Age Owner TLA Line data Source code
1 : /*-------------------------------------------------------------------------
2 : *
3 : * indexam.c
4 : * general index access method routines
5 : *
6 : * Portions Copyright (c) 1996-2023, 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/heapam.h"
48 : #include "access/reloptions.h"
49 : #include "access/relscan.h"
50 : #include "access/tableam.h"
51 : #include "access/transam.h"
52 : #include "access/xlog.h"
53 : #include "catalog/index.h"
54 : #include "catalog/pg_amproc.h"
55 : #include "catalog/pg_type.h"
56 : #include "commands/defrem.h"
57 : #include "nodes/makefuncs.h"
58 : #include "pgstat.h"
59 : #include "storage/bufmgr.h"
60 : #include "storage/lmgr.h"
61 : #include "storage/predicate.h"
62 : #include "utils/ruleutils.h"
63 : #include "utils/snapmgr.h"
64 : #include "utils/syscache.h"
65 :
66 :
67 : /* ----------------------------------------------------------------
68 : * macros used in index_ routines
69 : *
70 : * Note: the ReindexIsProcessingIndex() check in RELATION_CHECKS is there
71 : * to check that we don't try to scan or do retail insertions into an index
72 : * that is currently being rebuilt or pending rebuild. This helps to catch
73 : * things that don't work when reindexing system catalogs. The assertion
74 : * doesn't prevent the actual rebuild because we don't use RELATION_CHECKS
75 : * when calling the index AM's ambuild routine, and there is no reason for
76 : * ambuild to call its subsidiary routines through this file.
77 : * ----------------------------------------------------------------
78 : */
79 : #define RELATION_CHECKS \
80 : ( \
81 : AssertMacro(RelationIsValid(indexRelation)), \
82 : AssertMacro(PointerIsValid(indexRelation->rd_indam)), \
83 : AssertMacro(!ReindexIsProcessingIndex(RelationGetRelid(indexRelation))) \
84 : )
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 :
111 :
112 : /* ----------------------------------------------------------------
113 : * index_ interface functions
114 : * ----------------------------------------------------------------
115 : */
116 :
117 : /* ----------------
118 : * index_open - open an index relation by relation OID
119 : *
120 : * If lockmode is not "NoLock", the specified kind of lock is
121 : * obtained on the index. (Generally, NoLock should only be
122 : * used if the caller knows it has some appropriate lock on the
123 : * index already.)
124 : *
125 : * An error is raised if the index does not exist.
126 : *
127 : * This is a convenience routine adapted for indexscan use.
128 : * Some callers may prefer to use relation_open directly.
129 : * ----------------
130 : */
131 : Relation
6096 tgl 132 CBC 13672125 : index_open(Oid relationId, LOCKMODE lockmode)
133 : {
134 : Relation r;
135 :
136 13672125 : r = relation_open(relationId, lockmode);
137 :
1906 alvherre 138 13672119 : if (r->rd_rel->relkind != RELKIND_INDEX &&
139 5474 : r->rd_rel->relkind != RELKIND_PARTITIONED_INDEX)
7202 tgl 140 15 : ereport(ERROR,
141 : (errcode(ERRCODE_WRONG_OBJECT_TYPE),
142 : errmsg("\"%s\" is not an index",
143 : RelationGetRelationName(r))));
144 :
8604 145 13672104 : return r;
146 : }
147 :
148 : /* ----------------
149 : * index_close - close an index relation
150 : *
151 : * If lockmode is not "NoLock", we then release the specified lock.
152 : *
153 : * Note that it is often sensible to hold a lock beyond index_close;
154 : * in that case, the lock is released automatically at xact end.
155 : * ----------------
156 : */
157 : void
6096 158 13700317 : index_close(Relation relation, LOCKMODE lockmode)
159 : {
160 13700317 : LockRelId relid = relation->rd_lockInfo.lockRelId;
161 :
162 13700317 : Assert(lockmode >= NoLock && lockmode < MAX_LOCKMODES);
163 :
164 : /* The relcache does the real work... */
9345 bruce 165 13700317 : RelationClose(relation);
166 :
6096 tgl 167 13700317 : if (lockmode != NoLock)
168 12924021 : UnlockRelationId(&relid, lockmode);
9770 scrappy 169 13700317 : }
170 :
171 : /* ----------------
172 : * index_insert - insert an index tuple into a relation
173 : * ----------------
174 : */
175 : bool
7629 tgl 176 7828817 : index_insert(Relation indexRelation,
177 : Datum *values,
178 : bool *isnull,
179 : ItemPointer heap_t_ctid,
180 : Relation heapRelation,
181 : IndexUniqueCheck checkUnique,
182 : bool indexUnchanged,
183 : IndexInfo *indexInfo)
184 : {
9345 bruce 185 7828817 : RELATION_CHECKS;
2639 tgl 186 7828817 : CHECK_REL_PROCEDURE(aminsert);
187 :
1539 andres 188 7828817 : if (!(indexRelation->rd_indam->ampredlocks))
4444 heikki.linnakangas 189 264185 : CheckForSerializableConflictIn(indexRelation,
190 : (ItemPointer) NULL,
191 : InvalidBlockNumber);
192 :
1539 andres 193 7828817 : return indexRelation->rd_indam->aminsert(indexRelation, values, isnull,
194 : heap_t_ctid, heapRelation,
195 : checkUnique, indexUnchanged,
196 : indexInfo);
197 : }
198 :
199 : /*
200 : * index_beginscan - start a scan of an index with amgettuple
201 : *
202 : * Caller must be holding suitable locks on the heap and the index.
203 : */
204 : IndexScanDesc
7629 tgl 205 8896116 : index_beginscan(Relation heapRelation,
206 : Relation indexRelation,
207 : Snapshot snapshot,
208 : int nkeys, int norderbys)
209 : {
210 : IndexScanDesc scan;
211 :
124 akorotkov 212 GNC 8896116 : Assert(snapshot != InvalidSnapshot);
213 :
2266 rhaas 214 CBC 8896116 : scan = index_beginscan_internal(indexRelation, nkeys, norderbys, snapshot, NULL, false);
215 :
6587 tgl 216 ECB : /*
217 : * Save additional parameters into the scandesc. Everything else was set
218 : * up by RelationGetIndexScan.
219 : */
6587 tgl 220 GIC 8896116 : scan->heapRelation = heapRelation;
221 8896116 : scan->xs_snapshot = snapshot;
6587 tgl 222 ECB :
1490 andres 223 : /* prepare to fetch index matches from table */
1490 andres 224 GIC 8896116 : scan->xs_heapfetch = table_index_fetch_begin(heapRelation);
225 :
6587 tgl 226 CBC 8896116 : return scan;
227 : }
6587 tgl 228 ECB :
229 : /*
230 : * index_beginscan_bitmap - start a scan of an index with amgetbitmap
231 : *
232 : * As above, caller had better be holding some lock on the parent heap
233 : * relation, even though it's not explicitly mentioned here.
234 : */
235 : IndexScanDesc
5477 tgl 236 GIC 9068 : index_beginscan_bitmap(Relation indexRelation,
237 : Snapshot snapshot,
4511 tgl 238 ECB : int nkeys)
239 : {
240 : IndexScanDesc scan;
241 :
124 akorotkov 242 GNC 9068 : Assert(snapshot != InvalidSnapshot);
243 :
2266 rhaas 244 GIC 9068 : scan = index_beginscan_internal(indexRelation, nkeys, 0, snapshot, NULL, false);
245 :
6587 tgl 246 ECB : /*
247 : * Save additional parameters into the scandesc. Everything else was set
6385 bruce 248 : * up by RelationGetIndexScan.
249 : */
6587 tgl 250 GIC 9068 : scan->xs_snapshot = snapshot;
251 :
252 9068 : return scan;
253 : }
6587 tgl 254 ECB :
255 : /*
256 : * index_beginscan_internal --- common code for index_beginscan variants
257 : */
258 : static IndexScanDesc
6587 tgl 259 GIC 8905358 : index_beginscan_internal(Relation indexRelation,
260 : int nkeys, int norderbys, Snapshot snapshot,
261 : ParallelIndexScanDesc pscan, bool temp_snap)
262 : {
2266 rhaas 263 ECB : IndexScanDesc scan;
264 :
9345 bruce 265 GIC 8905358 : RELATION_CHECKS;
2639 tgl 266 8905358 : CHECK_REL_PROCEDURE(ambeginscan);
267 :
1539 andres 268 8905358 : if (!(indexRelation->rd_indam->ampredlocks))
4316 heikki.linnakangas 269 CBC 2129 : PredicateLockRelation(indexRelation, snapshot);
4444 heikki.linnakangas 270 ECB :
271 : /*
6096 tgl 272 : * We hold a reference count to the relcache entry throughout the scan.
6495 teodor 273 : */
6096 tgl 274 GIC 8905358 : RelationIncrementReferenceCount(indexRelation);
275 :
276 : /*
277 : * Tell the AM to open a scan.
7629 tgl 278 ECB : */
1539 andres 279 GIC 8905358 : scan = indexRelation->rd_indam->ambeginscan(indexRelation, nkeys,
280 : norderbys);
281 : /* Initialize information for parallel scan. */
2266 rhaas 282 8905358 : scan->parallel_scan = pscan;
2266 rhaas 283 CBC 8905358 : scan->xs_temp_snap = temp_snap;
284 :
2266 rhaas 285 GIC 8905358 : return scan;
9770 scrappy 286 ECB : }
287 :
288 : /* ----------------
7629 tgl 289 : * index_rescan - (re)start a scan of an index
290 : *
291 : * During a restart, the caller may specify a new set of scankeys and/or
292 : * orderbykeys; but the number of keys cannot differ from what index_beginscan
293 : * was told. (Later we might relax that to "must not exceed", but currently
294 : * the index AMs tend to assume that scan->numberOfKeys is what to believe.)
295 : * To restart the scan without changing keys, pass NULL for the key arrays.
296 : * (Of course, keys *must* be passed on the first call, unless
297 : * scan->numberOfKeys is zero.)
298 : * ----------------
299 : */
300 : void
4511 tgl 301 GIC 9091638 : index_rescan(IndexScanDesc scan,
302 : ScanKey keys, int nkeys,
303 : ScanKey orderbys, int norderbys)
304 : {
9345 bruce 305 CBC 9091638 : SCAN_CHECKS;
2639 tgl 306 GIC 9091638 : CHECK_SCAN_PROCEDURE(amrescan);
307 :
4511 308 9091638 : Assert(nkeys == scan->numberOfKeys);
4511 tgl 309 CBC 9091638 : Assert(norderbys == scan->numberOfOrderBys);
4511 tgl 310 ECB :
311 : /* Release resources (like buffer pins) from table accesses */
1490 andres 312 CBC 9091638 : if (scan->xs_heapfetch)
313 9081202 : table_index_fetch_reset(scan->xs_heapfetch);
314 :
2118 tgl 315 GIC 9091638 : scan->kill_prior_tuple = false; /* for safety */
1490 andres 316 CBC 9091638 : scan->xs_heap_continue = false;
7625 tgl 317 ECB :
1539 andres 318 GIC 9091638 : scan->indexRelation->rd_indam->amrescan(scan, keys, nkeys,
1539 andres 319 ECB : orderbys, norderbys);
9770 scrappy 320 CBC 9091638 : }
321 :
9770 scrappy 322 ECB : /* ----------------
323 : * index_endscan - end a scan
324 : * ----------------
325 : */
326 : void
9770 scrappy 327 GIC 8904646 : index_endscan(IndexScanDesc scan)
328 : {
9345 bruce 329 8904646 : SCAN_CHECKS;
2639 tgl 330 8904646 : CHECK_SCAN_PROCEDURE(amendscan);
9345 bruce 331 ECB :
332 : /* Release resources (like buffer pins) from table accesses */
1490 andres 333 CBC 8904646 : if (scan->xs_heapfetch)
7629 tgl 334 ECB : {
1490 andres 335 GIC 8895609 : table_index_fetch_end(scan->xs_heapfetch);
336 8895609 : scan->xs_heapfetch = NULL;
7629 tgl 337 ECB : }
338 :
339 : /* End the AM's scan */
1539 andres 340 CBC 8904646 : scan->indexRelation->rd_indam->amendscan(scan);
341 :
342 : /* Release index refcount acquired by index_beginscan */
7629 tgl 343 GIC 8904646 : RelationDecrementReferenceCount(scan->indexRelation);
8501 tgl 344 ECB :
2266 rhaas 345 GIC 8904646 : if (scan->xs_temp_snap)
346 174 : UnregisterSnapshot(scan->xs_snapshot);
2266 rhaas 347 ECB :
348 : /* Release the scan data structure itself */
8501 tgl 349 CBC 8904646 : IndexScanEnd(scan);
9770 scrappy 350 8904646 : }
351 :
352 : /* ----------------
9345 bruce 353 ECB : * index_markpos - mark a scan position
9770 scrappy 354 : * ----------------
355 : */
356 : void
9770 scrappy 357 GIC 65029 : index_markpos(IndexScanDesc scan)
358 : {
9345 bruce 359 65029 : SCAN_CHECKS;
2639 tgl 360 65029 : CHECK_SCAN_PROCEDURE(ammarkpos);
9345 bruce 361 ECB :
1539 andres 362 GIC 65029 : scan->indexRelation->rd_indam->ammarkpos(scan);
9770 scrappy 363 CBC 65029 : }
9345 bruce 364 ECB :
365 : /* ----------------
366 : * index_restrpos - restore a scan position
6538 tgl 367 : *
368 : * NOTE: this only restores the internal scan state of the index AM. See
369 : * comments for ExecRestrPos().
370 : *
371 : * NOTE: For heap, in the presence of HOT chains, mark/restore only works
372 : * correctly if the scan's snapshot is MVCC-safe; that ensures that there's at
373 : * most one returnable tuple in each HOT chain, and so restoring the prior
374 : * state at the granularity of the index AM is sufficient. Since the only
375 : * current user of mark/restore functionality is nodeMergejoin.c, this
376 : * effectively means that merge-join plans only work for MVCC snapshots. This
377 : * could be fixed if necessary, but for now it seems unimportant.
378 : * ----------------
379 : */
380 : void
9770 scrappy 381 GIC 27015 : index_restrpos(IndexScanDesc scan)
382 : {
5680 tgl 383 27015 : Assert(IsMVCCSnapshot(scan->xs_snapshot));
384 :
9345 bruce 385 CBC 27015 : SCAN_CHECKS;
2639 tgl 386 GIC 27015 : CHECK_SCAN_PROCEDURE(amrestrpos);
9345 bruce 387 ECB :
388 : /* release resources (like buffer pins) from table accesses */
1490 andres 389 CBC 27015 : if (scan->xs_heapfetch)
390 27015 : table_index_fetch_reset(scan->xs_heapfetch);
391 :
2118 tgl 392 GIC 27015 : scan->kill_prior_tuple = false; /* for safety */
1490 andres 393 CBC 27015 : scan->xs_heap_continue = false;
7396 tgl 394 ECB :
1539 andres 395 GIC 27015 : scan->indexRelation->rd_indam->amrestrpos(scan);
9770 scrappy 396 CBC 27015 : }
9345 bruce 397 ECB :
398 : /*
2266 rhaas 399 : * index_parallelscan_estimate - estimate shared memory for parallel scan
400 : *
401 : * Currently, we don't pass any information to the AM-specific estimator,
402 : * so it can probably only return a constant. In the future, we might need
403 : * to pass more information.
404 : */
405 : Size
2266 rhaas 406 GIC 26 : index_parallelscan_estimate(Relation indexRelation, Snapshot snapshot)
407 : {
408 : Size nbytes;
409 :
124 akorotkov 410 GNC 26 : Assert(snapshot != InvalidSnapshot);
411 :
2266 rhaas 412 CBC 26 : RELATION_CHECKS;
413 :
2266 rhaas 414 GIC 26 : nbytes = offsetof(ParallelIndexScanDescData, ps_snapshot_data);
415 26 : nbytes = add_size(nbytes, EstimateSnapshotSpace(snapshot));
2266 rhaas 416 CBC 26 : nbytes = MAXALIGN(nbytes);
417 :
2266 rhaas 418 ECB : /*
419 : * If amestimateparallelscan is not provided, assume there is no
420 : * AM-specific data needed. (It's hard to believe that could work, but
421 : * it's easy enough to cater to it here.)
422 : */
1539 andres 423 GIC 26 : if (indexRelation->rd_indam->amestimateparallelscan != NULL)
2266 rhaas 424 26 : nbytes = add_size(nbytes,
1539 andres 425 26 : indexRelation->rd_indam->amestimateparallelscan());
426 :
2266 rhaas 427 26 : return nbytes;
428 : }
2266 rhaas 429 ECB :
430 : /*
431 : * index_parallelscan_initialize - initialize parallel scan
432 : *
433 : * We initialize both the ParallelIndexScanDesc proper and the AM-specific
434 : * information which follows it.
435 : *
436 : * This function calls access method specific initialization routine to
437 : * initialize am specific information. Call this just once in the leader
438 : * process; then, individual workers attach via index_beginscan_parallel.
439 : */
440 : void
2266 rhaas 441 GIC 26 : index_parallelscan_initialize(Relation heapRelation, Relation indexRelation,
442 : Snapshot snapshot, ParallelIndexScanDesc target)
443 : {
444 : Size offset;
445 :
124 akorotkov 446 GNC 26 : Assert(snapshot != InvalidSnapshot);
447 :
2266 rhaas 448 GIC 26 : RELATION_CHECKS;
2266 rhaas 449 ECB :
2266 rhaas 450 GIC 26 : offset = add_size(offsetof(ParallelIndexScanDescData, ps_snapshot_data),
451 : EstimateSnapshotSpace(snapshot));
452 26 : offset = MAXALIGN(offset);
453 :
2266 rhaas 454 CBC 26 : target->ps_relid = RelationGetRelid(heapRelation);
2266 rhaas 455 GIC 26 : target->ps_indexid = RelationGetRelid(indexRelation);
2266 rhaas 456 CBC 26 : target->ps_offset = offset;
2266 rhaas 457 GIC 26 : SerializeSnapshot(snapshot, target->ps_snapshot_data);
2266 rhaas 458 ECB :
459 : /* aminitparallelscan is optional; assume no-op if not provided by AM */
1539 andres 460 CBC 26 : if (indexRelation->rd_indam->aminitparallelscan != NULL)
461 : {
2266 rhaas 462 ECB : void *amtarget;
463 :
2266 rhaas 464 CBC 26 : amtarget = OffsetToPointer(target, offset);
1539 andres 465 26 : indexRelation->rd_indam->aminitparallelscan(amtarget);
466 : }
2266 rhaas 467 GIC 26 : }
2266 rhaas 468 ECB :
469 : /* ----------------
470 : * index_parallelrescan - (re)start a parallel scan of an index
471 : * ----------------
472 : */
473 : void
2266 rhaas 474 GIC 12 : index_parallelrescan(IndexScanDesc scan)
2266 rhaas 475 ECB : {
2266 rhaas 476 GIC 12 : SCAN_CHECKS;
477 :
1490 andres 478 12 : if (scan->xs_heapfetch)
479 12 : table_index_fetch_reset(scan->xs_heapfetch);
480 :
481 : /* amparallelrescan is optional; assume no-op if not provided by AM */
1539 andres 482 CBC 12 : if (scan->indexRelation->rd_indam->amparallelrescan != NULL)
1539 andres 483 GIC 12 : scan->indexRelation->rd_indam->amparallelrescan(scan);
2266 rhaas 484 CBC 12 : }
485 :
2266 rhaas 486 ECB : /*
487 : * index_beginscan_parallel - join parallel index scan
488 : *
489 : * Caller must be holding suitable locks on the heap and the index.
490 : */
491 : IndexScanDesc
2266 rhaas 492 CBC 174 : index_beginscan_parallel(Relation heaprel, Relation indexrel, int nkeys,
493 : int norderbys, ParallelIndexScanDesc pscan)
494 : {
495 : Snapshot snapshot;
496 : IndexScanDesc scan;
497 :
2266 rhaas 498 GIC 174 : Assert(RelationGetRelid(heaprel) == pscan->ps_relid);
499 174 : snapshot = RestoreSnapshot(pscan->ps_snapshot_data);
2266 rhaas 500 CBC 174 : RegisterSnapshot(snapshot);
2266 rhaas 501 GIC 174 : scan = index_beginscan_internal(indexrel, nkeys, norderbys, snapshot,
502 : pscan, true);
503 :
504 : /*
505 : * Save additional parameters into the scandesc. Everything else was set
2266 rhaas 506 ECB : * up by index_beginscan_internal.
507 : */
2266 rhaas 508 CBC 174 : scan->heapRelation = heaprel;
509 174 : scan->xs_snapshot = snapshot;
510 :
511 : /* prepare to fetch index matches from table */
1490 andres 512 GIC 174 : scan->xs_heapfetch = table_index_fetch_begin(heaprel);
513 :
2266 rhaas 514 174 : return scan;
515 : }
2266 rhaas 516 ECB :
9770 scrappy 517 : /* ----------------
518 : * index_getnext_tid - get the next TID from a scan
519 : *
4202 tgl 520 : * The result is the next TID satisfying the scan keys,
521 : * or NULL if no more matching tuples exist.
522 : * ----------------
523 : */
524 : ItemPointer
4202 tgl 525 GIC 21962633 : index_getnext_tid(IndexScanDesc scan, ScanDirection direction)
526 : {
527 : bool found;
528 :
529 21962633 : SCAN_CHECKS;
2639 530 21962633 : CHECK_SCAN_PROCEDURE(amgettuple);
531 :
532 : /* XXX: we should assert that a snapshot is pushed or registered */
970 andres 533 CBC 21962633 : Assert(TransactionIdIsValid(RecentXmin));
534 :
535 : /*
536 : * The AM's amgettuple proc finds the next index entry matching the scan
1490 andres 537 ECB : * keys, and puts the TID into scan->xs_heaptid. It should also set
2232 tgl 538 : * scan->xs_recheck and possibly scan->xs_itup/scan->xs_hitup, though we
539 : * pay no attention to those fields here.
540 : */
1539 andres 541 CBC 21962633 : found = scan->indexRelation->rd_indam->amgettuple(scan, direction);
542 :
543 : /* Reset kill flag immediately for safety */
4202 tgl 544 GIC 21962632 : scan->kill_prior_tuple = false;
1490 andres 545 21962632 : scan->xs_heap_continue = false;
546 :
547 : /* If we're out of index entries, we're done */
4202 tgl 548 21962632 : if (!found)
4202 tgl 549 ECB : {
550 : /* release resources (like buffer pins) from table accesses */
1490 andres 551 GIC 5221147 : if (scan->xs_heapfetch)
1490 andres 552 CBC 5221147 : table_index_fetch_reset(scan->xs_heapfetch);
1490 andres 553 ECB :
4202 tgl 554 GIC 5221147 : return NULL;
555 : }
1490 andres 556 CBC 16741485 : Assert(ItemPointerIsValid(&scan->xs_heaptid));
557 :
4202 tgl 558 GIC 16741485 : pgstat_count_index_tuples(scan->indexRelation, 1);
4202 tgl 559 ECB :
560 : /* Return the TID of the tuple we found. */
1490 andres 561 GIC 16741485 : return &scan->xs_heaptid;
4202 tgl 562 ECB : }
563 :
564 : /* ----------------
565 : * index_fetch_heap - get the scan's next heap tuple
566 : *
567 : * The result is a visible heap tuple associated with the index TID most
568 : * recently fetched by index_getnext_tid, or NULL if no more matching tuples
569 : * exist. (There can be more than one matching tuple because of HOT chains,
570 : * although when using an MVCC snapshot it should be impossible for more than
571 : * one such tuple to exist.)
572 : *
573 : * On success, the buffer containing the heap tup is pinned (the pin will be
574 : * dropped in a future index_getnext_tid, index_fetch_heap or index_endscan
575 : * call).
576 : *
577 : * Note: caller must check scan->xs_recheck, and perform rechecking of the
578 : * scan keys if required. We do not do that here because we don't have
579 : * enough information to do it efficiently in the general case.
580 : * ----------------
581 : */
582 : bool
1490 andres 583 GIC 15331487 : index_fetch_heap(IndexScanDesc scan, TupleTableSlot *slot)
584 : {
4304 rhaas 585 15331487 : bool all_dead = false;
586 : bool found;
587 :
1490 andres 588 15331487 : found = table_index_fetch_tuple(scan->xs_heapfetch, &scan->xs_heaptid,
589 : scan->xs_snapshot, slot,
590 : &scan->xs_heap_continue, &all_dead);
5323 alvherre 591 ECB :
1490 andres 592 GIC 15331482 : if (found)
4202 tgl 593 CBC 14679918 : pgstat_count_heap_fetch(scan->indexRelation);
594 :
595 : /*
4202 tgl 596 ECB : * If we scanned a whole HOT chain and found only dead tuples, tell index
597 : * AM to kill its entry for that TID (this will take effect in the next
598 : * amgettuple call, in index_getnext_tid). We do not do this when in
599 : * recovery because it may violate MVCC to do so. See comments in
600 : * RelationGetIndexScan().
601 : */
4202 tgl 602 GIC 15331482 : if (!scan->xactStartedInRecovery)
603 15200175 : scan->kill_prior_tuple = all_dead;
604 :
1490 andres 605 15331482 : return found;
606 : }
607 :
608 : /* ----------------
609 : * index_getnext_slot - get the next tuple from a scan
4202 tgl 610 ECB : *
1490 andres 611 : * The result is true if a tuple satisfying the scan keys and the snapshot was
612 : * found, false otherwise. The tuple is stored in the specified slot.
4202 tgl 613 : *
614 : * On success, resources (like buffer pins) are likely to be held, and will be
615 : * dropped by a future index_getnext_tid, index_fetch_heap or index_endscan
616 : * call).
617 : *
618 : * Note: caller must check scan->xs_recheck, and perform rechecking of the
619 : * scan keys if required. We do not do that here because we don't have
620 : * enough information to do it efficiently in the general case.
621 : * ----------------
622 : */
623 : bool
1490 andres 624 GIC 18934292 : index_getnext_slot(IndexScanDesc scan, ScanDirection direction, TupleTableSlot *slot)
625 : {
626 : for (;;)
627 : {
628 19499099 : if (!scan->xs_heap_continue)
629 : {
630 : ItemPointer tid;
631 :
4202 tgl 632 ECB : /* Time to fetch the next TID from the index */
4202 tgl 633 GIC 19325307 : tid = index_getnext_tid(scan, direction);
634 :
635 : /* If we're out of index entries, we're done */
4202 tgl 636 CBC 19325306 : if (tid == NULL)
5680 tgl 637 GIC 5181865 : break;
638 :
1490 andres 639 14143441 : Assert(ItemPointerEquals(tid, &scan->xs_heaptid));
640 : }
7625 tgl 641 ECB :
642 : /*
643 : * Fetch the next (or only) visible heap tuple for this index entry.
4202 644 : * If we don't find anything, loop around and grab the next TID from
645 : * the index.
646 : */
1490 andres 647 CBC 14317233 : Assert(ItemPointerIsValid(&scan->xs_heaptid));
1490 andres 648 GIC 14317233 : if (index_fetch_heap(scan, slot))
649 13752421 : return true;
650 : }
651 :
652 5181865 : return false;
653 : }
654 :
6587 tgl 655 ECB : /* ----------------
5477 656 : * index_getbitmap - get all tuples at once from an index scan
6587 657 : *
658 : * Adds the TIDs of all heap tuples satisfying the scan keys to a bitmap.
659 : * Since there's no interlock between the index scan and the eventual heap
660 : * access, this is only safe to use with MVCC-based snapshots: the heap
661 : * item slot could have been replaced by a newer tuple by the time we get
662 : * to it.
663 : *
664 : * Returns the number of matching tuples found. (Note: this might be only
665 : * approximate, so it should only be used for statistical purposes.)
666 : * ----------------
667 : */
668 : int64
5477 tgl 669 GIC 8697 : index_getbitmap(IndexScanDesc scan, TIDBitmap *bitmap)
670 : {
671 : int64 ntids;
672 :
6587 673 8697 : SCAN_CHECKS;
2639 674 8697 : CHECK_SCAN_PROCEDURE(amgetbitmap);
675 :
676 : /* just make sure this is false... */
6587 tgl 677 CBC 8697 : scan->kill_prior_tuple = false;
678 :
679 : /*
680 : * have the am's getbitmap proc do all the work.
6587 tgl 681 ECB : */
1539 andres 682 CBC 8697 : ntids = scan->indexRelation->rd_indam->amgetbitmap(scan, bitmap);
683 :
5477 tgl 684 GIC 8697 : pgstat_count_index_tuples(scan->indexRelation, ntids);
6394 tgl 685 ECB :
5477 tgl 686 GIC 8697 : return ntids;
687 : }
688 :
689 : /* ----------------
7938 tgl 690 ECB : * index_bulk_delete - do mass deletion of index entries
691 : *
692 : * callback routine tells whether a given main-heap tuple is
693 : * to be deleted
6031 bruce 694 : *
695 : * return value is an optional palloc'd struct of statistics
696 : * ----------------
697 : */
698 : IndexBulkDeleteResult *
6186 tgl 699 GIC 4075 : index_bulk_delete(IndexVacuumInfo *info,
700 : IndexBulkDeleteResult *istat,
701 : IndexBulkDeleteCallback callback,
702 : void *callback_state)
703 : {
704 4075 : Relation indexRelation = info->index;
705 :
7938 706 4075 : RELATION_CHECKS;
2639 tgl 707 CBC 4075 : CHECK_REL_PROCEDURE(ambulkdelete);
708 :
734 pg 709 GIC 4075 : return indexRelation->rd_indam->ambulkdelete(info, istat,
710 : callback, callback_state);
711 : }
7938 tgl 712 ECB :
713 : /* ----------------
7351 714 : * index_vacuum_cleanup - do post-deletion cleanup of an index
715 : *
716 : * return value is an optional palloc'd struct of statistics
717 : * ----------------
718 : */
719 : IndexBulkDeleteResult *
6186 tgl 720 GIC 94662 : index_vacuum_cleanup(IndexVacuumInfo *info,
721 : IndexBulkDeleteResult *istat)
722 : {
723 94662 : Relation indexRelation = info->index;
724 :
7351 725 94662 : RELATION_CHECKS;
2639 726 94662 : CHECK_REL_PROCEDURE(amvacuumcleanup);
727 :
734 pg 728 CBC 94662 : return indexRelation->rd_indam->amvacuumcleanup(info, istat);
729 : }
730 :
4130 tgl 731 ECB : /* ----------------
732 : * index_can_return
2936 heikki.linnakangas 733 : *
734 : * Does the index access method support index-only scans for the given
735 : * column?
4130 tgl 736 : * ----------------
737 : */
738 : bool
2936 heikki.linnakangas 739 GIC 537461 : index_can_return(Relation indexRelation, int attno)
740 : {
4130 tgl 741 537461 : RELATION_CHECKS;
742 :
743 : /* amcanreturn is optional; assume false if not provided by AM */
1539 andres 744 537461 : if (indexRelation->rd_indam->amcanreturn == NULL)
4130 tgl 745 136077 : return false;
746 :
1539 andres 747 CBC 401384 : return indexRelation->rd_indam->amcanreturn(indexRelation, attno);
748 : }
4130 tgl 749 ECB :
750 : /* ----------------
751 : * index_getprocid
9770 scrappy 752 : *
5951 tgl 753 : * Index access methods typically require support routines that are
754 : * not directly the implementation of any WHERE-clause query operator
755 : * and so cannot be kept in pg_amop. Instead, such routines are kept
756 : * in pg_amproc. These registered procedure OIDs are assigned numbers
757 : * according to a convention established by the access method.
758 : * The general index code doesn't know anything about the routines
759 : * involved; it just builds an ordered list of them for
760 : * each attribute on which an index is defined.
761 : *
762 : * As of Postgres 8.3, support routines within an operator family
763 : * are further subdivided by the "left type" and "right type" of the
764 : * query operator(s) that they support. The "default" functions for a
765 : * particular indexed attribute are those with both types equal to
766 : * the index opclass' opcintype (note that this is subtly different
767 : * from the indexed attribute's own type: it may be a binary-compatible
768 : * type instead). Only the default functions are stored in relcache
769 : * entries --- access methods can use the syscache to look up non-default
770 : * functions.
771 : *
772 : * This routine returns the requested default procedure OID for a
773 : * particular indexed attribute.
774 : * ----------------
775 : */
776 : RegProcedure
9770 scrappy 777 GIC 9861858 : index_getprocid(Relation irel,
778 : AttrNumber attnum,
779 : uint16 procnum)
780 : {
781 : RegProcedure *loc;
782 : int nproc;
783 : int procindex;
784 :
1539 andres 785 CBC 9861858 : nproc = irel->rd_indam->amsupport;
786 :
1105 akorotkov 787 GIC 9861858 : Assert(procnum > 0 && procnum <= (uint16) nproc);
788 :
789 9861858 : procindex = (nproc * (attnum - 1)) + (procnum - 1);
790 :
9345 bruce 791 9861858 : loc = irel->rd_support;
792 :
9345 bruce 793 CBC 9861858 : Assert(loc != NULL);
794 :
7855 tgl 795 9861858 : return loc[procindex];
796 : }
7855 tgl 797 ECB :
798 : /* ----------------
799 : * index_getprocinfo
800 : *
801 : * This routine allows index AMs to keep fmgr lookup info for
802 : * support procs in the relcache. As above, only the "default"
5951 803 : * functions for any particular indexed attribute are cached.
804 : *
805 : * Note: the return value points into cached data that will be lost during
806 : * any relcache rebuild! Therefore, either use the callinfo right away,
807 : * or save it only after having acquired some type of lock on the index rel.
808 : * ----------------
809 : */
810 : FmgrInfo *
7855 tgl 811 GIC 35338164 : index_getprocinfo(Relation irel,
812 : AttrNumber attnum,
813 : uint16 procnum)
814 : {
815 : FmgrInfo *locinfo;
816 : int nproc;
817 : int optsproc;
818 : int procindex;
7855 tgl 819 ECB :
1539 andres 820 GIC 35338164 : nproc = irel->rd_indam->amsupport;
1105 akorotkov 821 35338164 : optsproc = irel->rd_indam->amoptsprocnum;
822 :
823 35338164 : Assert(procnum > 0 && procnum <= (uint16) nproc);
824 :
825 35338164 : procindex = (nproc * (attnum - 1)) + (procnum - 1);
826 :
7855 tgl 827 35338164 : locinfo = irel->rd_supportinfo;
7855 tgl 828 ECB :
7855 tgl 829 CBC 35338164 : Assert(locinfo != NULL);
830 :
831 35338164 : locinfo += procindex;
832 :
7855 tgl 833 ECB : /* Initialize the lookup info if first time through */
7855 tgl 834 GIC 35338164 : if (locinfo->fn_oid == InvalidOid)
7855 tgl 835 ECB : {
7855 tgl 836 GIC 512595 : RegProcedure *loc = irel->rd_support;
7662 tgl 837 ECB : RegProcedure procId;
838 :
7855 tgl 839 CBC 512595 : Assert(loc != NULL);
840 :
7662 tgl 841 GIC 512595 : procId = loc[procindex];
7662 tgl 842 ECB :
843 : /*
6385 bruce 844 : * Complain if function was not found during IndexSupportInitialize.
845 : * This should not happen unless the system tables contain bogus
846 : * entries for the index opclass. (If an AM wants to allow a support
847 : * function to be optional, it can use index_getprocid.)
848 : */
7662 tgl 849 CBC 512595 : if (!RegProcedureIsValid(procId))
7202 tgl 850 UIC 0 : elog(ERROR, "missing support function %d for attribute %d of index \"%s\"",
851 : procnum, attnum, RelationGetRelationName(irel));
852 :
7662 tgl 853 GIC 512595 : fmgr_info_cxt(procId, locinfo, irel->rd_indexcxt);
854 :
1105 akorotkov 855 512595 : if (procnum != optsproc)
856 : {
1105 akorotkov 857 ECB : /* Initialize locinfo->fn_expr with opclass options Const */
1105 akorotkov 858 GBC 511840 : bytea **attoptions = RelationGetIndexAttOptions(irel, false);
1105 akorotkov 859 GIC 511840 : MemoryContext oldcxt = MemoryContextSwitchTo(irel->rd_indexcxt);
860 :
1105 akorotkov 861 CBC 511840 : set_fn_opclass_options(locinfo, attoptions[attnum - 1]);
862 :
863 511840 : MemoryContextSwitchTo(oldcxt);
864 : }
865 : }
7855 tgl 866 ECB :
7855 tgl 867 CBC 35338164 : return locinfo;
868 : }
1663 akorotkov 869 ECB :
870 : /* ----------------
871 : * index_store_float8_orderby_distances
872 : *
873 : * Convert AM distance function's results (that can be inexact)
874 : * to ORDER BY types and save them into xs_orderbyvals/xs_orderbynulls
875 : * for a possible recheck.
876 : * ----------------
877 : */
878 : void
1663 akorotkov 879 GIC 182300 : index_store_float8_orderby_distances(IndexScanDesc scan, Oid *orderByTypes,
880 : IndexOrderByDistance *distances,
881 : bool recheckOrderBy)
882 : {
883 : int i;
884 :
1297 885 182300 : Assert(distances || !recheckOrderBy);
886 :
1297 akorotkov 887 CBC 182300 : scan->xs_recheckorderby = recheckOrderBy;
888 :
1663 akorotkov 889 GIC 364609 : for (i = 0; i < scan->numberOfOrderBys; i++)
890 : {
891 182309 : if (orderByTypes[i] == FLOAT8OID)
892 : {
1663 akorotkov 893 ECB : #ifndef USE_FLOAT8_BYVAL
894 : /* must free any old value to avoid memory leakage */
895 : if (!scan->xs_orderbynulls[i])
896 : pfree(DatumGetPointer(scan->xs_orderbyvals[i]));
897 : #endif
1297 akorotkov 898 GIC 182244 : if (distances && !distances[i].isnull)
1297 akorotkov 899 ECB : {
1298 akorotkov 900 GIC 182214 : scan->xs_orderbyvals[i] = Float8GetDatum(distances[i].value);
1297 901 182214 : scan->xs_orderbynulls[i] = false;
902 : }
903 : else
904 : {
905 30 : scan->xs_orderbyvals[i] = (Datum) 0;
1297 akorotkov 906 CBC 30 : scan->xs_orderbynulls[i] = true;
907 : }
1663 akorotkov 908 ECB : }
1663 akorotkov 909 CBC 65 : else if (orderByTypes[i] == FLOAT4OID)
910 : {
911 : /* convert distance function's result to ORDER BY type */
1297 akorotkov 912 GIC 35 : if (distances && !distances[i].isnull)
1297 akorotkov 913 ECB : {
1298 akorotkov 914 CBC 35 : scan->xs_orderbyvals[i] = Float4GetDatum((float4) distances[i].value);
1297 akorotkov 915 GIC 35 : scan->xs_orderbynulls[i] = false;
916 : }
1297 akorotkov 917 ECB : else
918 : {
1297 akorotkov 919 UIC 0 : scan->xs_orderbyvals[i] = (Datum) 0;
1297 akorotkov 920 LBC 0 : scan->xs_orderbynulls[i] = true;
921 : }
1663 akorotkov 922 ECB : }
923 : else
924 : {
925 : /*
926 : * If the ordering operator's return value is anything else, we
1663 akorotkov 927 EUB : * don't know how to convert the float8 bound calculated by the
928 : * distance function to that. The executor won't actually need
929 : * the order by values we return here, if there are no lossy
930 : * results, so only insist on converting if the *recheck flag is
931 : * set.
932 : */
1663 akorotkov 933 GIC 30 : if (scan->xs_recheckorderby)
1663 akorotkov 934 UIC 0 : elog(ERROR, "ORDER BY operator must return float8 or float4 if the distance function is lossy");
1663 akorotkov 935 GIC 30 : scan->xs_orderbynulls[i] = true;
936 : }
937 : }
938 182300 : }
939 :
940 : /* ----------------
1105 akorotkov 941 ECB : * index_opclass_options
1105 akorotkov 942 EUB : *
1105 akorotkov 943 ECB : * Parse opclass-specific options for index column.
944 : * ----------------
945 : */
946 : bytea *
1105 akorotkov 947 GIC 397949 : index_opclass_options(Relation indrel, AttrNumber attnum, Datum attoptions,
948 : bool validate)
949 : {
950 397949 : int amoptsprocnum = indrel->rd_indam->amoptsprocnum;
951 397949 : Oid procid = InvalidOid;
952 : FmgrInfo *procinfo;
953 : local_relopts relopts;
954 :
1105 akorotkov 955 ECB : /* fetch options support procedure if specified */
1105 akorotkov 956 GIC 397949 : if (amoptsprocnum != 0)
1060 tgl 957 397921 : procid = index_getprocid(indrel, attnum, amoptsprocnum);
1105 akorotkov 958 ECB :
1105 akorotkov 959 CBC 397949 : if (!OidIsValid(procid))
960 : {
961 : Oid opclass;
962 : Datum indclassDatum;
963 : oidvector *indclass;
1105 akorotkov 964 ECB :
1105 akorotkov 965 GIC 397116 : if (!DatumGetPointer(attoptions))
1060 tgl 966 CBC 397113 : return NULL; /* ok, no options, no procedure */
967 :
968 : /*
969 : * Report an error if the opclass's options-parsing procedure does not
970 : * exist but the opclass options are specified.
971 : */
15 dgustafsson 972 GNC 3 : indclassDatum = SysCacheGetAttrNotNull(INDEXRELID, indrel->rd_indextuple,
973 : Anum_pg_index_indclass);
1105 akorotkov 974 GIC 3 : indclass = (oidvector *) DatumGetPointer(indclassDatum);
975 3 : opclass = indclass->values[attnum - 1];
976 :
977 3 : ereport(ERROR,
1105 akorotkov 978 ECB : (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
979 : errmsg("operator class %s has no options",
980 : generate_opclass_name(opclass))));
981 : }
982 :
1105 akorotkov 983 CBC 833 : init_local_reloptions(&relopts, 0);
984 :
1105 akorotkov 985 GIC 833 : procinfo = index_getprocinfo(indrel, attnum, amoptsprocnum);
986 :
987 833 : (void) FunctionCall1(procinfo, PointerGetDatum(&relopts));
988 :
1105 akorotkov 989 CBC 833 : return build_local_reloptions(&relopts, attoptions, validate);
990 : }
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