Age Owner Branch data TLA Line data Source code
1 : : /*-------------------------------------------------------------------------
2 : : *
3 : : * execIndexing.c
4 : : * routines for inserting index tuples and enforcing unique and
5 : : * exclusion constraints.
6 : : *
7 : : * ExecInsertIndexTuples() is the main entry point. It's called after
8 : : * inserting a tuple to the heap, and it inserts corresponding index tuples
9 : : * into all indexes. At the same time, it enforces any unique and
10 : : * exclusion constraints:
11 : : *
12 : : * Unique Indexes
13 : : * --------------
14 : : *
15 : : * Enforcing a unique constraint is straightforward. When the index AM
16 : : * inserts the tuple to the index, it also checks that there are no
17 : : * conflicting tuples in the index already. It does so atomically, so that
18 : : * even if two backends try to insert the same key concurrently, only one
19 : : * of them will succeed. All the logic to ensure atomicity, and to wait
20 : : * for in-progress transactions to finish, is handled by the index AM.
21 : : *
22 : : * If a unique constraint is deferred, we request the index AM to not
23 : : * throw an error if a conflict is found. Instead, we make note that there
24 : : * was a conflict and return the list of indexes with conflicts to the
25 : : * caller. The caller must re-check them later, by calling index_insert()
26 : : * with the UNIQUE_CHECK_EXISTING option.
27 : : *
28 : : * Exclusion Constraints
29 : : * ---------------------
30 : : *
31 : : * Exclusion constraints are different from unique indexes in that when the
32 : : * tuple is inserted to the index, the index AM does not check for
33 : : * duplicate keys at the same time. After the insertion, we perform a
34 : : * separate scan on the index to check for conflicting tuples, and if one
35 : : * is found, we throw an error and the transaction is aborted. If the
36 : : * conflicting tuple's inserter or deleter is in-progress, we wait for it
37 : : * to finish first.
38 : : *
39 : : * There is a chance of deadlock, if two backends insert a tuple at the
40 : : * same time, and then perform the scan to check for conflicts. They will
41 : : * find each other's tuple, and both try to wait for each other. The
42 : : * deadlock detector will detect that, and abort one of the transactions.
43 : : * That's fairly harmless, as one of them was bound to abort with a
44 : : * "duplicate key error" anyway, although you get a different error
45 : : * message.
46 : : *
47 : : * If an exclusion constraint is deferred, we still perform the conflict
48 : : * checking scan immediately after inserting the index tuple. But instead
49 : : * of throwing an error if a conflict is found, we return that information
50 : : * to the caller. The caller must re-check them later by calling
51 : : * check_exclusion_constraint().
52 : : *
53 : : * Speculative insertion
54 : : * ---------------------
55 : : *
56 : : * Speculative insertion is a two-phase mechanism used to implement
57 : : * INSERT ... ON CONFLICT DO UPDATE/NOTHING. The tuple is first inserted
58 : : * to the heap and update the indexes as usual, but if a constraint is
59 : : * violated, we can still back out the insertion without aborting the whole
60 : : * transaction. In an INSERT ... ON CONFLICT statement, if a conflict is
61 : : * detected, the inserted tuple is backed out and the ON CONFLICT action is
62 : : * executed instead.
63 : : *
64 : : * Insertion to a unique index works as usual: the index AM checks for
65 : : * duplicate keys atomically with the insertion. But instead of throwing
66 : : * an error on a conflict, the speculatively inserted heap tuple is backed
67 : : * out.
68 : : *
69 : : * Exclusion constraints are slightly more complicated. As mentioned
70 : : * earlier, there is a risk of deadlock when two backends insert the same
71 : : * key concurrently. That was not a problem for regular insertions, when
72 : : * one of the transactions has to be aborted anyway, but with a speculative
73 : : * insertion we cannot let a deadlock happen, because we only want to back
74 : : * out the speculatively inserted tuple on conflict, not abort the whole
75 : : * transaction.
76 : : *
77 : : * When a backend detects that the speculative insertion conflicts with
78 : : * another in-progress tuple, it has two options:
79 : : *
80 : : * 1. back out the speculatively inserted tuple, then wait for the other
81 : : * transaction, and retry. Or,
82 : : * 2. wait for the other transaction, with the speculatively inserted tuple
83 : : * still in place.
84 : : *
85 : : * If two backends insert at the same time, and both try to wait for each
86 : : * other, they will deadlock. So option 2 is not acceptable. Option 1
87 : : * avoids the deadlock, but it is prone to a livelock instead. Both
88 : : * transactions will wake up immediately as the other transaction backs
89 : : * out. Then they both retry, and conflict with each other again, lather,
90 : : * rinse, repeat.
91 : : *
92 : : * To avoid the livelock, one of the backends must back out first, and then
93 : : * wait, while the other one waits without backing out. It doesn't matter
94 : : * which one backs out, so we employ an arbitrary rule that the transaction
95 : : * with the higher XID backs out.
96 : : *
97 : : *
98 : : * Portions Copyright (c) 1996-2025, PostgreSQL Global Development Group
99 : : * Portions Copyright (c) 1994, Regents of the University of California
100 : : *
101 : : *
102 : : * IDENTIFICATION
103 : : * src/backend/executor/execIndexing.c
104 : : *
105 : : *-------------------------------------------------------------------------
106 : : */
107 : : #include "postgres.h"
108 : :
109 : : #include "access/genam.h"
110 : : #include "access/relscan.h"
111 : : #include "access/tableam.h"
112 : : #include "access/xact.h"
113 : : #include "catalog/index.h"
114 : : #include "executor/executor.h"
115 : : #include "nodes/nodeFuncs.h"
116 : : #include "storage/lmgr.h"
117 : : #include "utils/injection_point.h"
118 : : #include "utils/multirangetypes.h"
119 : : #include "utils/rangetypes.h"
120 : : #include "utils/snapmgr.h"
121 : :
122 : : /* waitMode argument to check_exclusion_or_unique_constraint() */
123 : : typedef enum
124 : : {
125 : : CEOUC_WAIT,
126 : : CEOUC_NOWAIT,
127 : : CEOUC_LIVELOCK_PREVENTING_WAIT,
128 : : } CEOUC_WAIT_MODE;
129 : :
130 : : static bool check_exclusion_or_unique_constraint(Relation heap, Relation index,
131 : : IndexInfo *indexInfo,
132 : : const ItemPointerData *tupleid,
133 : : const Datum *values, const bool *isnull,
134 : : EState *estate, bool newIndex,
135 : : CEOUC_WAIT_MODE waitMode,
136 : : bool violationOK,
137 : : ItemPointer conflictTid);
138 : :
139 : : static bool index_recheck_constraint(Relation index, const Oid *constr_procs,
140 : : const Datum *existing_values, const bool *existing_isnull,
141 : : const Datum *new_values);
142 : : static bool index_unchanged_by_update(ResultRelInfo *resultRelInfo,
143 : : EState *estate, IndexInfo *indexInfo,
144 : : Relation indexRelation);
145 : : static bool index_expression_changed_walker(Node *node,
146 : : Bitmapset *allUpdatedCols);
147 : : static void ExecWithoutOverlapsNotEmpty(Relation rel, NameData attname, Datum attval,
148 : : char typtype, Oid atttypid);
149 : :
150 : : /* ----------------------------------------------------------------
151 : : * ExecOpenIndices
152 : : *
153 : : * Find the indices associated with a result relation, open them,
154 : : * and save information about them in the result ResultRelInfo.
155 : : *
156 : : * At entry, caller has already opened and locked
157 : : * resultRelInfo->ri_RelationDesc.
158 : : * ----------------------------------------------------------------
159 : : */
160 : : void
3875 andres@anarazel.de 161 :CBC 974274 : ExecOpenIndices(ResultRelInfo *resultRelInfo, bool speculative)
162 : : {
3889 heikki.linnakangas@i 163 : 974274 : Relation resultRelation = resultRelInfo->ri_RelationDesc;
164 : : List *indexoidlist;
165 : : ListCell *l;
166 : : int len,
167 : : i;
168 : : RelationPtr relationDescs;
169 : : IndexInfo **indexInfoArray;
170 : :
171 : 974274 : resultRelInfo->ri_NumIndices = 0;
172 : :
173 : : /* fast path if no indexes */
174 [ + + ]: 974274 : if (!RelationGetForm(resultRelation)->relhasindex)
175 : 41282 : return;
176 : :
177 : : /*
178 : : * Get cached list of index OIDs
179 : : */
180 : 932992 : indexoidlist = RelationGetIndexList(resultRelation);
181 : 932992 : len = list_length(indexoidlist);
182 [ + + ]: 932992 : if (len == 0)
183 : 20296 : return;
184 : :
185 : : /* This Assert will fail if ExecOpenIndices is called twice */
300 tgl@sss.pgh.pa.us 186 [ - + ]: 912696 : Assert(resultRelInfo->ri_IndexRelationDescs == NULL);
187 : :
188 : : /*
189 : : * allocate space for result arrays
190 : : */
6 michael@paquier.xyz 191 :GNC 912696 : relationDescs = palloc_array(Relation, len);
192 : 912696 : indexInfoArray = palloc_array(IndexInfo *, len);
193 : :
3889 heikki.linnakangas@i 194 :CBC 912696 : resultRelInfo->ri_NumIndices = len;
195 : 912696 : resultRelInfo->ri_IndexRelationDescs = relationDescs;
196 : 912696 : resultRelInfo->ri_IndexRelationInfo = indexInfoArray;
197 : :
198 : : /*
199 : : * For each index, open the index relation and save pg_index info. We
200 : : * acquire RowExclusiveLock, signifying we will update the index.
201 : : *
202 : : * Note: we do this even if the index is not indisready; it's not worth
203 : : * the trouble to optimize for the case where it isn't.
204 : : */
205 : 912696 : i = 0;
206 [ + - + + : 2748319 : foreach(l, indexoidlist)
+ + ]
207 : : {
208 : 1835623 : Oid indexOid = lfirst_oid(l);
209 : : Relation indexDesc;
210 : : IndexInfo *ii;
211 : :
212 : 1835623 : indexDesc = index_open(indexOid, RowExclusiveLock);
213 : :
214 : : /* extract index key information from the index's pg_index info */
215 : 1835623 : ii = BuildIndexInfo(indexDesc);
216 : :
217 : : /*
218 : : * If the indexes are to be used for speculative insertion, add extra
219 : : * information required by unique index entries.
220 : : */
455 peter@eisentraut.org 221 [ + + + + : 1835623 : if (speculative && ii->ii_Unique && !indexDesc->rd_index->indisexclusion)
+ + ]
3875 andres@anarazel.de 222 : 638 : BuildSpeculativeIndexInfo(indexDesc, ii);
223 : :
3889 heikki.linnakangas@i 224 : 1835623 : relationDescs[i] = indexDesc;
225 : 1835623 : indexInfoArray[i] = ii;
226 : 1835623 : i++;
227 : : }
228 : :
229 : 912696 : list_free(indexoidlist);
230 : : }
231 : :
232 : : /* ----------------------------------------------------------------
233 : : * ExecCloseIndices
234 : : *
235 : : * Close the index relations stored in resultRelInfo
236 : : * ----------------------------------------------------------------
237 : : */
238 : : void
239 : 1013508 : ExecCloseIndices(ResultRelInfo *resultRelInfo)
240 : : {
241 : : int i;
242 : : int numIndices;
243 : : RelationPtr indexDescs;
244 : : IndexInfo **indexInfos;
245 : :
246 : 1013508 : numIndices = resultRelInfo->ri_NumIndices;
247 : 1013508 : indexDescs = resultRelInfo->ri_IndexRelationDescs;
752 tomas.vondra@postgre 248 : 1013508 : indexInfos = resultRelInfo->ri_IndexRelationInfo;
249 : :
3889 heikki.linnakangas@i 250 [ + + ]: 2848121 : for (i = 0; i < numIndices; i++)
251 : : {
252 : : /* This Assert will fail if ExecCloseIndices is called twice */
300 tgl@sss.pgh.pa.us 253 [ - + ]: 1834613 : Assert(indexDescs[i] != NULL);
254 : :
255 : : /* Give the index a chance to do some post-insert cleanup */
752 tomas.vondra@postgre 256 : 1834613 : index_insert_cleanup(indexDescs[i], indexInfos[i]);
257 : :
258 : : /* Drop lock acquired by ExecOpenIndices */
3889 heikki.linnakangas@i 259 : 1834613 : index_close(indexDescs[i], RowExclusiveLock);
260 : :
261 : : /* Mark the index as closed */
300 tgl@sss.pgh.pa.us 262 : 1834613 : indexDescs[i] = NULL;
263 : : }
264 : :
265 : : /*
266 : : * We don't attempt to free the IndexInfo data structures or the arrays,
267 : : * instead assuming that such stuff will be cleaned up automatically in
268 : : * FreeExecutorState.
269 : : */
3889 heikki.linnakangas@i 270 : 1013508 : }
271 : :
272 : : /* ----------------------------------------------------------------
273 : : * ExecInsertIndexTuples
274 : : *
275 : : * This routine takes care of inserting index tuples
276 : : * into all the relations indexing the result relation
277 : : * when a heap tuple is inserted into the result relation.
278 : : *
279 : : * When 'update' is true and 'onlySummarizing' is false,
280 : : * executor is performing an UPDATE that could not use an
281 : : * optimization like heapam's HOT (in more general terms a
282 : : * call to table_tuple_update() took place and set
283 : : * 'update_indexes' to TU_All). Receiving this hint makes
284 : : * us consider if we should pass down the 'indexUnchanged'
285 : : * hint in turn. That's something that we figure out for
286 : : * each index_insert() call iff 'update' is true.
287 : : * (When 'update' is false we already know not to pass the
288 : : * hint to any index.)
289 : : *
290 : : * If onlySummarizing is set, an equivalent optimization to
291 : : * HOT has been applied and any updated columns are indexed
292 : : * only by summarizing indexes (or in more general terms a
293 : : * call to table_tuple_update() took place and set
294 : : * 'update_indexes' to TU_Summarizing). We can (and must)
295 : : * therefore only update the indexes that have
296 : : * 'amsummarizing' = true.
297 : : *
298 : : * Unique and exclusion constraints are enforced at the same
299 : : * time. This returns a list of index OIDs for any unique or
300 : : * exclusion constraints that are deferred and that had
301 : : * potential (unconfirmed) conflicts. (if noDupErr == true,
302 : : * the same is done for non-deferred constraints, but report
303 : : * if conflict was speculative or deferred conflict to caller)
304 : : *
305 : : * If 'arbiterIndexes' is nonempty, noDupErr applies only to
306 : : * those indexes. NIL means noDupErr applies to all indexes.
307 : : * ----------------------------------------------------------------
308 : : */
309 : : List *
1889 310 : 1824227 : ExecInsertIndexTuples(ResultRelInfo *resultRelInfo,
311 : : TupleTableSlot *slot,
312 : : EState *estate,
313 : : bool update,
314 : : bool noDupErr,
315 : : bool *specConflict,
316 : : List *arbiterIndexes,
317 : : bool onlySummarizing)
318 : : {
2460 andres@anarazel.de 319 : 1824227 : ItemPointer tupleid = &slot->tts_tid;
3889 heikki.linnakangas@i 320 : 1824227 : List *result = NIL;
321 : : int i;
322 : : int numIndices;
323 : : RelationPtr relationDescs;
324 : : Relation heapRelation;
325 : : IndexInfo **indexInfoArray;
326 : : ExprContext *econtext;
327 : : Datum values[INDEX_MAX_KEYS];
328 : : bool isnull[INDEX_MAX_KEYS];
329 : :
2460 andres@anarazel.de 330 [ - + ]: 1824227 : Assert(ItemPointerIsValid(tupleid));
331 : :
332 : : /*
333 : : * Get information from the result relation info structure.
334 : : */
3889 heikki.linnakangas@i 335 : 1824227 : numIndices = resultRelInfo->ri_NumIndices;
336 : 1824227 : relationDescs = resultRelInfo->ri_IndexRelationDescs;
337 : 1824227 : indexInfoArray = resultRelInfo->ri_IndexRelationInfo;
338 : 1824227 : heapRelation = resultRelInfo->ri_RelationDesc;
339 : :
340 : : /* Sanity check: slot must belong to the same rel as the resultRelInfo. */
2386 drowley@postgresql.o 341 [ - + ]: 1824227 : Assert(slot->tts_tableOid == RelationGetRelid(heapRelation));
342 : :
343 : : /*
344 : : * We will use the EState's per-tuple context for evaluating predicates
345 : : * and index expressions (creating it if it's not already there).
346 : : */
3889 heikki.linnakangas@i 347 [ + + ]: 1824227 : econtext = GetPerTupleExprContext(estate);
348 : :
349 : : /* Arrange for econtext's scan tuple to be the tuple under test */
350 : 1824227 : econtext->ecxt_scantuple = slot;
351 : :
352 : : /*
353 : : * for each index, form and insert the index tuple
354 : : */
355 [ + + ]: 3832632 : for (i = 0; i < numIndices; i++)
356 : : {
357 : 2008761 : Relation indexRelation = relationDescs[i];
358 : : IndexInfo *indexInfo;
359 : : bool applyNoDupErr;
360 : : IndexUniqueCheck checkUnique;
361 : : bool indexUnchanged;
362 : : bool satisfiesConstraint;
363 : :
364 [ - + ]: 2008761 : if (indexRelation == NULL)
3889 heikki.linnakangas@i 365 :UBC 0 : continue;
366 : :
3889 heikki.linnakangas@i 367 :CBC 2008761 : indexInfo = indexInfoArray[i];
368 : :
369 : : /* If the index is marked as read-only, ignore it */
370 [ + + ]: 2008761 : if (!indexInfo->ii_ReadyForInserts)
371 : 106 : continue;
372 : :
373 : : /*
374 : : * Skip processing of non-summarizing indexes if we only update
375 : : * summarizing indexes
376 : : */
1002 tomas.vondra@postgre 377 [ + + + + ]: 2008655 : if (onlySummarizing && !indexInfo->ii_Summarizing)
378 : 3 : continue;
379 : :
380 : : /* Check for partial index */
3889 heikki.linnakangas@i 381 [ + + ]: 2008652 : if (indexInfo->ii_Predicate != NIL)
382 : : {
383 : : ExprState *predicate;
384 : :
385 : : /*
386 : : * If predicate state not set up yet, create it (in the estate's
387 : : * per-query context)
388 : : */
389 : 200551 : predicate = indexInfo->ii_PredicateState;
3199 andres@anarazel.de 390 [ + + ]: 200551 : if (predicate == NULL)
391 : : {
392 : 136 : predicate = ExecPrepareQual(indexInfo->ii_Predicate, estate);
3889 heikki.linnakangas@i 393 : 136 : indexInfo->ii_PredicateState = predicate;
394 : : }
395 : :
396 : : /* Skip this index-update if the predicate isn't satisfied */
3199 andres@anarazel.de 397 [ + + ]: 200551 : if (!ExecQual(predicate, econtext))
3889 heikki.linnakangas@i 398 : 200280 : continue;
399 : : }
400 : :
401 : : /*
402 : : * FormIndexDatum fills in its values and isnull parameters with the
403 : : * appropriate values for the column(s) of the index.
404 : : */
405 : 1808372 : FormIndexDatum(indexInfo,
406 : : slot,
407 : : estate,
408 : : values,
409 : : isnull);
410 : :
411 : : /* Check whether to apply noDupErr to this index */
3452 tgl@sss.pgh.pa.us 412 [ + + + + ]: 1886201 : applyNoDupErr = noDupErr &&
413 [ + + ]: 77829 : (arbiterIndexes == NIL ||
414 : 77829 : list_member_oid(arbiterIndexes,
415 : 77829 : indexRelation->rd_index->indexrelid));
416 : :
417 : : /*
418 : : * The index AM does the actual insertion, plus uniqueness checking.
419 : : *
420 : : * For an immediate-mode unique index, we just tell the index AM to
421 : : * throw error if not unique.
422 : : *
423 : : * For a deferrable unique index, we tell the index AM to just detect
424 : : * possible non-uniqueness, and we add the index OID to the result
425 : : * list if further checking is needed.
426 : : *
427 : : * For a speculative insertion (used by INSERT ... ON CONFLICT), do
428 : : * the same as for a deferrable unique index.
429 : : */
3889 heikki.linnakangas@i 430 [ + + ]: 1808372 : if (!indexRelation->rd_index->indisunique)
431 : 956625 : checkUnique = UNIQUE_CHECK_NO;
3452 tgl@sss.pgh.pa.us 432 [ + + ]: 851747 : else if (applyNoDupErr)
3875 andres@anarazel.de 433 : 77867 : checkUnique = UNIQUE_CHECK_PARTIAL;
3889 heikki.linnakangas@i 434 [ + + ]: 773880 : else if (indexRelation->rd_index->indimmediate)
435 : 773805 : checkUnique = UNIQUE_CHECK_YES;
436 : : else
437 : 75 : checkUnique = UNIQUE_CHECK_PARTIAL;
438 : :
439 : : /*
440 : : * There's definitely going to be an index_insert() call for this
441 : : * index. If we're being called as part of an UPDATE statement,
442 : : * consider if the 'indexUnchanged' = true hint should be passed.
443 : : */
1798 pg@bowt.ie 444 [ + + + + ]: 1808372 : indexUnchanged = update && index_unchanged_by_update(resultRelInfo,
445 : : estate,
446 : : indexInfo,
447 : : indexRelation);
448 : :
449 : : satisfiesConstraint =
3889 heikki.linnakangas@i 450 : 1808372 : index_insert(indexRelation, /* index relation */
451 : : values, /* array of index Datums */
452 : : isnull, /* null flags */
453 : : tupleid, /* tid of heap tuple */
454 : : heapRelation, /* heap relation */
455 : : checkUnique, /* type of uniqueness check to do */
456 : : indexUnchanged, /* UPDATE without logical change? */
457 : : indexInfo); /* index AM may need this */
458 : :
459 : : /*
460 : : * If the index has an associated exclusion constraint, check that.
461 : : * This is simpler than the process for uniqueness checks since we
462 : : * always insert first and then check. If the constraint is deferred,
463 : : * we check now anyway, but don't throw error on violation or wait for
464 : : * a conclusive outcome from a concurrent insertion; instead we'll
465 : : * queue a recheck event. Similarly, noDupErr callers (speculative
466 : : * inserters) will recheck later, and wait for a conclusive outcome
467 : : * then.
468 : : *
469 : : * An index for an exclusion constraint can't also be UNIQUE (not an
470 : : * essential property, we just don't allow it in the grammar), so no
471 : : * need to preserve the prior state of satisfiesConstraint.
472 : : */
473 [ + + ]: 1808103 : if (indexInfo->ii_ExclusionOps != NULL)
474 : : {
475 : : bool violationOK;
476 : : CEOUC_WAIT_MODE waitMode;
477 : :
3452 tgl@sss.pgh.pa.us 478 [ + + ]: 997 : if (applyNoDupErr)
479 : : {
3875 andres@anarazel.de 480 : 72 : violationOK = true;
481 : 72 : waitMode = CEOUC_LIVELOCK_PREVENTING_WAIT;
482 : : }
483 [ + + ]: 925 : else if (!indexRelation->rd_index->indimmediate)
484 : : {
485 : 21 : violationOK = true;
486 : 21 : waitMode = CEOUC_NOWAIT;
487 : : }
488 : : else
489 : : {
490 : 904 : violationOK = false;
491 : 904 : waitMode = CEOUC_WAIT;
492 : : }
493 : :
494 : : satisfiesConstraint =
495 : 997 : check_exclusion_or_unique_constraint(heapRelation,
496 : : indexRelation, indexInfo,
497 : : tupleid, values, isnull,
498 : : estate, false,
499 : : waitMode, violationOK, NULL);
500 : : }
501 : :
3889 heikki.linnakangas@i 502 [ + + ]: 1808016 : if ((checkUnique == UNIQUE_CHECK_PARTIAL ||
503 [ + + ]: 1730074 : indexInfo->ii_ExclusionOps != NULL) &&
504 [ + + ]: 78780 : !satisfiesConstraint)
505 : : {
506 : : /*
507 : : * The tuple potentially violates the uniqueness or exclusion
508 : : * constraint, so make a note of the index so that we can re-check
509 : : * it later. Speculative inserters are told if there was a
510 : : * speculative conflict, since that always requires a restart.
511 : : */
512 : 118 : result = lappend_oid(result, RelationGetRelid(indexRelation));
3875 andres@anarazel.de 513 [ + + + - ]: 118 : if (indexRelation->rd_index->indimmediate && specConflict)
514 : 57 : *specConflict = true;
515 : : }
516 : : }
517 : :
3889 heikki.linnakangas@i 518 : 1823871 : return result;
519 : : }
520 : :
521 : : /* ----------------------------------------------------------------
522 : : * ExecCheckIndexConstraints
523 : : *
524 : : * This routine checks if a tuple violates any unique or
525 : : * exclusion constraints. Returns true if there is no conflict.
526 : : * Otherwise returns false, and the TID of the conflicting
527 : : * tuple is returned in *conflictTid.
528 : : *
529 : : * If 'arbiterIndexes' is given, only those indexes are checked.
530 : : * NIL means all indexes.
531 : : *
532 : : * Note that this doesn't lock the values in any way, so it's
533 : : * possible that a conflicting tuple is inserted immediately
534 : : * after this returns. This can be used for either a pre-check
535 : : * before insertion or a re-check after finding a conflict.
536 : : *
537 : : * 'tupleid' should be the TID of the tuple that has been recently
538 : : * inserted (or can be invalid if we haven't inserted a new tuple yet).
539 : : * This tuple will be excluded from conflict checking.
540 : : * ----------------------------------------------------------------
541 : : */
542 : : bool
1889 543 : 4857 : ExecCheckIndexConstraints(ResultRelInfo *resultRelInfo, TupleTableSlot *slot,
544 : : EState *estate, ItemPointer conflictTid,
545 : : const ItemPointerData *tupleid, List *arbiterIndexes)
546 : : {
547 : : int i;
548 : : int numIndices;
549 : : RelationPtr relationDescs;
550 : : Relation heapRelation;
551 : : IndexInfo **indexInfoArray;
552 : : ExprContext *econtext;
553 : : Datum values[INDEX_MAX_KEYS];
554 : : bool isnull[INDEX_MAX_KEYS];
555 : : ItemPointerData invalidItemPtr;
3875 andres@anarazel.de 556 : 4857 : bool checkedIndex = false;
557 : :
558 : 4857 : ItemPointerSetInvalid(conflictTid);
559 : 4857 : ItemPointerSetInvalid(&invalidItemPtr);
560 : :
561 : : /*
562 : : * Get information from the result relation info structure.
563 : : */
564 : 4857 : numIndices = resultRelInfo->ri_NumIndices;
565 : 4857 : relationDescs = resultRelInfo->ri_IndexRelationDescs;
566 : 4857 : indexInfoArray = resultRelInfo->ri_IndexRelationInfo;
567 : 4857 : heapRelation = resultRelInfo->ri_RelationDesc;
568 : :
569 : : /*
570 : : * We will use the EState's per-tuple context for evaluating predicates
571 : : * and index expressions (creating it if it's not already there).
572 : : */
573 [ + + ]: 4857 : econtext = GetPerTupleExprContext(estate);
574 : :
575 : : /* Arrange for econtext's scan tuple to be the tuple under test */
576 : 4857 : econtext->ecxt_scantuple = slot;
577 : :
578 : : /*
579 : : * For each index, form index tuple and check if it satisfies the
580 : : * constraint.
581 : : */
582 [ + + ]: 7010 : for (i = 0; i < numIndices; i++)
583 : : {
584 : 4927 : Relation indexRelation = relationDescs[i];
585 : : IndexInfo *indexInfo;
586 : : bool satisfiesConstraint;
587 : :
588 [ - + ]: 4927 : if (indexRelation == NULL)
3875 andres@anarazel.de 589 :UBC 0 : continue;
590 : :
3875 andres@anarazel.de 591 :CBC 4927 : indexInfo = indexInfoArray[i];
592 : :
593 [ + + + + ]: 4927 : if (!indexInfo->ii_Unique && !indexInfo->ii_ExclusionOps)
594 : 2 : continue;
595 : :
596 : : /* If the index is marked as read-only, ignore it */
597 [ - + ]: 4925 : if (!indexInfo->ii_ReadyForInserts)
3875 andres@anarazel.de 598 :UBC 0 : continue;
599 : :
600 : : /* When specific arbiter indexes requested, only examine them */
3875 andres@anarazel.de 601 [ + + ]:CBC 4925 : if (arbiterIndexes != NIL &&
602 [ + + ]: 4790 : !list_member_oid(arbiterIndexes,
603 : 4790 : indexRelation->rd_index->indexrelid))
604 : 65 : continue;
605 : :
606 [ + + ]: 4860 : if (!indexRelation->rd_index->indimmediate)
607 [ + - ]: 3 : ereport(ERROR,
608 : : (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
609 : : errmsg("ON CONFLICT does not support deferrable unique constraints/exclusion constraints as arbiters"),
610 : : errtableconstraint(heapRelation,
611 : : RelationGetRelationName(indexRelation))));
612 : :
613 : 4857 : checkedIndex = true;
614 : :
615 : : /* Check for partial index */
616 [ + + ]: 4857 : if (indexInfo->ii_Predicate != NIL)
617 : : {
618 : : ExprState *predicate;
619 : :
620 : : /*
621 : : * If predicate state not set up yet, create it (in the estate's
622 : : * per-query context)
623 : : */
624 : 18 : predicate = indexInfo->ii_PredicateState;
3199 625 [ + - ]: 18 : if (predicate == NULL)
626 : : {
627 : 18 : predicate = ExecPrepareQual(indexInfo->ii_Predicate, estate);
3875 628 : 18 : indexInfo->ii_PredicateState = predicate;
629 : : }
630 : :
631 : : /* Skip this index-update if the predicate isn't satisfied */
3199 632 [ - + ]: 18 : if (!ExecQual(predicate, econtext))
3875 andres@anarazel.de 633 :UBC 0 : continue;
634 : : }
635 : :
636 : : /*
637 : : * FormIndexDatum fills in its values and isnull parameters with the
638 : : * appropriate values for the column(s) of the index.
639 : : */
3875 andres@anarazel.de 640 :CBC 4857 : FormIndexDatum(indexInfo,
641 : : slot,
642 : : estate,
643 : : values,
644 : : isnull);
645 : :
646 : : satisfiesConstraint =
647 : 4857 : check_exclusion_or_unique_constraint(heapRelation, indexRelation,
648 : : indexInfo, tupleid,
649 : : values, isnull, estate, false,
650 : : CEOUC_WAIT, true,
651 : : conflictTid);
652 [ + + ]: 4856 : if (!satisfiesConstraint)
653 : 2770 : return false;
654 : : }
655 : :
656 [ + + - + ]: 2083 : if (arbiterIndexes != NIL && !checkedIndex)
3875 andres@anarazel.de 657 [ # # ]:UBC 0 : elog(ERROR, "unexpected failure to find arbiter index");
658 : :
3875 andres@anarazel.de 659 :CBC 2083 : return true;
660 : : }
661 : :
662 : : /*
663 : : * Check for violation of an exclusion or unique constraint
664 : : *
665 : : * heap: the table containing the new tuple
666 : : * index: the index supporting the constraint
667 : : * indexInfo: info about the index, including the exclusion properties
668 : : * tupleid: heap TID of the new tuple we have just inserted (invalid if we
669 : : * haven't inserted a new tuple yet)
670 : : * values, isnull: the *index* column values computed for the new tuple
671 : : * estate: an EState we can do evaluation in
672 : : * newIndex: if true, we are trying to build a new index (this affects
673 : : * only the wording of error messages)
674 : : * waitMode: whether to wait for concurrent inserters/deleters
675 : : * violationOK: if true, don't throw error for violation
676 : : * conflictTid: if not-NULL, the TID of the conflicting tuple is returned here
677 : : *
678 : : * Returns true if OK, false if actual or potential violation
679 : : *
680 : : * 'waitMode' determines what happens if a conflict is detected with a tuple
681 : : * that was inserted or deleted by a transaction that's still running.
682 : : * CEOUC_WAIT means that we wait for the transaction to commit, before
683 : : * throwing an error or returning. CEOUC_NOWAIT means that we report the
684 : : * violation immediately; so the violation is only potential, and the caller
685 : : * must recheck sometime later. This behavior is convenient for deferred
686 : : * exclusion checks; we need not bother queuing a deferred event if there is
687 : : * definitely no conflict at insertion time.
688 : : *
689 : : * CEOUC_LIVELOCK_PREVENTING_WAIT is like CEOUC_NOWAIT, but we will sometimes
690 : : * wait anyway, to prevent livelocking if two transactions try inserting at
691 : : * the same time. This is used with speculative insertions, for INSERT ON
692 : : * CONFLICT statements. (See notes in file header)
693 : : *
694 : : * If violationOK is true, we just report the potential or actual violation to
695 : : * the caller by returning 'false'. Otherwise we throw a descriptive error
696 : : * message here. When violationOK is false, a false result is impossible.
697 : : *
698 : : * Note: The indexam is normally responsible for checking unique constraints,
699 : : * so this normally only needs to be used for exclusion constraints. But this
700 : : * function is also called when doing a "pre-check" for conflicts on a unique
701 : : * constraint, when doing speculative insertion. Caller may use the returned
702 : : * conflict TID to take further steps.
703 : : */
704 : : static bool
705 : 6093 : check_exclusion_or_unique_constraint(Relation heap, Relation index,
706 : : IndexInfo *indexInfo,
707 : : const ItemPointerData *tupleid,
708 : : const Datum *values, const bool *isnull,
709 : : EState *estate, bool newIndex,
710 : : CEOUC_WAIT_MODE waitMode,
711 : : bool violationOK,
712 : : ItemPointer conflictTid)
713 : : {
714 : : Oid *constr_procs;
715 : : uint16 *constr_strats;
3889 heikki.linnakangas@i 716 : 6093 : Oid *index_collations = index->rd_indcollation;
2810 teodor@sigaev.ru 717 : 6093 : int indnkeyatts = IndexRelationGetNumberOfKeyAttributes(index);
718 : : IndexScanDesc index_scan;
719 : : ScanKeyData scankeys[INDEX_MAX_KEYS];
720 : : SnapshotData DirtySnapshot;
721 : : int i;
722 : : bool conflict;
723 : : bool found_self;
724 : : ExprContext *econtext;
725 : : TupleTableSlot *existing_slot;
726 : : TupleTableSlot *save_scantuple;
727 : :
3875 andres@anarazel.de 728 [ + + ]: 6093 : if (indexInfo->ii_ExclusionOps)
729 : : {
730 : 1314 : constr_procs = indexInfo->ii_ExclusionProcs;
731 : 1314 : constr_strats = indexInfo->ii_ExclusionStrats;
732 : : }
733 : : else
734 : : {
735 : 4779 : constr_procs = indexInfo->ii_UniqueProcs;
736 : 4779 : constr_strats = indexInfo->ii_UniqueStrats;
737 : : }
738 : :
739 : : /*
740 : : * If this is a WITHOUT OVERLAPS constraint, we must also forbid empty
741 : : * ranges/multiranges. This must happen before we look for NULLs below, or
742 : : * a UNIQUE constraint could insert an empty range along with a NULL
743 : : * scalar part.
744 : : */
455 peter@eisentraut.org 745 [ + + ]: 6093 : if (indexInfo->ii_WithoutOverlaps)
746 : : {
747 : : /*
748 : : * Look up the type from the heap tuple, but check the Datum from the
749 : : * index tuple.
750 : : */
751 : 1111 : AttrNumber attno = indexInfo->ii_IndexAttrNumbers[indnkeyatts - 1];
752 : :
753 [ + + ]: 1111 : if (!isnull[indnkeyatts - 1])
754 : : {
755 : 1081 : TupleDesc tupdesc = RelationGetDescr(heap);
756 : 1081 : Form_pg_attribute att = TupleDescAttr(tupdesc, attno - 1);
757 : 1081 : TypeCacheEntry *typcache = lookup_type_cache(att->atttypid, 0);
758 : :
759 : 1081 : ExecWithoutOverlapsNotEmpty(heap, att->attname,
760 : 1081 : values[indnkeyatts - 1],
761 : 1081 : typcache->typtype, att->atttypid);
762 : : }
763 : : }
764 : :
765 : : /*
766 : : * If any of the input values are NULL, and the index uses the default
767 : : * nulls-are-distinct mode, the constraint check is assumed to pass (i.e.,
768 : : * we assume the operators are strict). Otherwise, we interpret the
769 : : * constraint as specifying IS NULL for each column whose input value is
770 : : * NULL.
771 : : */
1230 tgl@sss.pgh.pa.us 772 [ + + ]: 6051 : if (!indexInfo->ii_NullsNotDistinct)
773 : : {
774 [ + + ]: 13189 : for (i = 0; i < indnkeyatts; i++)
775 : : {
776 [ + + ]: 7201 : if (isnull[i])
777 : 60 : return true;
778 : : }
779 : : }
780 : :
781 : : /*
782 : : * Search the tuples that are in the index for any violations, including
783 : : * tuples that aren't visible yet.
784 : : */
3889 heikki.linnakangas@i 785 : 5991 : InitDirtySnapshot(DirtySnapshot);
786 : :
2810 teodor@sigaev.ru 787 [ + + ]: 13105 : for (i = 0; i < indnkeyatts; i++)
788 : : {
3889 heikki.linnakangas@i 789 : 7114 : ScanKeyEntryInitialize(&scankeys[i],
1230 tgl@sss.pgh.pa.us 790 : 7114 : isnull[i] ? SK_ISNULL | SK_SEARCHNULL : 0,
3889 heikki.linnakangas@i 791 : 7114 : i + 1,
792 : 7114 : constr_strats[i],
793 : : InvalidOid,
794 : 7114 : index_collations[i],
795 : 7114 : constr_procs[i],
796 [ + + ]: 7114 : values[i]);
797 : : }
798 : :
799 : : /*
800 : : * Need a TupleTableSlot to put existing tuples in.
801 : : *
802 : : * To use FormIndexDatum, we have to make the econtext's scantuple point
803 : : * to this slot. Be sure to save and restore caller's value for
804 : : * scantuple.
805 : : */
2472 andres@anarazel.de 806 : 5991 : existing_slot = table_slot_create(heap, NULL);
807 : :
3889 heikki.linnakangas@i 808 [ + - ]: 5991 : econtext = GetPerTupleExprContext(estate);
809 : 5991 : save_scantuple = econtext->ecxt_scantuple;
810 : 5991 : econtext->ecxt_scantuple = existing_slot;
811 : :
812 : : /*
813 : : * May have to restart scan from this point if a potential conflict is
814 : : * found.
815 : : */
816 : 6027 : retry:
817 : 6027 : conflict = false;
818 : 6027 : found_self = false;
280 pg@bowt.ie 819 : 6027 : index_scan = index_beginscan(heap, index, &DirtySnapshot, NULL, indnkeyatts, 0);
2810 teodor@sigaev.ru 820 : 6027 : index_rescan(index_scan, scankeys, indnkeyatts, NULL, 0);
821 : :
2472 andres@anarazel.de 822 [ + + ]: 7102 : while (index_getnext_slot(index_scan, ForwardScanDirection, existing_slot))
823 : : {
824 : : TransactionId xwait;
825 : : XLTW_Oper reason_wait;
826 : : Datum existing_values[INDEX_MAX_KEYS];
827 : : bool existing_isnull[INDEX_MAX_KEYS];
828 : : char *error_new;
829 : : char *error_existing;
830 : :
831 : : /*
832 : : * Ignore the entry for the tuple we're trying to check.
833 : : */
3875 834 [ + + + + ]: 5201 : if (ItemPointerIsValid(tupleid) &&
2472 835 : 1223 : ItemPointerEquals(tupleid, &existing_slot->tts_tid))
836 : : {
3889 heikki.linnakangas@i 837 [ - + ]: 1048 : if (found_self) /* should not happen */
3889 heikki.linnakangas@i 838 [ # # ]:UBC 0 : elog(ERROR, "found self tuple multiple times in index \"%s\"",
839 : : RelationGetRelationName(index));
3889 heikki.linnakangas@i 840 :CBC 1048 : found_self = true;
841 : 1075 : continue;
842 : : }
843 : :
844 : : /*
845 : : * Extract the index column values and isnull flags from the existing
846 : : * tuple.
847 : : */
848 : 2930 : FormIndexDatum(indexInfo, existing_slot, estate,
849 : : existing_values, existing_isnull);
850 : :
851 : : /* If lossy indexscan, must recheck the condition */
852 [ + + ]: 2930 : if (index_scan->xs_recheck)
853 : : {
854 [ + + ]: 69 : if (!index_recheck_constraint(index,
855 : : constr_procs,
856 : : existing_values,
857 : : existing_isnull,
858 : : values))
859 : 27 : continue; /* tuple doesn't actually match, so no
860 : : * conflict */
861 : : }
862 : :
863 : : /*
864 : : * At this point we have either a conflict or a potential conflict.
865 : : *
866 : : * If an in-progress transaction is affecting the visibility of this
867 : : * tuple, we need to wait for it to complete and then recheck (unless
868 : : * the caller requested not to). For simplicity we do rechecking by
869 : : * just restarting the whole scan --- this case probably doesn't
870 : : * happen often enough to be worth trying harder, and anyway we don't
871 : : * want to hold any index internal locks while waiting.
872 : : */
873 : 5806 : xwait = TransactionIdIsValid(DirtySnapshot.xmin) ?
874 [ + + ]: 2903 : DirtySnapshot.xmin : DirtySnapshot.xmax;
875 : :
3875 andres@anarazel.de 876 [ + + - + ]: 2903 : if (TransactionIdIsValid(xwait) &&
3875 andres@anarazel.de 877 [ # # ]:UBC 0 : (waitMode == CEOUC_WAIT ||
878 : 0 : (waitMode == CEOUC_LIVELOCK_PREVENTING_WAIT &&
879 [ # # # # ]: 0 : DirtySnapshot.speculativeToken &&
880 : 0 : TransactionIdPrecedes(GetCurrentTransactionId(), xwait))))
881 : : {
3563 sfrost@snowman.net 882 :CBC 74 : reason_wait = indexInfo->ii_ExclusionOps ?
883 [ - + ]: 37 : XLTW_RecheckExclusionConstr : XLTW_InsertIndex;
3889 heikki.linnakangas@i 884 : 37 : index_endscan(index_scan);
3875 andres@anarazel.de 885 [ + + ]: 37 : if (DirtySnapshot.speculativeToken)
886 : 1 : SpeculativeInsertionWait(DirtySnapshot.xmin,
887 : : DirtySnapshot.speculativeToken);
888 : : else
2472 889 : 36 : XactLockTableWait(xwait, heap,
2472 andres@anarazel.de 890 :GIC 36 : &existing_slot->tts_tid, reason_wait);
3889 heikki.linnakangas@i 891 :CBC 36 : goto retry;
892 : : }
893 : :
894 : : /*
895 : : * We have a definite conflict (or a potential one, but the caller
896 : : * didn't want to wait). Return it to caller, or report it.
897 : : */
3875 andres@anarazel.de 898 [ + + ]: 2866 : if (violationOK)
899 : : {
900 : 2782 : conflict = true;
901 [ + + ]: 2782 : if (conflictTid)
2472 902 : 2770 : *conflictTid = existing_slot->tts_tid;
3875 903 : 2782 : break;
904 : : }
905 : :
3889 heikki.linnakangas@i 906 : 84 : error_new = BuildIndexValueDescription(index, values, isnull);
907 : 84 : error_existing = BuildIndexValueDescription(index, existing_values,
908 : : existing_isnull);
909 [ + + ]: 84 : if (newIndex)
910 [ + - + - : 18 : ereport(ERROR,
+ - ]
911 : : (errcode(ERRCODE_EXCLUSION_VIOLATION),
912 : : errmsg("could not create exclusion constraint \"%s\"",
913 : : RelationGetRelationName(index)),
914 : : error_new && error_existing ?
915 : : errdetail("Key %s conflicts with key %s.",
916 : : error_new, error_existing) :
917 : : errdetail("Key conflicts exist."),
918 : : errtableconstraint(heap,
919 : : RelationGetRelationName(index))));
920 : : else
921 [ + - + - : 66 : ereport(ERROR,
+ - ]
922 : : (errcode(ERRCODE_EXCLUSION_VIOLATION),
923 : : errmsg("conflicting key value violates exclusion constraint \"%s\"",
924 : : RelationGetRelationName(index)),
925 : : error_new && error_existing ?
926 : : errdetail("Key %s conflicts with existing key %s.",
927 : : error_new, error_existing) :
928 : : errdetail("Key conflicts with existing key."),
929 : : errtableconstraint(heap,
930 : : RelationGetRelationName(index))));
931 : : }
932 : :
933 : 5906 : index_endscan(index_scan);
934 : :
935 : : /*
936 : : * Ordinarily, at this point the search should have found the originally
937 : : * inserted tuple (if any), unless we exited the loop early because of
938 : : * conflict. However, it is possible to define exclusion constraints for
939 : : * which that wouldn't be true --- for instance, if the operator is <>. So
940 : : * we no longer complain if found_self is still false.
941 : : */
942 : :
943 : 5906 : econtext->ecxt_scantuple = save_scantuple;
944 : :
945 : 5906 : ExecDropSingleTupleTableSlot(existing_slot);
946 : :
947 : : #ifdef USE_INJECTION_POINTS
948 : : if (!conflict)
949 : : INJECTION_POINT("check-exclusion-or-unique-constraint-no-conflict", NULL);
950 : : #endif
951 : :
952 : 5906 : return !conflict;
953 : : }
954 : :
955 : : /*
956 : : * Check for violation of an exclusion constraint
957 : : *
958 : : * This is a dumbed down version of check_exclusion_or_unique_constraint
959 : : * for external callers. They don't need all the special modes.
960 : : */
961 : : void
3875 andres@anarazel.de 962 : 239 : check_exclusion_constraint(Relation heap, Relation index,
963 : : IndexInfo *indexInfo,
964 : : const ItemPointerData *tupleid,
965 : : const Datum *values, const bool *isnull,
966 : : EState *estate, bool newIndex)
967 : : {
968 : 239 : (void) check_exclusion_or_unique_constraint(heap, index, indexInfo, tupleid,
969 : : values, isnull,
970 : : estate, newIndex,
971 : : CEOUC_WAIT, false, NULL);
972 : 200 : }
973 : :
974 : : /*
975 : : * Check existing tuple's index values to see if it really matches the
976 : : * exclusion condition against the new_values. Returns true if conflict.
977 : : */
978 : : static bool
798 peter@eisentraut.org 979 : 69 : index_recheck_constraint(Relation index, const Oid *constr_procs,
980 : : const Datum *existing_values, const bool *existing_isnull,
981 : : const Datum *new_values)
982 : : {
2810 teodor@sigaev.ru 983 : 69 : int indnkeyatts = IndexRelationGetNumberOfKeyAttributes(index);
984 : : int i;
985 : :
986 [ + + ]: 171 : for (i = 0; i < indnkeyatts; i++)
987 : : {
988 : : /* Assume the exclusion operators are strict */
3889 heikki.linnakangas@i 989 [ - + ]: 129 : if (existing_isnull[i])
3889 heikki.linnakangas@i 990 :UBC 0 : return false;
991 : :
3889 heikki.linnakangas@i 992 [ + + ]:CBC 129 : if (!DatumGetBool(OidFunctionCall2Coll(constr_procs[i],
993 : 129 : index->rd_indcollation[i],
994 : 129 : existing_values[i],
995 : 129 : new_values[i])))
996 : 27 : return false;
997 : : }
998 : :
999 : 42 : return true;
1000 : : }
1001 : :
1002 : : /*
1003 : : * Check if ExecInsertIndexTuples() should pass indexUnchanged hint.
1004 : : *
1005 : : * When the executor performs an UPDATE that requires a new round of index
1006 : : * tuples, determine if we should pass 'indexUnchanged' = true hint for one
1007 : : * single index.
1008 : : */
1009 : : static bool
1798 pg@bowt.ie 1010 : 177583 : index_unchanged_by_update(ResultRelInfo *resultRelInfo, EState *estate,
1011 : : IndexInfo *indexInfo, Relation indexRelation)
1012 : : {
1013 : : Bitmapset *updatedCols;
1014 : : Bitmapset *extraUpdatedCols;
1015 : : Bitmapset *allUpdatedCols;
1016 : 177583 : bool hasexpression = false;
1017 : : List *idxExprs;
1018 : :
1019 : : /*
1020 : : * Check cache first
1021 : : */
1434 1022 [ + + ]: 177583 : if (indexInfo->ii_CheckedUnchanged)
1023 : 155542 : return indexInfo->ii_IndexUnchanged;
1024 : 22041 : indexInfo->ii_CheckedUnchanged = true;
1025 : :
1026 : : /*
1027 : : * Check for indexed attribute overlap with updated columns.
1028 : : *
1029 : : * Only do this for key columns. A change to a non-key column within an
1030 : : * INCLUDE index should not be counted here. Non-key column values are
1031 : : * opaque payload state to the index AM, a little like an extra table TID.
1032 : : *
1033 : : * Note that row-level BEFORE triggers won't affect our behavior, since
1034 : : * they don't affect the updatedCols bitmaps generally. It doesn't seem
1035 : : * worth the trouble of checking which attributes were changed directly.
1036 : : */
1037 : 22041 : updatedCols = ExecGetUpdatedCols(resultRelInfo, estate);
1038 : 22041 : extraUpdatedCols = ExecGetExtraUpdatedCols(resultRelInfo, estate);
1798 1039 [ + + ]: 23962 : for (int attr = 0; attr < indexInfo->ii_NumIndexKeyAttrs; attr++)
1040 : : {
1041 : 22859 : int keycol = indexInfo->ii_IndexAttrNumbers[attr];
1042 : :
1043 [ + + ]: 22859 : if (keycol <= 0)
1044 : : {
1045 : : /*
1046 : : * Skip expressions for now, but remember to deal with them later
1047 : : * on
1048 : : */
1049 : 15 : hasexpression = true;
1050 : 15 : continue;
1051 : : }
1052 : :
1053 [ + + ]: 22844 : if (bms_is_member(keycol - FirstLowInvalidHeapAttributeNumber,
1054 [ - + ]: 1906 : updatedCols) ||
1055 : 1906 : bms_is_member(keycol - FirstLowInvalidHeapAttributeNumber,
1056 : : extraUpdatedCols))
1057 : : {
1058 : : /* Changed key column -- don't hint for this index */
1434 1059 : 20938 : indexInfo->ii_IndexUnchanged = false;
1798 1060 : 20938 : return false;
1061 : : }
1062 : : }
1063 : :
1064 : : /*
1065 : : * When we get this far and index has no expressions, return true so that
1066 : : * index_insert() call will go on to pass 'indexUnchanged' = true hint.
1067 : : *
1068 : : * The _absence_ of an indexed key attribute that overlaps with updated
1069 : : * attributes (in addition to the total absence of indexed expressions)
1070 : : * shows that the index as a whole is logically unchanged by UPDATE.
1071 : : */
1072 [ + + ]: 1103 : if (!hasexpression)
1073 : : {
1434 1074 : 1091 : indexInfo->ii_IndexUnchanged = true;
1798 1075 : 1091 : return true;
1076 : : }
1077 : :
1078 : : /*
1079 : : * Need to pass only one bms to expression_tree_walker helper function.
1080 : : * Avoid allocating memory in common case where there are no extra cols.
1081 : : */
1082 [ + - ]: 12 : if (!extraUpdatedCols)
1083 : 12 : allUpdatedCols = updatedCols;
1084 : : else
1798 pg@bowt.ie 1085 :UBC 0 : allUpdatedCols = bms_union(updatedCols, extraUpdatedCols);
1086 : :
1087 : : /*
1088 : : * We have to work slightly harder in the event of indexed expressions,
1089 : : * but the principle is the same as before: try to find columns (Vars,
1090 : : * actually) that overlap with known-updated columns.
1091 : : *
1092 : : * If we find any matching Vars, don't pass hint for index. Otherwise
1093 : : * pass hint.
1094 : : */
1798 pg@bowt.ie 1095 :CBC 12 : idxExprs = RelationGetIndexExpressions(indexRelation);
1096 : 12 : hasexpression = index_expression_changed_walker((Node *) idxExprs,
1097 : : allUpdatedCols);
1098 : 12 : list_free(idxExprs);
1099 [ - + ]: 12 : if (extraUpdatedCols)
1798 pg@bowt.ie 1100 :UBC 0 : bms_free(allUpdatedCols);
1101 : :
1798 pg@bowt.ie 1102 [ + + ]:CBC 12 : if (hasexpression)
1103 : : {
1434 1104 : 9 : indexInfo->ii_IndexUnchanged = false;
1798 1105 : 9 : return false;
1106 : : }
1107 : :
1108 : : /*
1109 : : * Deliberately don't consider index predicates. We should even give the
1110 : : * hint when result rel's "updated tuple" has no corresponding index
1111 : : * tuple, which is possible with a partial index (provided the usual
1112 : : * conditions are met).
1113 : : */
1434 1114 : 3 : indexInfo->ii_IndexUnchanged = true;
1798 1115 : 3 : return true;
1116 : : }
1117 : :
1118 : : /*
1119 : : * Indexed expression helper for index_unchanged_by_update().
1120 : : *
1121 : : * Returns true when Var that appears within allUpdatedCols located.
1122 : : */
1123 : : static bool
1124 : 38 : index_expression_changed_walker(Node *node, Bitmapset *allUpdatedCols)
1125 : : {
1126 [ - + ]: 38 : if (node == NULL)
1798 pg@bowt.ie 1127 :UBC 0 : return false;
1128 : :
1798 pg@bowt.ie 1129 [ + + ]:CBC 38 : if (IsA(node, Var))
1130 : : {
1131 : 12 : Var *var = (Var *) node;
1132 : :
1133 [ + + ]: 12 : if (bms_is_member(var->varattno - FirstLowInvalidHeapAttributeNumber,
1134 : : allUpdatedCols))
1135 : : {
1136 : : /* Var was updated -- indicates that we should not hint */
1137 : 9 : return true;
1138 : : }
1139 : :
1140 : : /* Still haven't found a reason to not pass the hint */
1141 : 3 : return false;
1142 : : }
1143 : :
1144 : 26 : return expression_tree_walker(node, index_expression_changed_walker,
1145 : : allUpdatedCols);
1146 : : }
1147 : :
1148 : : /*
1149 : : * ExecWithoutOverlapsNotEmpty - raise an error if the tuple has an empty
1150 : : * range or multirange in the given attribute.
1151 : : */
1152 : : static void
455 peter@eisentraut.org 1153 : 1081 : ExecWithoutOverlapsNotEmpty(Relation rel, NameData attname, Datum attval, char typtype, Oid atttypid)
1154 : : {
1155 : : bool isempty;
1156 : : RangeType *r;
1157 : : MultirangeType *mr;
1158 : :
1159 [ + + - ]: 1081 : switch (typtype)
1160 : : {
1161 : 619 : case TYPTYPE_RANGE:
1162 : 619 : r = DatumGetRangeTypeP(attval);
1163 : 619 : isempty = RangeIsEmpty(r);
1164 : 619 : break;
1165 : 462 : case TYPTYPE_MULTIRANGE:
1166 : 462 : mr = DatumGetMultirangeTypeP(attval);
1167 : 462 : isempty = MultirangeIsEmpty(mr);
1168 : 462 : break;
455 peter@eisentraut.org 1169 :UBC 0 : default:
1170 [ # # ]: 0 : elog(ERROR, "WITHOUT OVERLAPS column \"%s\" is not a range or multirange",
1171 : : NameStr(attname));
1172 : : }
1173 : :
1174 : : /* Report a CHECK_VIOLATION */
455 peter@eisentraut.org 1175 [ + + ]:CBC 1081 : if (isempty)
1176 [ + - ]: 42 : ereport(ERROR,
1177 : : (errcode(ERRCODE_CHECK_VIOLATION),
1178 : : errmsg("empty WITHOUT OVERLAPS value found in column \"%s\" in relation \"%s\"",
1179 : : NameStr(attname), RelationGetRelationName(rel))));
1180 : 1039 : }
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