignore the RTE_GROUP RTE */
882 if (i == root->group_rtindex)
883 continue;
884
885 if (rel == NULL) /* must be an outer join */
886 {
887 Assert(bms_is_member(i, root->outer_join_rels));
888 continue;
889 }
890
891 Assert(rel->reloptkind == RELOPT_BASEREL);
892
893 rel->eclass_indexes = bms_add_member(rel->eclass_indexes,
894 ec_index);
895 }
896 }
897
898 MemoryContextSwitchTo(oldcontext);
899
900 return newec;
901}
902
903/*
904 * find_ec_member_matching_expr
905 * Locate an EquivalenceClass member matching the given expr, if any;
906 * return NULL if no match.
907 *
908 * "Matching" is defined as "equal after stripping RelabelTypes".
909 * This is used for identifying sort expressions, and we need to allow
910 * binary-compatible relabeling for some cases involving binary-compatible
911 * sort operators.
912 *
913 * Child EC members are ignored unless they belong to given 'relids'.
914 */
915EquivalenceMember *
916find_ec_member_matching_expr(EquivalenceClass *ec,
917 Expr *expr,
918 Relids relids)
919{
920 EquivalenceMemberIterator it;
921 EquivalenceMember *em;
922
923 /* We ignore binary-compatible relabeling on both ends */
924 while (expr && IsA(expr, RelabelType))
925 expr = ((RelabelType *) expr)->arg;
926
927 setup_eclass_member_iterator(&it, ec, relids);
928 while ((em = eclass_member_iterator_next(&it)) != NULL)
929 {
930 Expr *emexpr;
931
932 /*
933 * We shouldn't be trying to sort by an equivalence class that
934 * contains a constant, so no need to consider such cases any further.
935 */
936 if (em->em_is_const)
937 continue;
938
939 /*
940 * Ignore child members unless they belong to the requested rel.
941 */
942 if (em->em_is_child &&
943 !bms_is_subset(em->em_relids, relids))
944 continue;
945
946 /*
947 * Match if same expression (after stripping relabel).
948 */
949 emexpr = em->em_expr;
950 while (emexpr && IsA(emexpr, RelabelType))
951 emexpr = ((RelabelType *) emexpr)->arg;
952
953 if (equal(emexpr, expr))
954 return em;
955 }
956
957 return NULL;
958}
959
960/*
961 * find_computable_ec_member
962 * Locate an EquivalenceClass member that can be computed from the
963 * expressions appearing in "exprs"; return NULL if no match.
964 *
965 * "exprs" can be either a list of bare expression trees, or a list of
966 * TargetEntry nodes. Typically it will contain Vars and possibly Aggrefs
967 * and WindowFuncs; however, when considering an appendrel member the list
968 * could contain arbitrary expressions. We consider an EC member to be
969 * computable if all the Vars, PlaceHolderVars, Aggrefs, and WindowFuncs
970 * it needs are present in "exprs".
971 *
972 * There is some subtlety in that definition: for example, if an EC member is
973 * Var_A + 1 while what is in "exprs" is Var_A + 2, it's still computable.
974 * This works because in the final plan tree, the EC member's expression will
975 * be computed as part of the same plan node targetlist that is currently
976 * represented by "exprs". So if we have Var_A available for the existing
977 * tlist member, it must be OK to use it in the EC expression too.
978 *
979 * Unlike find_ec_member_matching_expr, there's no special provision here
980 * for binary-compatible relabeling. This is intentional: if we have to
981 * compute an expression in this way, setrefs.c is going to insist on exact
982 * matches of Vars to the source tlist.
983 *
984 * Child EC members are ignored unless they belong to given 'relids'.
985 * Also, non-parallel-safe expressions are ignored if 'require_parallel_safe'.
986 *
987 * Note: some callers pass root == NULL for notational reasons. This is OK
988 * when require_parallel_safe is false.
989 */
990EquivalenceMember *
991find_computable_ec_member(PlannerInfo *root,
992 EquivalenceClass *ec,
993 List *exprs,
994 Relids relids,
995 bool require_parallel_safe)
996{
997 List *exprvars;
998 EquivalenceMemberIterator it;
999 EquivalenceMember *em;
1000
1001 /*
1002 * Pull out the Vars and quasi-Vars present in "exprs". In the typical
1003 * non-appendrel case, this is just another representation of the same
1004 * list. However, it does remove the distinction between the case of a
1005 * list of plain expressions and a list of TargetEntrys.
1006 */
1007 exprvars = pull_var_clause((Node *) exprs,
1008 PVC_INCLUDE_AGGREGATES |
1009 PVC_INCLUDE_WINDOWFUNCS |
1010 PVC_INCLUDE_PLACEHOLDERS |
1011 PVC_INCLUDE_CONVERTROWTYPES);
1012
1013 setup_eclass_member_iterator(&it, ec, relids);
1014 while ((em = eclass_member_iterator_next(&it)) != NULL)
1015 {
1016 List *emvars;
1017 ListCell *lc2;
1018
1019 /*
1020 * We shouldn't be trying to sort by an equivalence class that
1021 * contains a constant, so no need to consider such cases any further.
1022 */
1023 if (em->em_is_const)
1024 continue;
1025
1026 /*
1027 * Ignore child members unless they belong to the requested rel.
1028 */
1029 if (em->em_is_child &&
1030 !bms_is_subset(em->em_relids, relids))
1031 continue;
1032
1033 /*
1034 * Match if all Vars and quasi-Vars are present in "exprs".
1035 */
1036 emvars = pull_var_clause((Node *) em->em_expr,
1037 PVC_INCLUDE_AGGREGATES |
1038 PVC_INCLUDE_WINDOWFUNCS |
1039 PVC_INCLUDE_PLACEHOLDERS);
1040 foreach(lc2, emvars)
1041 {
1042 if (!list_member(exprvars, lfirst(lc2)))
1043 break;
1044 }
1045 list_free(emvars);
1046 if (lc2)
1047 continue; /* we hit a non-available Var */
1048
1049 /*
1050 * If requested, reject expressions that are not parallel-safe. We
1051 * check this last because it's a rather expensive test.
1052 */
1053 if (require_parallel_safe &&
1054 !is_parallel_safe(root, (Node *) em->em_expr))
1055 continue;
1056
1057 return em; /* found usable expression */
1058 }
1059
1060 return NULL;
1061}
1062
1063/*
1064 * relation_can_be_sorted_early
1065 * Can this relation be sorted on this EC before the final output step?
1066 *
1067 * To succeed, we must find an EC member that prepare_sort_from_pathkeys knows
1068 * how to sort on, given the rel's reltarget as input. There are also a few
1069 * additional constraints based on the fact that the desired sort will be done
1070 * "early", within the scan/join part of the plan. Also, non-parallel-safe
1071 * expressions are ignored if 'require_parallel_safe'.
1072 *
1073 * At some point we might want to return the identified EquivalenceMember,
1074 * but for now, callers only want to know if there is one.
1075 */
1076bool
1077relation_can_be_sorted_early(PlannerInfo *root, RelOptInfo *rel,
1078 EquivalenceClass *ec, bool require_parallel_safe)
1079{
1080 PathTarget *target = rel->reltarget;
1081 EquivalenceMember *em;
1082 ListCell *lc;
1083
1084 /*
1085 * Reject volatile ECs immediately; such sorts must always be postponed.
1086 */
1087 if (ec->ec_has_volatile)
1088 return false;
1089
1090 /*
1091 * Try to find an EM directly matching some reltarget member.
1092 */
1093 foreach(lc, target->exprs)
1094 {
1095 Expr *targetexpr = (Expr *) lfirst(lc);
1096
1097 em = find_ec_member_matching_expr(ec, targetexpr, rel->relids);
1098 if (!em)
1099 continue;
1100
1101 /*
1102 * Reject expressions involving set-returning functions, as those
1103 * can't be computed early either. (Note: this test and the following
1104 * one are effectively checking properties of targetexpr, so there's
1105 * no point in asking whether some other EC member would be better.)
1106 */
1107 if (expression_returns_set((Node *) em->em_expr))
1108 continue;
1109
1110 /*
1111 * If requested, reject expressions that are not parallel-safe. We
1112 * check this last because it's a rather expensive test.
1113 */
1114 if (require_parallel_safe &&
1115 !is_parallel_safe(root, (Node *) em->em_expr))
1116 continue;
1117
1118 return true;
1119 }
1120
1121 /*
1122 * Try to find an expression computable from the reltarget.
1123 */
1124 em = find_computable_ec_member(root, ec, target->exprs, rel->relids,
1125 require_parallel_safe);
1126 if (!em)
1127 return false;
1128
1129 /*
1130 * Reject expressions involving set-returning functions, as those can't be
1131 * computed early either. (There's no point in looking for another EC
1132 * member in this case; since SRFs can't appear in WHERE, they cannot
1133 * belong to multi-member ECs.)
1134 */
1135 if (expression_returns_set((Node *) em->em_expr))
1136 return false;
1137
1138 return true;
1139}
1140
1141/*
1142 * generate_base_implied_equalities
1143 * Generate any restriction clauses that we can deduce from equivalence
1144 * classes.
1145 *
1146 * When an EC contains pseudoconstants, our strategy is to generate
1147 * "member = const1" clauses where const1 is the first constant member, for
1148 * every other member (including other constants). If we are able to do this
1149 * then we don't need any "var = var" comparisons because we've successfully
1150 * constrained all the vars at their points of creation. If we fail to
1151 * generate any of these clauses due to lack of cross-type operators, we fall
1152 * back to the "ec_broken" strategy described below. (XXX if there are
1153 * multiple constants of different types, it's possible that we might succeed
1154 * in forming all the required clauses if we started from a different const
1155 * member; but this seems a sufficiently hokey corner case to not be worth
1156 * spending lots of cycles on.)
1157 *
1158 * For ECs that contain no pseudoconstants, we generate derived clauses
1159 * "member1 = member2" for each pair of members belonging to the same base
1160 * relation (actually, if there are more than two for the same base relation,
1161 * we only need enough clauses to link each to each other). This provides
1162 * the base case for the recursion: each row emitted by a base relation scan
1163 * will constrain all computable members of the EC to be equal. As each
1164 * join path is formed, we'll add additional derived clauses on-the-fly
1165 * to maintain this invariant (see generate_join_implied_equalities).
1166 *
1167 * If the opfamilies used by the EC do not provide complete sets of cross-type
1168 * equality operators, it is possible that we will fail to generate a clause
1169 * that must be generated to maintain the invariant. (An example: given
1170 * "WHERE a.x = b.y AND b.y = a.z", the scheme breaks down if we cannot
1171 * generate "a.x = a.z" as a restriction clause for A.) In this case we mark
1172 * the EC "ec_broken" and fall back to regurgitating its original source
1173 * RestrictInfos at appropriate times. We do not try to retract any derived
1174 * clauses already generated from the broken EC, so the resulting plan could
1175 * be poor due to bad selectivity estimates caused by redundant clauses. But
1176 * the correct solution to that is to fix the opfamilies ...
1177 *
1178 * Equality clauses derived by this function are passed off to
1179 * process_implied_equality (in plan/initsplan.c) to be inserted into the
1180 * restrictinfo datastructures. Note that this must be called after initial
1181 * scanning of the quals and before Path construction begins.
1182 *
1183 * We make no attempt to avoid generating duplicate RestrictInfos here: we
1184 * don't search existing source or derived clauses in the EC for matches. It
1185 * doesn't really seem worth the trouble to do so.
1186 */
1187void
1188generate_base_implied_equalities(PlannerInfo *root)
1189{
1190 int ec_index;
1191 ListCell *lc;
1192
1193 /*
1194 * At this point, we're done absorbing knowledge of equivalences in the
1195 * query, so no further EC merging should happen, and ECs remaining in the
1196 * eq_classes list can be considered canonical. (But note that it's still
1197 * possible for new single-member ECs to be added through
1198 * get_eclass_for_sort_expr().)
1199 */
1200 root->ec_merging_done = true;
1201
1202 ec_index = 0;
1203 foreach(lc, root->eq_classes)
1204 {
1205 EquivalenceClass *ec = (EquivalenceClass *) lfirst(lc);
1206 bool can_generate_joinclause = false;
1207 int i;
1208
1209 Assert(ec->ec_merged == NULL); /* else shouldn't be in list */
1210 Assert(!ec->ec_broken); /* not yet anyway... */
1211
1212 /*
1213 * Generate implied equalities that are restriction clauses.
1214 * Single-member ECs won't generate any deductions, either here or at
1215 * the join level.
1216 */
1217 if (list_length(ec->ec_members) > 1)
1218 {
1219 if (ec->ec_has_const)
1220 generate_base_implied_equalities_const(root, ec);
1221 else
1222 generate_base_implied_equalities_no_const(root, ec);
1223
1224 /* Recover if we failed to generate required derived clauses */
1225 if (ec->ec_broken)
1226 generate_base_implied_equalities_broken(root, ec);
1227
1228 /* Detect whether this EC might generate join clauses */
1229 can_generate_joinclause =
1230 (bms_membership(ec->ec_relids) == BMS_MULTIPLE);
1231 }
1232
1233 /*
1234 * Mark the base rels cited in each eclass (which should all exist by
1235 * now) with the eq_classes indexes of all eclasses mentioning them.
1236 * This will let us avoid searching in subsequent lookups. While
1237 * we're at it, we can mark base rels that have pending eclass joins;
1238 * this is a cheap version of has_relevant_eclass_joinclause().
1239 */
1240 i = -1;
1241 while ((i = bms_next_member(ec->ec_relids, i)) > 0)
1242 {
1243 RelOptInfo *rel = root->simple_rel_array[i];
1244
1245 /* ignore the RTE_GROUP RTE */
1246 if (i == root->group_rtindex)
1247 continue;
1248
1249 if (rel == NULL) /* must be an outer join */
1250 {
1251 Assert(bms_is_member(i, root->outer_join_rels));
1252 continue;
1253 }
1254
1255 Assert(rel->reloptkind == RELOPT_BASEREL);
1256
1257 rel->eclass_indexes = bms_add_member(rel->eclass_indexes,
1258 ec_index);
1259
1260 if (can_generate_joinclause)
1261 rel->has_eclass_joins = true;
1262 }
1263
1264 ec_index++;
1265 }
1266}
1267
1268/*
1269 * generate_base_implied_equalities when EC contains pseudoconstant(s)
1270 */
1271static void
1272generate_base_implied_equalities_const(PlannerInfo *root,
1273 EquivalenceClass *ec)
1274{
1275 EquivalenceMember *const_em = NULL;
1276 ListCell *lc;
1277
1278 /*
1279 * In the trivial case where we just had one "var = const" clause, push
1280 * the original clause back into the main planner machinery. There is
1281 * nothing to be gained by doing it differently, and we save the effort to
1282 * re-build and re-analyze an equality clause that will be exactly
1283 * equivalent to the old one.
1284 */
1285 if (list_length(ec->ec_members) == 2 &&
1286 list_length(ec->ec_sources) == 1)
1287 {
1288 RestrictInfo *restrictinfo = (RestrictInfo *) linitial(ec->ec_sources);
1289
1290 distribute_restrictinfo_to_rels(root, restrictinfo);
1291 return;
1292 }
1293
1294 /* We don't expect any children yet */
1295 Assert(ec->ec_childmembers == NULL);
1296
1297 /*
1298 * Find the constant member to use. We prefer an actual constant to
1299 * pseudo-constants (such as Params), because the constraint exclusion
1300 * machinery might be able to exclude relations on the basis of generated
1301 * "var = const" equalities, but "var = param" won't work for that.
1302 */
1303 foreach(lc, ec->ec_members)
1304 {
1305 EquivalenceMember *cur_em = (EquivalenceMember *) lfirst(lc);
1306
1307 if (cur_em->em_is_const)
1308 {
1309 const_em = cur_em;
1310 if (IsA(cur_em->em_expr, Const))
1311 break;
1312 }
1313 }
1314 Assert(const_em != NULL);
1315
1316 /* Generate a derived equality against each other member */
1317 foreach(lc, ec->ec_members)
1318 {
1319 EquivalenceMember *cur_em = (EquivalenceMember *) lfirst(lc);
1320 Oid eq_op;
1321 RestrictInfo *rinfo;
1322
1323 /* Child members should not exist in ec_members */
1324 Assert(!cur_em->em_is_child);
1325 if (cur_em == const_em)
1326 continue;
1327 eq_op = select_equality_operator(ec,
1328 cur_em->em_datatype,
1329 const_em->em_datatype);
1330 if (!OidIsValid(eq_op))
1331 {
1332 /* failed... */
1333 ec->ec_broken = true;
1334 break;
1335 }
1336
1337 /*
1338 * We use the constant's em_jdomain as qualscope, so that if the
1339 * generated clause is variable-free (i.e, both EMs are consts) it
1340 * will be enforced at the join domain level.
1341 */
1342 rinfo = process_implied_equality(root, eq_op, ec->ec_collation,
1343 cur_em->em_expr, const_em->em_expr,
1344 const_em->em_jdomain->jd_relids,
1345 ec->ec_min_security,
1346 cur_em->em_is_const);
1347
1348 /*
1349 * If the clause didn't degenerate to a constant, fill in the correct
1350 * markings for a mergejoinable clause, and save it as a derived
1351 * clause. (We will not re-use such clauses directly, but selectivity
1352 * estimation may consult those later. Note that this use of derived
1353 * clauses does not overlap with its use for join clauses, since we
1354 * never generate join clauses from an ec_has_const eclass.)
1355 */
1356 if (rinfo && rinfo->mergeopfamilies)
1357 {
1358 /* it's not redundant, so don't set parent_ec */
1359 rinfo->left_ec = rinfo->right_ec = ec;
1360 rinfo->left_em = cur_em;
1361 rinfo->right_em = const_em;
1362 ec_add_derived_clause(ec, rinfo);
1363 }
1364 }
1365}
1366
1367/*
1368 * generate_base_implied_equalities when EC contains no pseudoconstants
1369 */
1370static void
1371generate_base_implied_equalities_no_const(PlannerInfo *root,
1372 EquivalenceClass *ec)
1373{
1374 EquivalenceMember **prev_ems;
1375 ListCell *lc;
1376
1377 /*
1378 * We scan the EC members once and track the last-seen member for each
1379 * base relation. When we see another member of the same base relation,
1380 * we generate "prev_em = cur_em". This results in the minimum number of
1381 * derived clauses, but it's possible that it will fail when a different
1382 * ordering would succeed. XXX FIXME: use a UNION-FIND algorithm similar
1383 * to the way we build merged ECs. (Use a list-of-lists for each rel.)
1384 */
1385 prev_ems = (EquivalenceMember **)
1386 palloc0(root->simple_rel_array_size * sizeof(EquivalenceMember *));
1387
1388 /* We don't expect any children yet */
1389 Assert(ec->ec_childmembers == NULL);
1390
1391 foreach(lc, ec->ec_members)
1392 {
1393 EquivalenceMember *cur_em = (EquivalenceMember *) lfirst(lc);
1394 int relid;
1395
1396 /* Child members should not exist in ec_members */
1397 Assert(!cur_em->em_is_child);
1398
1399 if (!bms_get_singleton_member(cur_em->em_relids, &relid))
1400 continue;
1401 Assert(relid < root->simple_rel_array_size);
1402
1403 if (prev_ems[relid] != NULL)
1404 {
1405 EquivalenceMember *prev_em = prev_ems[relid];
1406 Oid eq_op;
1407 RestrictInfo *rinfo;
1408
1409 eq_op = select_equality_operator(ec,
1410 prev_em->em_datatype,
1411 cur_em->em_datatype);
1412 if (!OidIsValid(eq_op))
1413 {
1414 /* failed... */
1415 ec->ec_broken = true;
1416 break;
1417 }
1418
1419 /*
1420 * The expressions aren't constants, so the passed qualscope will
1421 * never be used to place the generated clause. We just need to
1422 * be sure it covers both expressions, which em_relids should do.
1423 */
1424 rinfo = process_implied_equality(root, eq_op, ec->ec_collation,
1425 prev_em->em_expr, cur_em->em_expr,
1426 cur_em->em_relids,
1427 ec->ec_min_security,
1428 false);
1429
1430 /*
1431 * If the clause didn't degenerate to a constant, fill in the
1432 * correct markings for a mergejoinable clause. We don't record
1433 * it as a derived clause, since we don't currently need to
1434 * re-find such clauses, and don't want to clutter the
1435 * derived-clause set with non-join clauses.
1436 */
1437 if (rinfo && rinfo->mergeopfamilies)
1438 {
1439 /* it's not redundant, so don't set parent_ec */
1440 rinfo->left_ec = rinfo->right_ec = ec;
1441 rinfo->left_em = prev_em;
1442 rinfo->right_em = cur_em;
1443 }
1444 }
1445 prev_ems[relid] = cur_em;
1446 }
1447
1448 pfree(prev_ems);
1449
1450 /*
1451 * We also have to make sure that all the Vars used in the member clauses
1452 * will be available at any join node we might try to reference them at.
1453 * For the moment we force all the Vars to be available at all join nodes
1454 * for this eclass. Perhaps this could be improved by doing some
1455 * pre-analysis of which members we prefer to join, but it's no worse than
1456 * what happened in the pre-8.3 code. (Note: rebuild_eclass_attr_needed
1457 * needs to match this code.)
1458 */
1459 foreach(lc, ec->ec_members)
1460 {
1461 EquivalenceMember *cur_em = (EquivalenceMember *) lfirst(lc);
1462 List *vars = pull_var_clause((Node *) cur_em->em_expr,
1463 PVC_RECURSE_AGGREGATES |
1464 PVC_RECURSE_WINDOWFUNCS |
1465 PVC_INCLUDE_PLACEHOLDERS);
1466
1467 add_vars_to_targetlist(root, vars, ec->ec_relids);
1468 list_free(vars);
1469 }
1470}
1471
1472/*
1473 * generate_base_implied_equalities cleanup after failure
1474 *
1475 * What we must do here is push any zero- or one-relation source RestrictInfos
1476 * of the EC back into the main restrictinfo datastructures. Multi-relation
1477 * clauses will be regurgitated later by generate_join_implied_equalities().
1478 * (We do it this way to maintain continuity with the case that ec_broken
1479 * becomes set only after we've gone up a join level or two.) However, for
1480 * an EC that contains constants, we can adopt a simpler strategy and just
1481 * throw back all the source RestrictInfos immediately; that works because
1482 * we know that such an EC can't become broken later. (This rule justifies
1483 * ignoring ec_has_const ECs in generate_join_implied_equalities, even when
1484 * they are broken.)
1485 */
1486static void
1487generate_base_implied_equalities_broken(PlannerInfo *root,
1488 EquivalenceClass *ec)
1489{
1490 ListCell *lc;
1491
1492 foreach(lc, ec->ec_sources)
1493 {
1494 RestrictInfo *restrictinfo = (RestrictInfo *) lfirst(lc);
1495
1496 if (ec->ec_has_const ||
1497 bms_membership(restrictinfo->required_relids) != BMS_MULTIPLE)
1498 distribute_restrictinfo_to_rels(root, restrictinfo);
1499 }
1500}
1501
1502
1503/*
1504 * generate_join_implied_equalities
1505 * Generate any join clauses that we can deduce from equivalence classes.
1506 *
1507 * At a join node, we must enforce restriction clauses sufficient to ensure
1508 * that all equivalence-class members computable at that node are equal.
1509 * Since the set of clauses to enforce can vary depending on which subset
1510 * relations are the inputs, we have to compute this afresh for each join
1511 * relation pair. Hence a fresh List of RestrictInfo nodes is built and
1512 * passed back on each call.
1513 *
1514 * In addition to its use at join nodes, this can be applied to generate
1515 * eclass-based join clauses for use in a parameterized scan of a base rel.
1516 * The reason for the asymmetry of specifying the inner rel as a RelOptInfo
1517 * and the outer rel by Relids is that this usage occurs before we have
1518 * built any join RelOptInfos.
1519 *
1520 * An annoying special case for parameterized scans is that the inner rel can
1521 * be an appendrel child (an "other rel"). In this case we must generate
1522 * appropriate clauses using child EC members. add_child_rel_equivalences
1523 * must already have been done for the child rel.
1524 *
1525 * The results are sufficient for use in merge, hash, and plain nestloop join
1526 * methods. We do not worry here about selecting clauses that are optimal
1527 * for use in a parameterized indexscan. indxpath.c makes its own selections
1528 * of clauses to use, and if the ones we pick here are redundant with those,
1529 * the extras will be eliminated at createplan time, using the parent_ec
1530 * markers that we provide (see is_redundant_derived_clause()).
1531 *
1532 * Because the same join clauses are likely to be needed multiple times as
1533 * we consider different join paths, we avoid generating multiple copies:
1534 * whenever we select a particular pair of EquivalenceMembers to join,
1535 * we check to see if the pair matches any original clause (in ec_sources)
1536 * or previously-built derived clause. This saves memory and allows
1537 * re-use of information cached in RestrictInfos. We also avoid generating
1538 * commutative duplicates, i.e. if the algorithm selects "a.x = b.y" but
1539 * we already have "b.y = a.x", we return the existing clause.
1540 *
1541 * If we are considering an outer join, sjinfo is the associated OJ info,
1542 * otherwise it can be NULL.
1543 *
1544 * join_relids should always equal bms_union(outer_relids, inner_rel->relids)
1545 * plus whatever add_outer_joins_to_relids() would add. We could simplify
1546 * this function's API by computing it internally, but most callers have the
1547 * value at hand anyway.
1548 */
1549List *
1550generate_join_implied_equalities(PlannerInfo *root,
1551 Relids join_relids,
1552 Relids outer_relids,
1553 RelOptInfo *inner_rel,
1554 SpecialJoinInfo *sjinfo)
1555{
1556 List *result = NIL;
1557 Relids inner_relids = inner_rel->relids;
1558 Relids nominal_inner_relids;
1559 Relids nominal_join_relids;
1560 Bitmapset *matching_ecs;
1561 int i;
1562
1563 /* If inner rel is a child, extra setup work is needed */
1564 if (IS_OTHER_REL(inner_rel))
1565 {
1566 Assert(!bms_is_empty(inner_rel->top_parent_relids));
1567
1568 /* Fetch relid set for the topmost parent rel */
1569 nominal_inner_relids = inner_rel->top_parent_relids;
1570 /* ECs will be marked with the parent's relid, not the child's */
1571 nominal_join_relids = bms_union(outer_relids, nominal_inner_relids);
1572 nominal_join_relids = add_outer_joins_to_relids(root,
1573 nominal_join_relids,
1574 sjinfo,
1575 NULL);
1576 }
1577 else
1578 {
1579 nominal_inner_relids = inner_relids;
1580 nominal_join_relids = join_relids;
1581 }
1582
1583 /*
1584 * Examine all potentially-relevant eclasses.
1585 *
1586 * If we are considering an outer join, we must include "join" clauses
1587 * that mention either input rel plus the outer join's relid; these
1588 * represent post-join filter clauses that have to be applied at this
1589 * join. We don't have infrastructure that would let us identify such
1590 * eclasses cheaply, so just fall back to considering all eclasses
1591 * mentioning anything in nominal_join_relids.
1592 *
1593 * At inner joins, we can be smarter: only consider eclasses mentioning
1594 * both input rels.
1595 */
1596 if (sjinfo && sjinfo->ojrelid != 0)
1597 matching_ecs = get_eclass_indexes_for_relids(root, nominal_join_relids);
1598 else
1599 matching_ecs = get_common_eclass_indexes(root, nominal_inner_relids,
1600 outer_relids);
1601
1602 i = -1;
1603 while ((i = bms_next_member(matching_ecs, i)) >= 0)
1604 {
1605 EquivalenceClass *ec = (EquivalenceClass *) list_nth(root->eq_classes, i);
1606 List *sublist = NIL;
1607
1608 /* ECs containing consts do not need any further enforcement */
1609 if (ec->ec_has_const)
1610 continue;
1611
1612 /* Single-member ECs won't generate any deductions */
1613 if (list_length(ec->ec_members) <= 1)
1614 continue;
1615
1616 /* Sanity check that this eclass overlaps the join */
1617 Assert(bms_overlap(ec->ec_relids, nominal_join_relids));
1618
1619 if (!ec->ec_broken)
1620 sublist = generate_join_implied_equalities_normal(root,
1621 ec,
1622 join_relids,
1623 outer_relids,
1624 inner_relids);
1625
1626 /* Recover if we failed to generate required derived clauses */
1627 if (ec->ec_broken)
1628 sublist = generate_join_implied_equalities_broken(root,
1629 ec,
1630 nominal_join_relids,
1631 outer_relids,
1632 nominal_inner_relids,
1633 inner_rel);
1634
1635 result = list_concat(result, sublist);
1636 }
1637
1638 return result;
1639}
1640
1641/*
1642 * generate_join_implied_equalities_for_ecs
1643 * As above, but consider only the listed ECs.
1644 *
1645 * For the sole current caller, we can assume sjinfo == NULL, that is we are
1646 * not interested in outer-join filter clauses. This might need to change
1647 * in future.
1648 */
1649List *
1650generate_join_implied_equalities_for_ecs(PlannerInfo *root,
1651 List *eclasses,
1652 Relids join_relids,
1653 Relids outer_relids,
1654 RelOptInfo *inner_rel)
1655{
1656 List *result = NIL;
1657 Relids inner_relids = inner_rel->relids;
1658 Relids nominal_inner_relids;
1659 Relids nominal_join_relids;
1660 ListCell *lc;
1661
1662 /* If inner rel is a child, extra setup work is needed */
1663 if (IS_OTHER_REL(inner_rel))
1664 {
1665 Assert(!bms_is_empty(inner_rel->top_parent_relids));
1666
1667 /* Fetch relid set for the topmost parent rel */
1668 nominal_inner_relids = inner_rel->top_parent_relids;
1669 /* ECs will be marked with the parent's relid, not the child's */
1670 nominal_join_relids = bms_union(outer_relids, nominal_inner_relids);
1671 }
1672 else
1673 {
1674 nominal_inner_relids = inner_relids;
1675 nominal_join_relids = join_relids;
1676 }
1677
1678 foreach(lc, eclasses)
1679 {
1680 EquivalenceClass *ec = (EquivalenceClass *) lfirst(lc);
1681 List *sublist = NIL;
1682
1683 /* ECs containing consts do not need any further enforcement */
1684 if (ec->ec_has_const)
1685 continue;
1686
1687 /* Single-member ECs won't generate any deductions */
1688 if (list_length(ec->ec_members) <= 1)
1689 continue;
1690
1691 /* We can quickly ignore any that don't overlap the join, too */
1692 if (!bms_overlap(ec->ec_relids, nominal_join_relids))
1693 continue;
1694
1695 if (!ec->ec_broken)
1696 sublist = generate_join_implied_equalities_normal(root,
1697 ec,
1698 join_relids,
1699 outer_relids,
1700 inner_relids);
1701
1702 /* Recover if we failed to generate required derived clauses */
1703 if (ec->ec_broken)
1704 sublist = generate_join_implied_equalities_broken(root,
1705 ec,
1706 nominal_join_relids,
1707 outer_relids,
1708 nominal_inner_relids,
1709 inner_rel);
1710
1711 result = list_concat(result, sublist);
1712 }
1713
1714 return result;
1715}
1716
1717/*
1718 * generate_join_implied_equalities for a still-valid EC
1719 */
1720static List *
1721generate_join_implied_equalities_normal(PlannerInfo *root,
1722 EquivalenceClass *ec,
1723 Relids join_relids,
1724 Relids outer_relids,
1725 Relids inner_relids)
1726{
1727 List *result = NIL;
1728 List *new_members = NIL;
1729 List *outer_members = NIL;
1730 List *inner_members = NIL;
1731 EquivalenceMemberIterator it;
1732 EquivalenceMember *cur_em;
1733
1734 /*
1735 * First, scan the EC to identify member values that are computable at the
1736 * outer rel, at the inner rel, or at this relation but not in either
1737 * input rel. The outer-rel members should already be enforced equal,
1738 * likewise for the inner-rel members. We'll need to create clauses to
1739 * enforce that any newly computable members are all equal to each other
1740 * as well as to at least one input member, plus enforce at least one
1741 * outer-rel member equal to at least one inner-rel member.
1742 */
1743 setup_eclass_member_iterator(&it, ec, join_relids);
1744 while ((cur_em = eclass_member_iterator_next(&it)) != NULL)
1745 {
1746 /*
1747 * We don't need to check explicitly for child EC members. This test
1748 * against join_relids will cause them to be ignored except when
1749 * considering a child inner rel, which is what we want.
1750 */
1751 if (!bms_is_subset(cur_em->em_relids, join_relids))
1752 continue; /* not computable yet, or wrong child */
1753
1754 if (bms_is_subset(cur_em->em_relids, outer_relids))
1755 outer_members = lappend(outer_members, cur_em);
1756 else if (bms_is_subset(cur_em->em_relids, inner_relids))
1757 inner_members = lappend(inner_members, cur_em);
1758 else
1759 new_members = lappend(new_members, cur_em);
1760 }
1761
1762 /*
1763 * First, select the joinclause if needed. We can equate any one outer
1764 * member to any one inner member, but we have to find a datatype
1765 * combination for which an opfamily member operator exists. If we have
1766 * choices, we prefer simple Var members (possibly with RelabelType) since
1767 * these are (a) cheapest to compute at runtime and (b) most likely to
1768 * have useful statistics. Also, prefer operators that are also
1769 * hashjoinable.
1770 */
1771 if (outer_members && inner_members)
1772 {
1773 EquivalenceMember *best_outer_em = NULL;
1774 EquivalenceMember *best_inner_em = NULL;
1775 Oid best_eq_op = InvalidOid;
1776 int best_score = -1;
1777 RestrictInfo *rinfo;
1778 ListCell *lc1;
1779
1780 foreach(lc1, outer_members)
1781 {
1782 EquivalenceMember *outer_em = (EquivalenceMember *) lfirst(lc1);
1783 ListCell *lc2;
1784
1785 foreach(lc2, inner_members)
1786 {
1787 EquivalenceMember *inner_em = (EquivalenceMember *) lfirst(lc2);
1788 Oid eq_op;
1789 int score;
1790
1791 eq_op = select_equality_operator(ec,
1792 outer_em->em_datatype,
1793 inner_em->em_datatype);
1794 if (!OidIsValid(eq_op))
1795 continue;
1796 score = 0;
1797 if (IsA(outer_em->em_expr, Var) ||
1798 (IsA(outer_em->em_expr, RelabelType) &&
1799 IsA(((RelabelType *) outer_em->em_expr)->arg, Var)))
1800 score++;
1801 if (IsA(inner_em->em_expr, Var) ||
1802 (IsA(inner_em->em_expr, RelabelType) &&
1803 IsA(((RelabelType *) inner_em->em_expr)->arg, Var)))
1804 score++;
1805 if (op_hashjoinable(eq_op,
1806 exprType((Node *) outer_em->em_expr)))
1807 score++;
1808 if (score > best_score)
1809 {
1810 best_outer_em = outer_em;
1811 best_inner_em = inner_em;
1812 best_eq_op = eq_op;
1813 best_score = score;
1814 if (best_score == 3)
1815 break; /* no need to look further */
1816 }
1817 }
1818 if (best_score == 3)
1819 break; /* no need to look further */
1820 }
1821 if (best_score < 0)
1822 {
1823 /* failed... */
1824 ec->ec_broken = true;
1825 return NIL;
1826 }
1827
1828 /*
1829 * Create clause, setting parent_ec to mark it as redundant with other
1830 * joinclauses
1831 */
1832 rinfo = create_join_clause(root, ec, best_eq_op,
1833 best_outer_em, best_inner_em,
1834 ec);
1835
1836 result = lappend(result, rinfo);
1837 }
1838
1839 /*
1840 * Now deal with building restrictions for any expressions that involve
1841 * Vars from both sides of the join. We have to equate all of these to
1842 * each other as well as to at least one old member (if any).
1843 *
1844 * XXX as in generate_base_implied_equalities_no_const, we could be a lot
1845 * smarter here to avoid unnecessary failures in cross-type situations.
1846 * For now, use the same left-to-right method used there.
1847 */
1848 if (new_members)
1849 {
1850 List *old_members = list_concat(outer_members, inner_members);
1851 EquivalenceMember *prev_em = NULL;
1852 RestrictInfo *rinfo;
1853 ListCell *lc1;
1854
1855 /* For now, arbitrarily take the first old_member as the one to use */
1856 if (old_members)
1857 new_members = lappend(new_members, linitial(old_members));
1858
1859 foreach(lc1, new_members)
1860 {
1861 cur_em = (EquivalenceMember *) lfirst(lc1);
1862
1863 if (prev_em != NULL)
1864 {
1865 Oid eq_op;
1866
1867 eq_op = select_equality_operator(ec,
1868 prev_em->em_datatype,
1869 cur_em->em_datatype);
1870 if (!OidIsValid(eq_op))
1871 {
1872 /* failed... */
1873 ec->ec_broken = true;
1874 return NIL;
1875 }
1876 /* do NOT set parent_ec, this qual is not redundant! */
1877 rinfo = create_join_clause(root, ec, eq_op,
1878 prev_em, cur_em,
1879 NULL);
1880
1881 result = lappend(result, rinfo);
1882 }
1883 prev_em = cur_em;
1884 }
1885 }
1886
1887 return result;
1888}
1889
1890/*
1891 * generate_join_implied_equalities cleanup after failure
1892 *
1893 * Return any original RestrictInfos that are enforceable at this join.
1894 *
1895 * In the case of a child inner relation, we have to translate the
1896 * original RestrictInfos from parent to child Vars.
1897 */
1898static List *
1899generate_join_implied_equalities_broken(PlannerInfo *root,
1900 EquivalenceClass *ec,
1901 Relids nominal_join_relids,
1902 Relids outer_relids,
1903 Relids nominal_inner_relids,
1904 RelOptInfo *inner_rel)
1905{
1906 List *result = NIL;
1907 ListCell *lc;
1908
1909 foreach(lc, ec->ec_sources)
1910 {
1911 RestrictInfo *restrictinfo = (RestrictInfo *) lfirst(lc);
1912 Relids clause_relids = restrictinfo->required_relids;
1913
1914 if (bms_is_subset(clause_relids, nominal_join_relids) &&
1915 !bms_is_subset(clause_relids, outer_relids) &&
1916 !bms_is_subset(clause_relids, nominal_inner_relids))
1917 result = lappend(result, restrictinfo);
1918 }
1919
1920 /*
1921 * If we have to translate, just brute-force apply adjust_appendrel_attrs
1922 * to all the RestrictInfos at once. This will result in returning
1923 * RestrictInfos that are not included in EC's derived clauses, but there
1924 * shouldn't be any duplication, and it's a sufficiently narrow corner
1925 * case that we shouldn't sweat too much over it anyway.
1926 *
1927 * Since inner_rel might be an indirect descendant of the baserel
1928 * mentioned in the ec_sources clauses, we have to be prepared to apply
1929 * multiple levels of Var translation.
1930 */
1931 if (IS_OTHER_REL(inner_rel) && result != NIL)
1932 result = (List *) adjust_appendrel_attrs_multilevel(root,
1933 (Node *) result,
1934 inner_rel,
1935 inner_rel->top_parent);
1936
1937 return result;
1938}
1939
1940
1941/*
1942 * select_equality_operator
1943 * Select a suitable equality operator for comparing two EC members
1944 *
1945 * Returns InvalidOid if no operator can be found for this datatype combination
1946 */
1947static Oid
1948select_equality_operator(EquivalenceClass *ec, Oid lefttype, Oid righttype)
1949{
1950 ListCell *lc;
1951
1952 foreach(lc, ec->ec_opfamilies)
1953 {
1954 Oid opfamily = lfirst_oid(lc);
1955 Oid opno;
1956
1957 opno = get_opfamily_member_for_cmptype(opfamily, lefttype, righttype, COMPARE_EQ);
1958 if (!OidIsValid(opno))
1959 continue;
1960 /* If no barrier quals in query, don't worry about leaky operators */
1961 if (ec->ec_max_security == 0)
1962 return opno;
1963 /* Otherwise, insist that selected operators be leakproof */
1964 if (get_func_leakproof(get_opcode(opno)))
1965 return opno;
1966 }
1967 return InvalidOid;
1968}
1969
1970
1971/*
1972 * create_join_clause
1973 * Find or make a RestrictInfo comparing the two given EC members
1974 * with the given operator (or, possibly, its commutator, because
1975 * the ordering of the operands in the result is not guaranteed).
1976 *
1977 * parent_ec is either equal to ec (if the clause is a potentially-redundant
1978 * join clause) or NULL (if not). We have to treat this as part of the
1979 * match requirements --- it's possible that a clause comparing the same two
1980 * EMs is a join clause in one join path and a restriction clause in another.
1981 */
1982static RestrictInfo *
1983create_join_clause(PlannerInfo *root,
1984 EquivalenceClass *ec, Oid opno,
1985 EquivalenceMember *leftem,
1986 EquivalenceMember *rightem,
1987 EquivalenceClass *parent_ec)
1988{
1989 RestrictInfo *rinfo;
1990 RestrictInfo *parent_rinfo = NULL;
1991 MemoryContext oldcontext;
1992
1993 rinfo = ec_search_clause_for_ems(root, ec, leftem, rightem, parent_ec);
1994 if (rinfo)
1995 return rinfo;
1996
1997 /*
1998 * Not there, so build it, in planner context so we can re-use it. (Not
1999 * important in normal planning, but definitely so in GEQO.)
2000 */
2001 oldcontext = MemoryContextSwitchTo(root->planner_cxt);
2002
2003 /*
2004 * If either EM is a child, recursively create the corresponding
2005 * parent-to-parent clause, so that we can duplicate its rinfo_serial.
2006 */
2007 if (leftem->em_is_child || rightem->em_is_child)
2008 {
2009 EquivalenceMember *leftp = leftem->em_parent ? leftem->em_parent : leftem;
2010 EquivalenceMember *rightp = rightem->em_parent ? rightem->em_parent : rightem;
2011
2012 parent_rinfo = create_join_clause(root, ec, opno,
2013 leftp, rightp,
2014 parent_ec);
2015 }
2016
2017 rinfo = build_implied_join_equality(root,
2018 opno,
2019 ec->ec_collation,
2020 leftem->em_expr,
2021 rightem->em_expr,
2022 bms_union(leftem->em_relids,
2023 rightem->em_relids),
2024 ec->ec_min_security);
2025
2026 /*
2027 * If either EM is a child, force the clause's clause_relids to include
2028 * the relid(s) of the child rel. In normal cases it would already, but
2029 * not if we are considering appendrel child relations with pseudoconstant
2030 * translated variables (i.e., UNION ALL sub-selects with constant output
2031 * items). We must do this so that join_clause_is_movable_into() will
2032 * think that the clause should be evaluated at the correct place.
2033 */
2034 if (leftem->em_is_child)
2035 rinfo->clause_relids = bms_add_members(rinfo->clause_relids,
2036 leftem->em_relids);
2037 if (rightem->em_is_child)
2038 rinfo->clause_relids = bms_add_members(rinfo->clause_relids,
2039 rightem->em_relids);
2040
2041 /* If it's a child clause, copy the parent's rinfo_serial */
2042 if (parent_rinfo)
2043 rinfo->rinfo_serial = parent_rinfo->rinfo_serial;
2044
2045 /* Mark the clause as redundant, or not */
2046 rinfo->parent_ec = parent_ec;
2047
2048 /*
2049 * We know the correct values for left_ec/right_ec, ie this particular EC,
2050 * so we can just set them directly instead of forcing another lookup.
2051 */
2052 rinfo->left_ec = ec;
2053 rinfo->right_ec = ec;
2054
2055 /* Mark it as usable with these EMs */
2056 rinfo->left_em = leftem;
2057 rinfo->right_em = rightem;
2058 /* and save it for possible re-use */
2059 ec_add_derived_clause(ec, rinfo);
2060
2061 MemoryContextSwitchTo(oldcontext);
2062
2063 return rinfo;
2064}
2065
2066
2067/*
2068 * reconsider_outer_join_clauses
2069 * Re-examine any outer-join clauses that were set aside by
2070 * distribute_qual_to_rels(), and see if we can derive any
2071 * EquivalenceClasses from them. Then, if they were not made
2072 * redundant, push them out into the regular join-clause lists.
2073 *
2074 * When we have mergejoinable clauses A = B that are outer-join clauses,
2075 * we can't blindly combine them with other clauses A = C to deduce B = C,
2076 * since in fact the "equality" A = B won't necessarily hold above the
2077 * outer join (one of the variables might be NULL instead). Nonetheless
2078 * there are cases where we can add qual clauses using transitivity.
2079 *
2080 * One case that we look for here is an outer-join clause OUTERVAR = INNERVAR
2081 * for which there is also an equivalence clause OUTERVAR = CONSTANT.
2082 * It is safe and useful to push a clause INNERVAR = CONSTANT into the
2083 * evaluation of the inner (nullable) relation, because any inner rows not
2084 * meeting this condition will not contribute to the outer-join result anyway.
2085 * (Any outer rows they could join to will be eliminated by the pushed-down
2086 * equivalence clause.)
2087 *
2088 * Note that the above rule does not work for full outer joins; nor is it
2089 * very interesting to consider cases where the generated equivalence clause
2090 * would involve relations outside the outer join, since such clauses couldn't
2091 * be pushed into the inner side's scan anyway. So the restriction to
2092 * outervar = pseudoconstant is not really giving up anything.
2093 *
2094 * For full-join cases, we can only do something useful if it's a FULL JOIN
2095 * USING and a merged column has an equivalence MERGEDVAR = CONSTANT.
2096 * By the time it gets here, the merged column will look like
2097 * COALESCE(LEFTVAR, RIGHTVAR)
2098 * and we will have a full-join clause LEFTVAR = RIGHTVAR that we can match
2099 * the COALESCE expression to. In this situation we can push LEFTVAR = CONSTANT
2100 * and RIGHTVAR = CONSTANT into the input relations, since any rows not
2101 * meeting these conditions cannot contribute to the join result.
2102 *
2103 * Again, there isn't any traction to be gained by trying to deal with
2104 * clauses comparing a mergedvar to a non-pseudoconstant. So we can make
2105 * use of the EquivalenceClasses to search for matching variables that were
2106 * equivalenced to constants. The interesting outer-join clauses were
2107 * accumulated for us by distribute_qual_to_rels.
2108 *
2109 * When we find one of these cases, we implement the changes we want by
2110 * generating a new equivalence clause INNERVAR = CONSTANT (or LEFTVAR, etc)
2111 * and pushing it into the EquivalenceClass structures. This is because we
2112 * may already know that INNERVAR is equivalenced to some other var(s), and
2113 * we'd like the constant to propagate to them too. Note that it would be
2114 * unsafe to merge any existing EC for INNERVAR with the OUTERVAR's EC ---
2115 * that could result in propagating constant restrictions from
2116 * INNERVAR to OUTERVAR, which would be very wrong.
2117 *
2118 * It's possible that the INNERVAR is also an OUTERVAR for some other
2119 * outer-join clause, in which case the process can be repeated. So we repeat
2120 * looping over the lists of clauses until no further deductions can be made.
2121 * Whenever we do make a deduction, we remove the generating clause from the
2122 * lists, since we don't want to make the same deduction twice.
2123 *
2124 * If we don't find any match for a set-aside outer join clause, we must
2125 * throw it back into the regular joinclause processing by passing it to
2126 * distribute_restrictinfo_to_rels(). If we do generate a derived clause,
2127 * however, the outer-join clause is redundant. We must still put some
2128 * clause into the regular processing, because otherwise the join will be
2129 * seen as a clauseless join and avoided during join order searching.
2130 * We handle this by generating a constant-TRUE clause that is marked with
2131 * the same required_relids etc as the removed outer-join clause, thus
2132 * making it a join clause between the correct relations.
2133 */
2134void
2135reconsider_outer_join_clauses(PlannerInfo *root)
2136{
2137 bool found;
2138 ListCell *cell;
2139
2140 /* Outer loop repeats until we find no more deductions */
2141 do
2142 {
2143 found = false;
2144
2145 /* Process the LEFT JOIN clauses */
2146 foreach(cell, root->left_join_clauses)
2147 {
2148 OuterJoinClauseInfo *ojcinfo = (OuterJoinClauseInfo *) lfirst(cell);
2149
2150 if (reconsider_outer_join_clause(root, ojcinfo, true))
2151 {
2152 RestrictInfo *rinfo = ojcinfo->rinfo;
2153
2154 found = true;
2155 /* remove it from the list */
2156 root->left_join_clauses =
2157 foreach_delete_current(root->left_join_clauses, cell);
2158 /* throw back a dummy replacement clause (see notes above) */
2159 rinfo = make_restrictinfo(root,
2160 (Expr *) makeBoolConst(true, false),
2161 rinfo->is_pushed_down,
2162 rinfo->has_clone,
2163 rinfo->is_clone,
2164 false, /* pseudoconstant */
2165 0, /* security_level */
2166 rinfo->required_relids,
2167 rinfo->incompatible_relids,
2168 rinfo->outer_relids);
2169 distribute_restrictinfo_to_rels(root, rinfo);
2170 }
2171 }
2172
2173 /* Process the RIGHT JOIN clauses */
2174 foreach(cell, root->right_join_clauses)
2175 {
2176 OuterJoinClauseInfo *ojcinfo = (OuterJoinClauseInfo *) lfirst(cell);
2177
2178 if (reconsider_outer_join_clause(root, ojcinfo, false))
2179 {
2180 RestrictInfo *rinfo = ojcinfo->rinfo;
2181
2182 found = true;
2183 /* remove it from the list */
2184 root->right_join_clauses =
2185 foreach_delete_current(root->right_join_clauses, cell);
2186 /* throw back a dummy replacement clause (see notes above) */
2187 rinfo = make_restrictinfo(root,
2188 (Expr *) makeBoolConst(true, false),
2189 rinfo->is_pushed_down,
2190 rinfo->has_clone,
2191 rinfo->is_clone,
2192 false, /* pseudoconstant */
2193 0, /* security_level */
2194 rinfo->required_relids,
2195 rinfo->incompatible_relids,
2196 rinfo->outer_relids);
2197 distribute_restrictinfo_to_rels(root, rinfo);
2198 }
2199 }
2200
2201 /* Process the FULL JOIN clauses */
2202 foreach(cell, root->full_join_clauses)
2203 {
2204 OuterJoinClauseInfo *ojcinfo = (OuterJoinClauseInfo *) lfirst(cell);
2205
2206 if (reconsider_full_join_clause(root, ojcinfo))
2207 {
2208 RestrictInfo *rinfo = ojcinfo->rinfo;
2209
2210 found = true;
2211 /* remove it from the list */
2212 root->full_join_clauses =
2213 foreach_delete_current(root->full_join_clauses, cell);
2214 /* throw back a dummy replacement clause (see notes above) */
2215 rinfo = make_restrictinfo(root,
2216 (Expr *) makeBoolConst(true, false),
2217 rinfo->is_pushed_down,
2218 rinfo->has_clone,
2219 rinfo->is_clone,
2220 false, /* pseudoconstant */
2221 0, /* security_level */
2222 rinfo->required_relids,
2223 rinfo->incompatible_relids,
2224 rinfo->outer_relids);
2225 distribute_restrictinfo_to_rels(root, rinfo);
2226 }
2227 }
2228 } while (found);
2229
2230 /* Now, any remaining clauses have to be thrown back */
2231 foreach(cell, root->left_join_clauses)
2232 {
2233 OuterJoinClauseInfo *ojcinfo = (OuterJoinClauseInfo *) lfirst(cell);
2234
2235 distribute_restrictinfo_to_rels(root, ojcinfo->rinfo);
2236 }
2237 foreach(cell, root->right_join_clauses)
2238 {
2239 OuterJoinClauseInfo *ojcinfo = (OuterJoinClauseInfo *) lfirst(cell);
2240
2241 distribute_restrictinfo_to_rels(root, ojcinfo->rinfo);
2242 }
2243 foreach(cell, root->full_join_clauses)
2244 {
2245 OuterJoinClauseInfo *ojcinfo = (OuterJoinClauseInfo *) lfirst(cell);
2246
2247 distribute_restrictinfo_to_rels(root, ojcinfo->rinfo);
2248 }
2249}
2250
2251/*
2252 * reconsider_outer_join_clauses for a single LEFT/RIGHT JOIN clause
2253 *
2254 * Returns true if we were able to propagate a constant through the clause.
2255 */
2256static bool
2257reconsider_outer_join_clause(PlannerInfo *root, OuterJoinClauseInfo *ojcinfo,
2258 bool outer_on_left)
2259{
2260 RestrictInfo *rinfo = ojcinfo->rinfo;
2261 SpecialJoinInfo *sjinfo = ojcinfo->sjinfo;
2262 Expr *outervar,
2263 *innervar;
2264 Oid opno,
2265 collation,
2266 left_type,
2267 right_type,
2268 inner_datatype;
2269 Relids inner_relids;
2270 ListCell *lc1;
2271
2272 Assert(is_opclause(rinfo->clause));
2273 opno = ((OpExpr *) rinfo->clause)->opno;
2274 collation = ((OpExpr *) rinfo->clause)->inputcollid;
2275
2276 /* Extract needed info from the clause */
2277 op_input_types(opno, &left_type, &right_type);
2278 if (outer_on_left)
2279 {
2280 outervar = (Expr *) get_leftop(rinfo->clause);
2281 innervar = (Expr *) get_rightop(rinfo->clause);
2282 inner_datatype = right_type;
2283 inner_relids = rinfo->right_relids;
2284 }
2285 else
2286 {
2287 outervar = (Expr *) get_rightop(rinfo->clause);
2288 innervar = (Expr *) get_leftop(rinfo->clause);
2289 inner_datatype = left_type;
2290 inner_relids = rinfo->left_relids;
2291 }
2292
2293 /* Scan EquivalenceClasses for a match to outervar */
2294 foreach(lc1, root->eq_classes)
2295 {
2296 EquivalenceClass *cur_ec = (EquivalenceClass *) lfirst(lc1);
2297 bool match;
2298 ListCell *lc2;
2299
2300 /* We don't expect any children yet */
2301 Assert(cur_ec->ec_childmembers == NULL);
2302
2303 /* Ignore EC unless it contains pseudoconstants */
2304 if (!cur_ec->ec_has_const)
2305 continue;
2306 /* Never match to a volatile EC */
2307 if (cur_ec->ec_has_volatile)
2308 continue;
2309 /* It has to match the outer-join clause as to semantics, too */
2310 if (collation != cur_ec->ec_collation)
2311 continue;
2312 if (!equal(rinfo->mergeopfamilies, cur_ec->ec_opfamilies))
2313 continue;
2314 /* Does it contain a match to outervar? */
2315 match = false;
2316 foreach(lc2, cur_ec->ec_members)
2317 {
2318 EquivalenceMember *cur_em = (EquivalenceMember *) lfirst(lc2);
2319
2320 /* Child members should not exist in ec_members */
2321 Assert(!cur_em->em_is_child);
2322 if (equal(outervar, cur_em->em_expr))
2323 {
2324 match = true;
2325 break;
2326 }
2327 }
2328 if (!match)
2329 continue; /* no match, so ignore this EC */
2330
2331 /*
2332 * Yes it does! Try to generate a clause INNERVAR = CONSTANT for each
2333 * CONSTANT in the EC. Note that we must succeed with at least one
2334 * constant before we can decide to throw away the outer-join clause.
2335 */
2336 match = false;
2337 foreach(lc2, cur_ec->ec_members)
2338 {
2339 EquivalenceMember *cur_em = (EquivalenceMember *) lfirst(lc2);
2340 Oid eq_op;
2341 RestrictInfo *newrinfo;
2342 JoinDomain *jdomain;
2343
2344 if (!cur_em->em_is_const)
2345 continue; /* ignore non-const members */
2346 eq_op = select_equality_operator(cur_ec,
2347 inner_datatype,
2348 cur_em->em_datatype);
2349 if (!OidIsValid(eq_op))
2350 continue; /* can't generate equality */
2351 newrinfo = build_implied_join_equality(root,
2352 eq_op,
2353 cur_ec->ec_collation,
2354 innervar,
2355 cur_em->em_expr,
2356 bms_copy(inner_relids),
2357 cur_ec->ec_min_security);
2358 /* This equality holds within the OJ's child JoinDomain */
2359 jdomain = find_join_domain(root, sjinfo->syn_righthand);
2360 if (process_equivalence(root, &newrinfo, jdomain))
2361 match = true;
2362 }
2363
2364 /*
2365 * If we were able to equate INNERVAR to any constant, report success.
2366 * Otherwise, fall out of the search loop, since we know the OUTERVAR
2367 * appears in at most one EC.
2368 */
2369 if (match)
2370 return true;
2371 else
2372 break;
2373 }
2374
2375 return false; /* failed to make any deduction */
2376}
2377
2378/*
2379 * reconsider_outer_join_clauses for a single FULL JOIN clause
2380 *
2381 * Returns true if we were able to propagate a constant through the clause.
2382 */
2383static bool
2384reconsider_full_join_clause(PlannerInfo *root, OuterJoinClauseInfo *ojcinfo)
2385{
2386 RestrictInfo *rinfo = ojcinfo->rinfo;
2387 SpecialJoinInfo *sjinfo = ojcinfo->sjinfo;
2388 Relids fjrelids = bms_make_singleton(sjinfo->ojrelid);
2389 Expr *leftvar;
2390 Expr *rightvar;
2391 Oid opno,
2392 collation,
2393 left_type,
2394 right_type;
2395 Relids left_relids,
2396 right_relids;
2397 ListCell *lc1;
2398
2399 /* Extract needed info from the clause */
2400 Assert(is_opclause(rinfo->clause));
2401 opno = ((OpExpr *) rinfo->clause)->opno;
2402 collation = ((OpExpr *) rinfo->clause)->inputcollid;
2403 op_input_types(opno, &left_type, &right_type);
2404 leftvar = (Expr *) get_leftop(rinfo->clause);
2405 rightvar = (Expr *) get_rightop(rinfo->clause);
2406 left_relids = rinfo->left_relids;
2407 right_relids = rinfo->right_relids;
2408
2409 foreach(lc1, root->eq_classes)
2410 {
2411 EquivalenceClass *cur_ec = (EquivalenceClass *) lfirst(lc1);
2412 EquivalenceMember *coal_em = NULL;
2413 bool match;
2414 bool matchleft;
2415 bool matchright;
2416 ListCell *lc2;
2417 int coal_idx = -1;
2418
2419 /* We don't expect any children yet */
2420 Assert(cur_ec->ec_childmembers == NULL);
2421
2422 /* Ignore EC unless it contains pseudoconstants */
2423 if (!cur_ec->ec_has_const)
2424 continue;
2425 /* Never match to a volatile EC */
2426 if (cur_ec->ec_has_volatile)
2427 continue;
2428 /* It has to match the outer-join clause as to semantics, too */
2429 if (collation != cur_ec->ec_collation)
2430 continue;
2431 if (!equal(rinfo->mergeopfamilies, cur_ec->ec_opfamilies))
2432 continue;
2433
2434 /*
2435 * Does it contain a COALESCE(leftvar, rightvar) construct?
2436 *
2437 * We can assume the COALESCE() inputs are in the same order as the
2438 * join clause, since both were automatically generated in the cases
2439 * we care about.
2440 *
2441 * XXX currently this may fail to match in cross-type cases because
2442 * the COALESCE will contain typecast operations while the join clause
2443 * may not (if there is a cross-type mergejoin operator available for
2444 * the two column types). Is it OK to strip implicit coercions from
2445 * the COALESCE arguments?
2446 */
2447 match = false;
2448 foreach(lc2, cur_ec->ec_members)
2449 {
2450 coal_em = (EquivalenceMember *) lfirst(lc2);
2451
2452 /* Child members should not exist in ec_members */
2453 Assert(!coal_em->em_is_child);
2454 if (IsA(coal_em->em_expr, CoalesceExpr))
2455 {
2456 CoalesceExpr *cexpr = (CoalesceExpr *) coal_em->em_expr;
2457 Node *cfirst;
2458 Node *csecond;
2459
2460 if (list_length(cexpr->args) != 2)
2461 continue;
2462 cfirst = (Node *) linitial(cexpr->args);
2463 csecond = (Node *) lsecond(cexpr->args);
2464
2465 /*
2466 * The COALESCE arguments will be marked as possibly nulled by
2467 * the full join, while we wish to generate clauses that apply
2468 * to the join's inputs. So we must strip the join from the
2469 * nullingrels fields of cfirst/csecond before comparing them
2470 * to leftvar/rightvar. (Perhaps with a less hokey
2471 * representation for FULL JOIN USING output columns, this
2472 * wouldn't be needed?)
2473 */
2474 cfirst = remove_nulling_relids(cfirst, fjrelids, NULL);
2475 csecond = remove_nulling_relids(csecond, fjrelids, NULL);
2476
2477 if (equal(leftvar, cfirst) && equal(rightvar, csecond))
2478 {
2479 coal_idx = foreach_current_index(lc2);
2480 match = true;
2481 break;
2482 }
2483 }
2484 }
2485 if (!match)
2486 continue; /* no match, so ignore this EC */
2487
2488 /*
2489 * Yes it does! Try to generate clauses LEFTVAR = CONSTANT and
2490 * RIGHTVAR = CONSTANT for each CONSTANT in the EC. Note that we must
2491 * succeed with at least one constant for each var before we can
2492 * decide to throw away the outer-join clause.
2493 */
2494 matchleft = matchright = false;
2495 foreach(lc2, cur_ec->ec_members)
2496 {
2497 EquivalenceMember *cur_em = (EquivalenceMember *) lfirst(lc2);
2498 Oid eq_op;
2499 RestrictInfo *newrinfo;
2500 JoinDomain *jdomain;
2501
2502 if (!cur_em->em_is_const)
2503 continue; /* ignore non-const members */
2504 eq_op = select_equality_operator(cur_ec,
2505 left_type,
2506 cur_em->em_datatype);
2507 if (OidIsValid(eq_op))
2508 {
2509 newrinfo = build_implied_join_equality(root,
2510 eq_op,
2511 cur_ec->ec_collation,
2512 leftvar,
2513 cur_em->em_expr,
2514 bms_copy(left_relids),
2515 cur_ec->ec_min_security);
2516 /* This equality holds within the lefthand child JoinDomain */
2517 jdomain = find_join_domain(root, sjinfo->syn_lefthand);
2518 if (process_equivalence(root, &newrinfo, jdomain))
2519 matchleft = true;
2520 }
2521 eq_op = select_equality_operator(cur_ec,
2522 right_type,
2523 cur_em->em_datatype);
2524 if (OidIsValid(eq_op))
2525 {
2526 newrinfo = build_implied_join_equality(root,
2527 eq_op,
2528 cur_ec->ec_collation,
2529 rightvar,
2530 cur_em->em_expr,
2531 bms_copy(right_relids),
2532 cur_ec->ec_min_security);
2533 /* This equality holds within the righthand child JoinDomain */
2534 jdomain = find_join_domain(root, sjinfo->syn_righthand);
2535 if (process_equivalence(root, &newrinfo, jdomain))
2536 matchright = true;
2537 }
2538 }
2539
2540 /*
2541 * If we were able to equate both vars to constants, we're done, and
2542 * we can throw away the full-join clause as redundant. Moreover, we
2543 * can remove the COALESCE entry from the EC, since the added
2544 * restrictions ensure it will always have the expected value. (We
2545 * don't bother trying to update ec_relids or ec_sources.)
2546 */
2547 if (matchleft && matchright)
2548 {
2549 cur_ec->ec_members = list_delete_nth_cell(cur_ec->ec_members, coal_idx);
2550 return true;
2551 }
2552
2553 /*
2554 * Otherwise, fall out of the search loop, since we know the COALESCE
2555 * appears in at most one EC (XXX might stop being true if we allow
2556 * stripping of coercions above?)
2557 */
2558 break;
2559 }
2560
2561 return false; /* failed to make any deduction */
2562}
2563
2564/*
2565 * rebuild_eclass_attr_needed
2566 * Put back attr_needed bits for Vars/PHVs needed for join eclasses.
2567 *
2568 * This is used to rebuild attr_needed/ph_needed sets after removal of a
2569 * useless outer join. It should match what
2570 * generate_base_implied_equalities_no_const did, except that we call
2571 * add_vars_to_attr_needed not add_vars_to_targetlist.
2572 */
2573void
2574rebuild_eclass_attr_needed(PlannerInfo *root)
2575{
2576 ListCell *lc;
2577
2578 foreach(lc, root->eq_classes)
2579 {
2580 EquivalenceClass *ec = (EquivalenceClass *) lfirst(lc);
2581
2582 /*
2583 * We don't expect any EC child members to exist at this point. Ensure
2584 * that's the case, otherwise, we might be getting asked to do
2585 * something this function hasn't been coded for.
2586 */
2587 Assert(ec->ec_childmembers == NULL);
2588
2589 /* Need do anything only for a multi-member, no-const EC. */
2590 if (list_length(ec->ec_members) > 1 && !ec->ec_has_const)
2591 {
2592 ListCell *lc2;
2593
2594 foreach(lc2, ec->ec_members)
2595 {
2596 EquivalenceMember *cur_em = (EquivalenceMember *) lfirst(lc2);
2597 List *vars = pull_var_clause((Node *) cur_em->em_expr,
2598 PVC_RECURSE_AGGREGATES |
2599 PVC_RECURSE_WINDOWFUNCS |
2600 PVC_INCLUDE_PLACEHOLDERS);
2601
2602 add_vars_to_attr_needed(root, vars, ec->ec_relids);
2603 list_free(vars);
2604 }
2605 }
2606 }
2607}
2608
2609/*
2610 * find_join_domain
2611 * Find the highest JoinDomain enclosed within the given relid set.
2612 *
2613 * (We could avoid this search at the cost of complicating APIs elsewhere,
2614 * which doesn't seem worth it.)
2615 */
2616static JoinDomain *
2617find_join_domain(PlannerInfo *root, Relids relids)
2618{
2619 ListCell *lc;
2620
2621 foreach(lc, root->join_domains)
2622 {
2623 JoinDomain *jdomain = (JoinDomain *) lfirst(lc);
2624
2625 if (bms_is_subset(jdomain->jd_relids, relids))
2626 return jdomain;
2627 }
2628 elog(ERROR, "failed to find appropriate JoinDomain");
2629 return NULL; /* keep compiler quiet */
2630}
2631
2632
2633/*
2634 * exprs_known_equal
2635 * Detect whether two expressions are known equal due to equivalence
2636 * relationships.
2637 *
2638 * If opfamily is given, the expressions must be known equal per the semantics
2639 * of that opfamily (note it has to be a btree opfamily, since those are the
2640 * only opfamilies equivclass.c deals with). If opfamily is InvalidOid, we'll
2641 * return true if they're equal according to any opfamily, which is fuzzy but
2642 * OK for estimation purposes.
2643 *
2644 * Note: does not bother to check for "equal(item1, item2)"; caller must
2645 * check that case if it's possible to pass identical items.
2646 */
2647bool
2648exprs_known_equal(PlannerInfo *root, Node *item1, Node *item2, Oid opfamily)
2649{
2650 ListCell *lc1;
2651
2652 foreach(lc1, root->eq_classes)
2653 {
2654 EquivalenceClass *ec = (EquivalenceClass *) lfirst(lc1);
2655 bool item1member = false;
2656 bool item2member = false;
2657 ListCell *lc2;
2658
2659 /* Never match to a volatile EC */
2660 if (ec->ec_has_volatile)
2661 continue;
2662
2663 /*
2664 * It's okay to consider ec_broken ECs here. Brokenness just means we
2665 * couldn't derive all the implied clauses we'd have liked to; it does
2666 * not invalidate our knowledge that the members are equal.
2667 */
2668
2669 /* Ignore if this EC doesn't use specified opfamily */
2670 if (OidIsValid(opfamily) &&
2671 !list_member_oid(ec->ec_opfamilies, opfamily))
2672 continue;
2673
2674 /* Ignore children here */
2675 foreach(lc2, ec->ec_members)
2676 {
2677 EquivalenceMember *em = (EquivalenceMember *) lfirst(lc2);
2678
2679 /* Child members should not exist in ec_members */
2680 Assert(!em->em_is_child);
2681 if (equal(item1, em->em_expr))
2682 item1member = true;
2683 else if (equal(item2, em->em_expr))
2684 item2member = true;
2685 /* Exit as soon as equality is proven */
2686 if (item1member && item2member)
2687 return true;
2688 }
2689 }
2690 return false;
2691}
2692
2693
2694/*
2695 * match_eclasses_to_foreign_key_col
2696 * See whether a foreign key column match is proven by any eclass.
2697 *
2698 * If the referenced and referencing Vars of the fkey's colno'th column are
2699 * known equal due to any eclass, return that eclass; otherwise return NULL.
2700 * (In principle there might be more than one matching eclass if multiple
2701 * collations are involved, but since collation doesn't matter for equality,
2702 * we ignore that fine point here.) This is much like exprs_known_equal,
2703 * except for the format of the input.
2704 *
2705 * On success, we also set fkinfo->eclass[colno] to the matching eclass,
2706 * and set fkinfo->fk_eclass_member[colno] to the eclass member for the
2707 * referencing Var.
2708 */
2709EquivalenceClass *
2710match_eclasses_to_foreign_key_col(PlannerInfo *root,
2711 ForeignKeyOptInfo *fkinfo,
2712 int colno)
2713{
2714 Index var1varno = fkinfo->con_relid;
2715 AttrNumber var1attno = fkinfo->conkey[colno];
2716 Index var2varno = fkinfo->ref_relid;
2717 AttrNumber var2attno = fkinfo->confkey[colno];
2718 Oid eqop = fkinfo->conpfeqop[colno];
2719 RelOptInfo *rel1 = root->simple_rel_array[var1varno];
2720 RelOptInfo *rel2 = root->simple_rel_array[var2varno];
2721 List *opfamilies = NIL; /* compute only if needed */
2722 Bitmapset *matching_ecs;
2723 int i;
2724
2725 /* Consider only eclasses mentioning both relations */
2726 Assert(root->ec_merging_done);
2727 Assert(IS_SIMPLE_REL(rel1));
2728 Assert(IS_SIMPLE_REL(rel2));
2729 matching_ecs = bms_intersect(rel1->eclass_indexes,
2730 rel2->eclass_indexes);
2731
2732 i = -1;
2733 while ((i = bms_next_member(matching_ecs, i)) >= 0)
2734 {
2735 EquivalenceClass *ec = (EquivalenceClass *) list_nth(root->eq_classes,
2736 i);
2737 EquivalenceMember *item1_em = NULL;
2738 EquivalenceMember *item2_em = NULL;
2739 ListCell *lc2;
2740
2741 /* Never match to a volatile EC */
2742 if (ec->ec_has_volatile)
2743 continue;
2744
2745 /*
2746 * It's okay to consider "broken" ECs here, see exprs_known_equal.
2747 * Ignore children here.
2748 */
2749 foreach(lc2, ec->ec_members)
2750 {
2751 EquivalenceMember *em = (EquivalenceMember *) lfirst(lc2);
2752 Var *var;
2753
2754 /* Child members should not exist in ec_members */
2755 Assert(!em->em_is_child);
2756
2757 /* EM must be a Var, possibly with RelabelType */
2758 var = (Var *) em->em_expr;
2759 while (var && IsA(var, RelabelType))
2760 var = (Var *) ((RelabelType *) var)->arg;
2761 if (!(var && IsA(var, Var)))
2762 continue;
2763
2764 /* Match? */
2765 if (var->varno == var1varno && var->varattno == var1attno)
2766 item1_em = em;
2767 else if (var->varno == var2varno && var->varattno == var2attno)
2768 item2_em = em;
2769
2770 /* Have we found both PK and FK column in this EC? */
2771 if (item1_em && item2_em)
2772 {
2773 /*
2774 * Succeed if eqop matches EC's opfamilies. We could test
2775 * this before scanning the members, but it's probably cheaper
2776 * to test for member matches first.
2777 */
2778 if (opfamilies == NIL) /* compute if we didn't already */
2779 opfamilies = get_mergejoin_opfamilies(eqop);
2780 if (equal(opfamilies, ec->ec_opfamilies))
2781 {
2782 fkinfo->eclass[colno] = ec;
2783 fkinfo->fk_eclass_member[colno] = item2_em;
2784 return ec;
2785 }
2786 /* Otherwise, done with this EC, move on to the next */
2787 break;
2788 }
2789 }
2790 }
2791 return NULL;
2792}
2793
2794/*
2795 * find_derived_clause_for_ec_member
2796 * Search for a previously-derived clause mentioning the given EM.
2797 *
2798 * The eclass should be an ec_has_const EC, of which the EM is a non-const
2799 * member. This should ensure there is just one derived clause mentioning
2800 * the EM (and equating it to a constant).
2801 * Returns NULL if no such clause can be found.
2802 */
2803RestrictInfo *
2804find_derived_clause_for_ec_member(PlannerInfo *root,
2805 EquivalenceClass *ec,
2806 EquivalenceMember *em)
2807{
2808 Assert(ec->ec_has_const);
2809 Assert(!em->em_is_const);
2810
2811 return ec_search_derived_clause_for_ems(root, ec, em, NULL, NULL);
2812}
2813
2814
2815/*
2816 * add_child_rel_equivalences
2817 * Search for EC members that reference the root parent of child_rel, and
2818 * add transformed members referencing the child_rel.
2819 *
2820 * Note that this function won't be called at all unless we have at least some
2821 * reason to believe that the EC members it generates will be useful.
2822 *
2823 * parent_rel and child_rel could be derived from appinfo, but since the
2824 * caller has already computed them, we might as well just pass them in.
2825 *
2826 * The passed-in AppendRelInfo is not used when the parent_rel is not a
2827 * top-level baserel, since it shows the mapping from the parent_rel but
2828 * we need to translate EC expressions that refer to the top-level parent.
2829 * Using it is faster than using adjust_appendrel_attrs_multilevel(), though,
2830 * so we prefer it when we can.
2831 */
2832void
2833add_child_rel_equivalences(PlannerInfo *root,
2834 AppendRelInfo *appinfo,
2835 RelOptInfo *parent_rel,
2836 RelOptInfo *child_rel)
2837{
2838 Relids top_parent_relids = child_rel->top_parent_relids;
2839 Relids child_relids = child_rel->relids;
2840 int i;
2841
2842 /*
2843 * EC merging should be complete already, so we can use the parent rel's
2844 * eclass_indexes to avoid searching all of root->eq_classes.
2845 */
2846 Assert(root->ec_merging_done);
2847 Assert(IS_SIMPLE_REL(parent_rel));
2848
2849 i = -1;
2850 while ((i = bms_next_member(parent_rel->eclass_indexes, i)) >= 0)
2851 {
2852 EquivalenceClass *cur_ec = (EquivalenceClass *) list_nth(root->eq_classes, i);
2853
2854 /*
2855 * If this EC contains a volatile expression, then generating child
2856 * EMs would be downright dangerous, so skip it. We rely on a
2857 * volatile EC having only one EM.
2858 */
2859 if (cur_ec->ec_has_volatile)
2860 continue;
2861
2862 /* Sanity check eclass_indexes only contain ECs for parent_rel */
2863 Assert(bms_is_subset(top_parent_relids, cur_ec->ec_relids));
2864
2865 foreach_node(EquivalenceMember, cur_em, cur_ec->ec_members)
2866 {
2867 if (cur_em->em_is_const)
2868 continue; /* ignore consts here */
2869
2870 /* Child members should not exist in ec_members */
2871 Assert(!cur_em->em_is_child);
2872
2873 /*
2874 * Consider only members that reference and can be computed at
2875 * child's topmost parent rel. In particular we want to exclude
2876 * parent-rel Vars that have nonempty varnullingrels. Translating
2877 * those might fail, if the transformed expression wouldn't be a
2878 * simple Var; and in any case it wouldn't produce a member that
2879 * has any use in creating plans for the child rel.
2880 */
2881 if (bms_is_subset(cur_em->em_relids, top_parent_relids) &&
2882 !bms_is_empty(cur_em->em_relids))
2883 {
2884 /* OK, generate transformed child version */
2885 Expr *child_expr;
2886 Relids new_relids;
2887
2888 if (parent_rel->reloptkind == RELOPT_BASEREL)
2889 {
2890 /* Simple single-level transformation */
2891 child_expr = (Expr *)
2892 adjust_appendrel_attrs(root,
2893 (Node *) cur_em->em_expr,
2894 1, &appinfo);
2895 }
2896 else
2897 {
2898 /* Must do multi-level transformation */
2899 child_expr = (Expr *)
2900 adjust_appendrel_attrs_multilevel(root,
2901 (Node *) cur_em->em_expr,
2902 child_rel,
2903 child_rel->top_parent);
2904 }
2905
2906 /*
2907 * Transform em_relids to match. Note we do *not* do
2908 * pull_varnos(child_expr) here, as for example the
2909 * transformation might have substituted a constant, but we
2910 * don't want the child member to be marked as constant.
2911 */
2912 new_relids = bms_difference(cur_em->em_relids,
2913 top_parent_relids);
2914 new_relids = bms_add_members(new_relids, child_relids);
2915
2916 add_child_eq_member(root,
2917 cur_ec,
2918 i,
2919 child_expr,
2920 new_relids,
2921 cur_em->em_jdomain,
2922 cur_em,
2923 cur_em->em_datatype,
2924 child_rel->relid);
2925 }
2926 }
2927 }
2928}
2929
2930/*
2931 * add_child_join_rel_equivalences
2932 * Like add_child_rel_equivalences(), but for joinrels
2933 *
2934 * Here we find the ECs relevant to the top parent joinrel and add transformed
2935 * member expressions that refer to this child joinrel.
2936 *
2937 * Note that this function won't be called at all unless we have at least some
2938 * reason to believe that the EC members it generates will be useful.
2939 */
2940void
2941add_child_join_rel_equivalences(PlannerInfo *root,
2942 int nappinfos, AppendRelInfo **appinfos,
2943 RelOptInfo *parent_joinrel,
2944 RelOptInfo *child_joinrel)
2945{
2946 Relids top_parent_relids = child_joinrel->top_parent_relids;
2947 Relids child_relids = child_joinrel->relids;
2948 Bitmapset *matching_ecs;
2949 MemoryContext oldcontext;
2950 int i;
2951
2952 Assert(IS_JOIN_REL(child_joinrel) && IS_JOIN_REL(parent_joinrel));
2953
2954 /* We need consider only ECs that mention the parent joinrel */
2955 matching_ecs = get_eclass_indexes_for_relids(root, top_parent_relids);
2956
2957 /*
2958 * If we're being called during GEQO join planning, we still have to
2959 * create any new EC members in the main planner context, to avoid having
2960 * a corrupt EC data structure after the GEQO context is reset. This is
2961 * problematic since we'll leak memory across repeated GEQO cycles. For
2962 * now, though, bloat is better than crash. If it becomes a real issue
2963 * we'll have to do something to avoid generating duplicate EC members.
2964 */
2965 oldcontext = MemoryContextSwitchTo(root->planner_cxt);
2966
2967 i = -1;
2968 while ((i = bms_next_member(matching_ecs, i)) >= 0)
2969 {
2970 EquivalenceClass *cur_ec = (EquivalenceClass *) list_nth(root->eq_classes, i);
2971
2972 /*
2973 * If this EC contains a volatile expression, then generating child
2974 * EMs would be downright dangerous, so skip it. We rely on a
2975 * volatile EC having only one EM.
2976 */
2977 if (cur_ec->ec_has_volatile)
2978 continue;
2979
2980 /* Sanity check on get_eclass_indexes_for_relids result */
2981 Assert(bms_overlap(top_parent_relids, cur_ec->ec_relids));
2982
2983 foreach_node(EquivalenceMember, cur_em, cur_ec->ec_members)
2984 {
2985 if (cur_em->em_is_const)
2986 continue; /* ignore consts here */
2987
2988 /* Child members should not exist in ec_members */
2989 Assert(!cur_em->em_is_child);
2990
2991 /*
2992 * We may ignore expressions that reference a single baserel,
2993 * because add_child_rel_equivalences should have handled them.
2994 */
2995 if (bms_membership(cur_em->em_relids) != BMS_MULTIPLE)
2996 continue;
2997
2998 /* Does this member reference child's topmost parent rel? */
2999 if (bms_overlap(cur_em->em_relids, top_parent_relids))
3000 {
3001 /* Yes, generate transformed child version */
3002 Expr *child_expr;
3003 Relids new_relids;
3004
3005 if (parent_joinrel->reloptkind == RELOPT_JOINREL)
3006 {
3007 /* Simple single-level transformation */
3008 child_expr = (Expr *)
3009 adjust_appendrel_attrs(root,
3010 (Node *) cur_em->em_expr,
3011 nappinfos, appinfos);
3012 }
3013 else
3014 {
3015 /* Must do multi-level transformation */
3016 Assert(parent_joinrel->reloptkind == RELOPT_OTHER_JOINREL);
3017 child_expr = (Expr *)
3018 adjust_appendrel_attrs_multilevel(root,
3019 (Node *) cur_em->em_expr,
3020 child_joinrel,
3021 child_joinrel->top_parent);
3022 }
3023
3024 /*
3025 * Transform em_relids to match. Note we do *not* do
3026 * pull_varnos(child_expr) here, as for example the
3027 * transformation might have substituted a constant, but we
3028 * don't want the child member to be marked as constant.
3029 */
3030 new_relids = bms_difference(cur_em->em_relids,
3031 top_parent_relids);
3032 new_relids = bms_add_members(new_relids, child_relids);
3033
3034 /*
3035 * Add new child member to the EquivalenceClass. Because this
3036 * is a RELOPT_OTHER_JOINREL which has multiple component
3037 * relids, there is no ideal place to store these members in
3038 * the class. Ordinarily, child members are stored in the
3039 * ec_childmembers[] array element corresponding to their
3040 * relid, however, here we have multiple component relids, so
3041 * there's no single ec_childmembers[] array element to store
3042 * this member. So that we still correctly find this member
3043 * in loops iterating over an EquivalenceMemberIterator, we
3044 * opt to store the member in the ec_childmembers array in
3045 * only the first component relid slot of the array. This
3046 * allows the member to be found, providing callers of
3047 * setup_eclass_member_iterator() specify all the component
3048 * relids for the RELOPT_OTHER_JOINREL, which they do. If we
3049 * opted to store the member in each ec_childmembers[] element
3050 * for all the component relids, then that would just result
3051 * in eclass_member_iterator_next() finding the member
3052 * multiple times, which is a waste of effort.
3053 */
3054 add_child_eq_member(root,
3055 cur_ec,
3056 -1,
3057 child_expr,
3058 new_relids,
3059 cur_em->em_jdomain,
3060 cur_em,
3061 cur_em->em_datatype,
3062 bms_next_member(child_joinrel->relids, -1));
3063 }
3064 }
3065 }
3066
3067 MemoryContextSwitchTo(oldcontext);
3068}
3069
3070/*
3071 * add_setop_child_rel_equivalences
3072 * Add equivalence members for each non-resjunk target in 'child_tlist'
3073 * to the EquivalenceClass in the corresponding setop_pathkey's pk_eclass.
3074 *
3075 * 'root' is the PlannerInfo belonging to the top-level set operation.
3076 * 'child_rel' is the RelOptInfo of the child relation we're adding
3077 * EquivalenceMembers for.
3078 * 'child_tlist' is the target list for the setop child relation. The target
3079 * list expressions are what we add as EquivalenceMembers.
3080 * 'setop_pathkeys' is a list of PathKeys which must contain an entry for each
3081 * non-resjunk target in 'child_tlist'.
3082 */
3083void
3084add_setop_child_rel_equivalences(PlannerInfo *root, RelOptInfo *child_rel,
3085 List *child_tlist, List *setop_pathkeys)
3086{
3087 ListCell *lc;
3088 ListCell *lc2 = list_head(setop_pathkeys);
3089
3090 foreach(lc, child_tlist)
3091 {
3092 TargetEntry *tle = lfirst_node(TargetEntry, lc);
3093 EquivalenceMember *parent_em;
3094 PathKey *pk;
3095
3096 if (tle->resjunk)
3097 continue;
3098
3099 if (lc2 == NULL)
3100 elog(ERROR, "too few pathkeys for set operation");
3101
3102 pk = lfirst_node(PathKey, lc2);
3103 parent_em = linitial(pk->pk_eclass->ec_members);
3104
3105 /*
3106 * We can safely pass the parent member as the first member in the
3107 * ec_members list as this is added first in generate_union_paths,
3108 * likewise, the JoinDomain can be that of the initial member of the
3109 * Pathkey's EquivalenceClass. We pass -1 for ec_index since we
3110 * maintain the eclass_indexes for the child_rel after the loop.
3111 */
3112 add_child_eq_member(root,
3113 pk->pk_eclass,
3114 -1,
3115 tle->expr,
3116 child_rel->relids,
3117 parent_em->em_jdomain,
3118 parent_em,
3119 exprType((Node *) tle->expr),
3120 child_rel->relid);
3121
3122 lc2 = lnext(setop_pathkeys, lc2);
3123 }
3124
3125 /*
3126 * transformSetOperationStmt() ensures that the targetlist never contains
3127 * any resjunk columns, so all eclasses that exist in 'root' must have
3128 * received a new member in the loop above. Add them to the child_rel's
3129 * eclass_indexes.
3130 */
3131 child_rel->eclass_indexes = bms_add_range(child_rel->eclass_indexes, 0,
3132 list_length(root->eq_classes) - 1);
3133}
3134
3135/*
3136 * setup_eclass_member_iterator
3137 * Setup an EquivalenceMemberIterator 'it' to iterate over all parent
3138 * EquivalenceMembers and child members belonging to the given 'ec'.
3139 *
3140 * This iterator returns:
3141 * - All parent members stored directly in ec_members for 'ec', and;
3142 * - Any child member added to the given ec by add_child_eq_member() where
3143 * the child_relid specified in the add_child_eq_member() call is a member
3144 * of the 'child_relids' parameter.
3145 *
3146 * Note:
3147 * The given 'child_relids' must remain allocated and not be changed for the
3148 * lifetime of the iterator.
3149 *
3150 * Parameters:
3151 * 'it' is a pointer to the iterator to set up. Normally stack allocated.
3152 * 'ec' is the EquivalenceClass from which to iterate members for.
3153 * 'child_relids' is the relids to return child members for.
3154 */
3155void
3156setup_eclass_member_iterator(EquivalenceMemberIterator *it,
3157 EquivalenceClass *ec, Relids child_relids)
3158{
3159 it->ec = ec;
3160 /* no need to set this if the class has no child members array set */
3161 it->child_relids = ec->ec_childmembers != NULL ? child_relids : NULL;
3162 it->current_relid = -1;
3163 it->current_list = ec->ec_members;
3164 it->current_cell = list_head(it->current_list);
3165}
3166
3167/*
3168 * eclass_member_iterator_next
3169 * Get the next EquivalenceMember from the EquivalenceMemberIterator 'it',
3170 * as setup by setup_eclass_member_iterator(). NULL is returned if there
3171 * are no members left, after which callers must not call
3172 * eclass_member_iterator_next() again for the given iterator.
3173 */
3174EquivalenceMember *
3175eclass_member_iterator_next(EquivalenceMemberIterator *it)
3176{
3177 while (it->current_list != NULL)
3178 {
3179 while (it->current_cell != NULL)
3180 {
3181 EquivalenceMember *em;
3182
3183 nextcell:
3184 em = lfirst_node(EquivalenceMember, it->current_cell);
3185 it->current_cell = lnext(it->current_list, it->current_cell);
3186 return em;
3187 }
3188
3189 /* Search for the next list to return members from */
3190 while ((it->current_relid = bms_next_member(it->child_relids, it->current_relid)) > 0)
3191 {
3192 /*
3193 * Be paranoid in case we're given relids above what we've sized
3194 * the ec_childmembers array to.
3195 */
3196 if (it->current_relid >= it->ec->ec_childmembers_size)
3197 return NULL;
3198
3199 it->current_list = it->ec->ec_childmembers[it->current_relid];
3200
3201 /* If there are members in this list, use it. */
3202 if (it->current_list != NIL)
3203 {
3204 /* point current_cell to the head of this list */
3205 it->current_cell = list_head(it->current_list);
3206 goto nextcell;
3207 }
3208 }
3209 return NULL;
3210 }
3211
3212 return NULL;
3213}
3214
3215/*
3216 * generate_implied_equalities_for_column
3217 * Create EC-derived joinclauses usable with a specific column.
3218 *
3219 * This is used by indxpath.c to extract potentially indexable joinclauses
3220 * from ECs, and can be used by foreign data wrappers for similar purposes.
3221 * We assume that only expressions in Vars of a single table are of interest,
3222 * but the caller provides a callback function to identify exactly which
3223 * such expressions it would like to know about.
3224 *
3225 * We assume that any given table/index column could appear in only one EC.
3226 * (This should be true in all but the most pathological cases, and if it
3227 * isn't, we stop on the first match anyway.) Therefore, what we return
3228 * is a redundant list of clauses equating the table/index column to each of
3229 * the other-relation values it is known to be equal to. Any one of
3230 * these clauses can be used to create a parameterized path, and there
3231 * is no value in using more than one. (But it *is* worthwhile to create
3232 * a separate parameterized path for each one, since that leads to different
3233 * join orders.)
3234 *
3235 * The caller can pass a Relids set of rels we aren't interested in joining
3236 * to, so as to save the work of creating useless clauses.
3237 */
3238List *
3239generate_implied_equalities_for_column(PlannerInfo *root,
3240 RelOptInfo *rel,
3241 ec_matches_callback_type callback,
3242 void *callback_arg,
3243 Relids prohibited_rels)
3244{
3245 List *result = NIL;
3246 bool is_child_rel = (rel->reloptkind == RELOPT_OTHER_MEMBER_REL);
3247 Relids parent_relids;
3248 int i;
3249
3250 /* Should be OK to rely on eclass_indexes */
3251 Assert(root->ec_merging_done);
3252
3253 /* Indexes are available only on base or "other" member relations. */
3254 Assert(IS_SIMPLE_REL(rel));
3255
3256 /* If it's a child rel, we'll need to know what its parent(s) are */
3257 if (is_child_rel)
3258 parent_relids = find_childrel_parents(root, rel);
3259 else
3260 parent_relids = NULL; /* not used, but keep compiler quiet */
3261
3262 i = -1;
3263 while ((i = bms_next_member(rel->eclass_indexes, i)) >= 0)
3264 {
3265 EquivalenceClass *cur_ec = (EquivalenceClass *) list_nth(root->eq_classes, i);
3266 EquivalenceMemberIterator it;
3267 EquivalenceMember *cur_em;
3268 ListCell *lc2;
3269
3270 /* Sanity check eclass_indexes only contain ECs for rel */
3271 Assert(is_child_rel || bms_is_subset(rel->relids, cur_ec->ec_relids));
3272
3273 /*
3274 * Won't generate joinclauses if const or single-member (the latter
3275 * test covers the volatile case too)
3276 */
3277 if (cur_ec->ec_has_const || list_length(cur_ec->ec_members) <= 1)
3278 continue;
3279
3280 /*
3281 * Scan members, looking for a match to the target column. Note that
3282 * child EC members are considered, but only when they belong to the
3283 * target relation. (Unlike regular members, the same expression
3284 * could be a child member of more than one EC. Therefore, it's
3285 * potentially order-dependent which EC a child relation's target
3286 * column gets matched to. This is annoying but it only happens in
3287 * corner cases, so for now we live with just reporting the first
3288 * match. See also get_eclass_for_sort_expr.)
3289 */
3290 setup_eclass_member_iterator(&it, cur_ec, rel->relids);
3291 while ((cur_em = eclass_member_iterator_next(&it)) != NULL)
3292 {
3293 if (bms_equal(cur_em->em_relids, rel->relids) &&
3294 callback(root, rel, cur_ec, cur_em, callback_arg))
3295 break;
3296 }
3297
3298 if (!cur_em)
3299 continue;
3300
3301 /*
3302 * Found our match. Scan the other EC members and attempt to generate
3303 * joinclauses. Ignore children here.
3304 */
3305 foreach(lc2, cur_ec->ec_members)
3306 {
3307 EquivalenceMember *other_em = (EquivalenceMember *) lfirst(lc2);
3308 Oid eq_op;
3309 RestrictInfo *rinfo;
3310
3311 /* Child members should not exist in ec_members */
3312 Assert(!other_em->em_is_child);
3313
3314 /* Make sure it'll be a join to a different rel */
3315 if (other_em == cur_em ||
3316 bms_overlap(other_em->em_relids, rel->relids))
3317 continue;
3318
3319 /* Forget it if caller doesn't want joins to this rel */
3320 if (bms_overlap(other_em->em_relids, prohibited_rels))
3321 continue;
3322
3323 /*
3324 * Also, if this is a child rel, avoid generating a useless join
3325 * to its parent rel(s).
3326 */
3327 if (is_child_rel &&
3328 bms_overlap(parent_relids, other_em->em_relids))
3329 continue;
3330
3331 eq_op = select_equality_operator(cur_ec,
3332 cur_em->em_datatype,
3333 other_em->em_datatype);
3334 if (!OidIsValid(eq_op))
3335 continue;
3336
3337 /* set parent_ec to mark as redundant with other joinclauses */
3338 rinfo = create_join_clause(root, cur_ec, eq_op,
3339 cur_em, other_em,
3340 cur_ec);
3341
3342 result = lappend(result, rinfo);
3343 }
3344
3345 /*
3346 * If somehow we failed to create any join clauses, we might as well
3347 * keep scanning the ECs for another match. But if we did make any,
3348 * we're done, because we don't want to return non-redundant clauses.
3349 */
3350 if (result)
3351 break;
3352 }
3353
3354 return result;
3355}
3356
3357/*
3358 * have_relevant_eclass_joinclause
3359 * Detect whether there is an EquivalenceClass that could produce
3360 * a joinclause involving the two given relations.
3361 *
3362 * This is essentially a very cut-down version of
3363 * generate_join_implied_equalities(). Note it's OK to occasionally say "yes"
3364 * incorrectly. Hence we don't bother with details like whether the lack of a
3365 * cross-type operator might prevent the clause from actually being generated.
3366 * False negatives are not always fatal either: they will discourage, but not
3367 * completely prevent, investigation of particular join pathways.
3368 */
3369bool
3370have_relevant_eclass_joinclause(PlannerInfo *root,
3371 RelOptInfo *rel1, RelOptInfo *rel2)
3372{
3373 Bitmapset *matching_ecs;
3374 int i;
3375
3376 /*
3377 * Examine only eclasses mentioning both rel1 and rel2.
3378 *
3379 * Note that we do not consider the possibility of an eclass generating
3380 * "join" clauses that mention just one of the rels plus an outer join
3381 * that could be formed from them. Although such clauses must be
3382 * correctly enforced when we form the outer join, they don't seem like
3383 * sufficient reason to prioritize this join over other ones. The join
3384 * ordering rules will force the join to be made when necessary.
3385 */
3386 matching_ecs = get_common_eclass_indexes(root, rel1->relids,
3387 rel2->relids);
3388
3389 i = -1;
3390 while ((i = bms_next_member(matching_ecs, i)) >= 0)
3391 {
3392 EquivalenceClass *ec = (EquivalenceClass *) list_nth(root->eq_classes,
3393 i);
3394
3395 /*
3396 * Sanity check that get_common_eclass_indexes gave only ECs
3397 * containing both rels.
3398 */
3399 Assert(bms_overlap(rel1->relids, ec->ec_relids));
3400 Assert(bms_overlap(rel2->relids, ec->ec_relids));
3401
3402 /*
3403 * Won't generate joinclauses if single-member (this test covers the
3404 * volatile case too)
3405 */
3406 if (list_length(ec->ec_members) <= 1)
3407 continue;
3408
3409 /*
3410 * We do not need to examine the individual members of the EC, because
3411 * all that we care about is whether each rel overlaps the relids of
3412 * at least one member, and get_common_eclass_indexes() and the single
3413 * member check above are sufficient to prove that. (As with
3414 * have_relevant_joinclause(), it is not necessary that the EC be able
3415 * to form a joinclause relating exactly the two given rels, only that
3416 * it be able to form a joinclause mentioning both, and this will
3417 * surely be true if both of them overlap ec_relids.)
3418 *
3419 * Note we don't test ec_broken; if we did, we'd need a separate code
3420 * path to look through ec_sources. Checking the membership anyway is
3421 * OK as a possibly-overoptimistic heuristic.
3422 *
3423 * We don't test ec_has_const either, even though a const eclass won't
3424 * generate real join clauses. This is because if we had "WHERE a.x =
3425 * b.y and a.x = 42", it is worth considering a join between a and b,
3426 * since the join result is likely to be small even though it'll end
3427 * up being an unqualified nestloop.
3428 */
3429
3430 return true;
3431 }
3432
3433 return false;
3434}
3435
3436
3437/*
3438 * has_relevant_eclass_joinclause
3439 * Detect whether there is an EquivalenceClass that could produce
3440 * a joinclause involving the given relation and anything else.
3441 *
3442 * This is the same as have_relevant_eclass_joinclause with the other rel
3443 * implicitly defined as "everything else in the query".
3444 */
3445bool
3446has_relevant_eclass_joinclause(PlannerInfo *root, RelOptInfo *rel1)
3447{
3448 Bitmapset *matched_ecs;
3449 int i;
3450
3451 /* Examine only eclasses mentioning rel1 */
3452 matched_ecs = get_eclass_indexes_for_relids(root, rel1->relids);
3453
3454 i = -1;
3455 while ((i = bms_next_member(matched_ecs, i)) >= 0)
3456 {
3457 EquivalenceClass *ec = (EquivalenceClass *) list_nth(root->eq_classes,
3458 i);
3459
3460 /*
3461 * Won't generate joinclauses if single-member (this test covers the
3462 * volatile case too)
3463 */
3464 if (list_length(ec->ec_members) <= 1)
3465 continue;
3466
3467 /*
3468 * Per the comment in have_relevant_eclass_joinclause, it's sufficient
3469 * to find an EC that mentions both this rel and some other rel.
3470 */
3471 if (!bms_is_subset(ec->ec_relids, rel1->relids))
3472 return true;
3473 }
3474
3475 return false;
3476}
3477
3478
3479/*
3480 * eclass_useful_for_merging
3481 * Detect whether the EC could produce any mergejoinable join clauses
3482 * against the specified relation.
3483 *
3484 * This is just a heuristic test and doesn't have to be exact; it's better
3485 * to say "yes" incorrectly than "no". Hence we don't bother with details
3486 * like whether the lack of a cross-type operator might prevent the clause
3487 * from actually being generated.
3488 */
3489bool
3490eclass_useful_for_merging(PlannerInfo *root,
3491 EquivalenceClass *eclass,
3492 RelOptInfo *rel)
3493{
3494 Relids relids;
3495 ListCell *lc;
3496
3497 Assert(!eclass->ec_merged);
3498
3499 /*
3500 * Won't generate joinclauses if const or single-member (the latter test
3501 * covers the volatile case too)
3502 */
3503 if (eclass->ec_has_const || list_length(eclass->ec_members) <= 1)
3504 return false;
3505
3506 /*
3507 * Note we don't test ec_broken; if we did, we'd need a separate code path
3508 * to look through ec_sources. Checking the members anyway is OK as a
3509 * possibly-overoptimistic heuristic.
3510 */
3511
3512 /* If specified rel is a child, we must consider the topmost parent rel */
3513 if (IS_OTHER_REL(rel))
3514 {
3515 Assert(!bms_is_empty(rel->top_parent_relids));
3516 relids = rel->top_parent_relids;
3517 }
3518 else
3519 relids = rel->relids;
3520
3521 /* If rel already includes all members of eclass, no point in searching */
3522 if (bms_is_subset(eclass->ec_relids, relids))
3523 return false;
3524
3525 /*
3526 * To join, we need a member not in the given rel. Ignore children here.
3527 */
3528 foreach(lc, eclass->ec_members)
3529 {
3530 EquivalenceMember *cur_em = (EquivalenceMember *) lfirst(lc);
3531
3532 /* Child members should not exist in ec_members */
3533 Assert(!cur_em->em_is_child);
3534
3535 if (!bms_overlap(cur_em->em_relids, relids))
3536 return true;
3537 }
3538
3539 return false;
3540}
3541
3542
3543/*
3544 * is_redundant_derived_clause
3545 * Test whether rinfo is derived from same EC as any clause in clauselist;
3546 * if so, it can be presumed to represent a condition that's redundant
3547 * with that member of the list.
3548 */
3549bool
3550is_redundant_derived_clause(RestrictInfo *rinfo, List *clauselist)
3551{
3552 EquivalenceClass *parent_ec = rinfo->parent_ec;
3553 ListCell *lc;
3554
3555 /* Fail if it's not a potentially-redundant clause from some EC */
3556 if (parent_ec == NULL)
3557 return false;
3558
3559 foreach(lc, clauselist)
3560 {
3561 RestrictInfo *otherrinfo = (RestrictInfo *) lfirst(lc);
3562
3563 if (otherrinfo->parent_ec == parent_ec)
3564 return true;
3565 }
3566
3567 return false;
3568}
3569
3570/*
3571 * is_redundant_with_indexclauses
3572 * Test whether rinfo is redundant with any clause in the IndexClause
3573 * list. Here, for convenience, we test both simple identity and
3574 * whether it is derived from the same EC as any member of the list.
3575 */
3576bool
3577is_redundant_with_indexclauses(RestrictInfo *rinfo, List *indexclauses)
3578{
3579 EquivalenceClass *parent_ec = rinfo->parent_ec;
3580 ListCell *lc;
3581
3582 foreach(lc, indexclauses)
3583 {
3584 IndexClause *iclause = lfirst_node(IndexClause, lc);
3585 RestrictInfo *otherrinfo = iclause->rinfo;
3586
3587 /* If indexclause is lossy, it won't enforce the condition exactly */
3588 if (iclause->lossy)
3589 continue;
3590
3591 /* Match if it's same clause (pointer equality should be enough) */
3592 if (rinfo == otherrinfo)
3593 return true;
3594 /* Match if derived from same EC */
3595 if (parent_ec && otherrinfo->parent_ec == parent_ec)
3596 return true;
3597
3598 /*
3599 * No need to look at the derived clauses in iclause->indexquals; they
3600 * couldn't match if the parent clause didn't.
3601 */
3602 }
3603
3604 return false;
3605}
3606
3607/*
3608 * get_eclass_indexes_for_relids
3609 * Build and return a Bitmapset containing the indexes into root's
3610 * eq_classes list for all eclasses that mention any of these relids
3611 */
3612static Bitmapset *
3613get_eclass_indexes_for_relids(PlannerInfo *root, Relids relids)
3614{
3615 Bitmapset *ec_indexes = NULL;
3616 int i = -1;
3617
3618 /* Should be OK to rely on eclass_indexes */
3619 Assert(root->ec_merging_done);
3620
3621 while ((i = bms_next_member(relids, i)) > 0)
3622 {
3623 RelOptInfo *rel = root->simple_rel_array[i];
3624
3625 /* ignore the RTE_GROUP RTE */
3626 if (i == root->group_rtindex)
3627 continue;
3628
3629 if (rel == NULL) /* must be an outer join */
3630 {
3631 Assert(bms_is_member(i, root->outer_join_rels));
3632 continue;
3633 }
3634
3635 ec_indexes = bms_add_members(ec_indexes, rel->eclass_indexes);
3636 }
3637 return ec_indexes;
3638}
3639
3640/*
3641 * get_common_eclass_indexes
3642 * Build and return a Bitmapset containing the indexes into root's
3643 * eq_classes list for all eclasses that mention rels in both
3644 * relids1 and relids2.
3645 */
3646static Bitmapset *
3647get_common_eclass_indexes(PlannerInfo *root, Relids relids1, Relids relids2)
3648{
3649 Bitmapset *rel1ecs;
3650 Bitmapset *rel2ecs;
3651 int relid;
3652
3653 rel1ecs = get_eclass_indexes_for_relids(root, relids1);
3654
3655 /*
3656 * We can get away with just using the relation's eclass_indexes directly
3657 * when relids2 is a singleton set.
3658 */
3659 if (bms_get_singleton_member(relids2, &relid))
3660 rel2ecs = root->simple_rel_array[relid]->eclass_indexes;
3661 else
3662 rel2ecs = get_eclass_indexes_for_relids(root, relids2);
3663
3664 /* Calculate and return the common EC indexes, recycling the left input. */
3665 return bms_int_members(rel1ecs, rel2ecs);
3666}
3667
3668/*
3669 * ec_build_derives_hash
3670 * Construct the auxiliary hash table for derived clause lookups.
3671 */
3672static void
3673ec_build_derives_hash(PlannerInfo *root, EquivalenceClass *ec)
3674{
3675 Assert(!ec->ec_derives_hash);
3676
3677 /*
3678 * Create the hash table.
3679 *
3680 * We pass list_length(ec->ec_derives_list) as the initial size.
3681 * Simplehash will divide this by the fillfactor (typically 0.9) and round
3682 * up to the next power of two, so this will usually give us at least 64
3683 * buckets around the threshold. That avoids immediate resizing without
3684 * hardcoding a specific size.
3685 */
3686 ec->ec_derives_hash = derives_create(root->planner_cxt,
3687 list_length(ec->ec_derives_list),
3688 NULL);
3689
3690 foreach_node(RestrictInfo, rinfo, ec->ec_derives_list)
3691 ec_add_clause_to_derives_hash(ec, rinfo);
3692}
3693
3694/*
3695 * ec_add_derived_clause
3696 * Add a clause to the set of derived clauses for the given
3697 * EquivalenceClass. Always appends to ec_derives_list; also adds
3698 * to ec_derives_hash if it exists.
3699 *
3700 * Also asserts expected invariants of derived clauses.
3701 */
3702static void
3703ec_add_derived_clause(EquivalenceClass *ec, RestrictInfo *clause)
3704{
3705 /*
3706 * Constant, if present, is always placed on the RHS; see
3707 * generate_base_implied_equalities_const(). LHS is never a constant.
3708 */
3709 Assert(!clause->left_em->em_is_const);
3710
3711 /*
3712 * Clauses containing a constant are never considered redundant, so
3713 * parent_ec is not set.
3714 */
3715 Assert(!clause->parent_ec || !clause->right_em->em_is_const);
3716
3717 ec->ec_derives_list = lappend(ec->ec_derives_list, clause);
3718 if (ec->ec_derives_hash)
3719 ec_add_clause_to_derives_hash(ec, clause);
3720}
3721
3722/*
3723 * ec_add_derived_clauses
3724 * Add a list of clauses to the set of clauses derived from the given
3725 * EquivalenceClass; adding to the list and hash table if needed.
3726 *
3727 * This function is similar to ec_add_derived_clause() but optimized for adding
3728 * multiple clauses at a time to the ec_derives_list. The assertions from
3729 * ec_add_derived_clause() are not repeated here, as the input clauses are
3730 * assumed to have already been validated.
3731 */
3732static void
3733ec_add_derived_clauses(EquivalenceClass *ec, List *clauses)
3734{
3735 ec->ec_derives_list = list_concat(ec->ec_derives_list, clauses);
3736 if (ec->ec_derives_hash)
3737 foreach_node(RestrictInfo, rinfo, clauses)
3738 ec_add_clause_to_derives_hash(ec, rinfo);
3739}
3740
3741/*
3742 * fill_ec_derives_key
3743 * Compute a canonical key for ec_derives_hash lookup or insertion.
3744 *
3745 * Derived clauses are looked up using a pair of EquivalenceMembers and a
3746 * parent EquivalenceClass. To avoid storing or searching for both EM orderings,
3747 * we canonicalize the key:
3748 *
3749 * - For clauses involving two non-constant EMs, em1 is set to the EM with lower
3750 * memory address and em2 is set to the other one.
3751 * - For clauses involving a constant EM, the caller must pass the non-constant
3752 * EM as leftem and NULL as rightem; we then set em1 = NULL and em2 = leftem.
3753 */
3754static inline void
3755fill_ec_derives_key(ECDerivesKey *key,
3756 EquivalenceMember *leftem,
3757 EquivalenceMember *rightem,
3758 EquivalenceClass *parent_ec)
3759{
3760 Assert(leftem); /* Always required for lookup or insertion */
3761
3762 if (rightem == NULL)
3763 {
3764 key->em1 = NULL;
3765 key->em2 = leftem;
3766 }
3767 else if (leftem < rightem)
3768 {
3769 key->em1 = leftem;
3770 key->em2 = rightem;
3771 }
3772 else
3773 {
3774 key->em1 = rightem;
3775 key->em2 = leftem;
3776 }
3777 key->parent_ec = parent_ec;
3778}
3779
3780/*
3781 * ec_add_clause_to_derives_hash
3782 * Add a derived clause to ec_derives_hash in the given EquivalenceClass.
3783 *
3784 * Each clause is associated with a canonicalized key. For constant-containing
3785 * clauses, only the non-constant EM is used for lookup; see comments in
3786 * fill_ec_derives_key().
3787 */
3788static void
3789ec_add_clause_to_derives_hash(EquivalenceClass *ec, RestrictInfo *rinfo)
3790{
3791 ECDerivesKey key;
3792 ECDerivesEntry *entry;
3793 bool found;
3794
3795 /*
3796 * Constants are always placed on the RHS; see
3797 * generate_base_implied_equalities_const().
3798 */
3799 Assert(!rinfo->left_em->em_is_const);
3800
3801 /*
3802 * Clauses containing a constant are never considered redundant, so
3803 * parent_ec is not set.
3804 */
3805 Assert(!rinfo->parent_ec || !rinfo->right_em->em_is_const);
3806
3807 /*
3808 * See fill_ec_derives_key() for details: we use a canonicalized key to
3809 * avoid storing both EM orderings. For constant EMs, only the
3810 * non-constant EM is included in the key.
3811 */
3812 fill_ec_derives_key(&key,
3813 rinfo->left_em,
3814 rinfo->right_em->em_is_const ? NULL : rinfo->right_em,
3815 rinfo->parent_ec);
3816 entry = derives_insert(ec->ec_derives_hash, key, &found);
3817 Assert(!found);
3818 entry->rinfo = rinfo;
3819}
3820
3821/*
3822 * ec_clear_derived_clauses
3823 * Reset ec_derives_list and ec_derives_hash.
3824 *
3825 * We destroy the hash table explicitly, since it may consume significant
3826 * space. The list holds the same set of entries and can become equally large
3827 * when thousands of partitions are involved, so we free it as well -- even
3828 * though we do not typically free lists.
3829 */
3830void
3831ec_clear_derived_clauses(EquivalenceClass *ec)
3832{
3833 list_free(ec->ec_derives_list);
3834 ec->ec_derives_list = NIL;
3835
3836 if (ec->ec_derives_hash)
3837 {
3838 derives_destroy(ec->ec_derives_hash);
3839 ec->ec_derives_hash = NULL;
3840 }
3841}
3842
3843/*
3844 * ec_search_clause_for_ems
3845 * Search for an existing RestrictInfo that equates the given pair
3846 * of EquivalenceMembers, either from ec_sources or ec_derives.
3847 *
3848 * Returns a clause with matching operands in either given order or commuted
3849 * order. We used to require matching operator OIDs, but dropped that since any
3850 * semantically different operator here would indicate a broken operator family.
3851 *
3852 * Returns NULL if no matching clause is found.
3853 */
3854static RestrictInfo *
3855ec_search_clause_for_ems(PlannerInfo *root, EquivalenceClass *ec,
3856 EquivalenceMember *leftem, EquivalenceMember *rightem,
3857 EquivalenceClass *parent_ec)
3858{
3859 /* Check original source clauses */
3860 foreach_node(RestrictInfo, rinfo, ec->ec_sources)
3861 {
3862 if (rinfo->left_em == leftem &&
3863 rinfo->right_em == rightem &&
3864 rinfo->parent_ec == parent_ec)
3865 return rinfo;
3866 if (rinfo->left_em == rightem &&
3867 rinfo->right_em == leftem &&
3868 rinfo->parent_ec == parent_ec)
3869 return rinfo;
3870 }
3871
3872 /* Not found in ec_sources; search derived clauses */
3873 return ec_search_derived_clause_for_ems(root, ec, leftem, rightem,
3874 parent_ec);
3875}
3876
3877/*
3878 * ec_search_derived_clause_for_ems
3879 * Search for an existing derived clause between two EquivalenceMembers.
3880 *
3881 * If the number of derived clauses exceeds a threshold, switch to hash table
3882 * lookup; otherwise, scan ec_derives_list linearly.
3883 *
3884 * Clauses involving constants are looked up by passing the non-constant EM
3885 * as leftem and setting rightem to NULL. In that case, we expect to find a
3886 * clause with a constant on the RHS.
3887 *
3888 * While searching the list, we compare each given EM with both sides of each
3889 * clause. But for hash table lookups, we construct a canonicalized key and
3890 * perform a single lookup.
3891 */
3892static RestrictInfo *
3893ec_search_derived_clause_for_ems(PlannerInfo *root, EquivalenceClass *ec,
3894 EquivalenceMember *leftem,
3895 EquivalenceMember *rightem,
3896 EquivalenceClass *parent_ec)
3897{
3898 /* Switch to using hash lookup when list grows "too long". */
3899 if (!ec->ec_derives_hash &&
3900 list_length(ec->ec_derives_list) >= EC_DERIVES_HASH_THRESHOLD)
3901 ec_build_derives_hash(root, ec);
3902
3903 /* Perform hash table lookup if available */
3904 if (ec->ec_derives_hash)
3905 {
3906 ECDerivesKey key;
3907 RestrictInfo *rinfo;
3908 ECDerivesEntry *entry;
3909
3910 fill_ec_derives_key(&key, leftem, rightem, parent_ec);
3911 entry = derives_lookup(ec->ec_derives_hash, key);
3912 if (entry)
3913 {
3914 rinfo = entry->rinfo;
3915 Assert(rinfo);
3916 Assert(rightem || rinfo->right_em->em_is_const);
3917 return rinfo;
3918 }
3919 }
3920 else
3921 {
3922 /* Fallback to linear search over ec_derives_list */
3923 foreach_node(RestrictInfo, rinfo, ec->ec_derives_list)
3924 {
3925 /* Handle special case: lookup by non-const EM alone */
3926 if (!rightem &&
3927 rinfo->left_em == leftem)
3928 {
3929 Assert(rinfo->right_em->em_is_const);
3930 return rinfo;
3931 }
3932 if (rinfo->left_em == leftem &&
3933 rinfo->right_em == rightem &&
3934 rinfo->parent_ec == parent_ec)
3935 return rinfo;
3936 if (rinfo->left_em == rightem &&
3937 rinfo->right_em == leftem &&
3938 rinfo->parent_ec == parent_ec)
3939 return rinfo;
3940 }
3941 }
3942
3943 return NULL;
3944}
adjust_appendrel_attrs
Node * adjust_appendrel_attrs(PlannerInfo *root, Node *node, int nappinfos, AppendRelInfo **appinfos)
Definition: appendinfo.c:200
adjust_appendrel_attrs_multilevel
Node * adjust_appendrel_attrs_multilevel(PlannerInfo *root, Node *node, RelOptInfo *childrel, RelOptInfo *parentrel)
Definition: appendinfo.c:541
AttrNumber
int16 AttrNumber
Definition: attnum.h:21
bms_difference
Bitmapset * bms_difference(const Bitmapset *a, const Bitmapset *b)
Definition: bitmapset.c:346
bms_make_singleton
Bitmapset * bms_make_singleton(int x)
Definition: bitmapset.c:216
bms_int_members
Bitmapset * bms_int_members(Bitmapset *a, const Bitmapset *b)
Definition: bitmapset.c:1109
bms_intersect
Bitmapset * bms_intersect(const Bitmapset *a, const Bitmapset *b)
Definition: bitmapset.c:292
bms_equal
bool bms_equal(const Bitmapset *a, const Bitmapset *b)
Definition: bitmapset.c:142
bms_next_member
int bms_next_member(const Bitmapset *a, int prevbit)
Definition: bitmapset.c:1306
bms_add_range
Bitmapset * bms_add_range(Bitmapset *a, int lower, int upper)
Definition: bitmapset.c:1019
bms_is_subset
bool bms_is_subset(const Bitmapset *a, const Bitmapset *b)
Definition: bitmapset.c:412
bms_is_member
bool bms_is_member(int x, const Bitmapset *a)
Definition: bitmapset.c:510
bms_add_member
Bitmapset * bms_add_member(Bitmapset *a, int x)
Definition: bitmapset.c:815
bms_add_members
Bitmapset * bms_add_members(Bitmapset *a, const Bitmapset *b)
Definition: bitmapset.c:917
bms_union
Bitmapset * bms_union(const Bitmapset *a, const Bitmapset *b)
Definition: bitmapset.c:251
bms_membership
BMS_Membership bms_membership(const Bitmapset *a)
Definition: bitmapset.c:781
bms_overlap
bool bms_overlap(const Bitmapset *a, const Bitmapset *b)
Definition: bitmapset.c:582
bms_get_singleton_member
bool bms_get_singleton_member(const Bitmapset *a, int *member)
Definition: bitmapset.c:715
bms_join
Bitmapset * bms_join(Bitmapset *a, Bitmapset *b)
Definition: bitmapset.c:1230
bms_copy
Bitmapset * bms_copy(const Bitmapset *a)
Definition: bitmapset.c:122
bms_is_empty
#define bms_is_empty(a)
Definition: bitmapset.h:118
BMS_MULTIPLE
@ BMS_MULTIPLE
Definition: bitmapset.h:73
Min
#define Min(x, y)
Definition: c.h:975
Max
#define Max(x, y)
Definition: c.h:969
int32
int32_t int32
Definition: c.h:498
unlikely
#define unlikely(x)
Definition: c.h:347
uint32
uint32_t uint32
Definition: c.h:502
Index
unsigned int Index
Definition: c.h:585
OidIsValid
#define OidIsValid(objectId)
Definition: c.h:746
contain_agg_clause
bool contain_agg_clause(Node *clause)
Definition: clauses.c:179
contain_window_function
bool contain_window_function(Node *clause)
Definition: clauses.c:216
is_parallel_safe
bool is_parallel_safe(PlannerInfo *root, Node *node)
Definition: clauses.c:754
contain_volatile_functions
bool contain_volatile_functions(Node *clause)
Definition: clauses.c:539
COMPARE_EQ
@ COMPARE_EQ
Definition: cmptype.h:36
ERROR
#define ERROR
Definition: elog.h:39
elog
#define elog(elevel,...)
Definition: elog.h:225
equal
bool equal(const void *a, const void *b)
Definition: equalfuncs.c:223
rebuild_eclass_attr_needed
void rebuild_eclass_attr_needed(PlannerInfo *root)
Definition: equivclass.c:2574
get_eclass_for_sort_expr
EquivalenceClass * get_eclass_for_sort_expr(PlannerInfo *root, Expr *expr, List *opfamilies, Oid opcintype, Oid collation, Index sortref, Relids rel, bool create_it)
Definition: equivclass.c:736
add_child_rel_equivalences
void add_child_rel_equivalences(PlannerInfo *root, AppendRelInfo *appinfo, RelOptInfo *parent_rel, RelOptInfo *child_rel)
Definition: equivclass.c:2833
is_redundant_with_indexclauses
bool is_redundant_with_indexclauses(RestrictInfo *rinfo, List *indexclauses)
Definition: equivclass.c:3577
generate_base_implied_equalities
void generate_base_implied_equalities(PlannerInfo *root)
Definition: equivclass.c:1188
exprs_known_equal
bool exprs_known_equal(PlannerInfo *root, Node *item1, Node *item2, Oid opfamily)
Definition: equivclass.c:2648
generate_join_implied_equalities_normal
static List * generate_join_implied_equalities_normal(PlannerInfo *root, EquivalenceClass *ec, Relids join_relids, Relids outer_relids, Relids inner_relids)
Definition: equivclass.c:1721
ec_search_derived_clause_for_ems
static RestrictInfo * ec_search_derived_clause_for_ems(PlannerInfo *root, EquivalenceClass *ec, EquivalenceMember *leftem, EquivalenceMember *rightem, EquivalenceClass *parent_ec)
Definition: equivclass.c:3893
ec_build_derives_hash
static void ec_build_derives_hash(PlannerInfo *root, EquivalenceClass *ec)
Definition: equivclass.c:3673
canonicalize_ec_expression
Expr * canonicalize_ec_expression(Expr *expr, Oid req_type, Oid req_collation)
Definition: equivclass.c:545
find_ec_member_matching_expr
EquivalenceMember * find_ec_member_matching_expr(EquivalenceClass *ec, Expr *expr, Relids relids)
Definition: equivclass.c:916
ec_add_clause_to_derives_hash
static void ec_add_clause_to_derives_hash(EquivalenceClass *ec, RestrictInfo *rinfo)
Definition: equivclass.c:3789
find_join_domain
static JoinDomain * find_join_domain(PlannerInfo *root, Relids relids)
Definition: equivclass.c:2617
relation_can_be_sorted_early
bool relation_can_be_sorted_early(PlannerInfo *root, RelOptInfo *rel, EquivalenceClass *ec, bool require_parallel_safe)
Definition: equivclass.c:1077
setup_eclass_member_iterator
void setup_eclass_member_iterator(EquivalenceMemberIterator *it, EquivalenceClass *ec, Relids child_relids)
Definition: equivclass.c:3156
generate_base_implied_equalities_broken
static void generate_base_implied_equalities_broken(PlannerInfo *root, EquivalenceClass *ec)
Definition: equivclass.c:1487
ec_clear_derived_clauses
void ec_clear_derived_clauses(EquivalenceClass *ec)
Definition: equivclass.c:3831
ec_add_derived_clause
static void ec_add_derived_clause(EquivalenceClass *ec, RestrictInfo *clause)
Definition: equivclass.c:3703
process_equivalence
bool process_equivalence(PlannerInfo *root, RestrictInfo **p_restrictinfo, JoinDomain *jdomain)
Definition: equivclass.c:179
generate_implied_equalities_for_column
List * generate_implied_equalities_for_column(PlannerInfo *root, RelOptInfo *rel, ec_matches_callback_type callback, void *callback_arg, Relids prohibited_rels)
Definition: equivclass.c:3239
add_child_eq_member
static EquivalenceMember * add_child_eq_member(PlannerInfo *root, EquivalenceClass *ec, int ec_index, Expr *expr, Relids relids, JoinDomain *jdomain, EquivalenceMember *parent_em, Oid datatype, Index child_relid)
Definition: equivclass.c:661
EC_DERIVES_HASH_THRESHOLD
#define EC_DERIVES_HASH_THRESHOLD
Definition: equivclass.c:124
eclass_member_iterator_next
EquivalenceMember * eclass_member_iterator_next(EquivalenceMemberIterator *it)
Definition: equivclass.c:3175
have_relevant_eclass_joinclause
bool have_relevant_eclass_joinclause(PlannerInfo *root, RelOptInfo *rel1, RelOptInfo *rel2)
Definition: equivclass.c:3370
find_computable_ec_member
EquivalenceMember * find_computable_ec_member(PlannerInfo *root, EquivalenceClass *ec, List *exprs, Relids relids, bool require_parallel_safe)
Definition: equivclass.c:991
get_common_eclass_indexes
static Bitmapset * get_common_eclass_indexes(PlannerInfo *root, Relids relids1, Relids relids2)
Definition: equivclass.c:3647
generate_join_implied_equalities_for_ecs
List * generate_join_implied_equalities_for_ecs(PlannerInfo *root, List *eclasses, Relids join_relids, Relids outer_relids, RelOptInfo *inner_rel)
Definition: equivclass.c:1650
add_setop_child_rel_equivalences
void add_setop_child_rel_equivalences(PlannerInfo *root, RelOptInfo *child_rel, List *child_tlist, List *setop_pathkeys)
Definition: equivclass.c:3084
fill_ec_derives_key
static void fill_ec_derives_key(ECDerivesKey *key, EquivalenceMember *leftem, EquivalenceMember *rightem, EquivalenceClass *parent_ec)
Definition: equivclass.c:3755
reconsider_outer_join_clauses
void reconsider_outer_join_clauses(PlannerInfo *root)
Definition: equivclass.c:2135
eclass_useful_for_merging
bool eclass_useful_for_merging(PlannerInfo *root, EquivalenceClass *eclass, RelOptInfo *rel)
Definition: equivclass.c:3490
add_child_join_rel_equivalences
void add_child_join_rel_equivalences(PlannerInfo *root, int nappinfos, AppendRelInfo **appinfos, RelOptInfo *parent_joinrel, RelOptInfo *child_joinrel)
Definition: equivclass.c:2941
create_join_clause
static RestrictInfo * create_join_clause(PlannerInfo *root, EquivalenceClass *ec, Oid opno, EquivalenceMember *leftem, EquivalenceMember *rightem, EquivalenceClass *parent_ec)
Definition: equivclass.c:1983
ec_add_derived_clauses
static void ec_add_derived_clauses(EquivalenceClass *ec, List *clauses)
Definition: equivclass.c:3733
get_eclass_indexes_for_relids
static Bitmapset * get_eclass_indexes_for_relids(PlannerInfo *root, Relids relids)
Definition: equivclass.c:3613
is_redundant_derived_clause
bool is_redundant_derived_clause(RestrictInfo *rinfo, List *clauselist)
Definition: equivclass.c:3550
find_derived_clause_for_ec_member
RestrictInfo * find_derived_clause_for_ec_member(PlannerInfo *root, EquivalenceClass *ec, EquivalenceMember *em)
Definition: equivclass.c:2804
ec_search_clause_for_ems
static RestrictInfo * ec_search_clause_for_ems(PlannerInfo *root, EquivalenceClass *ec, EquivalenceMember *leftem, EquivalenceMember *rightem, EquivalenceClass *parent_ec)
Definition: equivclass.c:3855
generate_base_implied_equalities_no_const
static void generate_base_implied_equalities_no_const(PlannerInfo *root, EquivalenceClass *ec)
Definition: equivclass.c:1371
generate_base_implied_equalities_const
static void generate_base_implied_equalities_const(PlannerInfo *root, EquivalenceClass *ec)
Definition: equivclass.c:1272
select_equality_operator
static Oid select_equality_operator(EquivalenceClass *ec, Oid lefttype, Oid righttype)
Definition: equivclass.c:1948
match_eclasses_to_foreign_key_col
EquivalenceClass * match_eclasses_to_foreign_key_col(PlannerInfo *root, ForeignKeyOptInfo *fkinfo, int colno)
Definition: equivclass.c:2710
make_eq_member
static EquivalenceMember * make_eq_member(EquivalenceClass *ec, Expr *expr, Relids relids, JoinDomain *jdomain, EquivalenceMember *parent, Oid datatype)
Definition: equivclass.c:592
reconsider_outer_join_clause
static bool reconsider_outer_join_clause(PlannerInfo *root, OuterJoinClauseInfo *ojcinfo, bool outer_on_left)
Definition: equivclass.c:2257
generate_join_implied_equalities
List * generate_join_implied_equalities(PlannerInfo *root, Relids join_relids, Relids outer_relids, RelOptInfo *inner_rel, SpecialJoinInfo *sjinfo)
Definition: equivclass.c:1550
add_eq_member
static EquivalenceMember * add_eq_member(EquivalenceClass *ec, Expr *expr, Relids relids, JoinDomain *jdomain, Oid datatype)
Definition: equivclass.c:628
has_relevant_eclass_joinclause
bool has_relevant_eclass_joinclause(PlannerInfo *root, RelOptInfo *rel1)
Definition: equivclass.c:3446
reconsider_full_join_clause
static bool reconsider_full_join_clause(PlannerInfo *root, OuterJoinClauseInfo *ojcinfo)
Definition: equivclass.c:2384
generate_join_implied_equalities_broken
static List * generate_join_implied_equalities_broken(PlannerInfo *root, EquivalenceClass *ec, Relids nominal_join_relids, Relids outer_relids, Relids nominal_inner_relids, RelOptInfo *inner_rel)
Definition: equivclass.c:1899
palloc0_array
#define palloc0_array(type, count)
Definition: fe_memutils.h:77
Assert
Assert(PointerIsAligned(start, uint64))
distribute_restrictinfo_to_rels
void distribute_restrictinfo_to_rels(PlannerInfo *root, RestrictInfo *restrictinfo)
Definition: initsplan.c:3227
build_implied_join_equality
RestrictInfo * build_implied_join_equality(PlannerInfo *root, Oid opno, Oid collation, Expr *item1, Expr *item2, Relids qualscope, Index security_level)
Definition: initsplan.c:3456
add_vars_to_targetlist
void add_vars_to_targetlist(PlannerInfo *root, List *vars, Relids where_needed)
Definition: initsplan.c:282
process_implied_equality
RestrictInfo * process_implied_equality(PlannerInfo *root, Oid opno, Oid collation, Expr *item1, Expr *item2, Relids qualscope, Index security_level, bool both_const)
Definition: initsplan.c:3312
add_vars_to_attr_needed
void add_vars_to_attr_needed(PlannerInfo *root, List *vars, Relids where_needed)
Definition: initsplan.c:353
i
int i
Definition: isn.c:77
if
if(TABLE==NULL||TABLE_index==NULL)
Definition: isn.c:81
add_outer_joins_to_relids
Relids add_outer_joins_to_relids(PlannerInfo *root, Relids input_relids, SpecialJoinInfo *sjinfo, List **pushed_down_joins)
Definition: joinrels.c:802
lappend
List * lappend(List *list, void *datum)
Definition: list.c:339
list_delete_nth_cell
List * list_delete_nth_cell(List *list, int n)
Definition: list.c:767
list_concat
List * list_concat(List *list1, const List *list2)
Definition: list.c:561
list_copy
List * list_copy(const List *oldlist)
Definition: list.c:1573
list_free
void list_free(List *list)
Definition: list.c:1546
list_member_oid
bool list_member_oid(const List *list, Oid datum)
Definition: list.c:722
list_member
bool list_member(const List *list, const void *datum)
Definition: list.c:661
get_opfamily_member_for_cmptype
Oid get_opfamily_member_for_cmptype(Oid opfamily, Oid lefttype, Oid righttype, CompareType cmptype)
Definition: lsyscache.c:196
op_hashjoinable
bool op_hashjoinable(Oid opno, Oid inputtype)
Definition: lsyscache.c:1577
get_opcode
RegProcedure get_opcode(Oid opno)
Definition: lsyscache.c:1425
func_strict
bool func_strict(Oid funcid)
Definition: lsyscache.c:1901
get_func_leakproof
bool get_func_leakproof(Oid funcid)
Definition: lsyscache.c:1977
get_mergejoin_opfamilies
List * get_mergejoin_opfamilies(Oid opno)
Definition: lsyscache.c:434
op_input_types
void op_input_types(Oid opno, Oid *lefttype, Oid *righttype)
Definition: lsyscache.c:1498
makeBoolConst
Node * makeBoolConst(bool value, bool isnull)
Definition: makefuncs.c:408
pfree
void pfree(void *pointer)
Definition: mcxt.c:1528
palloc0
void * palloc0(Size size)
Definition: mcxt.c:1351
exprType
Oid exprType(const Node *expr)
Definition: nodeFuncs.c:42
exprTypmod
int32 exprTypmod(const Node *expr)
Definition: nodeFuncs.c:301
exprCollation
Oid exprCollation(const Node *expr)
Definition: nodeFuncs.c:821
applyRelabelType
Node * applyRelabelType(Node *arg, Oid rtype, int32 rtypmod, Oid rcollid, CoercionForm rformat, int rlocation, bool overwrite_ok)
Definition: nodeFuncs.c:636
expression_returns_set
bool expression_returns_set(Node *clause)
Definition: nodeFuncs.c:763
set_opfuncid
void set_opfuncid(OpExpr *opexpr)
Definition: nodeFuncs.c:1872
get_rightop
static Node * get_rightop(const void *clause)
Definition: nodeFuncs.h:95
is_opclause
static bool is_opclause(const void *clause)
Definition: nodeFuncs.h:76
get_leftop
static Node * get_leftop(const void *clause)
Definition: nodeFuncs.h:83
IsA
#define IsA(nodeptr, _type_)
Definition: nodes.h:164
copyObject
#define copyObject(obj)
Definition: nodes.h:230
makeNode
#define makeNode(_type_)
Definition: nodes.h:161
PVC_RECURSE_AGGREGATES
#define PVC_RECURSE_AGGREGATES
Definition: optimizer.h:193
PVC_RECURSE_WINDOWFUNCS
#define PVC_RECURSE_WINDOWFUNCS
Definition: optimizer.h:195
PVC_INCLUDE_WINDOWFUNCS
#define PVC_INCLUDE_WINDOWFUNCS
Definition: optimizer.h:194
PVC_INCLUDE_PLACEHOLDERS
#define PVC_INCLUDE_PLACEHOLDERS
Definition: optimizer.h:196
PVC_INCLUDE_CONVERTROWTYPES
#define PVC_INCLUDE_CONVERTROWTYPES
Definition: optimizer.h:198
PVC_INCLUDE_AGGREGATES
#define PVC_INCLUDE_AGGREGATES
Definition: optimizer.h:192
MemoryContextSwitchTo
static MemoryContext MemoryContextSwitchTo(MemoryContext context)
Definition: palloc.h:124
repalloc0_array
#define repalloc0_array(pointer, type, oldcount, count)
Definition: palloc.h:109
IS_SIMPLE_REL
#define IS_SIMPLE_REL(rel)
Definition: pathnodes.h:863
IS_JOIN_REL
#define IS_JOIN_REL(rel)
Definition: pathnodes.h:868
RELOPT_BASEREL
@ RELOPT_BASEREL
Definition: pathnodes.h:851
RELOPT_OTHER_MEMBER_REL
@ RELOPT_OTHER_MEMBER_REL
Definition: pathnodes.h:853
RELOPT_JOINREL
@ RELOPT_JOINREL
Definition: pathnodes.h:852
RELOPT_OTHER_JOINREL
@ RELOPT_OTHER_JOINREL
Definition: pathnodes.h:854
IS_OTHER_REL
#define IS_OTHER_REL(rel)
Definition: pathnodes.h:878
ec_matches_callback_type
bool(* ec_matches_callback_type)(PlannerInfo *root, RelOptInfo *rel, EquivalenceClass *ec, EquivalenceMember *em, void *arg)
Definition: paths.h:122
while
while(p+4<=pend)
Definition: pg_crc32c_sse42.c:58
lfirst
#define lfirst(lc)
Definition: pg_list.h:172
lfirst_node
#define lfirst_node(type, lc)
Definition: pg_list.h:176
list_length
static int list_length(const List *l)
Definition: pg_list.h:152
linitial_node
#define linitial_node(type, l)
Definition: pg_list.h:181
NIL
#define NIL
Definition: pg_list.h:68
foreach_current_index
#define foreach_current_index(var_or_cell)
Definition: pg_list.h:403
foreach_delete_current
#define foreach_delete_current(lst, var_or_cell)
Definition: pg_list.h:391
list_make1
#define list_make1(x1)
Definition: pg_list.h:212
list_nth
static void * list_nth(const List *list, int n)
Definition: pg_list.h:299
linitial
#define linitial(l)
Definition: pg_list.h:178
lsecond
#define lsecond(l)
Definition: pg_list.h:183
foreach_node
#define foreach_node(type, var, lst)
Definition: pg_list.h:496
list_head
static ListCell * list_head(const List *l)
Definition: pg_list.h:128
lnext
static ListCell * lnext(const List *l, const ListCell *c)
Definition: pg_list.h:343
lfirst_oid
#define lfirst_oid(lc)
Definition: pg_list.h:174
pg_type.h
InvalidOid
#define InvalidOid
Definition: postgres_ext.h:35
Oid
unsigned int Oid
Definition: postgres_ext.h:30
COERCE_IMPLICIT_CAST
@ COERCE_IMPLICIT_CAST
Definition: primnodes.h:753
IS_NOT_NULL
@ IS_NOT_NULL
Definition: primnodes.h:1957
root
tree ctl root
Definition: radixtree.h:1857
eclass
static struct cvec * eclass(struct vars *v, chr c, int cases)
Definition: regc_locale.c:500
find_childrel_parents
Relids find_childrel_parents(PlannerInfo *root, RelOptInfo *rel)
Definition: relnode.c:1509
make_restrictinfo
RestrictInfo * make_restrictinfo(PlannerInfo *root, Expr *clause, bool is_pushed_down, bool has_clone, bool is_clone, bool pseudoconstant, Index security_level, Relids required_relids, Relids incompatible_relids, Relids outer_relids)
Definition: restrictinfo.c:52
remove_nulling_relids
Node * remove_nulling_relids(Node *node, const Bitmapset *removable_relids, const Bitmapset *except_relids)
Definition: rewriteManip.c:1331
CoalesceExpr::args
List * args
Definition: primnodes.h:1497
ECDerivesEntry::rinfo
RestrictInfo * rinfo
Definition: equivclass.c:120
ECDerivesEntry::key
ECDerivesKey key
Definition: equivclass.c:119
ECDerivesKey::parent_ec
EquivalenceClass * parent_ec
Definition: equivclass.c:112
ECDerivesKey::em1
EquivalenceMember * em1
Definition: equivclass.c:110
ECDerivesKey::em2
EquivalenceMember * em2
Definition: equivclass.c:111
EquivalenceClass::ec_min_security
Index ec_min_security
Definition: pathnodes.h:1463
EquivalenceClass::ec_opfamilies
List * ec_opfamilies
Definition: pathnodes.h:1447
EquivalenceClass::ec_childmembers_size
int ec_childmembers_size
Definition: pathnodes.h:1449
EquivalenceClass::ec_childmembers
List ** ec_childmembers
Definition: pathnodes.h:1451
EquivalenceClass::ec_merged
struct EquivalenceClass * ec_merged
Definition: pathnodes.h:1465
EquivalenceClass::ec_derives_hash
struct derives_hash * ec_derives_hash
Definition: pathnodes.h:1454
EquivalenceClass::ec_max_security
Index ec_max_security
Definition: pathnodes.h:1464
EquivalenceClass::ec_derives_list
List * ec_derives_list
Definition: pathnodes.h:1453
EquivalenceMemberIterator::ec
EquivalenceClass * ec
Definition: pathnodes.h:1569
EquivalenceMember::em_jdomain
JoinDomain * em_jdomain
Definition: pathnodes.h:1513
ForeignKeyOptInfo::eclass
struct EquivalenceClass * eclass[INDEX_MAX_KEYS]
Definition: pathnodes.h:1284
ForeignKeyOptInfo::fk_eclass_member
struct EquivalenceMember * fk_eclass_member[INDEX_MAX_KEYS]
Definition: pathnodes.h:1286
IndexClause::rinfo
struct RestrictInfo * rinfo
Definition: pathnodes.h:1892
JoinDomain::jd_relids
Relids jd_relids
Definition: pathnodes.h:1355
List
Definition: pg_list.h:54
Node
Definition: nodes.h:135
NullTest::nulltesttype
NullTestType nulltesttype
Definition: primnodes.h:1964
NullTest::location
ParseLoc location
Definition: primnodes.h:1967
NullTest::arg
Expr * arg
Definition: primnodes.h:1963
OuterJoinClauseInfo::rinfo
RestrictInfo * rinfo
Definition: pathnodes.h:3064
OuterJoinClauseInfo::sjinfo
SpecialJoinInfo * sjinfo
Definition: pathnodes.h:3065
PathTarget::exprs
List * exprs
Definition: pathnodes.h:1666
RelOptInfo::relids
Relids relids
Definition: pathnodes.h:895
RelOptInfo::reltarget
struct PathTarget * reltarget
Definition: pathnodes.h:917
RelOptInfo::relid
Index relid
Definition: pathnodes.h:942
RelOptInfo::top_parent_relids
Relids top_parent_relids
Definition: pathnodes.h:1033
RelOptInfo::reloptkind
RelOptKind reloptkind
Definition: pathnodes.h:889
RelOptInfo::eclass_indexes
Bitmapset * eclass_indexes
Definition: pathnodes.h:976
RelOptInfo::has_eclass_joins
bool has_eclass_joins
Definition: pathnodes.h:1017
RestrictInfo::is_pushed_down
bool is_pushed_down
Definition: pathnodes.h:2708
RestrictInfo::security_level
Index security_level
Definition: pathnodes.h:2727
RestrictInfo::required_relids
Relids required_relids
Definition: pathnodes.h:2736
RestrictInfo::rinfo_serial
int rinfo_serial
Definition: pathnodes.h:2777
RestrictInfo::outer_relids
Relids outer_relids
Definition: pathnodes.h:2742
RestrictInfo::incompatible_relids
Relids incompatible_relids
Definition: pathnodes.h:2739
RestrictInfo::clause
Expr * clause
Definition: pathnodes.h:2705
RestrictInfo::has_clone
bool has_clone
Definition: pathnodes.h:2717
SpecialJoinInfo::syn_lefthand
Relids syn_lefthand
Definition: pathnodes.h:3037
SpecialJoinInfo::syn_righthand
Relids syn_righthand
Definition: pathnodes.h:3038
TargetEntry::expr
Expr * expr
Definition: primnodes.h:2219
Var
Definition: primnodes.h:262
Var::varattno
AttrNumber varattno
Definition: primnodes.h:274
Var::varno
int varno
Definition: primnodes.h:269
vars
Definition: regcomp.c:282
callback
static void callback(struct sockaddr *addr, struct sockaddr *mask, void *unused)
Definition: test_ifaddrs.c:46
pull_varnos
Relids pull_varnos(PlannerInfo *root, Node *node)
Definition: var.c:114
pull_var_clause
List * pull_var_clause(Node *node, int flags)
Definition: var.c:653