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tidpath.c File Reference
#include "postgres.h"
#include "access/sysattr.h"
#include "catalog/pg_operator.h"
#include "catalog/pg_type.h"
#include "nodes/nodeFuncs.h"
#include "optimizer/cost.h"
#include "optimizer/optimizer.h"
#include "optimizer/pathnode.h"
#include "optimizer/paths.h"
#include "optimizer/restrictinfo.h"
Include dependency graph for tidpath.c:

Go to the source code of this file.

Functions

static bool IsCTIDVar (Var *var, RelOptInfo *rel)
 
static bool IsBinaryTidClause (RestrictInfo *rinfo, RelOptInfo *rel)
 
static bool IsTidEqualClause (RestrictInfo *rinfo, RelOptInfo *rel)
 
static bool IsTidRangeClause (RestrictInfo *rinfo, RelOptInfo *rel)
 
static bool IsTidEqualAnyClause (PlannerInfo *root, RestrictInfo *rinfo, RelOptInfo *rel)
 
static bool IsCurrentOfClause (RestrictInfo *rinfo, RelOptInfo *rel)
 
static bool RestrictInfoIsTidQual (PlannerInfo *root, RestrictInfo *rinfo, RelOptInfo *rel)
 
static ListTidQualFromRestrictInfoList (PlannerInfo *root, List *rlist, RelOptInfo *rel, bool *isCurrentOf)
 
static ListTidRangeQualFromRestrictInfoList (List *rlist, RelOptInfo *rel)
 
static void BuildParameterizedTidPaths (PlannerInfo *root, RelOptInfo *rel, List *clauses)
 
static bool ec_member_matches_ctid (PlannerInfo *root, RelOptInfo *rel, EquivalenceClass *ec, EquivalenceMember *em, void *arg)
 
bool create_tidscan_paths (PlannerInfo *root, RelOptInfo *rel)
 

Function Documentation

◆ BuildParameterizedTidPaths()

static void BuildParameterizedTidPaths ( PlannerInfo root,
RelOptInfo rel,
List clauses 
)
static

Definition at line 426 of file tidpath.c.

427{
428 ListCell *l;
429
430 foreach(l, clauses)
431 {
433 List *tidquals;
434 Relids required_outer;
435
436 /*
437 * Validate whether each clause is actually usable; we must check this
438 * even when examining clauses generated from an EquivalenceClass,
439 * since they might not satisfy the restriction on not having Vars of
440 * our rel on the other side, or somebody might've built an operator
441 * class that accepts type "tid" but has other operators in it.
442 *
443 * We currently consider only TidEqual join clauses. In principle we
444 * might find a suitable ScalarArrayOpExpr in the rel's joininfo list,
445 * but it seems unlikely to be worth expending the cycles to check.
446 * And we definitely won't find a CurrentOfExpr here. Hence, we don't
447 * use RestrictInfoIsTidQual; but this must match that function
448 * otherwise.
449 */
450 if (rinfo->pseudoconstant ||
452 !IsTidEqualClause(rinfo, rel))
453 continue;
454
455 /*
456 * Check if clause can be moved to this rel; this is probably
457 * redundant when considering EC-derived clauses, but we must check it
458 * for "loose" join clauses.
459 */
460 if (!join_clause_is_movable_to(rinfo, rel))
461 continue;
462
463 /* OK, make list of clauses for this path */
464 tidquals = list_make1(rinfo);
465
466 /* Compute required outer rels for this path */
467 required_outer = bms_union(rinfo->required_relids, rel->lateral_relids);
468 required_outer = bms_del_member(required_outer, rel->relid);
469
470 add_path(rel, (Path *) create_tidscan_path(root, rel, tidquals,
471 required_outer));
472 }
473}
Bitmapset * bms_del_member(Bitmapset *a, int x)
Definition: bitmapset.c:868
Bitmapset * bms_union(const Bitmapset *a, const Bitmapset *b)
Definition: bitmapset.c:251
TidPath * create_tidscan_path(PlannerInfo *root, RelOptInfo *rel, List *tidquals, Relids required_outer)
Definition: pathnode.c:1235
void add_path(RelOptInfo *parent_rel, Path *new_path)
Definition: pathnode.c:461
#define lfirst_node(type, lc)
Definition: pg_list.h:176
#define list_make1(x1)
Definition: pg_list.h:212
tree ctl root
Definition: radixtree.h:1857
bool restriction_is_securely_promotable(RestrictInfo *restrictinfo, RelOptInfo *rel)
Definition: restrictinfo.c:422
bool join_clause_is_movable_to(RestrictInfo *rinfo, RelOptInfo *baserel)
Definition: restrictinfo.c:575
Definition: pg_list.h:54
Index relid
Definition: pathnodes.h:918
Relids lateral_relids
Definition: pathnodes.h:913
Relids required_relids
Definition: pathnodes.h:2606
static bool IsTidEqualClause(RestrictInfo *rinfo, RelOptInfo *rel)
Definition: tidpath.c:131

References add_path(), bms_del_member(), bms_union(), create_tidscan_path(), IsTidEqualClause(), join_clause_is_movable_to(), RelOptInfo::lateral_relids, lfirst_node, list_make1, RelOptInfo::relid, RestrictInfo::required_relids, restriction_is_securely_promotable(), and root.

Referenced by create_tidscan_paths().

◆ create_tidscan_paths()

bool create_tidscan_paths ( PlannerInfo root,
RelOptInfo rel 
)

Definition at line 498 of file tidpath.c.

499{
500 List *tidquals;
501 List *tidrangequals;
502 bool isCurrentOf;
503
504 /*
505 * If any suitable quals exist in the rel's baserestrict list, generate a
506 * plain (unparameterized) TidPath with them.
507 *
508 * We skip this when enable_tidscan = false, except when the qual is
509 * CurrentOfExpr. In that case, a TID scan is the only correct path.
510 */
512 &isCurrentOf);
513
514 if (tidquals != NIL && (enable_tidscan || isCurrentOf))
515 {
516 /*
517 * This path uses no join clauses, but it could still have required
518 * parameterization due to LATERAL refs in its tlist.
519 */
520 Relids required_outer = rel->lateral_relids;
521
522 add_path(rel, (Path *) create_tidscan_path(root, rel, tidquals,
523 required_outer));
524
525 /*
526 * When the qual is CurrentOfExpr, the path that we just added is the
527 * only one the executor can handle, so we should return before adding
528 * any others. Returning true lets the caller know not to add any
529 * others, either.
530 */
531 if (isCurrentOf)
532 return true;
533 }
534
535 /* Skip the rest if TID scans are disabled. */
536 if (!enable_tidscan)
537 return false;
538
539 /*
540 * If there are range quals in the baserestrict list, generate a
541 * TidRangePath.
542 */
544 rel);
545
546 if (tidrangequals != NIL)
547 {
548 /*
549 * This path uses no join clauses, but it could still have required
550 * parameterization due to LATERAL refs in its tlist.
551 */
552 Relids required_outer = rel->lateral_relids;
553
555 tidrangequals,
556 required_outer));
557 }
558
559 /*
560 * Try to generate parameterized TidPaths using equality clauses extracted
561 * from EquivalenceClasses. (This is important since simple "t1.ctid =
562 * t2.ctid" clauses will turn into ECs.)
563 */
564 if (rel->has_eclass_joins)
565 {
566 List *clauses;
567
568 /* Generate clauses, skipping any that join to lateral_referencers */
570 rel,
572 NULL,
574
575 /* Generate a path for each usable join clause */
576 BuildParameterizedTidPaths(root, rel, clauses);
577 }
578
579 /*
580 * Also consider parameterized TidPaths using "loose" join quals. Quals
581 * of the form "t1.ctid = t2.ctid" would turn into these if they are outer
582 * join quals, for example.
583 */
585
586 return false;
587}
bool enable_tidscan
Definition: costsize.c:149
List * generate_implied_equalities_for_column(PlannerInfo *root, RelOptInfo *rel, ec_matches_callback_type callback, void *callback_arg, Relids prohibited_rels)
Definition: equivclass.c:3014
TidRangePath * create_tidrangescan_path(PlannerInfo *root, RelOptInfo *rel, List *tidrangequals, Relids required_outer)
Definition: pathnode.c:1264
#define NIL
Definition: pg_list.h:68
List * baserestrictinfo
Definition: pathnodes.h:985
List * joininfo
Definition: pathnodes.h:991
Relids lateral_referencers
Definition: pathnodes.h:942
bool has_eclass_joins
Definition: pathnodes.h:993
static List * TidQualFromRestrictInfoList(PlannerInfo *root, List *rlist, RelOptInfo *rel, bool *isCurrentOf)
Definition: tidpath.c:281
static void BuildParameterizedTidPaths(PlannerInfo *root, RelOptInfo *rel, List *clauses)
Definition: tidpath.c:426
static List * TidRangeQualFromRestrictInfoList(List *rlist, RelOptInfo *rel)
Definition: tidpath.c:398
static bool ec_member_matches_ctid(PlannerInfo *root, RelOptInfo *rel, EquivalenceClass *ec, EquivalenceMember *em, void *arg)
Definition: tidpath.c:481

References add_path(), RelOptInfo::baserestrictinfo, BuildParameterizedTidPaths(), create_tidrangescan_path(), create_tidscan_path(), ec_member_matches_ctid(), enable_tidscan, generate_implied_equalities_for_column(), RelOptInfo::has_eclass_joins, RelOptInfo::joininfo, RelOptInfo::lateral_referencers, RelOptInfo::lateral_relids, NIL, root, TidQualFromRestrictInfoList(), and TidRangeQualFromRestrictInfoList().

Referenced by set_plain_rel_pathlist().

◆ ec_member_matches_ctid()

static bool ec_member_matches_ctid ( PlannerInfo root,
RelOptInfo rel,
EquivalenceClass ec,
EquivalenceMember em,
void *  arg 
)
static

Definition at line 481 of file tidpath.c.

484{
485 if (em->em_expr && IsA(em->em_expr, Var) &&
486 IsCTIDVar((Var *) em->em_expr, rel))
487 return true;
488 return false;
489}
#define IsA(nodeptr, _type_)
Definition: nodes.h:158
Definition: primnodes.h:261
static bool IsCTIDVar(Var *var, RelOptInfo *rel)
Definition: tidpath.c:56

References EquivalenceMember::em_expr, IsA, and IsCTIDVar().

Referenced by create_tidscan_paths().

◆ IsBinaryTidClause()

static bool IsBinaryTidClause ( RestrictInfo rinfo,
RelOptInfo rel 
)
static

Definition at line 77 of file tidpath.c.

78{
79 OpExpr *node;
80 Node *arg1,
81 *arg2,
82 *other;
83 Relids other_relids;
84
85 /* Must be an OpExpr */
86 if (!is_opclause(rinfo->clause))
87 return false;
88 node = (OpExpr *) rinfo->clause;
89
90 /* OpExpr must have two arguments */
91 if (list_length(node->args) != 2)
92 return false;
93 arg1 = linitial(node->args);
94 arg2 = lsecond(node->args);
95
96 /* Look for CTID as either argument */
97 other = NULL;
98 other_relids = NULL;
99 if (arg1 && IsA(arg1, Var) &&
100 IsCTIDVar((Var *) arg1, rel))
101 {
102 other = arg2;
103 other_relids = rinfo->right_relids;
104 }
105 if (!other && arg2 && IsA(arg2, Var) &&
106 IsCTIDVar((Var *) arg2, rel))
107 {
108 other = arg1;
109 other_relids = rinfo->left_relids;
110 }
111 if (!other)
112 return false;
113
114 /* The other argument must be a pseudoconstant */
115 if (bms_is_member(rel->relid, other_relids) ||
117 return false;
118
119 return true; /* success */
120}
bool bms_is_member(int x, const Bitmapset *a)
Definition: bitmapset.c:510
bool contain_volatile_functions(Node *clause)
Definition: clauses.c:537
if(TABLE==NULL||TABLE_index==NULL)
Definition: isn.c:76
static bool is_opclause(const void *clause)
Definition: nodeFuncs.h:76
static int list_length(const List *l)
Definition: pg_list.h:152
#define linitial(l)
Definition: pg_list.h:178
#define lsecond(l)
Definition: pg_list.h:183
Definition: nodes.h:129
List * args
Definition: primnodes.h:852
Expr * clause
Definition: pathnodes.h:2575

References OpExpr::args, bms_is_member(), RestrictInfo::clause, contain_volatile_functions(), if(), is_opclause(), IsA, IsCTIDVar(), linitial, list_length(), lsecond, and RelOptInfo::relid.

Referenced by IsTidEqualClause(), and IsTidRangeClause().

◆ IsCTIDVar()

static bool IsCTIDVar ( Var var,
RelOptInfo rel 
)
inlinestatic

Definition at line 56 of file tidpath.c.

57{
58 /* The vartype check is strictly paranoia */
60 var->vartype == TIDOID &&
61 var->varno == rel->relid &&
62 var->varnullingrels == NULL &&
63 var->varlevelsup == 0)
64 return true;
65 return false;
66}
AttrNumber varattno
Definition: primnodes.h:273
int varno
Definition: primnodes.h:268
Index varlevelsup
Definition: primnodes.h:293
#define SelfItemPointerAttributeNumber
Definition: sysattr.h:21

References RelOptInfo::relid, SelfItemPointerAttributeNumber, Var::varattno, Var::varlevelsup, and Var::varno.

Referenced by ec_member_matches_ctid(), IsBinaryTidClause(), and IsTidEqualAnyClause().

◆ IsCurrentOfClause()

static bool IsCurrentOfClause ( RestrictInfo rinfo,
RelOptInfo rel 
)
static

Definition at line 212 of file tidpath.c.

213{
214 CurrentOfExpr *node;
215
216 /* Must be a CurrentOfExpr */
217 if (!(rinfo->clause && IsA(rinfo->clause, CurrentOfExpr)))
218 return false;
219 node = (CurrentOfExpr *) rinfo->clause;
220
221 /* If it references this rel, we're good */
222 if (node->cvarno == rel->relid)
223 return true;
224
225 return false;
226}

References RestrictInfo::clause, CurrentOfExpr::cvarno, if(), IsA, and RelOptInfo::relid.

Referenced by RestrictInfoIsTidQual(), and TidQualFromRestrictInfoList().

◆ IsTidEqualAnyClause()

static bool IsTidEqualAnyClause ( PlannerInfo root,
RestrictInfo rinfo,
RelOptInfo rel 
)
static

Definition at line 173 of file tidpath.c.

174{
175 ScalarArrayOpExpr *node;
176 Node *arg1,
177 *arg2;
178
179 /* Must be a ScalarArrayOpExpr */
180 if (!(rinfo->clause && IsA(rinfo->clause, ScalarArrayOpExpr)))
181 return false;
182 node = (ScalarArrayOpExpr *) rinfo->clause;
183
184 /* Operator must be tideq */
185 if (node->opno != TIDEqualOperator)
186 return false;
187 if (!node->useOr)
188 return false;
189 Assert(list_length(node->args) == 2);
190 arg1 = linitial(node->args);
191 arg2 = lsecond(node->args);
192
193 /* CTID must be first argument */
194 if (arg1 && IsA(arg1, Var) &&
195 IsCTIDVar((Var *) arg1, rel))
196 {
197 /* The other argument must be a pseudoconstant */
198 if (bms_is_member(rel->relid, pull_varnos(root, arg2)) ||
200 return false;
201
202 return true; /* success */
203 }
204
205 return false;
206}
#define Assert(condition)
Definition: c.h:815
Relids pull_varnos(PlannerInfo *root, Node *node)
Definition: var.c:114

References ScalarArrayOpExpr::args, Assert, bms_is_member(), RestrictInfo::clause, contain_volatile_functions(), if(), IsA, IsCTIDVar(), linitial, list_length(), lsecond, ScalarArrayOpExpr::opno, pull_varnos(), RelOptInfo::relid, root, and ScalarArrayOpExpr::useOr.

Referenced by RestrictInfoIsTidQual().

◆ IsTidEqualClause()

static bool IsTidEqualClause ( RestrictInfo rinfo,
RelOptInfo rel 
)
static

Definition at line 131 of file tidpath.c.

132{
133 if (!IsBinaryTidClause(rinfo, rel))
134 return false;
135
136 if (((OpExpr *) rinfo->clause)->opno == TIDEqualOperator)
137 return true;
138
139 return false;
140}
static bool IsBinaryTidClause(RestrictInfo *rinfo, RelOptInfo *rel)
Definition: tidpath.c:77

References RestrictInfo::clause, and IsBinaryTidClause().

Referenced by BuildParameterizedTidPaths(), and RestrictInfoIsTidQual().

◆ IsTidRangeClause()

static bool IsTidRangeClause ( RestrictInfo rinfo,
RelOptInfo rel 
)
static

Definition at line 151 of file tidpath.c.

152{
153 Oid opno;
154
155 if (!IsBinaryTidClause(rinfo, rel))
156 return false;
157 opno = ((OpExpr *) rinfo->clause)->opno;
158
159 if (opno == TIDLessOperator || opno == TIDLessEqOperator ||
160 opno == TIDGreaterOperator || opno == TIDGreaterEqOperator)
161 return true;
162
163 return false;
164}
unsigned int Oid
Definition: postgres_ext.h:32

References RestrictInfo::clause, and IsBinaryTidClause().

Referenced by TidRangeQualFromRestrictInfoList().

◆ RestrictInfoIsTidQual()

static bool RestrictInfoIsTidQual ( PlannerInfo root,
RestrictInfo rinfo,
RelOptInfo rel 
)
static

Definition at line 235 of file tidpath.c.

236{
237 /*
238 * We may ignore pseudoconstant clauses (they can't contain Vars, so could
239 * not match anyway).
240 */
241 if (rinfo->pseudoconstant)
242 return false;
243
244 /*
245 * If clause must wait till after some lower-security-level restriction
246 * clause, reject it.
247 */
248 if (!restriction_is_securely_promotable(rinfo, rel))
249 return false;
250
251 /*
252 * Check all base cases.
253 */
254 if (IsTidEqualClause(rinfo, rel) ||
255 IsTidEqualAnyClause(root, rinfo, rel) ||
256 IsCurrentOfClause(rinfo, rel))
257 return true;
258
259 return false;
260}
static bool IsCurrentOfClause(RestrictInfo *rinfo, RelOptInfo *rel)
Definition: tidpath.c:212
static bool IsTidEqualAnyClause(PlannerInfo *root, RestrictInfo *rinfo, RelOptInfo *rel)
Definition: tidpath.c:173

References IsCurrentOfClause(), IsTidEqualAnyClause(), IsTidEqualClause(), restriction_is_securely_promotable(), and root.

Referenced by TidQualFromRestrictInfoList().

◆ TidQualFromRestrictInfoList()

static List * TidQualFromRestrictInfoList ( PlannerInfo root,
List rlist,
RelOptInfo rel,
bool *  isCurrentOf 
)
static

Definition at line 281 of file tidpath.c.

283{
284 RestrictInfo *tidclause = NULL; /* best simple CTID qual so far */
285 List *orlist = NIL; /* best OR'ed CTID qual so far */
286 ListCell *l;
287
288 *isCurrentOf = false;
289
290 foreach(l, rlist)
291 {
293
294 if (restriction_is_or_clause(rinfo))
295 {
296 List *rlst = NIL;
297 ListCell *j;
298
299 /*
300 * We must be able to extract a CTID condition from every
301 * sub-clause of an OR, or we can't use it.
302 */
303 foreach(j, ((BoolExpr *) rinfo->orclause)->args)
304 {
305 Node *orarg = (Node *) lfirst(j);
306 List *sublist;
307
308 /* OR arguments should be ANDs or sub-RestrictInfos */
309 if (is_andclause(orarg))
310 {
311 List *andargs = ((BoolExpr *) orarg)->args;
312 bool sublistIsCurrentOf;
313
314 /* Recurse in case there are sub-ORs */
315 sublist = TidQualFromRestrictInfoList(root, andargs, rel,
316 &sublistIsCurrentOf);
317 if (sublistIsCurrentOf)
318 elog(ERROR, "IS CURRENT OF within OR clause");
319 }
320 else
321 {
322 RestrictInfo *ri = castNode(RestrictInfo, orarg);
323
325 if (RestrictInfoIsTidQual(root, ri, rel))
326 sublist = list_make1(ri);
327 else
328 sublist = NIL;
329 }
330
331 /*
332 * If nothing found in this arm, we can't do anything with
333 * this OR clause.
334 */
335 if (sublist == NIL)
336 {
337 rlst = NIL; /* forget anything we had */
338 break; /* out of loop over OR args */
339 }
340
341 /*
342 * OK, continue constructing implicitly-OR'ed result list.
343 */
344 rlst = list_concat(rlst, sublist);
345 }
346
347 if (rlst)
348 {
349 /*
350 * Accept the OR'ed list if it's the first one, or if it's
351 * shorter than the previous one.
352 */
353 if (orlist == NIL || list_length(rlst) < list_length(orlist))
354 orlist = rlst;
355 }
356 }
357 else
358 {
359 /* Not an OR clause, so handle base cases */
360 if (RestrictInfoIsTidQual(root, rinfo, rel))
361 {
362 /* We can stop immediately if it's a CurrentOfExpr */
363 if (IsCurrentOfClause(rinfo, rel))
364 {
365 *isCurrentOf = true;
366 return list_make1(rinfo);
367 }
368
369 /*
370 * Otherwise, remember the first non-OR CTID qual. We could
371 * try to apply some preference order if there's more than
372 * one, but such usage seems very unlikely, so don't bother.
373 */
374 if (tidclause == NULL)
375 tidclause = rinfo;
376 }
377 }
378 }
379
380 /*
381 * Prefer any singleton CTID qual to an OR'ed list. Again, it seems
382 * unlikely to be worth thinking harder than that.
383 */
384 if (tidclause)
385 return list_make1(tidclause);
386 return orlist;
387}
#define ERROR
Definition: elog.h:39
#define elog(elevel,...)
Definition: elog.h:225
int j
Definition: isn.c:73
List * list_concat(List *list1, const List *list2)
Definition: list.c:561
static bool is_andclause(const void *clause)
Definition: nodeFuncs.h:107
#define castNode(_type_, nodeptr)
Definition: nodes.h:176
#define lfirst(lc)
Definition: pg_list.h:172
bool restriction_is_or_clause(RestrictInfo *restrictinfo)
Definition: restrictinfo.c:407
static bool RestrictInfoIsTidQual(PlannerInfo *root, RestrictInfo *rinfo, RelOptInfo *rel)
Definition: tidpath.c:235

References Assert, castNode, elog, ERROR, is_andclause(), IsCurrentOfClause(), j, lfirst, lfirst_node, list_concat(), list_length(), list_make1, NIL, RestrictInfoIsTidQual(), restriction_is_or_clause(), root, and TidQualFromRestrictInfoList().

Referenced by create_tidscan_paths(), and TidQualFromRestrictInfoList().

◆ TidRangeQualFromRestrictInfoList()

static List * TidRangeQualFromRestrictInfoList ( List rlist,
RelOptInfo rel 
)
static

Definition at line 398 of file tidpath.c.

399{
400 List *rlst = NIL;
401 ListCell *l;
402
403 if ((rel->amflags & AMFLAG_HAS_TID_RANGE) == 0)
404 return NIL;
405
406 foreach(l, rlist)
407 {
409
410 if (IsTidRangeClause(rinfo, rel))
411 rlst = lappend(rlst, rinfo);
412 }
413
414 return rlst;
415}
List * lappend(List *list, void *datum)
Definition: list.c:339
#define AMFLAG_HAS_TID_RANGE
Definition: pathnodes.h:823
uint32 amflags
Definition: pathnodes.h:958
static bool IsTidRangeClause(RestrictInfo *rinfo, RelOptInfo *rel)
Definition: tidpath.c:151

References AMFLAG_HAS_TID_RANGE, RelOptInfo::amflags, IsTidRangeClause(), lappend(), lfirst_node, and NIL.

Referenced by create_tidscan_paths().