Line data Source code
1 : /*-------------------------------------------------------------------------
2 : *
3 : * indexam.c
4 : * general index access method routines
5 : *
6 : * Portions Copyright (c) 1996-2025, PostgreSQL Global Development Group
7 : * Portions Copyright (c) 1994, Regents of the University of California
8 : *
9 : *
10 : * IDENTIFICATION
11 : * src/backend/access/index/indexam.c
12 : *
13 : * INTERFACE ROUTINES
14 : * index_open - open an index relation by relation OID
15 : * index_close - close an index relation
16 : * index_beginscan - start a scan of an index with amgettuple
17 : * index_beginscan_bitmap - start a scan of an index with amgetbitmap
18 : * index_rescan - restart a scan of an index
19 : * index_endscan - end a scan
20 : * index_insert - insert an index tuple into a relation
21 : * index_markpos - mark a scan position
22 : * index_restrpos - restore a scan position
23 : * index_parallelscan_estimate - estimate shared memory for parallel scan
24 : * index_parallelscan_initialize - initialize parallel scan
25 : * index_parallelrescan - (re)start a parallel scan of an index
26 : * index_beginscan_parallel - join parallel index scan
27 : * index_getnext_tid - get the next TID from a scan
28 : * index_fetch_heap - get the scan's next heap tuple
29 : * index_getnext_slot - get the next tuple from a scan
30 : * index_getbitmap - get all tuples from a scan
31 : * index_bulk_delete - bulk deletion of index tuples
32 : * index_vacuum_cleanup - post-deletion cleanup of an index
33 : * index_can_return - does index support index-only scans?
34 : * index_getprocid - get a support procedure OID
35 : * index_getprocinfo - get a support procedure's lookup info
36 : *
37 : * NOTES
38 : * This file contains the index_ routines which used
39 : * to be a scattered collection of stuff in access/genam.
40 : *
41 : *-------------------------------------------------------------------------
42 : */
43 :
44 : #include "postgres.h"
45 :
46 : #include "access/amapi.h"
47 : #include "access/relation.h"
48 : #include "access/reloptions.h"
49 : #include "access/relscan.h"
50 : #include "access/tableam.h"
51 : #include "catalog/index.h"
52 : #include "catalog/pg_type.h"
53 : #include "nodes/execnodes.h"
54 : #include "pgstat.h"
55 : #include "storage/lmgr.h"
56 : #include "storage/predicate.h"
57 : #include "utils/ruleutils.h"
58 : #include "utils/snapmgr.h"
59 : #include "utils/syscache.h"
60 :
61 :
62 : /* ----------------------------------------------------------------
63 : * macros used in index_ routines
64 : *
65 : * Note: the ReindexIsProcessingIndex() check in RELATION_CHECKS is there
66 : * to check that we don't try to scan or do retail insertions into an index
67 : * that is currently being rebuilt or pending rebuild. This helps to catch
68 : * things that don't work when reindexing system catalogs, as well as prevent
69 : * user errors like index expressions that access their own tables. The check
70 : * doesn't prevent the actual rebuild because we don't use RELATION_CHECKS
71 : * when calling the index AM's ambuild routine, and there is no reason for
72 : * ambuild to call its subsidiary routines through this file.
73 : * ----------------------------------------------------------------
74 : */
75 : #define RELATION_CHECKS \
76 : do { \
77 : Assert(RelationIsValid(indexRelation)); \
78 : Assert(PointerIsValid(indexRelation->rd_indam)); \
79 : if (unlikely(ReindexIsProcessingIndex(RelationGetRelid(indexRelation)))) \
80 : ereport(ERROR, \
81 : (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), \
82 : errmsg("cannot access index \"%s\" while it is being reindexed", \
83 : RelationGetRelationName(indexRelation)))); \
84 : } while(0)
85 :
86 : #define SCAN_CHECKS \
87 : ( \
88 : AssertMacro(IndexScanIsValid(scan)), \
89 : AssertMacro(RelationIsValid(scan->indexRelation)), \
90 : AssertMacro(PointerIsValid(scan->indexRelation->rd_indam)) \
91 : )
92 :
93 : #define CHECK_REL_PROCEDURE(pname) \
94 : do { \
95 : if (indexRelation->rd_indam->pname == NULL) \
96 : elog(ERROR, "function \"%s\" is not defined for index \"%s\"", \
97 : CppAsString(pname), RelationGetRelationName(indexRelation)); \
98 : } while(0)
99 :
100 : #define CHECK_SCAN_PROCEDURE(pname) \
101 : do { \
102 : if (scan->indexRelation->rd_indam->pname == NULL) \
103 : elog(ERROR, "function \"%s\" is not defined for index \"%s\"", \
104 : CppAsString(pname), RelationGetRelationName(scan->indexRelation)); \
105 : } while(0)
106 :
107 : static IndexScanDesc index_beginscan_internal(Relation indexRelation,
108 : int nkeys, int norderbys, Snapshot snapshot,
109 : ParallelIndexScanDesc pscan, bool temp_snap);
110 : static inline void validate_relation_kind(Relation r);
111 :
112 :
113 : /* ----------------------------------------------------------------
114 : * index_ interface functions
115 : * ----------------------------------------------------------------
116 : */
117 :
118 : /* ----------------
119 : * index_open - open an index relation by relation OID
120 : *
121 : * If lockmode is not "NoLock", the specified kind of lock is
122 : * obtained on the index. (Generally, NoLock should only be
123 : * used if the caller knows it has some appropriate lock on the
124 : * index already.)
125 : *
126 : * An error is raised if the index does not exist.
127 : *
128 : * This is a convenience routine adapted for indexscan use.
129 : * Some callers may prefer to use relation_open directly.
130 : * ----------------
131 : */
132 : Relation
133 19542166 : index_open(Oid relationId, LOCKMODE lockmode)
134 : {
135 : Relation r;
136 :
137 19542166 : r = relation_open(relationId, lockmode);
138 :
139 19542156 : validate_relation_kind(r);
140 :
141 19542134 : return r;
142 : }
143 :
144 : /* ----------------
145 : * try_index_open - open an index relation by relation OID
146 : *
147 : * Same as index_open, except return NULL instead of failing
148 : * if the relation does not exist.
149 : * ----------------
150 : */
151 : Relation
152 2132 : try_index_open(Oid relationId, LOCKMODE lockmode)
153 : {
154 : Relation r;
155 :
156 2132 : r = try_relation_open(relationId, lockmode);
157 :
158 : /* leave if index does not exist */
159 2132 : if (!r)
160 0 : return NULL;
161 :
162 2132 : validate_relation_kind(r);
163 :
164 2132 : return r;
165 : }
166 :
167 : /* ----------------
168 : * index_close - close an index relation
169 : *
170 : * If lockmode is not "NoLock", we then release the specified lock.
171 : *
172 : * Note that it is often sensible to hold a lock beyond index_close;
173 : * in that case, the lock is released automatically at xact end.
174 : * ----------------
175 : */
176 : void
177 19577442 : index_close(Relation relation, LOCKMODE lockmode)
178 : {
179 19577442 : LockRelId relid = relation->rd_lockInfo.lockRelId;
180 :
181 : Assert(lockmode >= NoLock && lockmode < MAX_LOCKMODES);
182 :
183 : /* The relcache does the real work... */
184 19577442 : RelationClose(relation);
185 :
186 19577442 : if (lockmode != NoLock)
187 17970808 : UnlockRelationId(&relid, lockmode);
188 19577442 : }
189 :
190 : /* ----------------
191 : * validate_relation_kind - check the relation's kind
192 : *
193 : * Make sure relkind is an index or a partitioned index.
194 : * ----------------
195 : */
196 : static inline void
197 19544288 : validate_relation_kind(Relation r)
198 : {
199 19544288 : if (r->rd_rel->relkind != RELKIND_INDEX &&
200 11202 : r->rd_rel->relkind != RELKIND_PARTITIONED_INDEX)
201 22 : ereport(ERROR,
202 : (errcode(ERRCODE_WRONG_OBJECT_TYPE),
203 : errmsg("\"%s\" is not an index",
204 : RelationGetRelationName(r))));
205 19544266 : }
206 :
207 :
208 : /* ----------------
209 : * index_insert - insert an index tuple into a relation
210 : * ----------------
211 : */
212 : bool
213 8656072 : index_insert(Relation indexRelation,
214 : Datum *values,
215 : bool *isnull,
216 : ItemPointer heap_t_ctid,
217 : Relation heapRelation,
218 : IndexUniqueCheck checkUnique,
219 : bool indexUnchanged,
220 : IndexInfo *indexInfo)
221 : {
222 8656072 : RELATION_CHECKS;
223 8656072 : CHECK_REL_PROCEDURE(aminsert);
224 :
225 8656072 : if (!(indexRelation->rd_indam->ampredlocks))
226 576952 : CheckForSerializableConflictIn(indexRelation,
227 : (ItemPointer) NULL,
228 : InvalidBlockNumber);
229 :
230 8656072 : return indexRelation->rd_indam->aminsert(indexRelation, values, isnull,
231 : heap_t_ctid, heapRelation,
232 : checkUnique, indexUnchanged,
233 : indexInfo);
234 : }
235 :
236 : /* -------------------------
237 : * index_insert_cleanup - clean up after all index inserts are done
238 : * -------------------------
239 : */
240 : void
241 3447188 : index_insert_cleanup(Relation indexRelation,
242 : IndexInfo *indexInfo)
243 : {
244 3447188 : RELATION_CHECKS;
245 :
246 3447188 : if (indexRelation->rd_indam->aminsertcleanup)
247 1154 : indexRelation->rd_indam->aminsertcleanup(indexRelation, indexInfo);
248 3447188 : }
249 :
250 : /*
251 : * index_beginscan - start a scan of an index with amgettuple
252 : *
253 : * Caller must be holding suitable locks on the heap and the index.
254 : */
255 : IndexScanDesc
256 14662132 : index_beginscan(Relation heapRelation,
257 : Relation indexRelation,
258 : Snapshot snapshot,
259 : IndexScanInstrumentation *instrument,
260 : int nkeys, int norderbys)
261 : {
262 : IndexScanDesc scan;
263 :
264 : Assert(snapshot != InvalidSnapshot);
265 :
266 14662132 : scan = index_beginscan_internal(indexRelation, nkeys, norderbys, snapshot, NULL, false);
267 :
268 : /*
269 : * Save additional parameters into the scandesc. Everything else was set
270 : * up by RelationGetIndexScan.
271 : */
272 14662132 : scan->heapRelation = heapRelation;
273 14662132 : scan->xs_snapshot = snapshot;
274 14662132 : scan->instrument = instrument;
275 :
276 : /* prepare to fetch index matches from table */
277 14662132 : scan->xs_heapfetch = table_index_fetch_begin(heapRelation);
278 :
279 14662132 : return scan;
280 : }
281 :
282 : /*
283 : * index_beginscan_bitmap - start a scan of an index with amgetbitmap
284 : *
285 : * As above, caller had better be holding some lock on the parent heap
286 : * relation, even though it's not explicitly mentioned here.
287 : */
288 : IndexScanDesc
289 18170 : index_beginscan_bitmap(Relation indexRelation,
290 : Snapshot snapshot,
291 : IndexScanInstrumentation *instrument,
292 : int nkeys)
293 : {
294 : IndexScanDesc scan;
295 :
296 : Assert(snapshot != InvalidSnapshot);
297 :
298 18170 : scan = index_beginscan_internal(indexRelation, nkeys, 0, snapshot, NULL, false);
299 :
300 : /*
301 : * Save additional parameters into the scandesc. Everything else was set
302 : * up by RelationGetIndexScan.
303 : */
304 18170 : scan->xs_snapshot = snapshot;
305 18170 : scan->instrument = instrument;
306 :
307 18170 : return scan;
308 : }
309 :
310 : /*
311 : * index_beginscan_internal --- common code for index_beginscan variants
312 : */
313 : static IndexScanDesc
314 14680692 : index_beginscan_internal(Relation indexRelation,
315 : int nkeys, int norderbys, Snapshot snapshot,
316 : ParallelIndexScanDesc pscan, bool temp_snap)
317 : {
318 : IndexScanDesc scan;
319 :
320 14680692 : RELATION_CHECKS;
321 14680692 : CHECK_REL_PROCEDURE(ambeginscan);
322 :
323 14680692 : if (!(indexRelation->rd_indam->ampredlocks))
324 4624 : PredicateLockRelation(indexRelation, snapshot);
325 :
326 : /*
327 : * We hold a reference count to the relcache entry throughout the scan.
328 : */
329 14680692 : RelationIncrementReferenceCount(indexRelation);
330 :
331 : /*
332 : * Tell the AM to open a scan.
333 : */
334 14680692 : scan = indexRelation->rd_indam->ambeginscan(indexRelation, nkeys,
335 : norderbys);
336 : /* Initialize information for parallel scan. */
337 14680692 : scan->parallel_scan = pscan;
338 14680692 : scan->xs_temp_snap = temp_snap;
339 :
340 14680692 : return scan;
341 : }
342 :
343 : /* ----------------
344 : * index_rescan - (re)start a scan of an index
345 : *
346 : * During a restart, the caller may specify a new set of scankeys and/or
347 : * orderbykeys; but the number of keys cannot differ from what index_beginscan
348 : * was told. (Later we might relax that to "must not exceed", but currently
349 : * the index AMs tend to assume that scan->numberOfKeys is what to believe.)
350 : * To restart the scan without changing keys, pass NULL for the key arrays.
351 : * (Of course, keys *must* be passed on the first call, unless
352 : * scan->numberOfKeys is zero.)
353 : * ----------------
354 : */
355 : void
356 15383418 : index_rescan(IndexScanDesc scan,
357 : ScanKey keys, int nkeys,
358 : ScanKey orderbys, int norderbys)
359 : {
360 : SCAN_CHECKS;
361 15383418 : CHECK_SCAN_PROCEDURE(amrescan);
362 :
363 : Assert(nkeys == scan->numberOfKeys);
364 : Assert(norderbys == scan->numberOfOrderBys);
365 :
366 : /* Release resources (like buffer pins) from table accesses */
367 15383418 : if (scan->xs_heapfetch)
368 15361180 : table_index_fetch_reset(scan->xs_heapfetch);
369 :
370 15383418 : scan->kill_prior_tuple = false; /* for safety */
371 15383418 : scan->xs_heap_continue = false;
372 :
373 15383418 : scan->indexRelation->rd_indam->amrescan(scan, keys, nkeys,
374 : orderbys, norderbys);
375 15383418 : }
376 :
377 : /* ----------------
378 : * index_endscan - end a scan
379 : * ----------------
380 : */
381 : void
382 14678860 : index_endscan(IndexScanDesc scan)
383 : {
384 : SCAN_CHECKS;
385 14678860 : CHECK_SCAN_PROCEDURE(amendscan);
386 :
387 : /* Release resources (like buffer pins) from table accesses */
388 14678860 : if (scan->xs_heapfetch)
389 : {
390 14660792 : table_index_fetch_end(scan->xs_heapfetch);
391 14660792 : scan->xs_heapfetch = NULL;
392 : }
393 :
394 : /* End the AM's scan */
395 14678860 : scan->indexRelation->rd_indam->amendscan(scan);
396 :
397 : /* Release index refcount acquired by index_beginscan */
398 14678860 : RelationDecrementReferenceCount(scan->indexRelation);
399 :
400 14678860 : if (scan->xs_temp_snap)
401 390 : UnregisterSnapshot(scan->xs_snapshot);
402 :
403 : /* Release the scan data structure itself */
404 14678860 : IndexScanEnd(scan);
405 14678860 : }
406 :
407 : /* ----------------
408 : * index_markpos - mark a scan position
409 : * ----------------
410 : */
411 : void
412 130074 : index_markpos(IndexScanDesc scan)
413 : {
414 : SCAN_CHECKS;
415 130074 : CHECK_SCAN_PROCEDURE(ammarkpos);
416 :
417 130074 : scan->indexRelation->rd_indam->ammarkpos(scan);
418 130074 : }
419 :
420 : /* ----------------
421 : * index_restrpos - restore a scan position
422 : *
423 : * NOTE: this only restores the internal scan state of the index AM. See
424 : * comments for ExecRestrPos().
425 : *
426 : * NOTE: For heap, in the presence of HOT chains, mark/restore only works
427 : * correctly if the scan's snapshot is MVCC-safe; that ensures that there's at
428 : * most one returnable tuple in each HOT chain, and so restoring the prior
429 : * state at the granularity of the index AM is sufficient. Since the only
430 : * current user of mark/restore functionality is nodeMergejoin.c, this
431 : * effectively means that merge-join plans only work for MVCC snapshots. This
432 : * could be fixed if necessary, but for now it seems unimportant.
433 : * ----------------
434 : */
435 : void
436 54018 : index_restrpos(IndexScanDesc scan)
437 : {
438 : Assert(IsMVCCSnapshot(scan->xs_snapshot));
439 :
440 : SCAN_CHECKS;
441 54018 : CHECK_SCAN_PROCEDURE(amrestrpos);
442 :
443 : /* release resources (like buffer pins) from table accesses */
444 54018 : if (scan->xs_heapfetch)
445 54018 : table_index_fetch_reset(scan->xs_heapfetch);
446 :
447 54018 : scan->kill_prior_tuple = false; /* for safety */
448 54018 : scan->xs_heap_continue = false;
449 :
450 54018 : scan->indexRelation->rd_indam->amrestrpos(scan);
451 54018 : }
452 :
453 : /*
454 : * index_parallelscan_estimate - estimate shared memory for parallel scan
455 : *
456 : * When instrument=true, estimate includes SharedIndexScanInstrumentation
457 : * space. When parallel_aware=true, estimate includes whatever space the
458 : * index AM's amestimateparallelscan routine requested when called.
459 : */
460 : Size
461 334 : index_parallelscan_estimate(Relation indexRelation, int nkeys, int norderbys,
462 : Snapshot snapshot, bool instrument,
463 : bool parallel_aware, int nworkers)
464 : {
465 : Size nbytes;
466 :
467 : Assert(instrument || parallel_aware);
468 :
469 334 : RELATION_CHECKS;
470 :
471 334 : nbytes = offsetof(ParallelIndexScanDescData, ps_snapshot_data);
472 334 : nbytes = add_size(nbytes, EstimateSnapshotSpace(snapshot));
473 334 : nbytes = MAXALIGN(nbytes);
474 :
475 334 : if (instrument)
476 : {
477 : Size sharedinfosz;
478 :
479 270 : sharedinfosz = offsetof(SharedIndexScanInstrumentation, winstrument) +
480 : nworkers * sizeof(IndexScanInstrumentation);
481 270 : nbytes = add_size(nbytes, sharedinfosz);
482 270 : nbytes = MAXALIGN(nbytes);
483 : }
484 :
485 : /*
486 : * If parallel scan index AM interface can't be used (or index AM provides
487 : * no such interface), assume there is no AM-specific data needed
488 : */
489 334 : if (parallel_aware &&
490 64 : indexRelation->rd_indam->amestimateparallelscan != NULL)
491 64 : nbytes = add_size(nbytes,
492 64 : indexRelation->rd_indam->amestimateparallelscan(indexRelation,
493 : nkeys,
494 : norderbys));
495 :
496 334 : return nbytes;
497 : }
498 :
499 : /*
500 : * index_parallelscan_initialize - initialize parallel scan
501 : *
502 : * We initialize both the ParallelIndexScanDesc proper and the AM-specific
503 : * information which follows it.
504 : *
505 : * This function calls access method specific initialization routine to
506 : * initialize am specific information. Call this just once in the leader
507 : * process; then, individual workers attach via index_beginscan_parallel.
508 : */
509 : void
510 334 : index_parallelscan_initialize(Relation heapRelation, Relation indexRelation,
511 : Snapshot snapshot, bool instrument,
512 : bool parallel_aware, int nworkers,
513 : SharedIndexScanInstrumentation **sharedinfo,
514 : ParallelIndexScanDesc target)
515 : {
516 : Size offset;
517 :
518 : Assert(instrument || parallel_aware);
519 :
520 334 : RELATION_CHECKS;
521 :
522 334 : offset = add_size(offsetof(ParallelIndexScanDescData, ps_snapshot_data),
523 : EstimateSnapshotSpace(snapshot));
524 334 : offset = MAXALIGN(offset);
525 :
526 334 : target->ps_locator = heapRelation->rd_locator;
527 334 : target->ps_indexlocator = indexRelation->rd_locator;
528 334 : target->ps_offset_ins = 0;
529 334 : target->ps_offset_am = 0;
530 334 : SerializeSnapshot(snapshot, target->ps_snapshot_data);
531 :
532 334 : if (instrument)
533 : {
534 : Size sharedinfosz;
535 :
536 270 : target->ps_offset_ins = offset;
537 270 : sharedinfosz = offsetof(SharedIndexScanInstrumentation, winstrument) +
538 : nworkers * sizeof(IndexScanInstrumentation);
539 270 : offset = add_size(offset, sharedinfosz);
540 270 : offset = MAXALIGN(offset);
541 :
542 : /* Set leader's *sharedinfo pointer, and initialize stats */
543 270 : *sharedinfo = (SharedIndexScanInstrumentation *)
544 270 : OffsetToPointer(target, target->ps_offset_ins);
545 270 : memset(*sharedinfo, 0, sharedinfosz);
546 270 : (*sharedinfo)->num_workers = nworkers;
547 : }
548 :
549 : /* aminitparallelscan is optional; assume no-op if not provided by AM */
550 334 : if (parallel_aware && indexRelation->rd_indam->aminitparallelscan != NULL)
551 : {
552 : void *amtarget;
553 :
554 64 : target->ps_offset_am = offset;
555 64 : amtarget = OffsetToPointer(target, target->ps_offset_am);
556 64 : indexRelation->rd_indam->aminitparallelscan(amtarget);
557 : }
558 334 : }
559 :
560 : /* ----------------
561 : * index_parallelrescan - (re)start a parallel scan of an index
562 : * ----------------
563 : */
564 : void
565 24 : index_parallelrescan(IndexScanDesc scan)
566 : {
567 : SCAN_CHECKS;
568 :
569 24 : if (scan->xs_heapfetch)
570 24 : table_index_fetch_reset(scan->xs_heapfetch);
571 :
572 : /* amparallelrescan is optional; assume no-op if not provided by AM */
573 24 : if (scan->indexRelation->rd_indam->amparallelrescan != NULL)
574 24 : scan->indexRelation->rd_indam->amparallelrescan(scan);
575 24 : }
576 :
577 : /*
578 : * index_beginscan_parallel - join parallel index scan
579 : *
580 : * Caller must be holding suitable locks on the heap and the index.
581 : */
582 : IndexScanDesc
583 390 : index_beginscan_parallel(Relation heaprel, Relation indexrel,
584 : IndexScanInstrumentation *instrument,
585 : int nkeys, int norderbys,
586 : ParallelIndexScanDesc pscan)
587 : {
588 : Snapshot snapshot;
589 : IndexScanDesc scan;
590 :
591 : Assert(RelFileLocatorEquals(heaprel->rd_locator, pscan->ps_locator));
592 : Assert(RelFileLocatorEquals(indexrel->rd_locator, pscan->ps_indexlocator));
593 :
594 390 : snapshot = RestoreSnapshot(pscan->ps_snapshot_data);
595 390 : RegisterSnapshot(snapshot);
596 390 : scan = index_beginscan_internal(indexrel, nkeys, norderbys, snapshot,
597 : pscan, true);
598 :
599 : /*
600 : * Save additional parameters into the scandesc. Everything else was set
601 : * up by index_beginscan_internal.
602 : */
603 390 : scan->heapRelation = heaprel;
604 390 : scan->xs_snapshot = snapshot;
605 390 : scan->instrument = instrument;
606 :
607 : /* prepare to fetch index matches from table */
608 390 : scan->xs_heapfetch = table_index_fetch_begin(heaprel);
609 :
610 390 : return scan;
611 : }
612 :
613 : /* ----------------
614 : * index_getnext_tid - get the next TID from a scan
615 : *
616 : * The result is the next TID satisfying the scan keys,
617 : * or NULL if no more matching tuples exist.
618 : * ----------------
619 : */
620 : ItemPointer
621 36571658 : index_getnext_tid(IndexScanDesc scan, ScanDirection direction)
622 : {
623 : bool found;
624 :
625 : SCAN_CHECKS;
626 36571658 : CHECK_SCAN_PROCEDURE(amgettuple);
627 :
628 : /* XXX: we should assert that a snapshot is pushed or registered */
629 : Assert(TransactionIdIsValid(RecentXmin));
630 :
631 : /*
632 : * The AM's amgettuple proc finds the next index entry matching the scan
633 : * keys, and puts the TID into scan->xs_heaptid. It should also set
634 : * scan->xs_recheck and possibly scan->xs_itup/scan->xs_hitup, though we
635 : * pay no attention to those fields here.
636 : */
637 36571658 : found = scan->indexRelation->rd_indam->amgettuple(scan, direction);
638 :
639 : /* Reset kill flag immediately for safety */
640 36571658 : scan->kill_prior_tuple = false;
641 36571658 : scan->xs_heap_continue = false;
642 :
643 : /* If we're out of index entries, we're done */
644 36571658 : if (!found)
645 : {
646 : /* release resources (like buffer pins) from table accesses */
647 6962272 : if (scan->xs_heapfetch)
648 6962272 : table_index_fetch_reset(scan->xs_heapfetch);
649 :
650 6962272 : return NULL;
651 : }
652 : Assert(ItemPointerIsValid(&scan->xs_heaptid));
653 :
654 29609386 : pgstat_count_index_tuples(scan->indexRelation, 1);
655 :
656 : /* Return the TID of the tuple we found. */
657 29609386 : return &scan->xs_heaptid;
658 : }
659 :
660 : /* ----------------
661 : * index_fetch_heap - get the scan's next heap tuple
662 : *
663 : * The result is a visible heap tuple associated with the index TID most
664 : * recently fetched by index_getnext_tid, or NULL if no more matching tuples
665 : * exist. (There can be more than one matching tuple because of HOT chains,
666 : * although when using an MVCC snapshot it should be impossible for more than
667 : * one such tuple to exist.)
668 : *
669 : * On success, the buffer containing the heap tup is pinned (the pin will be
670 : * dropped in a future index_getnext_tid, index_fetch_heap or index_endscan
671 : * call).
672 : *
673 : * Note: caller must check scan->xs_recheck, and perform rechecking of the
674 : * scan keys if required. We do not do that here because we don't have
675 : * enough information to do it efficiently in the general case.
676 : * ----------------
677 : */
678 : bool
679 26168130 : index_fetch_heap(IndexScanDesc scan, TupleTableSlot *slot)
680 : {
681 26168130 : bool all_dead = false;
682 : bool found;
683 :
684 26168130 : found = table_index_fetch_tuple(scan->xs_heapfetch, &scan->xs_heaptid,
685 : scan->xs_snapshot, slot,
686 : &scan->xs_heap_continue, &all_dead);
687 :
688 26168120 : if (found)
689 25058592 : pgstat_count_heap_fetch(scan->indexRelation);
690 :
691 : /*
692 : * If we scanned a whole HOT chain and found only dead tuples, tell index
693 : * AM to kill its entry for that TID (this will take effect in the next
694 : * amgettuple call, in index_getnext_tid). We do not do this when in
695 : * recovery because it may violate MVCC to do so. See comments in
696 : * RelationGetIndexScan().
697 : */
698 26168120 : if (!scan->xactStartedInRecovery)
699 25724196 : scan->kill_prior_tuple = all_dead;
700 :
701 26168120 : return found;
702 : }
703 :
704 : /* ----------------
705 : * index_getnext_slot - get the next tuple from a scan
706 : *
707 : * The result is true if a tuple satisfying the scan keys and the snapshot was
708 : * found, false otherwise. The tuple is stored in the specified slot.
709 : *
710 : * On success, resources (like buffer pins) are likely to be held, and will be
711 : * dropped by a future index_getnext_tid, index_fetch_heap or index_endscan
712 : * call).
713 : *
714 : * Note: caller must check scan->xs_recheck, and perform rechecking of the
715 : * scan keys if required. We do not do that here because we don't have
716 : * enough information to do it efficiently in the general case.
717 : * ----------------
718 : */
719 : bool
720 30730032 : index_getnext_slot(IndexScanDesc scan, ScanDirection direction, TupleTableSlot *slot)
721 : {
722 : for (;;)
723 : {
724 30730032 : if (!scan->xs_heap_continue)
725 : {
726 : ItemPointer tid;
727 :
728 : /* Time to fetch the next TID from the index */
729 30566974 : tid = index_getnext_tid(scan, direction);
730 :
731 : /* If we're out of index entries, we're done */
732 30566974 : if (tid == NULL)
733 6759234 : break;
734 :
735 : Assert(ItemPointerEquals(tid, &scan->xs_heaptid));
736 : }
737 :
738 : /*
739 : * Fetch the next (or only) visible heap tuple for this index entry.
740 : * If we don't find anything, loop around and grab the next TID from
741 : * the index.
742 : */
743 : Assert(ItemPointerIsValid(&scan->xs_heaptid));
744 23970798 : if (index_fetch_heap(scan, slot))
745 23028170 : return true;
746 : }
747 :
748 6759234 : return false;
749 : }
750 :
751 : /* ----------------
752 : * index_getbitmap - get all tuples at once from an index scan
753 : *
754 : * Adds the TIDs of all heap tuples satisfying the scan keys to a bitmap.
755 : * Since there's no interlock between the index scan and the eventual heap
756 : * access, this is only safe to use with MVCC-based snapshots: the heap
757 : * item slot could have been replaced by a newer tuple by the time we get
758 : * to it.
759 : *
760 : * Returns the number of matching tuples found. (Note: this might be only
761 : * approximate, so it should only be used for statistical purposes.)
762 : * ----------------
763 : */
764 : int64
765 20974 : index_getbitmap(IndexScanDesc scan, TIDBitmap *bitmap)
766 : {
767 : int64 ntids;
768 :
769 : SCAN_CHECKS;
770 20974 : CHECK_SCAN_PROCEDURE(amgetbitmap);
771 :
772 : /* just make sure this is false... */
773 20974 : scan->kill_prior_tuple = false;
774 :
775 : /*
776 : * have the am's getbitmap proc do all the work.
777 : */
778 20974 : ntids = scan->indexRelation->rd_indam->amgetbitmap(scan, bitmap);
779 :
780 20974 : pgstat_count_index_tuples(scan->indexRelation, ntids);
781 :
782 20974 : return ntids;
783 : }
784 :
785 : /* ----------------
786 : * index_bulk_delete - do mass deletion of index entries
787 : *
788 : * callback routine tells whether a given main-heap tuple is
789 : * to be deleted
790 : *
791 : * return value is an optional palloc'd struct of statistics
792 : * ----------------
793 : */
794 : IndexBulkDeleteResult *
795 3086 : index_bulk_delete(IndexVacuumInfo *info,
796 : IndexBulkDeleteResult *istat,
797 : IndexBulkDeleteCallback callback,
798 : void *callback_state)
799 : {
800 3086 : Relation indexRelation = info->index;
801 :
802 3086 : RELATION_CHECKS;
803 3086 : CHECK_REL_PROCEDURE(ambulkdelete);
804 :
805 3086 : return indexRelation->rd_indam->ambulkdelete(info, istat,
806 : callback, callback_state);
807 : }
808 :
809 : /* ----------------
810 : * index_vacuum_cleanup - do post-deletion cleanup of an index
811 : *
812 : * return value is an optional palloc'd struct of statistics
813 : * ----------------
814 : */
815 : IndexBulkDeleteResult *
816 174082 : index_vacuum_cleanup(IndexVacuumInfo *info,
817 : IndexBulkDeleteResult *istat)
818 : {
819 174082 : Relation indexRelation = info->index;
820 :
821 174082 : RELATION_CHECKS;
822 174082 : CHECK_REL_PROCEDURE(amvacuumcleanup);
823 :
824 174082 : return indexRelation->rd_indam->amvacuumcleanup(info, istat);
825 : }
826 :
827 : /* ----------------
828 : * index_can_return
829 : *
830 : * Does the index access method support index-only scans for the given
831 : * column?
832 : * ----------------
833 : */
834 : bool
835 1411892 : index_can_return(Relation indexRelation, int attno)
836 : {
837 1411892 : RELATION_CHECKS;
838 :
839 : /* amcanreturn is optional; assume false if not provided by AM */
840 1411892 : if (indexRelation->rd_indam->amcanreturn == NULL)
841 272950 : return false;
842 :
843 1138942 : return indexRelation->rd_indam->amcanreturn(indexRelation, attno);
844 : }
845 :
846 : /* ----------------
847 : * index_getprocid
848 : *
849 : * Index access methods typically require support routines that are
850 : * not directly the implementation of any WHERE-clause query operator
851 : * and so cannot be kept in pg_amop. Instead, such routines are kept
852 : * in pg_amproc. These registered procedure OIDs are assigned numbers
853 : * according to a convention established by the access method.
854 : * The general index code doesn't know anything about the routines
855 : * involved; it just builds an ordered list of them for
856 : * each attribute on which an index is defined.
857 : *
858 : * As of Postgres 8.3, support routines within an operator family
859 : * are further subdivided by the "left type" and "right type" of the
860 : * query operator(s) that they support. The "default" functions for a
861 : * particular indexed attribute are those with both types equal to
862 : * the index opclass' opcintype (note that this is subtly different
863 : * from the indexed attribute's own type: it may be a binary-compatible
864 : * type instead). Only the default functions are stored in relcache
865 : * entries --- access methods can use the syscache to look up non-default
866 : * functions.
867 : *
868 : * This routine returns the requested default procedure OID for a
869 : * particular indexed attribute.
870 : * ----------------
871 : */
872 : RegProcedure
873 2111596 : index_getprocid(Relation irel,
874 : AttrNumber attnum,
875 : uint16 procnum)
876 : {
877 : RegProcedure *loc;
878 : int nproc;
879 : int procindex;
880 :
881 2111596 : nproc = irel->rd_indam->amsupport;
882 :
883 : Assert(procnum > 0 && procnum <= (uint16) nproc);
884 :
885 2111596 : procindex = (nproc * (attnum - 1)) + (procnum - 1);
886 :
887 2111596 : loc = irel->rd_support;
888 :
889 : Assert(loc != NULL);
890 :
891 2111596 : return loc[procindex];
892 : }
893 :
894 : /* ----------------
895 : * index_getprocinfo
896 : *
897 : * This routine allows index AMs to keep fmgr lookup info for
898 : * support procs in the relcache. As above, only the "default"
899 : * functions for any particular indexed attribute are cached.
900 : *
901 : * Note: the return value points into cached data that will be lost during
902 : * any relcache rebuild! Therefore, either use the callinfo right away,
903 : * or save it only after having acquired some type of lock on the index rel.
904 : * ----------------
905 : */
906 : FmgrInfo *
907 48190004 : index_getprocinfo(Relation irel,
908 : AttrNumber attnum,
909 : uint16 procnum)
910 : {
911 : FmgrInfo *locinfo;
912 : int nproc;
913 : int optsproc;
914 : int procindex;
915 :
916 48190004 : nproc = irel->rd_indam->amsupport;
917 48190004 : optsproc = irel->rd_indam->amoptsprocnum;
918 :
919 : Assert(procnum > 0 && procnum <= (uint16) nproc);
920 :
921 48190004 : procindex = (nproc * (attnum - 1)) + (procnum - 1);
922 :
923 48190004 : locinfo = irel->rd_supportinfo;
924 :
925 : Assert(locinfo != NULL);
926 :
927 48190004 : locinfo += procindex;
928 :
929 : /* Initialize the lookup info if first time through */
930 48190004 : if (locinfo->fn_oid == InvalidOid)
931 : {
932 1236766 : RegProcedure *loc = irel->rd_support;
933 : RegProcedure procId;
934 :
935 : Assert(loc != NULL);
936 :
937 1236766 : procId = loc[procindex];
938 :
939 : /*
940 : * Complain if function was not found during IndexSupportInitialize.
941 : * This should not happen unless the system tables contain bogus
942 : * entries for the index opclass. (If an AM wants to allow a support
943 : * function to be optional, it can use index_getprocid.)
944 : */
945 1236766 : if (!RegProcedureIsValid(procId))
946 0 : elog(ERROR, "missing support function %d for attribute %d of index \"%s\"",
947 : procnum, attnum, RelationGetRelationName(irel));
948 :
949 1236766 : fmgr_info_cxt(procId, locinfo, irel->rd_indexcxt);
950 :
951 1236766 : if (procnum != optsproc)
952 : {
953 : /* Initialize locinfo->fn_expr with opclass options Const */
954 1234664 : bytea **attoptions = RelationGetIndexAttOptions(irel, false);
955 1234664 : MemoryContext oldcxt = MemoryContextSwitchTo(irel->rd_indexcxt);
956 :
957 1234664 : set_fn_opclass_options(locinfo, attoptions[attnum - 1]);
958 :
959 1234664 : MemoryContextSwitchTo(oldcxt);
960 : }
961 : }
962 :
963 48190004 : return locinfo;
964 : }
965 :
966 : /* ----------------
967 : * index_store_float8_orderby_distances
968 : *
969 : * Convert AM distance function's results (that can be inexact)
970 : * to ORDER BY types and save them into xs_orderbyvals/xs_orderbynulls
971 : * for a possible recheck.
972 : * ----------------
973 : */
974 : void
975 364600 : index_store_float8_orderby_distances(IndexScanDesc scan, Oid *orderByTypes,
976 : IndexOrderByDistance *distances,
977 : bool recheckOrderBy)
978 : {
979 : int i;
980 :
981 : Assert(distances || !recheckOrderBy);
982 :
983 364600 : scan->xs_recheckorderby = recheckOrderBy;
984 :
985 729218 : for (i = 0; i < scan->numberOfOrderBys; i++)
986 : {
987 364618 : if (orderByTypes[i] == FLOAT8OID)
988 : {
989 : #ifndef USE_FLOAT8_BYVAL
990 : /* must free any old value to avoid memory leakage */
991 : if (!scan->xs_orderbynulls[i])
992 : pfree(DatumGetPointer(scan->xs_orderbyvals[i]));
993 : #endif
994 364488 : if (distances && !distances[i].isnull)
995 : {
996 364428 : scan->xs_orderbyvals[i] = Float8GetDatum(distances[i].value);
997 364428 : scan->xs_orderbynulls[i] = false;
998 : }
999 : else
1000 : {
1001 60 : scan->xs_orderbyvals[i] = (Datum) 0;
1002 60 : scan->xs_orderbynulls[i] = true;
1003 : }
1004 : }
1005 130 : else if (orderByTypes[i] == FLOAT4OID)
1006 : {
1007 : /* convert distance function's result to ORDER BY type */
1008 70 : if (distances && !distances[i].isnull)
1009 : {
1010 70 : scan->xs_orderbyvals[i] = Float4GetDatum((float4) distances[i].value);
1011 70 : scan->xs_orderbynulls[i] = false;
1012 : }
1013 : else
1014 : {
1015 0 : scan->xs_orderbyvals[i] = (Datum) 0;
1016 0 : scan->xs_orderbynulls[i] = true;
1017 : }
1018 : }
1019 : else
1020 : {
1021 : /*
1022 : * If the ordering operator's return value is anything else, we
1023 : * don't know how to convert the float8 bound calculated by the
1024 : * distance function to that. The executor won't actually need
1025 : * the order by values we return here, if there are no lossy
1026 : * results, so only insist on converting if the *recheck flag is
1027 : * set.
1028 : */
1029 60 : if (scan->xs_recheckorderby)
1030 0 : elog(ERROR, "ORDER BY operator must return float8 or float4 if the distance function is lossy");
1031 60 : scan->xs_orderbynulls[i] = true;
1032 : }
1033 : }
1034 364600 : }
1035 :
1036 : /* ----------------
1037 : * index_opclass_options
1038 : *
1039 : * Parse opclass-specific options for index column.
1040 : * ----------------
1041 : */
1042 : bytea *
1043 1051606 : index_opclass_options(Relation indrel, AttrNumber attnum, Datum attoptions,
1044 : bool validate)
1045 : {
1046 1051606 : int amoptsprocnum = indrel->rd_indam->amoptsprocnum;
1047 1051606 : Oid procid = InvalidOid;
1048 : FmgrInfo *procinfo;
1049 : local_relopts relopts;
1050 :
1051 : /* fetch options support procedure if specified */
1052 1051606 : if (amoptsprocnum != 0)
1053 1051546 : procid = index_getprocid(indrel, attnum, amoptsprocnum);
1054 :
1055 1051606 : if (!OidIsValid(procid))
1056 : {
1057 : Oid opclass;
1058 : Datum indclassDatum;
1059 : oidvector *indclass;
1060 :
1061 1048684 : if (!DatumGetPointer(attoptions))
1062 1048678 : return NULL; /* ok, no options, no procedure */
1063 :
1064 : /*
1065 : * Report an error if the opclass's options-parsing procedure does not
1066 : * exist but the opclass options are specified.
1067 : */
1068 6 : indclassDatum = SysCacheGetAttrNotNull(INDEXRELID, indrel->rd_indextuple,
1069 : Anum_pg_index_indclass);
1070 6 : indclass = (oidvector *) DatumGetPointer(indclassDatum);
1071 6 : opclass = indclass->values[attnum - 1];
1072 :
1073 6 : ereport(ERROR,
1074 : (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
1075 : errmsg("operator class %s has no options",
1076 : generate_opclass_name(opclass))));
1077 : }
1078 :
1079 2922 : init_local_reloptions(&relopts, 0);
1080 :
1081 2922 : procinfo = index_getprocinfo(indrel, attnum, amoptsprocnum);
1082 :
1083 2922 : (void) FunctionCall1(procinfo, PointerGetDatum(&relopts));
1084 :
1085 2922 : return build_local_reloptions(&relopts, attoptions, validate);
1086 : }
|
