TLA Line data Source code
1 : /*-------------------------------------------------------------------------
2 : *
3 : * ri_triggers.c
4 : *
5 : * Generic trigger procedures for referential integrity constraint
6 : * checks.
7 : *
8 : * Note about memory management: the private hashtables kept here live
9 : * across query and transaction boundaries, in fact they live as long as
10 : * the backend does. This works because the hashtable structures
11 : * themselves are allocated by dynahash.c in its permanent DynaHashCxt,
12 : * and the SPI plans they point to are saved using SPI_keepplan().
13 : * There is not currently any provision for throwing away a no-longer-needed
14 : * plan --- consider improving this someday.
15 : *
16 : *
17 : * Portions Copyright (c) 1996-2023, PostgreSQL Global Development Group
18 : *
19 : * src/backend/utils/adt/ri_triggers.c
20 : *
21 : *-------------------------------------------------------------------------
22 : */
23 :
24 : #include "postgres.h"
25 :
26 : #include "access/htup_details.h"
27 : #include "access/sysattr.h"
28 : #include "access/table.h"
29 : #include "access/tableam.h"
30 : #include "access/xact.h"
31 : #include "catalog/pg_collation.h"
32 : #include "catalog/pg_constraint.h"
33 : #include "catalog/pg_operator.h"
34 : #include "catalog/pg_type.h"
35 : #include "commands/trigger.h"
36 : #include "executor/executor.h"
37 : #include "executor/spi.h"
38 : #include "lib/ilist.h"
39 : #include "miscadmin.h"
40 : #include "parser/parse_coerce.h"
41 : #include "parser/parse_relation.h"
42 : #include "storage/bufmgr.h"
43 : #include "utils/acl.h"
44 : #include "utils/builtins.h"
45 : #include "utils/datum.h"
46 : #include "utils/fmgroids.h"
47 : #include "utils/guc.h"
48 : #include "utils/inval.h"
49 : #include "utils/lsyscache.h"
50 : #include "utils/memutils.h"
51 : #include "utils/rel.h"
52 : #include "utils/rls.h"
53 : #include "utils/ruleutils.h"
54 : #include "utils/snapmgr.h"
55 : #include "utils/syscache.h"
56 :
57 : /*
58 : * Local definitions
59 : */
60 :
61 : #define RI_MAX_NUMKEYS INDEX_MAX_KEYS
62 :
63 : #define RI_INIT_CONSTRAINTHASHSIZE 64
64 : #define RI_INIT_QUERYHASHSIZE (RI_INIT_CONSTRAINTHASHSIZE * 4)
65 :
66 : #define RI_KEYS_ALL_NULL 0
67 : #define RI_KEYS_SOME_NULL 1
68 : #define RI_KEYS_NONE_NULL 2
69 :
70 : /* RI query type codes */
71 : /* these queries are executed against the PK (referenced) table: */
72 : #define RI_PLAN_CHECK_LOOKUPPK 1
73 : #define RI_PLAN_CHECK_LOOKUPPK_FROM_PK 2
74 : #define RI_PLAN_LAST_ON_PK RI_PLAN_CHECK_LOOKUPPK_FROM_PK
75 : /* these queries are executed against the FK (referencing) table: */
76 : #define RI_PLAN_CASCADE_ONDELETE 3
77 : #define RI_PLAN_CASCADE_ONUPDATE 4
78 : /* For RESTRICT, the same plan can be used for both ON DELETE and ON UPDATE triggers. */
79 : #define RI_PLAN_RESTRICT 5
80 : #define RI_PLAN_SETNULL_ONDELETE 6
81 : #define RI_PLAN_SETNULL_ONUPDATE 7
82 : #define RI_PLAN_SETDEFAULT_ONDELETE 8
83 : #define RI_PLAN_SETDEFAULT_ONUPDATE 9
84 :
85 : #define MAX_QUOTED_NAME_LEN (NAMEDATALEN*2+3)
86 : #define MAX_QUOTED_REL_NAME_LEN (MAX_QUOTED_NAME_LEN*2)
87 :
88 : #define RIAttName(rel, attnum) NameStr(*attnumAttName(rel, attnum))
89 : #define RIAttType(rel, attnum) attnumTypeId(rel, attnum)
90 : #define RIAttCollation(rel, attnum) attnumCollationId(rel, attnum)
91 :
92 : #define RI_TRIGTYPE_INSERT 1
93 : #define RI_TRIGTYPE_UPDATE 2
94 : #define RI_TRIGTYPE_DELETE 3
95 :
96 :
97 : /*
98 : * RI_ConstraintInfo
99 : *
100 : * Information extracted from an FK pg_constraint entry. This is cached in
101 : * ri_constraint_cache.
102 : */
103 : typedef struct RI_ConstraintInfo
104 : {
105 : Oid constraint_id; /* OID of pg_constraint entry (hash key) */
106 : bool valid; /* successfully initialized? */
107 : Oid constraint_root_id; /* OID of topmost ancestor constraint;
108 : * same as constraint_id if not inherited */
109 : uint32 oidHashValue; /* hash value of constraint_id */
110 : uint32 rootHashValue; /* hash value of constraint_root_id */
111 : NameData conname; /* name of the FK constraint */
112 : Oid pk_relid; /* referenced relation */
113 : Oid fk_relid; /* referencing relation */
114 : char confupdtype; /* foreign key's ON UPDATE action */
115 : char confdeltype; /* foreign key's ON DELETE action */
116 : int ndelsetcols; /* number of columns referenced in ON DELETE
117 : * SET clause */
118 : int16 confdelsetcols[RI_MAX_NUMKEYS]; /* attnums of cols to set on
119 : * delete */
120 : char confmatchtype; /* foreign key's match type */
121 : int nkeys; /* number of key columns */
122 : int16 pk_attnums[RI_MAX_NUMKEYS]; /* attnums of referenced cols */
123 : int16 fk_attnums[RI_MAX_NUMKEYS]; /* attnums of referencing cols */
124 : Oid pf_eq_oprs[RI_MAX_NUMKEYS]; /* equality operators (PK = FK) */
125 : Oid pp_eq_oprs[RI_MAX_NUMKEYS]; /* equality operators (PK = PK) */
126 : Oid ff_eq_oprs[RI_MAX_NUMKEYS]; /* equality operators (FK = FK) */
127 : dlist_node valid_link; /* Link in list of valid entries */
128 : } RI_ConstraintInfo;
129 :
130 : /*
131 : * RI_QueryKey
132 : *
133 : * The key identifying a prepared SPI plan in our query hashtable
134 : */
135 : typedef struct RI_QueryKey
136 : {
137 : Oid constr_id; /* OID of pg_constraint entry */
138 : int32 constr_queryno; /* query type ID, see RI_PLAN_XXX above */
139 : } RI_QueryKey;
140 :
141 : /*
142 : * RI_QueryHashEntry
143 : */
144 : typedef struct RI_QueryHashEntry
145 : {
146 : RI_QueryKey key;
147 : SPIPlanPtr plan;
148 : } RI_QueryHashEntry;
149 :
150 : /*
151 : * RI_CompareKey
152 : *
153 : * The key identifying an entry showing how to compare two values
154 : */
155 : typedef struct RI_CompareKey
156 : {
157 : Oid eq_opr; /* the equality operator to apply */
158 : Oid typeid; /* the data type to apply it to */
159 : } RI_CompareKey;
160 :
161 : /*
162 : * RI_CompareHashEntry
163 : */
164 : typedef struct RI_CompareHashEntry
165 : {
166 : RI_CompareKey key;
167 : bool valid; /* successfully initialized? */
168 : FmgrInfo eq_opr_finfo; /* call info for equality fn */
169 : FmgrInfo cast_func_finfo; /* in case we must coerce input */
170 : } RI_CompareHashEntry;
171 :
172 :
173 : /*
174 : * Local data
175 : */
176 : static HTAB *ri_constraint_cache = NULL;
177 : static HTAB *ri_query_cache = NULL;
178 : static HTAB *ri_compare_cache = NULL;
179 : static dclist_head ri_constraint_cache_valid_list;
180 :
181 :
182 : /*
183 : * Local function prototypes
184 : */
185 : static bool ri_Check_Pk_Match(Relation pk_rel, Relation fk_rel,
186 : TupleTableSlot *oldslot,
187 : const RI_ConstraintInfo *riinfo);
188 : static Datum ri_restrict(TriggerData *trigdata, bool is_no_action);
189 : static Datum ri_set(TriggerData *trigdata, bool is_set_null, int tgkind);
190 : static void quoteOneName(char *buffer, const char *name);
191 : static void quoteRelationName(char *buffer, Relation rel);
192 : static void ri_GenerateQual(StringInfo buf,
193 : const char *sep,
194 : const char *leftop, Oid leftoptype,
195 : Oid opoid,
196 : const char *rightop, Oid rightoptype);
197 : static void ri_GenerateQualCollation(StringInfo buf, Oid collation);
198 : static int ri_NullCheck(TupleDesc tupDesc, TupleTableSlot *slot,
199 : const RI_ConstraintInfo *riinfo, bool rel_is_pk);
200 : static void ri_BuildQueryKey(RI_QueryKey *key,
201 : const RI_ConstraintInfo *riinfo,
202 : int32 constr_queryno);
203 : static bool ri_KeysEqual(Relation rel, TupleTableSlot *oldslot, TupleTableSlot *newslot,
204 : const RI_ConstraintInfo *riinfo, bool rel_is_pk);
205 : static bool ri_AttributesEqual(Oid eq_opr, Oid typeid,
206 : Datum oldvalue, Datum newvalue);
207 :
208 : static void ri_InitHashTables(void);
209 : static void InvalidateConstraintCacheCallBack(Datum arg, int cacheid, uint32 hashvalue);
210 : static SPIPlanPtr ri_FetchPreparedPlan(RI_QueryKey *key);
211 : static void ri_HashPreparedPlan(RI_QueryKey *key, SPIPlanPtr plan);
212 : static RI_CompareHashEntry *ri_HashCompareOp(Oid eq_opr, Oid typeid);
213 :
214 : static void ri_CheckTrigger(FunctionCallInfo fcinfo, const char *funcname,
215 : int tgkind);
216 : static const RI_ConstraintInfo *ri_FetchConstraintInfo(Trigger *trigger,
217 : Relation trig_rel, bool rel_is_pk);
218 : static const RI_ConstraintInfo *ri_LoadConstraintInfo(Oid constraintOid);
219 : static Oid get_ri_constraint_root(Oid constrOid);
220 : static SPIPlanPtr ri_PlanCheck(const char *querystr, int nargs, Oid *argtypes,
221 : RI_QueryKey *qkey, Relation fk_rel, Relation pk_rel);
222 : static bool ri_PerformCheck(const RI_ConstraintInfo *riinfo,
223 : RI_QueryKey *qkey, SPIPlanPtr qplan,
224 : Relation fk_rel, Relation pk_rel,
225 : TupleTableSlot *oldslot, TupleTableSlot *newslot,
226 : bool detectNewRows, int expect_OK);
227 : static void ri_ExtractValues(Relation rel, TupleTableSlot *slot,
228 : const RI_ConstraintInfo *riinfo, bool rel_is_pk,
229 : Datum *vals, char *nulls);
230 : static void ri_ReportViolation(const RI_ConstraintInfo *riinfo,
231 : Relation pk_rel, Relation fk_rel,
232 : TupleTableSlot *violatorslot, TupleDesc tupdesc,
233 : int queryno, bool partgone) pg_attribute_noreturn();
234 :
235 :
236 : /*
237 : * RI_FKey_check -
238 : *
239 : * Check foreign key existence (combined for INSERT and UPDATE).
240 : */
241 ECB : static Datum
242 GIC 2046 : RI_FKey_check(TriggerData *trigdata)
243 : {
244 : const RI_ConstraintInfo *riinfo;
245 : Relation fk_rel;
246 : Relation pk_rel;
247 : TupleTableSlot *newslot;
248 : RI_QueryKey qkey;
249 : SPIPlanPtr qplan;
250 ECB :
251 GIC 2046 : riinfo = ri_FetchConstraintInfo(trigdata->tg_trigger,
252 : trigdata->tg_relation, false);
253 ECB :
254 CBC 2046 : if (TRIGGER_FIRED_BY_UPDATE(trigdata->tg_event))
255 GIC 212 : newslot = trigdata->tg_newslot;
256 ECB : else
257 GIC 1834 : newslot = trigdata->tg_trigslot;
258 :
259 : /*
260 : * We should not even consider checking the row if it is no longer valid,
261 : * since it was either deleted (so the deferred check should be skipped)
262 : * or updated (in which case only the latest version of the row should be
263 : * checked). Test its liveness according to SnapshotSelf. We need pin
264 : * and lock on the buffer to call HeapTupleSatisfiesVisibility. Caller
265 : * should be holding pin, but not lock.
266 ECB : */
267 CBC 2046 : if (!table_tuple_satisfies_snapshot(trigdata->tg_relation, newslot, SnapshotSelf))
268 GIC 30 : return PointerGetDatum(NULL);
269 :
270 : /*
271 : * Get the relation descriptors of the FK and PK tables.
272 : *
273 : * pk_rel is opened in RowShareLock mode since that's what our eventual
274 : * SELECT FOR KEY SHARE will get on it.
275 ECB : */
276 CBC 2016 : fk_rel = trigdata->tg_relation;
277 GIC 2016 : pk_rel = table_open(riinfo->pk_relid, RowShareLock);
278 ECB :
279 GIC 2016 : switch (ri_NullCheck(RelationGetDescr(fk_rel), newslot, riinfo, false))
280 ECB : {
281 GIC 66 : case RI_KEYS_ALL_NULL:
282 :
283 : /*
284 : * No further check needed - an all-NULL key passes every type of
285 : * foreign key constraint.
286 ECB : */
287 CBC 66 : table_close(pk_rel, RowShareLock);
288 GIC 66 : return PointerGetDatum(NULL);
289 ECB :
290 GIC 78 : case RI_KEYS_SOME_NULL:
291 :
292 : /*
293 : * This is the only case that differs between the three kinds of
294 : * MATCH.
295 ECB : */
296 GIC 78 : switch (riinfo->confmatchtype)
297 ECB : {
298 GIC 18 : case FKCONSTR_MATCH_FULL:
299 :
300 : /*
301 : * Not allowed - MATCH FULL says either all or none of the
302 : * attributes can be NULLs
303 ECB : */
304 GIC 18 : ereport(ERROR,
305 : (errcode(ERRCODE_FOREIGN_KEY_VIOLATION),
306 : errmsg("insert or update on table \"%s\" violates foreign key constraint \"%s\"",
307 : RelationGetRelationName(fk_rel),
308 : NameStr(riinfo->conname)),
309 : errdetail("MATCH FULL does not allow mixing of null and nonnull key values."),
310 : errtableconstraint(fk_rel,
311 : NameStr(riinfo->conname))));
312 : table_close(pk_rel, RowShareLock);
313 : return PointerGetDatum(NULL);
314 ECB :
315 GIC 60 : case FKCONSTR_MATCH_SIMPLE:
316 :
317 : /*
318 : * MATCH SIMPLE - if ANY column is null, the key passes
319 : * the constraint.
320 ECB : */
321 CBC 60 : table_close(pk_rel, RowShareLock);
322 GIC 60 : return PointerGetDatum(NULL);
323 :
324 : #ifdef NOT_USED
325 : case FKCONSTR_MATCH_PARTIAL:
326 :
327 : /*
328 : * MATCH PARTIAL - all non-null columns must match. (not
329 : * implemented, can be done by modifying the query below
330 : * to only include non-null columns, or by writing a
331 : * special version here)
332 : */
333 : break;
334 : #endif
335 : }
336 :
337 : case RI_KEYS_NONE_NULL:
338 :
339 : /*
340 : * Have a full qualified key - continue below for all three kinds
341 : * of MATCH.
342 ECB : */
343 GIC 1872 : break;
344 : }
345 ECB :
346 GBC 1872 : if (SPI_connect() != SPI_OK_CONNECT)
347 UIC 0 : elog(ERROR, "SPI_connect failed");
348 :
349 ECB : /* Fetch or prepare a saved plan for the real check */
350 GIC 1872 : ri_BuildQueryKey(&qkey, riinfo, RI_PLAN_CHECK_LOOKUPPK);
351 ECB :
352 GIC 1872 : if ((qplan = ri_FetchPreparedPlan(&qkey)) == NULL)
353 : {
354 : StringInfoData querybuf;
355 : char pkrelname[MAX_QUOTED_REL_NAME_LEN];
356 : char attname[MAX_QUOTED_NAME_LEN];
357 : char paramname[16];
358 : const char *querysep;
359 : Oid queryoids[RI_MAX_NUMKEYS];
360 : const char *pk_only;
361 :
362 : /* ----------
363 : * The query string built is
364 : * SELECT 1 FROM [ONLY] <pktable> x WHERE pkatt1 = $1 [AND ...]
365 : * FOR KEY SHARE OF x
366 : * The type id's for the $ parameters are those of the
367 : * corresponding FK attributes.
368 : * ----------
369 ECB : */
370 CBC 1024 : initStringInfo(&querybuf);
371 2048 : pk_only = pk_rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE ?
372 1024 : "" : "ONLY ";
373 1024 : quoteRelationName(pkrelname, pk_rel);
374 GIC 1024 : appendStringInfo(&querybuf, "SELECT 1 FROM %s%s x",
375 ECB : pk_only, pkrelname);
376 CBC 1024 : querysep = "WHERE";
377 GIC 2160 : for (int i = 0; i < riinfo->nkeys; i++)
378 ECB : {
379 CBC 1136 : Oid pk_type = RIAttType(pk_rel, riinfo->pk_attnums[i]);
380 GIC 1136 : Oid fk_type = RIAttType(fk_rel, riinfo->fk_attnums[i]);
381 ECB :
382 CBC 1136 : quoteOneName(attname,
383 1136 : RIAttName(pk_rel, riinfo->pk_attnums[i]));
384 1136 : sprintf(paramname, "$%d", i + 1);
385 GIC 1136 : ri_GenerateQual(&querybuf, querysep,
386 ECB : attname, pk_type,
387 GIC 1136 : riinfo->pf_eq_oprs[i],
388 ECB : paramname, fk_type);
389 CBC 1136 : querysep = "AND";
390 GIC 1136 : queryoids[i] = fk_type;
391 ECB : }
392 GIC 1024 : appendStringInfoString(&querybuf, " FOR KEY SHARE OF x");
393 :
394 ECB : /* Prepare and save the plan */
395 GIC 1024 : qplan = ri_PlanCheck(querybuf.data, riinfo->nkeys, queryoids,
396 : &qkey, fk_rel, pk_rel);
397 : }
398 :
399 : /*
400 : * Now check that foreign key exists in PK table
401 : *
402 : * XXX detectNewRows must be true when a partitioned table is on the
403 : * referenced side. The reason is that our snapshot must be fresh in
404 : * order for the hack in find_inheritance_children() to work.
405 ECB : */
406 GIC 1872 : ri_PerformCheck(riinfo, &qkey, qplan,
407 : fk_rel, pk_rel,
408 ECB : NULL, newslot,
409 GIC 1872 : pk_rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE,
410 : SPI_OK_SELECT);
411 ECB :
412 GBC 1628 : if (SPI_finish() != SPI_OK_FINISH)
413 UIC 0 : elog(ERROR, "SPI_finish failed");
414 ECB :
415 GIC 1628 : table_close(pk_rel, RowShareLock);
416 ECB :
417 GIC 1628 : return PointerGetDatum(NULL);
418 : }
419 :
420 :
421 : /*
422 : * RI_FKey_check_ins -
423 : *
424 : * Check foreign key existence at insert event on FK table.
425 : */
426 ECB : Datum
427 GIC 1834 : RI_FKey_check_ins(PG_FUNCTION_ARGS)
428 : {
429 ECB : /* Check that this is a valid trigger call on the right time and event. */
430 GIC 1834 : ri_CheckTrigger(fcinfo, "RI_FKey_check_ins", RI_TRIGTYPE_INSERT);
431 :
432 ECB : /* Share code with UPDATE case. */
433 GIC 1834 : return RI_FKey_check((TriggerData *) fcinfo->context);
434 : }
435 :
436 :
437 : /*
438 : * RI_FKey_check_upd -
439 : *
440 : * Check foreign key existence at update event on FK table.
441 : */
442 ECB : Datum
443 GIC 212 : RI_FKey_check_upd(PG_FUNCTION_ARGS)
444 : {
445 ECB : /* Check that this is a valid trigger call on the right time and event. */
446 GIC 212 : ri_CheckTrigger(fcinfo, "RI_FKey_check_upd", RI_TRIGTYPE_UPDATE);
447 :
448 ECB : /* Share code with INSERT case. */
449 GIC 212 : return RI_FKey_check((TriggerData *) fcinfo->context);
450 : }
451 :
452 :
453 : /*
454 : * ri_Check_Pk_Match
455 : *
456 : * Check to see if another PK row has been created that provides the same
457 : * key values as the "oldslot" that's been modified or deleted in our trigger
458 : * event. Returns true if a match is found in the PK table.
459 : *
460 : * We assume the caller checked that the oldslot contains no NULL key values,
461 : * since otherwise a match is impossible.
462 : */
463 ECB : static bool
464 GIC 369 : ri_Check_Pk_Match(Relation pk_rel, Relation fk_rel,
465 : TupleTableSlot *oldslot,
466 : const RI_ConstraintInfo *riinfo)
467 : {
468 : SPIPlanPtr qplan;
469 : RI_QueryKey qkey;
470 : bool result;
471 :
472 ECB : /* Only called for non-null rows */
473 GIC 369 : Assert(ri_NullCheck(RelationGetDescr(pk_rel), oldslot, riinfo, true) == RI_KEYS_NONE_NULL);
474 ECB :
475 GBC 369 : if (SPI_connect() != SPI_OK_CONNECT)
476 UIC 0 : elog(ERROR, "SPI_connect failed");
477 :
478 : /*
479 : * Fetch or prepare a saved plan for checking PK table with values coming
480 : * from a PK row
481 ECB : */
482 GIC 369 : ri_BuildQueryKey(&qkey, riinfo, RI_PLAN_CHECK_LOOKUPPK_FROM_PK);
483 ECB :
484 GIC 369 : if ((qplan = ri_FetchPreparedPlan(&qkey)) == NULL)
485 : {
486 : StringInfoData querybuf;
487 : char pkrelname[MAX_QUOTED_REL_NAME_LEN];
488 : char attname[MAX_QUOTED_NAME_LEN];
489 : char paramname[16];
490 : const char *querysep;
491 : const char *pk_only;
492 : Oid queryoids[RI_MAX_NUMKEYS];
493 :
494 : /* ----------
495 : * The query string built is
496 : * SELECT 1 FROM [ONLY] <pktable> x WHERE pkatt1 = $1 [AND ...]
497 : * FOR KEY SHARE OF x
498 : * The type id's for the $ parameters are those of the
499 : * PK attributes themselves.
500 : * ----------
501 ECB : */
502 CBC 164 : initStringInfo(&querybuf);
503 328 : pk_only = pk_rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE ?
504 164 : "" : "ONLY ";
505 164 : quoteRelationName(pkrelname, pk_rel);
506 GIC 164 : appendStringInfo(&querybuf, "SELECT 1 FROM %s%s x",
507 ECB : pk_only, pkrelname);
508 CBC 164 : querysep = "WHERE";
509 GIC 381 : for (int i = 0; i < riinfo->nkeys; i++)
510 ECB : {
511 GIC 217 : Oid pk_type = RIAttType(pk_rel, riinfo->pk_attnums[i]);
512 ECB :
513 CBC 217 : quoteOneName(attname,
514 217 : RIAttName(pk_rel, riinfo->pk_attnums[i]));
515 217 : sprintf(paramname, "$%d", i + 1);
516 GIC 217 : ri_GenerateQual(&querybuf, querysep,
517 ECB : attname, pk_type,
518 GIC 217 : riinfo->pp_eq_oprs[i],
519 ECB : paramname, pk_type);
520 CBC 217 : querysep = "AND";
521 GIC 217 : queryoids[i] = pk_type;
522 ECB : }
523 GIC 164 : appendStringInfoString(&querybuf, " FOR KEY SHARE OF x");
524 :
525 ECB : /* Prepare and save the plan */
526 GIC 164 : qplan = ri_PlanCheck(querybuf.data, riinfo->nkeys, queryoids,
527 : &qkey, fk_rel, pk_rel);
528 : }
529 :
530 : /*
531 : * We have a plan now. Run it.
532 ECB : */
533 GIC 369 : result = ri_PerformCheck(riinfo, &qkey, qplan,
534 : fk_rel, pk_rel,
535 : oldslot, NULL,
536 : true, /* treat like update */
537 : SPI_OK_SELECT);
538 ECB :
539 GBC 369 : if (SPI_finish() != SPI_OK_FINISH)
540 UIC 0 : elog(ERROR, "SPI_finish failed");
541 ECB :
542 GIC 369 : return result;
543 : }
544 :
545 :
546 : /*
547 : * RI_FKey_noaction_del -
548 : *
549 : * Give an error and roll back the current transaction if the
550 : * delete has resulted in a violation of the given referential
551 : * integrity constraint.
552 : */
553 ECB : Datum
554 GIC 153 : RI_FKey_noaction_del(PG_FUNCTION_ARGS)
555 : {
556 ECB : /* Check that this is a valid trigger call on the right time and event. */
557 GIC 153 : ri_CheckTrigger(fcinfo, "RI_FKey_noaction_del", RI_TRIGTYPE_DELETE);
558 :
559 ECB : /* Share code with RESTRICT/UPDATE cases. */
560 GIC 153 : return ri_restrict((TriggerData *) fcinfo->context, true);
561 : }
562 :
563 : /*
564 : * RI_FKey_restrict_del -
565 : *
566 : * Restrict delete from PK table to rows unreferenced by foreign key.
567 : *
568 : * The SQL standard intends that this referential action occur exactly when
569 : * the delete is performed, rather than after. This appears to be
570 : * the only difference between "NO ACTION" and "RESTRICT". In Postgres
571 : * we still implement this as an AFTER trigger, but it's non-deferrable.
572 : */
573 ECB : Datum
574 GIC 6 : RI_FKey_restrict_del(PG_FUNCTION_ARGS)
575 : {
576 ECB : /* Check that this is a valid trigger call on the right time and event. */
577 GIC 6 : ri_CheckTrigger(fcinfo, "RI_FKey_restrict_del", RI_TRIGTYPE_DELETE);
578 :
579 ECB : /* Share code with NO ACTION/UPDATE cases. */
580 GIC 6 : return ri_restrict((TriggerData *) fcinfo->context, false);
581 : }
582 :
583 : /*
584 : * RI_FKey_noaction_upd -
585 : *
586 : * Give an error and roll back the current transaction if the
587 : * update has resulted in a violation of the given referential
588 : * integrity constraint.
589 : */
590 ECB : Datum
591 GIC 150 : RI_FKey_noaction_upd(PG_FUNCTION_ARGS)
592 : {
593 ECB : /* Check that this is a valid trigger call on the right time and event. */
594 GIC 150 : ri_CheckTrigger(fcinfo, "RI_FKey_noaction_upd", RI_TRIGTYPE_UPDATE);
595 :
596 ECB : /* Share code with RESTRICT/DELETE cases. */
597 GIC 150 : return ri_restrict((TriggerData *) fcinfo->context, true);
598 : }
599 :
600 : /*
601 : * RI_FKey_restrict_upd -
602 : *
603 : * Restrict update of PK to rows unreferenced by foreign key.
604 : *
605 : * The SQL standard intends that this referential action occur exactly when
606 : * the update is performed, rather than after. This appears to be
607 : * the only difference between "NO ACTION" and "RESTRICT". In Postgres
608 : * we still implement this as an AFTER trigger, but it's non-deferrable.
609 : */
610 ECB : Datum
611 GIC 12 : RI_FKey_restrict_upd(PG_FUNCTION_ARGS)
612 : {
613 ECB : /* Check that this is a valid trigger call on the right time and event. */
614 GIC 12 : ri_CheckTrigger(fcinfo, "RI_FKey_restrict_upd", RI_TRIGTYPE_UPDATE);
615 :
616 ECB : /* Share code with NO ACTION/DELETE cases. */
617 GIC 12 : return ri_restrict((TriggerData *) fcinfo->context, false);
618 : }
619 :
620 : /*
621 : * ri_restrict -
622 : *
623 : * Common code for ON DELETE RESTRICT, ON DELETE NO ACTION,
624 : * ON UPDATE RESTRICT, and ON UPDATE NO ACTION.
625 : */
626 ECB : static Datum
627 GIC 387 : ri_restrict(TriggerData *trigdata, bool is_no_action)
628 : {
629 : const RI_ConstraintInfo *riinfo;
630 : Relation fk_rel;
631 : Relation pk_rel;
632 : TupleTableSlot *oldslot;
633 : RI_QueryKey qkey;
634 : SPIPlanPtr qplan;
635 ECB :
636 GIC 387 : riinfo = ri_FetchConstraintInfo(trigdata->tg_trigger,
637 : trigdata->tg_relation, true);
638 :
639 : /*
640 : * Get the relation descriptors of the FK and PK tables and the old tuple.
641 : *
642 : * fk_rel is opened in RowShareLock mode since that's what our eventual
643 : * SELECT FOR KEY SHARE will get on it.
644 ECB : */
645 CBC 387 : fk_rel = table_open(riinfo->fk_relid, RowShareLock);
646 387 : pk_rel = trigdata->tg_relation;
647 GIC 387 : oldslot = trigdata->tg_trigslot;
648 :
649 : /*
650 : * If another PK row now exists providing the old key values, we should
651 : * not do anything. However, this check should only be made in the NO
652 : * ACTION case; in RESTRICT cases we don't wish to allow another row to be
653 : * substituted.
654 ECB : */
655 CBC 756 : if (is_no_action &&
656 GIC 369 : ri_Check_Pk_Match(pk_rel, fk_rel, oldslot, riinfo))
657 ECB : {
658 CBC 26 : table_close(fk_rel, RowShareLock);
659 GIC 26 : return PointerGetDatum(NULL);
660 : }
661 ECB :
662 GBC 361 : if (SPI_connect() != SPI_OK_CONNECT)
663 UIC 0 : elog(ERROR, "SPI_connect failed");
664 :
665 : /*
666 : * Fetch or prepare a saved plan for the restrict lookup (it's the same
667 : * query for delete and update cases)
668 ECB : */
669 GIC 361 : ri_BuildQueryKey(&qkey, riinfo, RI_PLAN_RESTRICT);
670 ECB :
671 GIC 361 : if ((qplan = ri_FetchPreparedPlan(&qkey)) == NULL)
672 : {
673 : StringInfoData querybuf;
674 : char fkrelname[MAX_QUOTED_REL_NAME_LEN];
675 : char attname[MAX_QUOTED_NAME_LEN];
676 : char paramname[16];
677 : const char *querysep;
678 : Oid queryoids[RI_MAX_NUMKEYS];
679 : const char *fk_only;
680 :
681 : /* ----------
682 : * The query string built is
683 : * SELECT 1 FROM [ONLY] <fktable> x WHERE $1 = fkatt1 [AND ...]
684 : * FOR KEY SHARE OF x
685 : * The type id's for the $ parameters are those of the
686 : * corresponding PK attributes.
687 : * ----------
688 ECB : */
689 CBC 143 : initStringInfo(&querybuf);
690 286 : fk_only = fk_rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE ?
691 143 : "" : "ONLY ";
692 143 : quoteRelationName(fkrelname, fk_rel);
693 GIC 143 : appendStringInfo(&querybuf, "SELECT 1 FROM %s%s x",
694 ECB : fk_only, fkrelname);
695 CBC 143 : querysep = "WHERE";
696 GIC 337 : for (int i = 0; i < riinfo->nkeys; i++)
697 ECB : {
698 CBC 194 : Oid pk_type = RIAttType(pk_rel, riinfo->pk_attnums[i]);
699 194 : Oid fk_type = RIAttType(fk_rel, riinfo->fk_attnums[i]);
700 194 : Oid pk_coll = RIAttCollation(pk_rel, riinfo->pk_attnums[i]);
701 GIC 194 : Oid fk_coll = RIAttCollation(fk_rel, riinfo->fk_attnums[i]);
702 ECB :
703 CBC 194 : quoteOneName(attname,
704 194 : RIAttName(fk_rel, riinfo->fk_attnums[i]));
705 194 : sprintf(paramname, "$%d", i + 1);
706 GIC 194 : ri_GenerateQual(&querybuf, querysep,
707 ECB : paramname, pk_type,
708 GIC 194 : riinfo->pf_eq_oprs[i],
709 ECB : attname, fk_type);
710 GBC 194 : if (pk_coll != fk_coll && !get_collation_isdeterministic(pk_coll))
711 LBC 0 : ri_GenerateQualCollation(&querybuf, pk_coll);
712 CBC 194 : querysep = "AND";
713 GIC 194 : queryoids[i] = pk_type;
714 ECB : }
715 GIC 143 : appendStringInfoString(&querybuf, " FOR KEY SHARE OF x");
716 :
717 ECB : /* Prepare and save the plan */
718 GIC 143 : qplan = ri_PlanCheck(querybuf.data, riinfo->nkeys, queryoids,
719 : &qkey, fk_rel, pk_rel);
720 : }
721 :
722 : /*
723 : * We have a plan now. Run it to check for existing references.
724 ECB : */
725 GIC 361 : ri_PerformCheck(riinfo, &qkey, qplan,
726 : fk_rel, pk_rel,
727 : oldslot, NULL,
728 : true, /* must detect new rows */
729 : SPI_OK_SELECT);
730 ECB :
731 GBC 206 : if (SPI_finish() != SPI_OK_FINISH)
732 UIC 0 : elog(ERROR, "SPI_finish failed");
733 ECB :
734 GIC 206 : table_close(fk_rel, RowShareLock);
735 ECB :
736 GIC 206 : return PointerGetDatum(NULL);
737 : }
738 :
739 :
740 : /*
741 : * RI_FKey_cascade_del -
742 : *
743 : * Cascaded delete foreign key references at delete event on PK table.
744 : */
745 ECB : Datum
746 GIC 78 : RI_FKey_cascade_del(PG_FUNCTION_ARGS)
747 ECB : {
748 GIC 78 : TriggerData *trigdata = (TriggerData *) fcinfo->context;
749 : const RI_ConstraintInfo *riinfo;
750 : Relation fk_rel;
751 : Relation pk_rel;
752 : TupleTableSlot *oldslot;
753 : RI_QueryKey qkey;
754 : SPIPlanPtr qplan;
755 :
756 ECB : /* Check that this is a valid trigger call on the right time and event. */
757 GIC 78 : ri_CheckTrigger(fcinfo, "RI_FKey_cascade_del", RI_TRIGTYPE_DELETE);
758 ECB :
759 GIC 78 : riinfo = ri_FetchConstraintInfo(trigdata->tg_trigger,
760 : trigdata->tg_relation, true);
761 :
762 : /*
763 : * Get the relation descriptors of the FK and PK tables and the old tuple.
764 : *
765 : * fk_rel is opened in RowExclusiveLock mode since that's what our
766 : * eventual DELETE will get on it.
767 ECB : */
768 CBC 78 : fk_rel = table_open(riinfo->fk_relid, RowExclusiveLock);
769 78 : pk_rel = trigdata->tg_relation;
770 GIC 78 : oldslot = trigdata->tg_trigslot;
771 ECB :
772 GBC 78 : if (SPI_connect() != SPI_OK_CONNECT)
773 UIC 0 : elog(ERROR, "SPI_connect failed");
774 :
775 ECB : /* Fetch or prepare a saved plan for the cascaded delete */
776 GIC 78 : ri_BuildQueryKey(&qkey, riinfo, RI_PLAN_CASCADE_ONDELETE);
777 ECB :
778 GIC 78 : if ((qplan = ri_FetchPreparedPlan(&qkey)) == NULL)
779 : {
780 : StringInfoData querybuf;
781 : char fkrelname[MAX_QUOTED_REL_NAME_LEN];
782 : char attname[MAX_QUOTED_NAME_LEN];
783 : char paramname[16];
784 : const char *querysep;
785 : Oid queryoids[RI_MAX_NUMKEYS];
786 : const char *fk_only;
787 :
788 : /* ----------
789 : * The query string built is
790 : * DELETE FROM [ONLY] <fktable> WHERE $1 = fkatt1 [AND ...]
791 : * The type id's for the $ parameters are those of the
792 : * corresponding PK attributes.
793 : * ----------
794 ECB : */
795 CBC 49 : initStringInfo(&querybuf);
796 98 : fk_only = fk_rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE ?
797 49 : "" : "ONLY ";
798 49 : quoteRelationName(fkrelname, fk_rel);
799 GIC 49 : appendStringInfo(&querybuf, "DELETE FROM %s%s",
800 ECB : fk_only, fkrelname);
801 CBC 49 : querysep = "WHERE";
802 GIC 109 : for (int i = 0; i < riinfo->nkeys; i++)
803 ECB : {
804 CBC 60 : Oid pk_type = RIAttType(pk_rel, riinfo->pk_attnums[i]);
805 60 : Oid fk_type = RIAttType(fk_rel, riinfo->fk_attnums[i]);
806 60 : Oid pk_coll = RIAttCollation(pk_rel, riinfo->pk_attnums[i]);
807 GIC 60 : Oid fk_coll = RIAttCollation(fk_rel, riinfo->fk_attnums[i]);
808 ECB :
809 CBC 60 : quoteOneName(attname,
810 60 : RIAttName(fk_rel, riinfo->fk_attnums[i]));
811 60 : sprintf(paramname, "$%d", i + 1);
812 GIC 60 : ri_GenerateQual(&querybuf, querysep,
813 ECB : paramname, pk_type,
814 GIC 60 : riinfo->pf_eq_oprs[i],
815 ECB : attname, fk_type);
816 CBC 60 : if (pk_coll != fk_coll && !get_collation_isdeterministic(pk_coll))
817 3 : ri_GenerateQualCollation(&querybuf, pk_coll);
818 60 : querysep = "AND";
819 GIC 60 : queryoids[i] = pk_type;
820 : }
821 :
822 ECB : /* Prepare and save the plan */
823 GIC 49 : qplan = ri_PlanCheck(querybuf.data, riinfo->nkeys, queryoids,
824 : &qkey, fk_rel, pk_rel);
825 : }
826 :
827 : /*
828 : * We have a plan now. Build up the arguments from the key values in the
829 : * deleted PK tuple and delete the referencing rows
830 ECB : */
831 GIC 78 : ri_PerformCheck(riinfo, &qkey, qplan,
832 : fk_rel, pk_rel,
833 : oldslot, NULL,
834 : true, /* must detect new rows */
835 : SPI_OK_DELETE);
836 ECB :
837 GBC 78 : if (SPI_finish() != SPI_OK_FINISH)
838 UIC 0 : elog(ERROR, "SPI_finish failed");
839 ECB :
840 GIC 78 : table_close(fk_rel, RowExclusiveLock);
841 ECB :
842 GIC 78 : return PointerGetDatum(NULL);
843 : }
844 :
845 :
846 : /*
847 : * RI_FKey_cascade_upd -
848 : *
849 : * Cascaded update foreign key references at update event on PK table.
850 : */
851 ECB : Datum
852 GIC 102 : RI_FKey_cascade_upd(PG_FUNCTION_ARGS)
853 ECB : {
854 GIC 102 : TriggerData *trigdata = (TriggerData *) fcinfo->context;
855 : const RI_ConstraintInfo *riinfo;
856 : Relation fk_rel;
857 : Relation pk_rel;
858 : TupleTableSlot *newslot;
859 : TupleTableSlot *oldslot;
860 : RI_QueryKey qkey;
861 : SPIPlanPtr qplan;
862 :
863 ECB : /* Check that this is a valid trigger call on the right time and event. */
864 GIC 102 : ri_CheckTrigger(fcinfo, "RI_FKey_cascade_upd", RI_TRIGTYPE_UPDATE);
865 ECB :
866 GIC 102 : riinfo = ri_FetchConstraintInfo(trigdata->tg_trigger,
867 : trigdata->tg_relation, true);
868 :
869 : /*
870 : * Get the relation descriptors of the FK and PK tables and the new and
871 : * old tuple.
872 : *
873 : * fk_rel is opened in RowExclusiveLock mode since that's what our
874 : * eventual UPDATE will get on it.
875 ECB : */
876 CBC 102 : fk_rel = table_open(riinfo->fk_relid, RowExclusiveLock);
877 102 : pk_rel = trigdata->tg_relation;
878 102 : newslot = trigdata->tg_newslot;
879 GIC 102 : oldslot = trigdata->tg_trigslot;
880 ECB :
881 GBC 102 : if (SPI_connect() != SPI_OK_CONNECT)
882 UIC 0 : elog(ERROR, "SPI_connect failed");
883 :
884 ECB : /* Fetch or prepare a saved plan for the cascaded update */
885 GIC 102 : ri_BuildQueryKey(&qkey, riinfo, RI_PLAN_CASCADE_ONUPDATE);
886 ECB :
887 GIC 102 : if ((qplan = ri_FetchPreparedPlan(&qkey)) == NULL)
888 : {
889 : StringInfoData querybuf;
890 : StringInfoData qualbuf;
891 : char fkrelname[MAX_QUOTED_REL_NAME_LEN];
892 : char attname[MAX_QUOTED_NAME_LEN];
893 : char paramname[16];
894 : const char *querysep;
895 : const char *qualsep;
896 : Oid queryoids[RI_MAX_NUMKEYS * 2];
897 : const char *fk_only;
898 :
899 : /* ----------
900 : * The query string built is
901 : * UPDATE [ONLY] <fktable> SET fkatt1 = $1 [, ...]
902 : * WHERE $n = fkatt1 [AND ...]
903 : * The type id's for the $ parameters are those of the
904 : * corresponding PK attributes. Note that we are assuming
905 : * there is an assignment cast from the PK to the FK type;
906 : * else the parser will fail.
907 : * ----------
908 ECB : */
909 CBC 57 : initStringInfo(&querybuf);
910 57 : initStringInfo(&qualbuf);
911 114 : fk_only = fk_rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE ?
912 57 : "" : "ONLY ";
913 57 : quoteRelationName(fkrelname, fk_rel);
914 GIC 57 : appendStringInfo(&querybuf, "UPDATE %s%s SET",
915 ECB : fk_only, fkrelname);
916 CBC 57 : querysep = "";
917 57 : qualsep = "WHERE";
918 GIC 126 : for (int i = 0, j = riinfo->nkeys; i < riinfo->nkeys; i++, j++)
919 ECB : {
920 CBC 69 : Oid pk_type = RIAttType(pk_rel, riinfo->pk_attnums[i]);
921 69 : Oid fk_type = RIAttType(fk_rel, riinfo->fk_attnums[i]);
922 69 : Oid pk_coll = RIAttCollation(pk_rel, riinfo->pk_attnums[i]);
923 GIC 69 : Oid fk_coll = RIAttCollation(fk_rel, riinfo->fk_attnums[i]);
924 ECB :
925 CBC 69 : quoteOneName(attname,
926 69 : RIAttName(fk_rel, riinfo->fk_attnums[i]));
927 GIC 69 : appendStringInfo(&querybuf,
928 : "%s %s = $%d",
929 ECB : querysep, attname, i + 1);
930 CBC 69 : sprintf(paramname, "$%d", j + 1);
931 GIC 69 : ri_GenerateQual(&qualbuf, qualsep,
932 ECB : paramname, pk_type,
933 GIC 69 : riinfo->pf_eq_oprs[i],
934 ECB : attname, fk_type);
935 CBC 69 : if (pk_coll != fk_coll && !get_collation_isdeterministic(pk_coll))
936 3 : ri_GenerateQualCollation(&querybuf, pk_coll);
937 69 : querysep = ",";
938 69 : qualsep = "AND";
939 69 : queryoids[i] = pk_type;
940 GIC 69 : queryoids[j] = pk_type;
941 ECB : }
942 GIC 57 : appendBinaryStringInfo(&querybuf, qualbuf.data, qualbuf.len);
943 :
944 ECB : /* Prepare and save the plan */
945 GIC 57 : qplan = ri_PlanCheck(querybuf.data, riinfo->nkeys * 2, queryoids,
946 : &qkey, fk_rel, pk_rel);
947 : }
948 :
949 : /*
950 : * We have a plan now. Run it to update the existing references.
951 ECB : */
952 GIC 102 : ri_PerformCheck(riinfo, &qkey, qplan,
953 : fk_rel, pk_rel,
954 : oldslot, newslot,
955 : true, /* must detect new rows */
956 : SPI_OK_UPDATE);
957 ECB :
958 GBC 102 : if (SPI_finish() != SPI_OK_FINISH)
959 UIC 0 : elog(ERROR, "SPI_finish failed");
960 ECB :
961 GIC 102 : table_close(fk_rel, RowExclusiveLock);
962 ECB :
963 GIC 102 : return PointerGetDatum(NULL);
964 : }
965 :
966 :
967 : /*
968 : * RI_FKey_setnull_del -
969 : *
970 : * Set foreign key references to NULL values at delete event on PK table.
971 : */
972 ECB : Datum
973 GIC 48 : RI_FKey_setnull_del(PG_FUNCTION_ARGS)
974 : {
975 ECB : /* Check that this is a valid trigger call on the right time and event. */
976 GIC 48 : ri_CheckTrigger(fcinfo, "RI_FKey_setnull_del", RI_TRIGTYPE_DELETE);
977 :
978 ECB : /* Share code with UPDATE case */
979 GIC 48 : return ri_set((TriggerData *) fcinfo->context, true, RI_TRIGTYPE_DELETE);
980 : }
981 :
982 : /*
983 : * RI_FKey_setnull_upd -
984 : *
985 : * Set foreign key references to NULL at update event on PK table.
986 : */
987 ECB : Datum
988 GIC 15 : RI_FKey_setnull_upd(PG_FUNCTION_ARGS)
989 : {
990 ECB : /* Check that this is a valid trigger call on the right time and event. */
991 GIC 15 : ri_CheckTrigger(fcinfo, "RI_FKey_setnull_upd", RI_TRIGTYPE_UPDATE);
992 :
993 ECB : /* Share code with DELETE case */
994 GIC 15 : return ri_set((TriggerData *) fcinfo->context, true, RI_TRIGTYPE_UPDATE);
995 : }
996 :
997 : /*
998 : * RI_FKey_setdefault_del -
999 : *
1000 : * Set foreign key references to defaults at delete event on PK table.
1001 : */
1002 ECB : Datum
1003 GIC 42 : RI_FKey_setdefault_del(PG_FUNCTION_ARGS)
1004 : {
1005 ECB : /* Check that this is a valid trigger call on the right time and event. */
1006 GIC 42 : ri_CheckTrigger(fcinfo, "RI_FKey_setdefault_del", RI_TRIGTYPE_DELETE);
1007 :
1008 ECB : /* Share code with UPDATE case */
1009 GIC 42 : return ri_set((TriggerData *) fcinfo->context, false, RI_TRIGTYPE_DELETE);
1010 : }
1011 :
1012 : /*
1013 : * RI_FKey_setdefault_upd -
1014 : *
1015 : * Set foreign key references to defaults at update event on PK table.
1016 : */
1017 ECB : Datum
1018 GIC 24 : RI_FKey_setdefault_upd(PG_FUNCTION_ARGS)
1019 : {
1020 ECB : /* Check that this is a valid trigger call on the right time and event. */
1021 GIC 24 : ri_CheckTrigger(fcinfo, "RI_FKey_setdefault_upd", RI_TRIGTYPE_UPDATE);
1022 :
1023 ECB : /* Share code with DELETE case */
1024 GIC 24 : return ri_set((TriggerData *) fcinfo->context, false, RI_TRIGTYPE_UPDATE);
1025 : }
1026 :
1027 : /*
1028 : * ri_set -
1029 : *
1030 : * Common code for ON DELETE SET NULL, ON DELETE SET DEFAULT, ON UPDATE SET
1031 : * NULL, and ON UPDATE SET DEFAULT.
1032 : */
1033 ECB : static Datum
1034 GIC 129 : ri_set(TriggerData *trigdata, bool is_set_null, int tgkind)
1035 : {
1036 : const RI_ConstraintInfo *riinfo;
1037 : Relation fk_rel;
1038 : Relation pk_rel;
1039 : TupleTableSlot *oldslot;
1040 : RI_QueryKey qkey;
1041 : SPIPlanPtr qplan;
1042 : int32 queryno;
1043 ECB :
1044 GIC 129 : riinfo = ri_FetchConstraintInfo(trigdata->tg_trigger,
1045 : trigdata->tg_relation, true);
1046 :
1047 : /*
1048 : * Get the relation descriptors of the FK and PK tables and the old tuple.
1049 : *
1050 : * fk_rel is opened in RowExclusiveLock mode since that's what our
1051 : * eventual UPDATE will get on it.
1052 ECB : */
1053 CBC 129 : fk_rel = table_open(riinfo->fk_relid, RowExclusiveLock);
1054 129 : pk_rel = trigdata->tg_relation;
1055 GIC 129 : oldslot = trigdata->tg_trigslot;
1056 ECB :
1057 GBC 129 : if (SPI_connect() != SPI_OK_CONNECT)
1058 UIC 0 : elog(ERROR, "SPI_connect failed");
1059 :
1060 : /*
1061 : * Fetch or prepare a saved plan for the trigger.
1062 ECB : */
1063 GIC 129 : switch (tgkind)
1064 ECB : {
1065 CBC 39 : case RI_TRIGTYPE_UPDATE:
1066 GIC 39 : queryno = is_set_null
1067 ECB : ? RI_PLAN_SETNULL_ONUPDATE
1068 CBC 39 : : RI_PLAN_SETDEFAULT_ONUPDATE;
1069 39 : break;
1070 90 : case RI_TRIGTYPE_DELETE:
1071 GIC 90 : queryno = is_set_null
1072 ECB : ? RI_PLAN_SETNULL_ONDELETE
1073 CBC 90 : : RI_PLAN_SETDEFAULT_ONDELETE;
1074 GBC 90 : break;
1075 UBC 0 : default:
1076 UIC 0 : elog(ERROR, "invalid tgkind passed to ri_set");
1077 : }
1078 ECB :
1079 GIC 129 : ri_BuildQueryKey(&qkey, riinfo, queryno);
1080 ECB :
1081 GIC 129 : if ((qplan = ri_FetchPreparedPlan(&qkey)) == NULL)
1082 : {
1083 : StringInfoData querybuf;
1084 : char fkrelname[MAX_QUOTED_REL_NAME_LEN];
1085 : char attname[MAX_QUOTED_NAME_LEN];
1086 : char paramname[16];
1087 : const char *querysep;
1088 : const char *qualsep;
1089 : Oid queryoids[RI_MAX_NUMKEYS];
1090 : const char *fk_only;
1091 : int num_cols_to_set;
1092 : const int16 *set_cols;
1093 ECB :
1094 GIC 76 : switch (tgkind)
1095 ECB : {
1096 CBC 24 : case RI_TRIGTYPE_UPDATE:
1097 24 : num_cols_to_set = riinfo->nkeys;
1098 24 : set_cols = riinfo->fk_attnums;
1099 24 : break;
1100 GIC 52 : case RI_TRIGTYPE_DELETE:
1101 :
1102 : /*
1103 : * If confdelsetcols are present, then we only update the
1104 : * columns specified in that array, otherwise we update all
1105 : * the referencing columns.
1106 ECB : */
1107 GIC 52 : if (riinfo->ndelsetcols != 0)
1108 ECB : {
1109 CBC 12 : num_cols_to_set = riinfo->ndelsetcols;
1110 GIC 12 : set_cols = riinfo->confdelsetcols;
1111 : }
1112 : else
1113 ECB : {
1114 CBC 40 : num_cols_to_set = riinfo->nkeys;
1115 GIC 40 : set_cols = riinfo->fk_attnums;
1116 ECB : }
1117 GBC 52 : break;
1118 UBC 0 : default:
1119 UIC 0 : elog(ERROR, "invalid tgkind passed to ri_set");
1120 : }
1121 :
1122 : /* ----------
1123 : * The query string built is
1124 : * UPDATE [ONLY] <fktable> SET fkatt1 = {NULL|DEFAULT} [, ...]
1125 : * WHERE $1 = fkatt1 [AND ...]
1126 : * The type id's for the $ parameters are those of the
1127 : * corresponding PK attributes.
1128 : * ----------
1129 ECB : */
1130 CBC 76 : initStringInfo(&querybuf);
1131 152 : fk_only = fk_rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE ?
1132 76 : "" : "ONLY ";
1133 76 : quoteRelationName(fkrelname, fk_rel);
1134 GIC 76 : appendStringInfo(&querybuf, "UPDATE %s%s SET",
1135 : fk_only, fkrelname);
1136 :
1137 : /*
1138 : * Add assignment clauses
1139 ECB : */
1140 CBC 76 : querysep = "";
1141 GIC 201 : for (int i = 0; i < num_cols_to_set; i++)
1142 ECB : {
1143 CBC 125 : quoteOneName(attname, RIAttName(fk_rel, set_cols[i]));
1144 GIC 125 : appendStringInfo(&querybuf,
1145 : "%s %s = %s",
1146 : querysep, attname,
1147 ECB : is_set_null ? "NULL" : "DEFAULT");
1148 GIC 125 : querysep = ",";
1149 : }
1150 :
1151 : /*
1152 : * Add WHERE clause
1153 ECB : */
1154 CBC 76 : qualsep = "WHERE";
1155 GIC 213 : for (int i = 0; i < riinfo->nkeys; i++)
1156 ECB : {
1157 CBC 137 : Oid pk_type = RIAttType(pk_rel, riinfo->pk_attnums[i]);
1158 137 : Oid fk_type = RIAttType(fk_rel, riinfo->fk_attnums[i]);
1159 137 : Oid pk_coll = RIAttCollation(pk_rel, riinfo->pk_attnums[i]);
1160 GIC 137 : Oid fk_coll = RIAttCollation(fk_rel, riinfo->fk_attnums[i]);
1161 ECB :
1162 CBC 137 : quoteOneName(attname,
1163 GIC 137 : RIAttName(fk_rel, riinfo->fk_attnums[i]));
1164 ECB :
1165 CBC 137 : sprintf(paramname, "$%d", i + 1);
1166 GIC 137 : ri_GenerateQual(&querybuf, qualsep,
1167 ECB : paramname, pk_type,
1168 GIC 137 : riinfo->pf_eq_oprs[i],
1169 ECB : attname, fk_type);
1170 GBC 137 : if (pk_coll != fk_coll && !get_collation_isdeterministic(pk_coll))
1171 LBC 0 : ri_GenerateQualCollation(&querybuf, pk_coll);
1172 CBC 137 : qualsep = "AND";
1173 GIC 137 : queryoids[i] = pk_type;
1174 : }
1175 :
1176 ECB : /* Prepare and save the plan */
1177 GIC 76 : qplan = ri_PlanCheck(querybuf.data, riinfo->nkeys, queryoids,
1178 : &qkey, fk_rel, pk_rel);
1179 : }
1180 :
1181 : /*
1182 : * We have a plan now. Run it to update the existing references.
1183 ECB : */
1184 GIC 129 : ri_PerformCheck(riinfo, &qkey, qplan,
1185 : fk_rel, pk_rel,
1186 : oldslot, NULL,
1187 : true, /* must detect new rows */
1188 : SPI_OK_UPDATE);
1189 ECB :
1190 GBC 129 : if (SPI_finish() != SPI_OK_FINISH)
1191 UIC 0 : elog(ERROR, "SPI_finish failed");
1192 ECB :
1193 GIC 129 : table_close(fk_rel, RowExclusiveLock);
1194 ECB :
1195 CBC 129 : if (is_set_null)
1196 GIC 63 : return PointerGetDatum(NULL);
1197 : else
1198 : {
1199 : /*
1200 : * If we just deleted or updated the PK row whose key was equal to the
1201 : * FK columns' default values, and a referencing row exists in the FK
1202 : * table, we would have updated that row to the same values it already
1203 : * had --- and RI_FKey_fk_upd_check_required would hence believe no
1204 : * check is necessary. So we need to do another lookup now and in
1205 : * case a reference still exists, abort the operation. That is
1206 : * already implemented in the NO ACTION trigger, so just run it. (This
1207 : * recheck is only needed in the SET DEFAULT case, since CASCADE would
1208 : * remove such rows in case of a DELETE operation or would change the
1209 : * FK key values in case of an UPDATE, while SET NULL is certain to
1210 : * result in rows that satisfy the FK constraint.)
1211 ECB : */
1212 GIC 66 : return ri_restrict(trigdata, true);
1213 : }
1214 : }
1215 :
1216 :
1217 : /*
1218 : * RI_FKey_pk_upd_check_required -
1219 : *
1220 : * Check if we really need to fire the RI trigger for an update or delete to a PK
1221 : * relation. This is called by the AFTER trigger queue manager to see if
1222 : * it can skip queuing an instance of an RI trigger. Returns true if the
1223 : * trigger must be fired, false if we can prove the constraint will still
1224 : * be satisfied.
1225 : *
1226 : * newslot will be NULL if this is called for a delete.
1227 : */
1228 ECB : bool
1229 GIC 988 : RI_FKey_pk_upd_check_required(Trigger *trigger, Relation pk_rel,
1230 : TupleTableSlot *oldslot, TupleTableSlot *newslot)
1231 : {
1232 : const RI_ConstraintInfo *riinfo;
1233 ECB :
1234 GIC 988 : riinfo = ri_FetchConstraintInfo(trigger, pk_rel, true);
1235 :
1236 : /*
1237 : * If any old key value is NULL, the row could not have been referenced by
1238 : * an FK row, so no check is needed.
1239 ECB : */
1240 CBC 988 : if (ri_NullCheck(RelationGetDescr(pk_rel), oldslot, riinfo, true) != RI_KEYS_NONE_NULL)
1241 GIC 3 : return false;
1242 :
1243 ECB : /* If all old and new key values are equal, no check is needed */
1244 CBC 985 : if (newslot && ri_KeysEqual(pk_rel, oldslot, newslot, riinfo, true))
1245 GIC 268 : return false;
1246 :
1247 ECB : /* Else we need to fire the trigger. */
1248 GIC 717 : return true;
1249 : }
1250 :
1251 : /*
1252 : * RI_FKey_fk_upd_check_required -
1253 : *
1254 : * Check if we really need to fire the RI trigger for an update to an FK
1255 : * relation. This is called by the AFTER trigger queue manager to see if
1256 : * it can skip queuing an instance of an RI trigger. Returns true if the
1257 : * trigger must be fired, false if we can prove the constraint will still
1258 : * be satisfied.
1259 : */
1260 ECB : bool
1261 GIC 507 : RI_FKey_fk_upd_check_required(Trigger *trigger, Relation fk_rel,
1262 : TupleTableSlot *oldslot, TupleTableSlot *newslot)
1263 : {
1264 : const RI_ConstraintInfo *riinfo;
1265 : int ri_nullcheck;
1266 : Datum xminDatum;
1267 : TransactionId xmin;
1268 : bool isnull;
1269 :
1270 : /*
1271 : * AfterTriggerSaveEvent() handles things such that this function is never
1272 : * called for partitioned tables.
1273 ECB : */
1274 GIC 507 : Assert(fk_rel->rd_rel->relkind != RELKIND_PARTITIONED_TABLE);
1275 ECB :
1276 GIC 507 : riinfo = ri_FetchConstraintInfo(trigger, fk_rel, false);
1277 ECB :
1278 GIC 507 : ri_nullcheck = ri_NullCheck(RelationGetDescr(fk_rel), newslot, riinfo, false);
1279 :
1280 : /*
1281 : * If all new key values are NULL, the row satisfies the constraint, so no
1282 : * check is needed.
1283 ECB : */
1284 CBC 507 : if (ri_nullcheck == RI_KEYS_ALL_NULL)
1285 GIC 63 : return false;
1286 :
1287 : /*
1288 : * If some new key values are NULL, the behavior depends on the match
1289 : * type.
1290 ECB : */
1291 GIC 444 : else if (ri_nullcheck == RI_KEYS_SOME_NULL)
1292 ECB : {
1293 GIC 15 : switch (riinfo->confmatchtype)
1294 ECB : {
1295 GIC 12 : case FKCONSTR_MATCH_SIMPLE:
1296 :
1297 : /*
1298 : * If any new key value is NULL, the row must satisfy the
1299 : * constraint, so no check is needed.
1300 ECB : */
1301 GIC 12 : return false;
1302 EUB :
1303 UIC 0 : case FKCONSTR_MATCH_PARTIAL:
1304 :
1305 : /*
1306 : * Don't know, must run full check.
1307 EUB : */
1308 UIC 0 : break;
1309 ECB :
1310 GIC 3 : case FKCONSTR_MATCH_FULL:
1311 :
1312 : /*
1313 : * If some new key values are NULL, the row fails the
1314 : * constraint. We must not throw error here, because the row
1315 : * might get invalidated before the constraint is to be
1316 : * checked, but we should queue the event to apply the check
1317 : * later.
1318 ECB : */
1319 GIC 3 : return true;
1320 : }
1321 : }
1322 :
1323 : /*
1324 : * Continues here for no new key values are NULL, or we couldn't decide
1325 : * yet.
1326 : */
1327 :
1328 : /*
1329 : * If the original row was inserted by our own transaction, we must fire
1330 : * the trigger whether or not the keys are equal. This is because our
1331 : * UPDATE will invalidate the INSERT so that the INSERT RI trigger will
1332 : * not do anything; so we had better do the UPDATE check. (We could skip
1333 : * this if we knew the INSERT trigger already fired, but there is no easy
1334 : * way to know that.)
1335 ECB : */
1336 CBC 429 : xminDatum = slot_getsysattr(oldslot, MinTransactionIdAttributeNumber, &isnull);
1337 429 : Assert(!isnull);
1338 429 : xmin = DatumGetTransactionId(xminDatum);
1339 429 : if (TransactionIdIsCurrentTransactionId(xmin))
1340 GIC 62 : return true;
1341 :
1342 ECB : /* If all old and new key values are equal, no check is needed */
1343 CBC 367 : if (ri_KeysEqual(fk_rel, oldslot, newslot, riinfo, false))
1344 GIC 217 : return false;
1345 :
1346 ECB : /* Else we need to fire the trigger. */
1347 GIC 150 : return true;
1348 : }
1349 :
1350 : /*
1351 : * RI_Initial_Check -
1352 : *
1353 : * Check an entire table for non-matching values using a single query.
1354 : * This is not a trigger procedure, but is called during ALTER TABLE
1355 : * ADD FOREIGN KEY to validate the initial table contents.
1356 : *
1357 : * We expect that the caller has made provision to prevent any problems
1358 : * caused by concurrent actions. This could be either by locking rel and
1359 : * pkrel at ShareRowExclusiveLock or higher, or by otherwise ensuring
1360 : * that triggers implementing the checks are already active.
1361 : * Hence, we do not need to lock individual rows for the check.
1362 : *
1363 : * If the check fails because the current user doesn't have permissions
1364 : * to read both tables, return false to let our caller know that they will
1365 : * need to do something else to check the constraint.
1366 : */
1367 ECB : bool
1368 GIC 466 : RI_Initial_Check(Trigger *trigger, Relation fk_rel, Relation pk_rel)
1369 : {
1370 : const RI_ConstraintInfo *riinfo;
1371 : StringInfoData querybuf;
1372 : char pkrelname[MAX_QUOTED_REL_NAME_LEN];
1373 : char fkrelname[MAX_QUOTED_REL_NAME_LEN];
1374 : char pkattname[MAX_QUOTED_NAME_LEN + 3];
1375 : char fkattname[MAX_QUOTED_NAME_LEN + 3];
1376 : RangeTblEntry *pkrte;
1377 : RangeTblEntry *fkrte;
1378 : RTEPermissionInfo *pk_perminfo;
1379 : RTEPermissionInfo *fk_perminfo;
1380 : const char *sep;
1381 : const char *fk_only;
1382 : const char *pk_only;
1383 : int save_nestlevel;
1384 : char workmembuf[32];
1385 : int spi_result;
1386 : SPIPlanPtr qplan;
1387 :
1388 466 : riinfo = ri_FetchConstraintInfo(trigger, fk_rel, false);
1389 ECB :
1390 : /*
1391 : * Check to make sure current user has enough permissions to do the test
1392 : * query. (If not, caller can fall back to the trigger method, which
1393 : * works because it changes user IDs on the fly.)
1394 : *
1395 : * XXX are there any other show-stopper conditions to check?
1396 : */
1397 GIC 466 : pkrte = makeNode(RangeTblEntry);
1398 CBC 466 : pkrte->rtekind = RTE_RELATION;
1399 466 : pkrte->relid = RelationGetRelid(pk_rel);
1400 466 : pkrte->relkind = pk_rel->rd_rel->relkind;
1401 466 : pkrte->rellockmode = AccessShareLock;
1402 :
1403 GNC 466 : pk_perminfo = makeNode(RTEPermissionInfo);
1404 466 : pk_perminfo->relid = RelationGetRelid(pk_rel);
1405 466 : pk_perminfo->requiredPerms = ACL_SELECT;
1406 :
1407 CBC 466 : fkrte = makeNode(RangeTblEntry);
1408 466 : fkrte->rtekind = RTE_RELATION;
1409 466 : fkrte->relid = RelationGetRelid(fk_rel);
1410 GIC 466 : fkrte->relkind = fk_rel->rd_rel->relkind;
1411 CBC 466 : fkrte->rellockmode = AccessShareLock;
1412 :
1413 GNC 466 : fk_perminfo = makeNode(RTEPermissionInfo);
1414 466 : fk_perminfo->relid = RelationGetRelid(fk_rel);
1415 466 : fk_perminfo->requiredPerms = ACL_SELECT;
1416 ECB :
1417 CBC 1086 : for (int i = 0; i < riinfo->nkeys; i++)
1418 ECB : {
1419 : int attno;
1420 :
1421 CBC 620 : attno = riinfo->pk_attnums[i] - FirstLowInvalidHeapAttributeNumber;
1422 GNC 620 : pk_perminfo->selectedCols = bms_add_member(pk_perminfo->selectedCols, attno);
1423 :
1424 CBC 620 : attno = riinfo->fk_attnums[i] - FirstLowInvalidHeapAttributeNumber;
1425 GNC 620 : fk_perminfo->selectedCols = bms_add_member(fk_perminfo->selectedCols, attno);
1426 : }
1427 :
1428 466 : if (!ExecCheckPermissions(list_make2(fkrte, pkrte),
1429 466 : list_make2(fk_perminfo, pk_perminfo), false))
1430 CBC 6 : return false;
1431 :
1432 ECB : /*
1433 : * Also punt if RLS is enabled on either table unless this role has the
1434 : * bypassrls right or is the table owner of the table(s) involved which
1435 : * have RLS enabled.
1436 : */
1437 CBC 460 : if (!has_bypassrls_privilege(GetUserId()) &&
1438 LBC 0 : ((pk_rel->rd_rel->relrowsecurity &&
1439 UNC 0 : !object_ownercheck(RelationRelationId, pkrte->relid, GetUserId())) ||
1440 UIC 0 : (fk_rel->rd_rel->relrowsecurity &&
1441 UNC 0 : !object_ownercheck(RelationRelationId, fkrte->relid, GetUserId()))))
1442 UIC 0 : return false;
1443 :
1444 : /*----------
1445 ECB : * The query string built is:
1446 EUB : * SELECT fk.keycols FROM [ONLY] relname fk
1447 : * LEFT OUTER JOIN [ONLY] pkrelname pk
1448 : * ON (pk.pkkeycol1=fk.keycol1 [AND ...])
1449 : * WHERE pk.pkkeycol1 IS NULL AND
1450 : * For MATCH SIMPLE:
1451 : * (fk.keycol1 IS NOT NULL [AND ...])
1452 : * For MATCH FULL:
1453 : * (fk.keycol1 IS NOT NULL [OR ...])
1454 : *
1455 : * We attach COLLATE clauses to the operators when comparing columns
1456 : * that have different collations.
1457 : *----------
1458 : */
1459 GIC 460 : initStringInfo(&querybuf);
1460 460 : appendStringInfoString(&querybuf, "SELECT ");
1461 460 : sep = "";
1462 1068 : for (int i = 0; i < riinfo->nkeys; i++)
1463 : {
1464 608 : quoteOneName(fkattname,
1465 608 : RIAttName(fk_rel, riinfo->fk_attnums[i]));
1466 608 : appendStringInfo(&querybuf, "%sfk.%s", sep, fkattname);
1467 CBC 608 : sep = ", ";
1468 ECB : }
1469 :
1470 CBC 460 : quoteRelationName(pkrelname, pk_rel);
1471 GIC 460 : quoteRelationName(fkrelname, fk_rel);
1472 CBC 920 : fk_only = fk_rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE ?
1473 460 : "" : "ONLY ";
1474 920 : pk_only = pk_rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE ?
1475 460 : "" : "ONLY ";
1476 GIC 460 : appendStringInfo(&querybuf,
1477 : " FROM %s%s fk LEFT OUTER JOIN %s%s pk ON",
1478 ECB : fk_only, fkrelname, pk_only, pkrelname);
1479 :
1480 CBC 460 : strcpy(pkattname, "pk.");
1481 460 : strcpy(fkattname, "fk.");
1482 460 : sep = "(";
1483 1068 : for (int i = 0; i < riinfo->nkeys; i++)
1484 ECB : {
1485 GIC 608 : Oid pk_type = RIAttType(pk_rel, riinfo->pk_attnums[i]);
1486 608 : Oid fk_type = RIAttType(fk_rel, riinfo->fk_attnums[i]);
1487 608 : Oid pk_coll = RIAttCollation(pk_rel, riinfo->pk_attnums[i]);
1488 CBC 608 : Oid fk_coll = RIAttCollation(fk_rel, riinfo->fk_attnums[i]);
1489 ECB :
1490 CBC 608 : quoteOneName(pkattname + 3,
1491 608 : RIAttName(pk_rel, riinfo->pk_attnums[i]));
1492 GIC 608 : quoteOneName(fkattname + 3,
1493 CBC 608 : RIAttName(fk_rel, riinfo->fk_attnums[i]));
1494 608 : ri_GenerateQual(&querybuf, sep,
1495 ECB : pkattname, pk_type,
1496 CBC 608 : riinfo->pf_eq_oprs[i],
1497 : fkattname, fk_type);
1498 608 : if (pk_coll != fk_coll)
1499 6 : ri_GenerateQualCollation(&querybuf, pk_coll);
1500 608 : sep = "AND";
1501 ECB : }
1502 :
1503 : /*
1504 : * It's sufficient to test any one pk attribute for null to detect a join
1505 : * failure.
1506 : */
1507 CBC 460 : quoteOneName(pkattname, RIAttName(pk_rel, riinfo->pk_attnums[0]));
1508 460 : appendStringInfo(&querybuf, ") WHERE pk.%s IS NULL AND (", pkattname);
1509 :
1510 GIC 460 : sep = "";
1511 1068 : for (int i = 0; i < riinfo->nkeys; i++)
1512 : {
1513 608 : quoteOneName(fkattname, RIAttName(fk_rel, riinfo->fk_attnums[i]));
1514 608 : appendStringInfo(&querybuf,
1515 ECB : "%sfk.%s IS NOT NULL",
1516 : sep, fkattname);
1517 GIC 608 : switch (riinfo->confmatchtype)
1518 ECB : {
1519 CBC 558 : case FKCONSTR_MATCH_SIMPLE:
1520 GIC 558 : sep = " AND ";
1521 CBC 558 : break;
1522 50 : case FKCONSTR_MATCH_FULL:
1523 GIC 50 : sep = " OR ";
1524 50 : break;
1525 ECB : }
1526 : }
1527 CBC 460 : appendStringInfoChar(&querybuf, ')');
1528 ECB :
1529 : /*
1530 : * Temporarily increase work_mem so that the check query can be executed
1531 : * more efficiently. It seems okay to do this because the query is simple
1532 : * enough to not use a multiple of work_mem, and one typically would not
1533 : * have many large foreign-key validations happening concurrently. So
1534 : * this seems to meet the criteria for being considered a "maintenance"
1535 : * operation, and accordingly we use maintenance_work_mem. However, we
1536 : * must also set hash_mem_multiplier to 1, since it is surely not okay to
1537 : * let that get applied to the maintenance_work_mem value.
1538 : *
1539 : * We use the equivalent of a function SET option to allow the setting to
1540 : * persist for exactly the duration of the check query. guc.c also takes
1541 : * care of undoing the setting on error.
1542 : */
1543 GIC 460 : save_nestlevel = NewGUCNestLevel();
1544 :
1545 460 : snprintf(workmembuf, sizeof(workmembuf), "%d", maintenance_work_mem);
1546 460 : (void) set_config_option("work_mem", workmembuf,
1547 : PGC_USERSET, PGC_S_SESSION,
1548 : GUC_ACTION_SAVE, true, 0, false);
1549 460 : (void) set_config_option("hash_mem_multiplier", "1",
1550 : PGC_USERSET, PGC_S_SESSION,
1551 ECB : GUC_ACTION_SAVE, true, 0, false);
1552 :
1553 CBC 460 : if (SPI_connect() != SPI_OK_CONNECT)
1554 LBC 0 : elog(ERROR, "SPI_connect failed");
1555 :
1556 : /*
1557 ECB : * Generate the plan. We don't need to cache it, and there are no
1558 : * arguments to the plan.
1559 : */
1560 GIC 460 : qplan = SPI_prepare(querybuf.data, 0, NULL);
1561 ECB :
1562 GBC 460 : if (qplan == NULL)
1563 UIC 0 : elog(ERROR, "SPI_prepare returned %s for %s",
1564 : SPI_result_code_string(SPI_result), querybuf.data);
1565 :
1566 : /*
1567 : * Run the plan. For safety we force a current snapshot to be used. (In
1568 ECB : * transaction-snapshot mode, this arguably violates transaction isolation
1569 : * rules, but we really haven't got much choice.) We don't need to
1570 : * register the snapshot, because SPI_execute_snapshot will see to it. We
1571 EUB : * need at most one tuple returned, so pass limit = 1.
1572 : */
1573 GIC 460 : spi_result = SPI_execute_snapshot(qplan,
1574 : NULL, NULL,
1575 : GetLatestSnapshot(),
1576 : InvalidSnapshot,
1577 : true, false, 1);
1578 :
1579 : /* Check result */
1580 460 : if (spi_result != SPI_OK_SELECT)
1581 LBC 0 : elog(ERROR, "SPI_execute_snapshot returned %s", SPI_result_code_string(spi_result));
1582 :
1583 : /* Did we find a tuple violating the constraint? */
1584 GIC 460 : if (SPI_processed > 0)
1585 : {
1586 : TupleTableSlot *slot;
1587 28 : HeapTuple tuple = SPI_tuptable->vals[0];
1588 CBC 28 : TupleDesc tupdesc = SPI_tuptable->tupdesc;
1589 EUB : RI_ConstraintInfo fake_riinfo;
1590 :
1591 GIC 28 : slot = MakeSingleTupleTableSlot(tupdesc, &TTSOpsVirtual);
1592 ECB :
1593 GIC 28 : heap_deform_tuple(tuple, tupdesc,
1594 : slot->tts_values, slot->tts_isnull);
1595 CBC 28 : ExecStoreVirtualTuple(slot);
1596 ECB :
1597 : /*
1598 : * The columns to look at in the result tuple are 1..N, not whatever
1599 : * they are in the fk_rel. Hack up riinfo so that the subroutines
1600 : * called here will behave properly.
1601 : *
1602 : * In addition to this, we have to pass the correct tupdesc to
1603 : * ri_ReportViolation, overriding its normal habit of using the pk_rel
1604 : * or fk_rel's tupdesc.
1605 : */
1606 GIC 28 : memcpy(&fake_riinfo, riinfo, sizeof(RI_ConstraintInfo));
1607 65 : for (int i = 0; i < fake_riinfo.nkeys; i++)
1608 37 : fake_riinfo.fk_attnums[i] = i + 1;
1609 :
1610 : /*
1611 : * If it's MATCH FULL, and there are any nulls in the FK keys,
1612 : * complain about that rather than the lack of a match. MATCH FULL
1613 : * disallows partially-null FK rows.
1614 ECB : */
1615 CBC 40 : if (fake_riinfo.confmatchtype == FKCONSTR_MATCH_FULL &&
1616 12 : ri_NullCheck(tupdesc, slot, &fake_riinfo, false) != RI_KEYS_NONE_NULL)
1617 GIC 6 : ereport(ERROR,
1618 : (errcode(ERRCODE_FOREIGN_KEY_VIOLATION),
1619 : errmsg("insert or update on table \"%s\" violates foreign key constraint \"%s\"",
1620 : RelationGetRelationName(fk_rel),
1621 : NameStr(fake_riinfo.conname)),
1622 : errdetail("MATCH FULL does not allow mixing of null and nonnull key values."),
1623 ECB : errtableconstraint(fk_rel,
1624 : NameStr(fake_riinfo.conname))));
1625 :
1626 : /*
1627 : * We tell ri_ReportViolation we were doing the RI_PLAN_CHECK_LOOKUPPK
1628 : * query, which isn't true, but will cause it to use
1629 : * fake_riinfo.fk_attnums as we need.
1630 : */
1631 GIC 22 : ri_ReportViolation(&fake_riinfo,
1632 : pk_rel, fk_rel,
1633 : slot, tupdesc,
1634 : RI_PLAN_CHECK_LOOKUPPK, false);
1635 :
1636 : ExecDropSingleTupleTableSlot(slot);
1637 : }
1638 :
1639 CBC 432 : if (SPI_finish() != SPI_OK_FINISH)
1640 UIC 0 : elog(ERROR, "SPI_finish failed");
1641 :
1642 : /*
1643 : * Restore work_mem and hash_mem_multiplier.
1644 : */
1645 GIC 432 : AtEOXact_GUC(true, save_nestlevel);
1646 :
1647 CBC 432 : return true;
1648 EUB : }
1649 :
1650 : /*
1651 : * RI_PartitionRemove_Check -
1652 : *
1653 ECB : * Verify no referencing values exist, when a partition is detached on
1654 : * the referenced side of a foreign key constraint.
1655 : */
1656 : void
1657 GIC 43 : RI_PartitionRemove_Check(Trigger *trigger, Relation fk_rel, Relation pk_rel)
1658 : {
1659 : const RI_ConstraintInfo *riinfo;
1660 : StringInfoData querybuf;
1661 : char *constraintDef;
1662 : char pkrelname[MAX_QUOTED_REL_NAME_LEN];
1663 : char fkrelname[MAX_QUOTED_REL_NAME_LEN];
1664 : char pkattname[MAX_QUOTED_NAME_LEN + 3];
1665 ECB : char fkattname[MAX_QUOTED_NAME_LEN + 3];
1666 : const char *sep;
1667 : const char *fk_only;
1668 : int save_nestlevel;
1669 : char workmembuf[32];
1670 : int spi_result;
1671 : SPIPlanPtr qplan;
1672 : int i;
1673 :
1674 GIC 43 : riinfo = ri_FetchConstraintInfo(trigger, fk_rel, false);
1675 :
1676 : /*
1677 : * We don't check permissions before displaying the error message, on the
1678 : * assumption that the user detaching the partition must have enough
1679 : * privileges to examine the table contents anyhow.
1680 : */
1681 :
1682 ECB : /*----------
1683 : * The query string built is:
1684 : * SELECT fk.keycols FROM [ONLY] relname fk
1685 : * JOIN pkrelname pk
1686 : * ON (pk.pkkeycol1=fk.keycol1 [AND ...])
1687 : * WHERE (<partition constraint>) AND
1688 : * For MATCH SIMPLE:
1689 : * (fk.keycol1 IS NOT NULL [AND ...])
1690 : * For MATCH FULL:
1691 : * (fk.keycol1 IS NOT NULL [OR ...])
1692 : *
1693 : * We attach COLLATE clauses to the operators when comparing columns
1694 : * that have different collations.
1695 : *----------
1696 : */
1697 GIC 43 : initStringInfo(&querybuf);
1698 43 : appendStringInfoString(&querybuf, "SELECT ");
1699 43 : sep = "";
1700 86 : for (i = 0; i < riinfo->nkeys; i++)
1701 : {
1702 43 : quoteOneName(fkattname,
1703 43 : RIAttName(fk_rel, riinfo->fk_attnums[i]));
1704 43 : appendStringInfo(&querybuf, "%sfk.%s", sep, fkattname);
1705 CBC 43 : sep = ", ";
1706 ECB : }
1707 :
1708 CBC 43 : quoteRelationName(pkrelname, pk_rel);
1709 GIC 43 : quoteRelationName(fkrelname, fk_rel);
1710 CBC 86 : fk_only = fk_rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE ?
1711 43 : "" : "ONLY ";
1712 43 : appendStringInfo(&querybuf,
1713 ECB : " FROM %s%s fk JOIN %s pk ON",
1714 : fk_only, fkrelname, pkrelname);
1715 GIC 43 : strcpy(pkattname, "pk.");
1716 CBC 43 : strcpy(fkattname, "fk.");
1717 43 : sep = "(";
1718 86 : for (i = 0; i < riinfo->nkeys; i++)
1719 ECB : {
1720 CBC 43 : Oid pk_type = RIAttType(pk_rel, riinfo->pk_attnums[i]);
1721 GIC 43 : Oid fk_type = RIAttType(fk_rel, riinfo->fk_attnums[i]);
1722 43 : Oid pk_coll = RIAttCollation(pk_rel, riinfo->pk_attnums[i]);
1723 CBC 43 : Oid fk_coll = RIAttCollation(fk_rel, riinfo->fk_attnums[i]);
1724 ECB :
1725 CBC 43 : quoteOneName(pkattname + 3,
1726 43 : RIAttName(pk_rel, riinfo->pk_attnums[i]));
1727 GIC 43 : quoteOneName(fkattname + 3,
1728 CBC 43 : RIAttName(fk_rel, riinfo->fk_attnums[i]));
1729 43 : ri_GenerateQual(&querybuf, sep,
1730 ECB : pkattname, pk_type,
1731 CBC 43 : riinfo->pf_eq_oprs[i],
1732 : fkattname, fk_type);
1733 43 : if (pk_coll != fk_coll)
1734 LBC 0 : ri_GenerateQualCollation(&querybuf, pk_coll);
1735 CBC 43 : sep = "AND";
1736 ECB : }
1737 :
1738 : /*
1739 : * Start the WHERE clause with the partition constraint (except if this is
1740 : * the default partition and there's no other partition, because the
1741 : * partition constraint is the empty string in that case.)
1742 EUB : */
1743 CBC 43 : constraintDef = pg_get_partconstrdef_string(RelationGetRelid(pk_rel), "pk");
1744 GIC 43 : if (constraintDef && constraintDef[0] != '\0')
1745 43 : appendStringInfo(&querybuf, ") WHERE %s AND (",
1746 : constraintDef);
1747 : else
1748 UIC 0 : appendStringInfoString(&querybuf, ") WHERE (");
1749 :
1750 GIC 43 : sep = "";
1751 CBC 86 : for (i = 0; i < riinfo->nkeys; i++)
1752 ECB : {
1753 CBC 43 : quoteOneName(fkattname, RIAttName(fk_rel, riinfo->fk_attnums[i]));
1754 GIC 43 : appendStringInfo(&querybuf,
1755 : "%sfk.%s IS NOT NULL",
1756 EUB : sep, fkattname);
1757 GIC 43 : switch (riinfo->confmatchtype)
1758 ECB : {
1759 CBC 43 : case FKCONSTR_MATCH_SIMPLE:
1760 GIC 43 : sep = " AND ";
1761 CBC 43 : break;
1762 LBC 0 : case FKCONSTR_MATCH_FULL:
1763 UIC 0 : sep = " OR ";
1764 0 : break;
1765 ECB : }
1766 : }
1767 CBC 43 : appendStringInfoChar(&querybuf, ')');
1768 ECB :
1769 : /*
1770 EUB : * Temporarily increase work_mem so that the check query can be executed
1771 : * more efficiently. It seems okay to do this because the query is simple
1772 : * enough to not use a multiple of work_mem, and one typically would not
1773 : * have many large foreign-key validations happening concurrently. So
1774 : * this seems to meet the criteria for being considered a "maintenance"
1775 ECB : * operation, and accordingly we use maintenance_work_mem. However, we
1776 : * must also set hash_mem_multiplier to 1, since it is surely not okay to
1777 : * let that get applied to the maintenance_work_mem value.
1778 : *
1779 : * We use the equivalent of a function SET option to allow the setting to
1780 : * persist for exactly the duration of the check query. guc.c also takes
1781 : * care of undoing the setting on error.
1782 : */
1783 GIC 43 : save_nestlevel = NewGUCNestLevel();
1784 :
1785 43 : snprintf(workmembuf, sizeof(workmembuf), "%d", maintenance_work_mem);
1786 43 : (void) set_config_option("work_mem", workmembuf,
1787 : PGC_USERSET, PGC_S_SESSION,
1788 : GUC_ACTION_SAVE, true, 0, false);
1789 43 : (void) set_config_option("hash_mem_multiplier", "1",
1790 : PGC_USERSET, PGC_S_SESSION,
1791 ECB : GUC_ACTION_SAVE, true, 0, false);
1792 :
1793 CBC 43 : if (SPI_connect() != SPI_OK_CONNECT)
1794 LBC 0 : elog(ERROR, "SPI_connect failed");
1795 :
1796 : /*
1797 ECB : * Generate the plan. We don't need to cache it, and there are no
1798 : * arguments to the plan.
1799 : */
1800 GIC 43 : qplan = SPI_prepare(querybuf.data, 0, NULL);
1801 ECB :
1802 GBC 43 : if (qplan == NULL)
1803 UIC 0 : elog(ERROR, "SPI_prepare returned %s for %s",
1804 : SPI_result_code_string(SPI_result), querybuf.data);
1805 :
1806 : /*
1807 : * Run the plan. For safety we force a current snapshot to be used. (In
1808 ECB : * transaction-snapshot mode, this arguably violates transaction isolation
1809 : * rules, but we really haven't got much choice.) We don't need to
1810 : * register the snapshot, because SPI_execute_snapshot will see to it. We
1811 EUB : * need at most one tuple returned, so pass limit = 1.
1812 : */
1813 GIC 43 : spi_result = SPI_execute_snapshot(qplan,
1814 : NULL, NULL,
1815 : GetLatestSnapshot(),
1816 : InvalidSnapshot,
1817 : true, false, 1);
1818 :
1819 : /* Check result */
1820 43 : if (spi_result != SPI_OK_SELECT)
1821 LBC 0 : elog(ERROR, "SPI_execute_snapshot returned %s", SPI_result_code_string(spi_result));
1822 :
1823 : /* Did we find a tuple that would violate the constraint? */
1824 GIC 43 : if (SPI_processed > 0)
1825 : {
1826 : TupleTableSlot *slot;
1827 17 : HeapTuple tuple = SPI_tuptable->vals[0];
1828 CBC 17 : TupleDesc tupdesc = SPI_tuptable->tupdesc;
1829 EUB : RI_ConstraintInfo fake_riinfo;
1830 :
1831 GIC 17 : slot = MakeSingleTupleTableSlot(tupdesc, &TTSOpsVirtual);
1832 ECB :
1833 GIC 17 : heap_deform_tuple(tuple, tupdesc,
1834 : slot->tts_values, slot->tts_isnull);
1835 CBC 17 : ExecStoreVirtualTuple(slot);
1836 ECB :
1837 : /*
1838 : * The columns to look at in the result tuple are 1..N, not whatever
1839 : * they are in the fk_rel. Hack up riinfo so that ri_ReportViolation
1840 : * will behave properly.
1841 : *
1842 : * In addition to this, we have to pass the correct tupdesc to
1843 : * ri_ReportViolation, overriding its normal habit of using the pk_rel
1844 : * or fk_rel's tupdesc.
1845 : */
1846 GIC 17 : memcpy(&fake_riinfo, riinfo, sizeof(RI_ConstraintInfo));
1847 34 : for (i = 0; i < fake_riinfo.nkeys; i++)
1848 17 : fake_riinfo.pk_attnums[i] = i + 1;
1849 :
1850 17 : ri_ReportViolation(&fake_riinfo, pk_rel, fk_rel,
1851 : slot, tupdesc, 0, true);
1852 : }
1853 :
1854 CBC 26 : if (SPI_finish() != SPI_OK_FINISH)
1855 LBC 0 : elog(ERROR, "SPI_finish failed");
1856 ECB :
1857 : /*
1858 : * Restore work_mem and hash_mem_multiplier.
1859 : */
1860 GIC 26 : AtEOXact_GUC(true, save_nestlevel);
1861 26 : }
1862 ECB :
1863 EUB :
1864 : /* ----------
1865 : * Local functions below
1866 : * ----------
1867 : */
1868 ECB :
1869 :
1870 : /*
1871 : * quoteOneName --- safely quote a single SQL name
1872 : *
1873 : * buffer must be MAX_QUOTED_NAME_LEN long (includes room for \0)
1874 : */
1875 : static void
1876 GIC 10064 : quoteOneName(char *buffer, const char *name)
1877 : {
1878 : /* Rather than trying to be smart, just always quote it. */
1879 10064 : *buffer++ = '"';
1880 60466 : while (*name)
1881 : {
1882 50402 : if (*name == '"')
1883 UIC 0 : *buffer++ = '"';
1884 CBC 50402 : *buffer++ = *name++;
1885 : }
1886 GIC 10064 : *buffer++ = '"';
1887 CBC 10064 : *buffer = '\0';
1888 10064 : }
1889 :
1890 ECB : /*
1891 EUB : * quoteRelationName --- safely quote a fully qualified relation name
1892 ECB : *
1893 : * buffer must be MAX_QUOTED_REL_NAME_LEN long (includes room for \0)
1894 : */
1895 : static void
1896 CBC 2519 : quoteRelationName(char *buffer, Relation rel)
1897 : {
1898 GIC 2519 : quoteOneName(buffer, get_namespace_name(RelationGetNamespace(rel)));
1899 2519 : buffer += strlen(buffer);
1900 2519 : *buffer++ = '.';
1901 2519 : quoteOneName(buffer, RelationGetRelationName(rel));
1902 2519 : }
1903 :
1904 ECB : /*
1905 : * ri_GenerateQual --- generate a WHERE clause equating two variables
1906 : *
1907 : * This basically appends " sep leftop op rightop" to buf, adding casts
1908 : * and schema qualification as needed to ensure that the parser will select
1909 : * the operator we specify. leftop and rightop should be parenthesized
1910 : * if they aren't variables or parameters.
1911 : */
1912 : static void
1913 GIC 2464 : ri_GenerateQual(StringInfo buf,
1914 : const char *sep,
1915 : const char *leftop, Oid leftoptype,
1916 : Oid opoid,
1917 : const char *rightop, Oid rightoptype)
1918 : {
1919 2464 : appendStringInfo(buf, " %s ", sep);
1920 2464 : generate_operator_clause(buf, leftop, leftoptype, opoid,
1921 ECB : rightop, rightoptype);
1922 GIC 2464 : }
1923 :
1924 : /*
1925 : * ri_GenerateQualCollation --- add a COLLATE spec to a WHERE clause
1926 : *
1927 ECB : * At present, we intentionally do not use this function for RI queries that
1928 : * compare a variable to a $n parameter. Since parameter symbols always have
1929 : * default collation, the effect will be to use the variable's collation.
1930 : * Now that is only strictly correct when testing the referenced column, since
1931 : * the SQL standard specifies that RI comparisons should use the referenced
1932 : * column's collation. However, so long as all collations have the same
1933 : * notion of equality (which they do, because texteq reduces to bitwise
1934 : * equality), there's no visible semantic impact from using the referencing
1935 : * column's collation when testing it, and this is a good thing to do because
1936 : * it lets us use a normal index on the referencing column. However, we do
1937 : * have to use this function when directly comparing the referencing and
1938 : * referenced columns, if they are of different collations; else the parser
1939 : * will fail to resolve the collation to use.
1940 : */
1941 : static void
1942 GIC 12 : ri_GenerateQualCollation(StringInfo buf, Oid collation)
1943 : {
1944 : HeapTuple tp;
1945 : Form_pg_collation colltup;
1946 : char *collname;
1947 : char onename[MAX_QUOTED_NAME_LEN];
1948 :
1949 : /* Nothing to do if it's a noncollatable data type */
1950 CBC 12 : if (!OidIsValid(collation))
1951 UIC 0 : return;
1952 :
1953 GIC 12 : tp = SearchSysCache1(COLLOID, ObjectIdGetDatum(collation));
1954 12 : if (!HeapTupleIsValid(tp))
1955 UIC 0 : elog(ERROR, "cache lookup failed for collation %u", collation);
1956 GIC 12 : colltup = (Form_pg_collation) GETSTRUCT(tp);
1957 12 : collname = NameStr(colltup->collname);
1958 ECB :
1959 EUB : /*
1960 : * We qualify the name always, for simplicity and to ensure the query is
1961 ECB : * not search-path-dependent.
1962 : */
1963 GBC 12 : quoteOneName(onename, get_namespace_name(colltup->collnamespace));
1964 CBC 12 : appendStringInfo(buf, " COLLATE %s", onename);
1965 12 : quoteOneName(onename, collname);
1966 GIC 12 : appendStringInfo(buf, ".%s", onename);
1967 :
1968 12 : ReleaseSysCache(tp);
1969 : }
1970 :
1971 ECB : /* ----------
1972 : * ri_BuildQueryKey -
1973 : *
1974 : * Construct a hashtable key for a prepared SPI plan of an FK constraint.
1975 : *
1976 : * key: output argument, *key is filled in based on the other arguments
1977 : * riinfo: info derived from pg_constraint entry
1978 : * constr_queryno: an internal number identifying the query type
1979 : * (see RI_PLAN_XXX constants at head of file)
1980 : * ----------
1981 : */
1982 : static void
1983 GIC 2911 : ri_BuildQueryKey(RI_QueryKey *key, const RI_ConstraintInfo *riinfo,
1984 : int32 constr_queryno)
1985 : {
1986 : /*
1987 : * Inherited constraints with a common ancestor can share ri_query_cache
1988 : * entries for all query types except RI_PLAN_CHECK_LOOKUPPK_FROM_PK.
1989 : * Except in that case, the query processes the other table involved in
1990 : * the FK constraint (i.e., not the table on which the trigger has been
1991 ECB : * fired), and so it will be the same for all members of the inheritance
1992 : * tree. So we may use the root constraint's OID in the hash key, rather
1993 : * than the constraint's own OID. This avoids creating duplicate SPI
1994 : * plans, saving lots of work and memory when there are many partitions
1995 : * with similar FK constraints.
1996 : *
1997 : * (Note that we must still have a separate RI_ConstraintInfo for each
1998 : * constraint, because partitions can have different column orders,
1999 : * resulting in different pk_attnums[] or fk_attnums[] array contents.)
2000 : *
2001 : * We assume struct RI_QueryKey contains no padding bytes, else we'd need
2002 : * to use memset to clear them.
2003 : */
2004 GIC 2911 : if (constr_queryno != RI_PLAN_CHECK_LOOKUPPK_FROM_PK)
2005 2542 : key->constr_id = riinfo->constraint_root_id;
2006 : else
2007 369 : key->constr_id = riinfo->constraint_id;
2008 2911 : key->constr_queryno = constr_queryno;
2009 2911 : }
2010 :
2011 : /*
2012 ECB : * Check that RI trigger function was called in expected context
2013 : */
2014 : static void
2015 CBC 2676 : ri_CheckTrigger(FunctionCallInfo fcinfo, const char *funcname, int tgkind)
2016 ECB : {
2017 CBC 2676 : TriggerData *trigdata = (TriggerData *) fcinfo->context;
2018 :
2019 GIC 2676 : if (!CALLED_AS_TRIGGER(fcinfo))
2020 UIC 0 : ereport(ERROR,
2021 : (errcode(ERRCODE_E_R_I_E_TRIGGER_PROTOCOL_VIOLATED),
2022 : errmsg("function \"%s\" was not called by trigger manager", funcname)));
2023 ECB :
2024 : /*
2025 : * Check proper event
2026 : */
2027 CBC 2676 : if (!TRIGGER_FIRED_AFTER(trigdata->tg_event) ||
2028 GBC 2676 : !TRIGGER_FIRED_FOR_ROW(trigdata->tg_event))
2029 UIC 0 : ereport(ERROR,
2030 : (errcode(ERRCODE_E_R_I_E_TRIGGER_PROTOCOL_VIOLATED),
2031 : errmsg("function \"%s\" must be fired AFTER ROW", funcname)));
2032 :
2033 GIC 2676 : switch (tgkind)
2034 : {
2035 CBC 1834 : case RI_TRIGTYPE_INSERT:
2036 1834 : if (!TRIGGER_FIRED_BY_INSERT(trigdata->tg_event))
2037 UBC 0 : ereport(ERROR,
2038 : (errcode(ERRCODE_E_R_I_E_TRIGGER_PROTOCOL_VIOLATED),
2039 : errmsg("function \"%s\" must be fired for INSERT", funcname)));
2040 GIC 1834 : break;
2041 CBC 515 : case RI_TRIGTYPE_UPDATE:
2042 GIC 515 : if (!TRIGGER_FIRED_BY_UPDATE(trigdata->tg_event))
2043 LBC 0 : ereport(ERROR,
2044 ECB : (errcode(ERRCODE_E_R_I_E_TRIGGER_PROTOCOL_VIOLATED),
2045 EUB : errmsg("function \"%s\" must be fired for UPDATE", funcname)));
2046 GIC 515 : break;
2047 327 : case RI_TRIGTYPE_DELETE:
2048 CBC 327 : if (!TRIGGER_FIRED_BY_DELETE(trigdata->tg_event))
2049 LBC 0 : ereport(ERROR,
2050 ECB : (errcode(ERRCODE_E_R_I_E_TRIGGER_PROTOCOL_VIOLATED),
2051 EUB : errmsg("function \"%s\" must be fired for DELETE", funcname)));
2052 GIC 327 : break;
2053 : }
2054 CBC 2676 : }
2055 ECB :
2056 :
2057 EUB : /*
2058 : * Fetch the RI_ConstraintInfo struct for the trigger's FK constraint.
2059 : */
2060 ECB : static const RI_ConstraintInfo *
2061 GIC 4746 : ri_FetchConstraintInfo(Trigger *trigger, Relation trig_rel, bool rel_is_pk)
2062 ECB : {
2063 GIC 4746 : Oid constraintOid = trigger->tgconstraint;
2064 : const RI_ConstraintInfo *riinfo;
2065 :
2066 : /*
2067 : * Check that the FK constraint's OID is available; it might not be if
2068 : * we've been invoked via an ordinary trigger or an old-style "constraint
2069 ECB : * trigger".
2070 : */
2071 CBC 4746 : if (!OidIsValid(constraintOid))
2072 UIC 0 : ereport(ERROR,
2073 : (errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
2074 : errmsg("no pg_constraint entry for trigger \"%s\" on table \"%s\"",
2075 : trigger->tgname, RelationGetRelationName(trig_rel)),
2076 : errhint("Remove this referential integrity trigger and its mates, then do ALTER TABLE ADD CONSTRAINT.")));
2077 :
2078 : /* Find or create a hashtable entry for the constraint */
2079 CBC 4746 : riinfo = ri_LoadConstraintInfo(constraintOid);
2080 EUB :
2081 : /* Do some easy cross-checks against the trigger call data */
2082 GIC 4746 : if (rel_is_pk)
2083 : {
2084 1684 : if (riinfo->fk_relid != trigger->tgconstrrelid ||
2085 1684 : riinfo->pk_relid != RelationGetRelid(trig_rel))
2086 UIC 0 : elog(ERROR, "wrong pg_constraint entry for trigger \"%s\" on table \"%s\"",
2087 ECB : trigger->tgname, RelationGetRelationName(trig_rel));
2088 : }
2089 : else
2090 : {
2091 GIC 3062 : if (riinfo->fk_relid != RelationGetRelid(trig_rel) ||
2092 CBC 3062 : riinfo->pk_relid != trigger->tgconstrrelid)
2093 LBC 0 : elog(ERROR, "wrong pg_constraint entry for trigger \"%s\" on table \"%s\"",
2094 EUB : trigger->tgname, RelationGetRelationName(trig_rel));
2095 : }
2096 :
2097 GIC 4746 : if (riinfo->confmatchtype != FKCONSTR_MATCH_FULL &&
2098 4514 : riinfo->confmatchtype != FKCONSTR_MATCH_PARTIAL &&
2099 CBC 4514 : riinfo->confmatchtype != FKCONSTR_MATCH_SIMPLE)
2100 LBC 0 : elog(ERROR, "unrecognized confmatchtype: %d",
2101 EUB : riinfo->confmatchtype);
2102 :
2103 GIC 4746 : if (riinfo->confmatchtype == FKCONSTR_MATCH_PARTIAL)
2104 UIC 0 : ereport(ERROR,
2105 ECB : (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
2106 : errmsg("MATCH PARTIAL not yet implemented")));
2107 :
2108 GBC 4746 : return riinfo;
2109 : }
2110 :
2111 ECB : /*
2112 EUB : * Fetch or create the RI_ConstraintInfo struct for an FK constraint.
2113 : */
2114 : static const RI_ConstraintInfo *
2115 GIC 4746 : ri_LoadConstraintInfo(Oid constraintOid)
2116 ECB : {
2117 : RI_ConstraintInfo *riinfo;
2118 : bool found;
2119 : HeapTuple tup;
2120 : Form_pg_constraint conForm;
2121 :
2122 : /*
2123 : * On the first call initialize the hashtable
2124 : */
2125 GIC 4746 : if (!ri_constraint_cache)
2126 207 : ri_InitHashTables();
2127 :
2128 : /*
2129 : * Find or create a hash entry. If we find a valid one, just return it.
2130 : */
2131 4746 : riinfo = (RI_ConstraintInfo *) hash_search(ri_constraint_cache,
2132 : &constraintOid,
2133 ECB : HASH_ENTER, &found);
2134 CBC 4746 : if (!found)
2135 GIC 1812 : riinfo->valid = false;
2136 2934 : else if (riinfo->valid)
2137 2841 : return riinfo;
2138 :
2139 ECB : /*
2140 : * Fetch the pg_constraint row so we can fill in the entry.
2141 : */
2142 CBC 1905 : tup = SearchSysCache1(CONSTROID, ObjectIdGetDatum(constraintOid));
2143 1905 : if (!HeapTupleIsValid(tup)) /* should not happen */
2144 LBC 0 : elog(ERROR, "cache lookup failed for constraint %u", constraintOid);
2145 CBC 1905 : conForm = (Form_pg_constraint) GETSTRUCT(tup);
2146 :
2147 GIC 1905 : if (conForm->contype != CONSTRAINT_FOREIGN) /* should not happen */
2148 UIC 0 : elog(ERROR, "constraint %u is not a foreign key constraint",
2149 : constraintOid);
2150 ECB :
2151 : /* And extract data */
2152 GBC 1905 : Assert(riinfo->constraint_id == constraintOid);
2153 CBC 1905 : if (OidIsValid(conForm->conparentid))
2154 GIC 663 : riinfo->constraint_root_id =
2155 CBC 663 : get_ri_constraint_root(conForm->conparentid);
2156 EUB : else
2157 GIC 1242 : riinfo->constraint_root_id = constraintOid;
2158 1905 : riinfo->oidHashValue = GetSysCacheHashValue1(CONSTROID,
2159 : ObjectIdGetDatum(constraintOid));
2160 CBC 1905 : riinfo->rootHashValue = GetSysCacheHashValue1(CONSTROID,
2161 ECB : ObjectIdGetDatum(riinfo->constraint_root_id));
2162 CBC 1905 : memcpy(&riinfo->conname, &conForm->conname, sizeof(NameData));
2163 1905 : riinfo->pk_relid = conForm->confrelid;
2164 GIC 1905 : riinfo->fk_relid = conForm->conrelid;
2165 CBC 1905 : riinfo->confupdtype = conForm->confupdtype;
2166 1905 : riinfo->confdeltype = conForm->confdeltype;
2167 GIC 1905 : riinfo->confmatchtype = conForm->confmatchtype;
2168 ECB :
2169 GIC 1905 : DeconstructFkConstraintRow(tup,
2170 ECB : &riinfo->nkeys,
2171 CBC 1905 : riinfo->fk_attnums,
2172 1905 : riinfo->pk_attnums,
2173 1905 : riinfo->pf_eq_oprs,
2174 1905 : riinfo->pp_eq_oprs,
2175 1905 : riinfo->ff_eq_oprs,
2176 : &riinfo->ndelsetcols,
2177 1905 : riinfo->confdelsetcols);
2178 :
2179 1905 : ReleaseSysCache(tup);
2180 ECB :
2181 : /*
2182 : * For efficient processing of invalidation messages below, we keep a
2183 : * doubly-linked count list of all currently valid entries.
2184 : */
2185 GNC 1905 : dclist_push_tail(&ri_constraint_cache_valid_list, &riinfo->valid_link);
2186 ECB :
2187 GIC 1905 : riinfo->valid = true;
2188 :
2189 1905 : return riinfo;
2190 : }
2191 :
2192 ECB : /*
2193 : * get_ri_constraint_root
2194 : * Returns the OID of the constraint's root parent
2195 : */
2196 : static Oid
2197 GIC 663 : get_ri_constraint_root(Oid constrOid)
2198 : {
2199 : for (;;)
2200 146 : {
2201 : HeapTuple tuple;
2202 : Oid constrParentOid;
2203 :
2204 CBC 809 : tuple = SearchSysCache1(CONSTROID, ObjectIdGetDatum(constrOid));
2205 GIC 809 : if (!HeapTupleIsValid(tuple))
2206 UIC 0 : elog(ERROR, "cache lookup failed for constraint %u", constrOid);
2207 CBC 809 : constrParentOid = ((Form_pg_constraint) GETSTRUCT(tuple))->conparentid;
2208 GIC 809 : ReleaseSysCache(tuple);
2209 809 : if (!OidIsValid(constrParentOid))
2210 663 : break; /* we reached the root constraint */
2211 CBC 146 : constrOid = constrParentOid;
2212 ECB : }
2213 GBC 663 : return constrOid;
2214 ECB : }
2215 :
2216 : /*
2217 : * Callback for pg_constraint inval events
2218 : *
2219 : * While most syscache callbacks just flush all their entries, pg_constraint
2220 : * gets enough update traffic that it's probably worth being smarter.
2221 : * Invalidate any ri_constraint_cache entry associated with the syscache
2222 : * entry with the specified hash value, or all entries if hashvalue == 0.
2223 : *
2224 : * Note: at the time a cache invalidation message is processed there may be
2225 : * active references to the cache. Because of this we never remove entries
2226 : * from the cache, but only mark them invalid, which is harmless to active
2227 : * uses. (Any query using an entry should hold a lock sufficient to keep that
2228 : * data from changing under it --- but we may get cache flushes anyway.)
2229 : */
2230 : static void
2231 GIC 21890 : InvalidateConstraintCacheCallBack(Datum arg, int cacheid, uint32 hashvalue)
2232 : {
2233 : dlist_mutable_iter iter;
2234 :
2235 21890 : Assert(ri_constraint_cache != NULL);
2236 :
2237 : /*
2238 ECB : * If the list of currently valid entries gets excessively large, we mark
2239 : * them all invalid so we can empty the list. This arrangement avoids
2240 : * O(N^2) behavior in situations where a session touches many foreign keys
2241 : * and also does many ALTER TABLEs, such as a restore from pg_dump.
2242 : */
2243 GNC 21890 : if (dclist_count(&ri_constraint_cache_valid_list) > 1000)
2244 UIC 0 : hashvalue = 0; /* pretend it's a cache reset */
2245 :
2246 GNC 79517 : dclist_foreach_modify(iter, &ri_constraint_cache_valid_list)
2247 : {
2248 57627 : RI_ConstraintInfo *riinfo = dclist_container(RI_ConstraintInfo,
2249 : valid_link, iter.cur);
2250 ECB :
2251 EUB : /*
2252 : * We must invalidate not only entries directly matching the given
2253 ECB : * hash value, but also child entries, in case the invalidation
2254 : * affects a root constraint.
2255 : */
2256 GIC 57627 : if (hashvalue == 0 ||
2257 57625 : riinfo->oidHashValue == hashvalue ||
2258 56519 : riinfo->rootHashValue == hashvalue)
2259 : {
2260 1242 : riinfo->valid = false;
2261 : /* Remove invalidated entries from the list, too */
2262 GNC 1242 : dclist_delete_from(&ri_constraint_cache_valid_list, iter.cur);
2263 ECB : }
2264 : }
2265 GIC 21890 : }
2266 ECB :
2267 :
2268 : /*
2269 : * Prepare execution plan for a query to enforce an RI restriction
2270 : */
2271 : static SPIPlanPtr
2272 GIC 1513 : ri_PlanCheck(const char *querystr, int nargs, Oid *argtypes,
2273 : RI_QueryKey *qkey, Relation fk_rel, Relation pk_rel)
2274 : {
2275 : SPIPlanPtr qplan;
2276 : Relation query_rel;
2277 : Oid save_userid;
2278 ECB : int save_sec_context;
2279 :
2280 : /*
2281 : * Use the query type code to determine whether the query is run against
2282 : * the PK or FK table; we'll do the check as that table's owner
2283 : */
2284 GIC 1513 : if (qkey->constr_queryno <= RI_PLAN_LAST_ON_PK)
2285 1188 : query_rel = pk_rel;
2286 : else
2287 325 : query_rel = fk_rel;
2288 :
2289 : /* Switch to proper UID to perform check as */
2290 CBC 1513 : GetUserIdAndSecContext(&save_userid, &save_sec_context);
2291 1513 : SetUserIdAndSecContext(RelationGetForm(query_rel)->relowner,
2292 : save_sec_context | SECURITY_LOCAL_USERID_CHANGE |
2293 ECB : SECURITY_NOFORCE_RLS);
2294 :
2295 : /* Create the plan */
2296 CBC 1513 : qplan = SPI_prepare(querystr, nargs, argtypes);
2297 ECB :
2298 GIC 1513 : if (qplan == NULL)
2299 UIC 0 : elog(ERROR, "SPI_prepare returned %s for %s", SPI_result_code_string(SPI_result), querystr);
2300 :
2301 : /* Restore UID and security context */
2302 CBC 1513 : SetUserIdAndSecContext(save_userid, save_sec_context);
2303 :
2304 ECB : /* Save the plan */
2305 GBC 1513 : SPI_keepplan(qplan);
2306 GIC 1513 : ri_HashPreparedPlan(qkey, qplan);
2307 :
2308 CBC 1513 : return qplan;
2309 : }
2310 :
2311 ECB : /*
2312 : * Perform a query to enforce an RI restriction
2313 : */
2314 : static bool
2315 GIC 2911 : ri_PerformCheck(const RI_ConstraintInfo *riinfo,
2316 : RI_QueryKey *qkey, SPIPlanPtr qplan,
2317 : Relation fk_rel, Relation pk_rel,
2318 : TupleTableSlot *oldslot, TupleTableSlot *newslot,
2319 : bool detectNewRows, int expect_OK)
2320 : {
2321 ECB : Relation query_rel,
2322 : source_rel;
2323 : bool source_is_pk;
2324 : Snapshot test_snapshot;
2325 : Snapshot crosscheck_snapshot;
2326 : int limit;
2327 : int spi_result;
2328 : Oid save_userid;
2329 : int save_sec_context;
2330 : Datum vals[RI_MAX_NUMKEYS * 2];
2331 : char nulls[RI_MAX_NUMKEYS * 2];
2332 :
2333 : /*
2334 : * Use the query type code to determine whether the query is run against
2335 : * the PK or FK table; we'll do the check as that table's owner
2336 : */
2337 GIC 2911 : if (qkey->constr_queryno <= RI_PLAN_LAST_ON_PK)
2338 2241 : query_rel = pk_rel;
2339 : else
2340 670 : query_rel = fk_rel;
2341 :
2342 : /*
2343 ECB : * The values for the query are taken from the table on which the trigger
2344 : * is called - it is normally the other one with respect to query_rel. An
2345 : * exception is ri_Check_Pk_Match(), which uses the PK table for both (and
2346 : * sets queryno to RI_PLAN_CHECK_LOOKUPPK_FROM_PK). We might eventually
2347 : * need some less klugy way to determine this.
2348 : */
2349 GIC 2911 : if (qkey->constr_queryno == RI_PLAN_CHECK_LOOKUPPK)
2350 : {
2351 1872 : source_rel = fk_rel;
2352 1872 : source_is_pk = false;
2353 : }
2354 : else
2355 ECB : {
2356 GIC 1039 : source_rel = pk_rel;
2357 CBC 1039 : source_is_pk = true;
2358 ECB : }
2359 :
2360 : /* Extract the parameters to be passed into the query */
2361 GIC 2911 : if (newslot)
2362 ECB : {
2363 CBC 1974 : ri_ExtractValues(source_rel, newslot, riinfo, source_is_pk,
2364 : vals, nulls);
2365 GIC 1974 : if (oldslot)
2366 102 : ri_ExtractValues(source_rel, oldslot, riinfo, source_is_pk,
2367 CBC 102 : vals + riinfo->nkeys, nulls + riinfo->nkeys);
2368 : }
2369 ECB : else
2370 : {
2371 CBC 937 : ri_ExtractValues(source_rel, oldslot, riinfo, source_is_pk,
2372 ECB : vals, nulls);
2373 : }
2374 :
2375 : /*
2376 : * In READ COMMITTED mode, we just need to use an up-to-date regular
2377 : * snapshot, and we will see all rows that could be interesting. But in
2378 : * transaction-snapshot mode, we can't change the transaction snapshot. If
2379 : * the caller passes detectNewRows == false then it's okay to do the query
2380 : * with the transaction snapshot; otherwise we use a current snapshot, and
2381 : * tell the executor to error out if it finds any rows under the current
2382 : * snapshot that wouldn't be visible per the transaction snapshot. Note
2383 : * that SPI_execute_snapshot will register the snapshots, so we don't need
2384 : * to bother here.
2385 : */
2386 GIC 2911 : if (IsolationUsesXactSnapshot() && detectNewRows)
2387 : {
2388 13 : CommandCounterIncrement(); /* be sure all my own work is visible */
2389 13 : test_snapshot = GetLatestSnapshot();
2390 13 : crosscheck_snapshot = GetTransactionSnapshot();
2391 : }
2392 ECB : else
2393 : {
2394 : /* the default SPI behavior is okay */
2395 CBC 2898 : test_snapshot = InvalidSnapshot;
2396 2898 : crosscheck_snapshot = InvalidSnapshot;
2397 : }
2398 :
2399 : /*
2400 : * If this is a select query (e.g., for a 'no action' or 'restrict'
2401 ECB : * trigger), we only need to see if there is a single row in the table,
2402 : * matching the key. Otherwise, limit = 0 - because we want the query to
2403 : * affect ALL the matching rows.
2404 : */
2405 GIC 2911 : limit = (expect_OK == SPI_OK_SELECT) ? 1 : 0;
2406 :
2407 : /* Switch to proper UID to perform check as */
2408 2911 : GetUserIdAndSecContext(&save_userid, &save_sec_context);
2409 2911 : SetUserIdAndSecContext(RelationGetForm(query_rel)->relowner,
2410 : save_sec_context | SECURITY_LOCAL_USERID_CHANGE |
2411 ECB : SECURITY_NOFORCE_RLS);
2412 :
2413 : /* Finally we can run the query. */
2414 CBC 2911 : spi_result = SPI_execute_snapshot(qplan,
2415 ECB : vals, nulls,
2416 : test_snapshot, crosscheck_snapshot,
2417 : false, false, limit);
2418 :
2419 : /* Restore UID and security context */
2420 CBC 2906 : SetUserIdAndSecContext(save_userid, save_sec_context);
2421 :
2422 : /* Check result */
2423 GIC 2906 : if (spi_result < 0)
2424 UIC 0 : elog(ERROR, "SPI_execute_snapshot returned %s", SPI_result_code_string(spi_result));
2425 :
2426 CBC 2906 : if (expect_OK >= 0 && spi_result != expect_OK)
2427 UIC 0 : ereport(ERROR,
2428 : (errcode(ERRCODE_INTERNAL_ERROR),
2429 ECB : errmsg("referential integrity query on \"%s\" from constraint \"%s\" on \"%s\" gave unexpected result",
2430 EUB : RelationGetRelationName(pk_rel),
2431 : NameStr(riinfo->conname),
2432 ECB : RelationGetRelationName(fk_rel)),
2433 EUB : errhint("This is most likely due to a rule having rewritten the query.")));
2434 :
2435 : /* XXX wouldn't it be clearer to do this part at the caller? */
2436 GIC 2906 : if (qkey->constr_queryno != RI_PLAN_CHECK_LOOKUPPK_FROM_PK &&
2437 2228 : expect_OK == SPI_OK_SELECT &&
2438 2228 : (SPI_processed == 0) == (qkey->constr_queryno == RI_PLAN_CHECK_LOOKUPPK))
2439 394 : ri_ReportViolation(riinfo,
2440 : pk_rel, fk_rel,
2441 : newslot ? newslot : oldslot,
2442 ECB : NULL,
2443 : qkey->constr_queryno, false);
2444 :
2445 CBC 2512 : return SPI_processed != 0;
2446 : }
2447 :
2448 : /*
2449 : * Extract fields from a tuple into Datum/nulls arrays
2450 : */
2451 ECB : static void
2452 GIC 3013 : ri_ExtractValues(Relation rel, TupleTableSlot *slot,
2453 : const RI_ConstraintInfo *riinfo, bool rel_is_pk,
2454 : Datum *vals, char *nulls)
2455 : {
2456 : const int16 *attnums;
2457 : bool isnull;
2458 ECB :
2459 GIC 3013 : if (rel_is_pk)
2460 1141 : attnums = riinfo->pk_attnums;
2461 : else
2462 1872 : attnums = riinfo->fk_attnums;
2463 :
2464 6827 : for (int i = 0; i < riinfo->nkeys; i++)
2465 ECB : {
2466 CBC 3814 : vals[i] = slot_getattr(slot, attnums[i], &isnull);
2467 GIC 3814 : nulls[i] = isnull ? 'n' : ' ';
2468 ECB : }
2469 GIC 3013 : }
2470 ECB :
2471 : /*
2472 : * Produce an error report
2473 : *
2474 : * If the failed constraint was on insert/update to the FK table,
2475 : * we want the key names and values extracted from there, and the error
2476 : * message to look like 'key blah is not present in PK'.
2477 : * Otherwise, the attr names and values come from the PK table and the
2478 : * message looks like 'key blah is still referenced from FK'.
2479 : */
2480 : static void
2481 GIC 433 : ri_ReportViolation(const RI_ConstraintInfo *riinfo,
2482 : Relation pk_rel, Relation fk_rel,
2483 : TupleTableSlot *violatorslot, TupleDesc tupdesc,
2484 : int queryno, bool partgone)
2485 : {
2486 : StringInfoData key_names;
2487 ECB : StringInfoData key_values;
2488 : bool onfk;
2489 : const int16 *attnums;
2490 : Oid rel_oid;
2491 : AclResult aclresult;
2492 GIC 433 : bool has_perm = true;
2493 :
2494 : /*
2495 : * Determine which relation to complain about. If tupdesc wasn't passed
2496 : * by caller, assume the violator tuple came from there.
2497 : */
2498 CBC 433 : onfk = (queryno == RI_PLAN_CHECK_LOOKUPPK);
2499 GIC 433 : if (onfk)
2500 : {
2501 261 : attnums = riinfo->fk_attnums;
2502 261 : rel_oid = fk_rel->rd_id;
2503 261 : if (tupdesc == NULL)
2504 CBC 239 : tupdesc = fk_rel->rd_att;
2505 ECB : }
2506 : else
2507 : {
2508 CBC 172 : attnums = riinfo->pk_attnums;
2509 172 : rel_oid = pk_rel->rd_id;
2510 172 : if (tupdesc == NULL)
2511 GIC 155 : tupdesc = pk_rel->rd_att;
2512 : }
2513 :
2514 ECB : /*
2515 : * Check permissions- if the user does not have access to view the data in
2516 : * any of the key columns then we don't include the errdetail() below.
2517 : *
2518 : * Check if RLS is enabled on the relation first. If so, we don't return
2519 : * any specifics to avoid leaking data.
2520 : *
2521 : * Check table-level permissions next and, failing that, column-level
2522 : * privileges.
2523 : *
2524 : * When a partition at the referenced side is being detached/dropped, we
2525 : * needn't check, since the user must be the table owner anyway.
2526 : */
2527 GIC 433 : if (partgone)
2528 17 : has_perm = true;
2529 416 : else if (check_enable_rls(rel_oid, InvalidOid, true) != RLS_ENABLED)
2530 : {
2531 413 : aclresult = pg_class_aclcheck(rel_oid, GetUserId(), ACL_SELECT);
2532 413 : if (aclresult != ACLCHECK_OK)
2533 ECB : {
2534 : /* Try for column-level permissions */
2535 LBC 0 : for (int idx = 0; idx < riinfo->nkeys; idx++)
2536 : {
2537 0 : aclresult = pg_attribute_aclcheck(rel_oid, attnums[idx],
2538 ECB : GetUserId(),
2539 : ACL_SELECT);
2540 :
2541 EUB : /* No access to the key */
2542 UIC 0 : if (aclresult != ACLCHECK_OK)
2543 EUB : {
2544 UIC 0 : has_perm = false;
2545 0 : break;
2546 : }
2547 : }
2548 EUB : }
2549 : }
2550 : else
2551 GBC 3 : has_perm = false;
2552 :
2553 GIC 433 : if (has_perm)
2554 : {
2555 : /* Get printable versions of the keys involved */
2556 430 : initStringInfo(&key_names);
2557 CBC 430 : initStringInfo(&key_values);
2558 GIC 1007 : for (int idx = 0; idx < riinfo->nkeys; idx++)
2559 ECB : {
2560 GIC 577 : int fnum = attnums[idx];
2561 577 : Form_pg_attribute att = TupleDescAttr(tupdesc, fnum - 1);
2562 ECB : char *name,
2563 : *val;
2564 : Datum datum;
2565 : bool isnull;
2566 :
2567 CBC 577 : name = NameStr(att->attname);
2568 :
2569 GIC 577 : datum = slot_getattr(violatorslot, fnum, &isnull);
2570 577 : if (!isnull)
2571 : {
2572 : Oid foutoid;
2573 ECB : bool typisvarlena;
2574 :
2575 CBC 577 : getTypeOutputInfo(att->atttypid, &foutoid, &typisvarlena);
2576 577 : val = OidOutputFunctionCall(foutoid, datum);
2577 : }
2578 : else
2579 UIC 0 : val = "null";
2580 :
2581 CBC 577 : if (idx > 0)
2582 ECB : {
2583 GIC 147 : appendStringInfoString(&key_names, ", ");
2584 147 : appendStringInfoString(&key_values, ", ");
2585 EUB : }
2586 GIC 577 : appendStringInfoString(&key_names, name);
2587 CBC 577 : appendStringInfoString(&key_values, val);
2588 : }
2589 ECB : }
2590 :
2591 GIC 433 : if (partgone)
2592 CBC 17 : ereport(ERROR,
2593 ECB : (errcode(ERRCODE_FOREIGN_KEY_VIOLATION),
2594 : errmsg("removing partition \"%s\" violates foreign key constraint \"%s\"",
2595 : RelationGetRelationName(pk_rel),
2596 : NameStr(riinfo->conname)),
2597 : errdetail("Key (%s)=(%s) is still referenced from table \"%s\".",
2598 : key_names.data, key_values.data,
2599 : RelationGetRelationName(fk_rel)),
2600 : errtableconstraint(fk_rel, NameStr(riinfo->conname))));
2601 GIC 416 : else if (onfk)
2602 261 : ereport(ERROR,
2603 : (errcode(ERRCODE_FOREIGN_KEY_VIOLATION),
2604 : errmsg("insert or update on table \"%s\" violates foreign key constraint \"%s\"",
2605 : RelationGetRelationName(fk_rel),
2606 : NameStr(riinfo->conname)),
2607 ECB : has_perm ?
2608 : errdetail("Key (%s)=(%s) is not present in table \"%s\".",
2609 : key_names.data, key_values.data,
2610 : RelationGetRelationName(pk_rel)) :
2611 : errdetail("Key is not present in table \"%s\".",
2612 : RelationGetRelationName(pk_rel)),
2613 : errtableconstraint(fk_rel, NameStr(riinfo->conname))));
2614 : else
2615 GIC 155 : ereport(ERROR,
2616 : (errcode(ERRCODE_FOREIGN_KEY_VIOLATION),
2617 : errmsg("update or delete on table \"%s\" violates foreign key constraint \"%s\" on table \"%s\"",
2618 : RelationGetRelationName(pk_rel),
2619 : NameStr(riinfo->conname),
2620 : RelationGetRelationName(fk_rel)),
2621 ECB : has_perm ?
2622 : errdetail("Key (%s)=(%s) is still referenced from table \"%s\".",
2623 : key_names.data, key_values.data,
2624 : RelationGetRelationName(fk_rel)) :
2625 : errdetail("Key is still referenced from table \"%s\".",
2626 : RelationGetRelationName(fk_rel)),
2627 : errtableconstraint(fk_rel, NameStr(riinfo->conname))));
2628 : }
2629 :
2630 :
2631 : /*
2632 : * ri_NullCheck -
2633 : *
2634 : * Determine the NULL state of all key values in a tuple
2635 : *
2636 : * Returns one of RI_KEYS_ALL_NULL, RI_KEYS_NONE_NULL or RI_KEYS_SOME_NULL.
2637 : */
2638 : static int
2639 GIC 3892 : ri_NullCheck(TupleDesc tupDesc,
2640 : TupleTableSlot *slot,
2641 : const RI_ConstraintInfo *riinfo, bool rel_is_pk)
2642 : {
2643 : const int16 *attnums;
2644 3892 : bool allnull = true;
2645 CBC 3892 : bool nonenull = true;
2646 :
2647 GIC 3892 : if (rel_is_pk)
2648 1357 : attnums = riinfo->pk_attnums;
2649 : else
2650 CBC 2535 : attnums = riinfo->fk_attnums;
2651 ECB :
2652 GIC 8771 : for (int i = 0; i < riinfo->nkeys; i++)
2653 ECB : {
2654 CBC 4879 : if (slot_attisnull(slot, attnums[i]))
2655 GIC 267 : nonenull = false;
2656 ECB : else
2657 GIC 4612 : allnull = false;
2658 ECB : }
2659 :
2660 CBC 3892 : if (allnull)
2661 129 : return RI_KEYS_ALL_NULL;
2662 :
2663 3763 : if (nonenull)
2664 GIC 3661 : return RI_KEYS_NONE_NULL;
2665 :
2666 CBC 102 : return RI_KEYS_SOME_NULL;
2667 ECB : }
2668 :
2669 :
2670 : /*
2671 : * ri_InitHashTables -
2672 : *
2673 : * Initialize our internal hash tables.
2674 : */
2675 : static void
2676 GIC 207 : ri_InitHashTables(void)
2677 : {
2678 : HASHCTL ctl;
2679 :
2680 207 : ctl.keysize = sizeof(Oid);
2681 207 : ctl.entrysize = sizeof(RI_ConstraintInfo);
2682 CBC 207 : ri_constraint_cache = hash_create("RI constraint cache",
2683 : RI_INIT_CONSTRAINTHASHSIZE,
2684 : &ctl, HASH_ELEM | HASH_BLOBS);
2685 :
2686 ECB : /* Arrange to flush cache on pg_constraint changes */
2687 CBC 207 : CacheRegisterSyscacheCallback(CONSTROID,
2688 ECB : InvalidateConstraintCacheCallBack,
2689 : (Datum) 0);
2690 :
2691 GIC 207 : ctl.keysize = sizeof(RI_QueryKey);
2692 207 : ctl.entrysize = sizeof(RI_QueryHashEntry);
2693 CBC 207 : ri_query_cache = hash_create("RI query cache",
2694 : RI_INIT_QUERYHASHSIZE,
2695 : &ctl, HASH_ELEM | HASH_BLOBS);
2696 :
2697 207 : ctl.keysize = sizeof(RI_CompareKey);
2698 207 : ctl.entrysize = sizeof(RI_CompareHashEntry);
2699 207 : ri_compare_cache = hash_create("RI compare cache",
2700 : RI_INIT_QUERYHASHSIZE,
2701 : &ctl, HASH_ELEM | HASH_BLOBS);
2702 GIC 207 : }
2703 ECB :
2704 :
2705 : /*
2706 : * ri_FetchPreparedPlan -
2707 : *
2708 : * Lookup for a query key in our private hash table of prepared
2709 : * and saved SPI execution plans. Return the plan if found or NULL.
2710 : */
2711 : static SPIPlanPtr
2712 GIC 2911 : ri_FetchPreparedPlan(RI_QueryKey *key)
2713 : {
2714 : RI_QueryHashEntry *entry;
2715 : SPIPlanPtr plan;
2716 :
2717 : /*
2718 ECB : * On the first call initialize the hashtable
2719 : */
2720 GIC 2911 : if (!ri_query_cache)
2721 UIC 0 : ri_InitHashTables();
2722 :
2723 : /*
2724 : * Lookup for the key
2725 : */
2726 CBC 2911 : entry = (RI_QueryHashEntry *) hash_search(ri_query_cache,
2727 : key,
2728 : HASH_FIND, NULL);
2729 GIC 2911 : if (entry == NULL)
2730 1374 : return NULL;
2731 :
2732 ECB : /*
2733 : * Check whether the plan is still valid. If it isn't, we don't want to
2734 : * simply rely on plancache.c to regenerate it; rather we should start
2735 : * from scratch and rebuild the query text too. This is to cover cases
2736 : * such as table/column renames. We depend on the plancache machinery to
2737 : * detect possible invalidations, though.
2738 : *
2739 : * CAUTION: this check is only trustworthy if the caller has already
2740 : * locked both FK and PK rels.
2741 : */
2742 GIC 1537 : plan = entry->plan;
2743 1537 : if (plan && SPI_plan_is_valid(plan))
2744 1398 : return plan;
2745 :
2746 : /*
2747 : * Otherwise we might as well flush the cached plan now, to free a little
2748 ECB : * memory space before we make a new one.
2749 : */
2750 CBC 139 : entry->plan = NULL;
2751 GIC 139 : if (plan)
2752 139 : SPI_freeplan(plan);
2753 :
2754 139 : return NULL;
2755 : }
2756 ECB :
2757 :
2758 : /*
2759 : * ri_HashPreparedPlan -
2760 : *
2761 : * Add another plan to our private SPI query plan hashtable.
2762 : */
2763 : static void
2764 GIC 1513 : ri_HashPreparedPlan(RI_QueryKey *key, SPIPlanPtr plan)
2765 : {
2766 : RI_QueryHashEntry *entry;
2767 : bool found;
2768 :
2769 : /*
2770 ECB : * On the first call initialize the hashtable
2771 : */
2772 GIC 1513 : if (!ri_query_cache)
2773 UIC 0 : ri_InitHashTables();
2774 :
2775 : /*
2776 : * Add the new plan. We might be overwriting an entry previously found
2777 : * invalid by ri_FetchPreparedPlan.
2778 ECB : */
2779 GBC 1513 : entry = (RI_QueryHashEntry *) hash_search(ri_query_cache,
2780 : key,
2781 : HASH_ENTER, &found);
2782 GIC 1513 : Assert(!found || entry->plan == NULL);
2783 1513 : entry->plan = plan;
2784 1513 : }
2785 ECB :
2786 :
2787 : /*
2788 : * ri_KeysEqual -
2789 : *
2790 : * Check if all key values in OLD and NEW are equal.
2791 : *
2792 : * Note: at some point we might wish to redefine this as checking for
2793 : * "IS NOT DISTINCT" rather than "=", that is, allow two nulls to be
2794 : * considered equal. Currently there is no need since all callers have
2795 : * previously found at least one of the rows to contain no nulls.
2796 : */
2797 : static bool
2798 GIC 995 : ri_KeysEqual(Relation rel, TupleTableSlot *oldslot, TupleTableSlot *newslot,
2799 : const RI_ConstraintInfo *riinfo, bool rel_is_pk)
2800 : {
2801 : const int16 *attnums;
2802 :
2803 995 : if (rel_is_pk)
2804 CBC 628 : attnums = riinfo->pk_attnums;
2805 : else
2806 GIC 367 : attnums = riinfo->fk_attnums;
2807 :
2808 : /* XXX: could be worthwhile to fetch all necessary attrs at once */
2809 CBC 1540 : for (int i = 0; i < riinfo->nkeys; i++)
2810 ECB : {
2811 : Datum oldvalue;
2812 : Datum newvalue;
2813 : bool isnull;
2814 :
2815 : /*
2816 : * Get one attribute's oldvalue. If it is NULL - they're not equal.
2817 : */
2818 GIC 1055 : oldvalue = slot_getattr(oldslot, attnums[i], &isnull);
2819 1055 : if (isnull)
2820 510 : return false;
2821 :
2822 : /*
2823 : * Get one attribute's newvalue. If it is NULL - they're not equal.
2824 ECB : */
2825 CBC 1040 : newvalue = slot_getattr(newslot, attnums[i], &isnull);
2826 1040 : if (isnull)
2827 UIC 0 : return false;
2828 :
2829 GIC 1040 : if (rel_is_pk)
2830 : {
2831 ECB : /*
2832 : * If we are looking at the PK table, then do a bytewise
2833 EUB : * comparison. We must propagate PK changes if the value is
2834 : * changed to one that "looks" different but would compare as
2835 ECB : * equal using the equality operator. This only makes a
2836 : * difference for ON UPDATE CASCADE, but for consistency we treat
2837 : * all changes to the PK the same.
2838 : */
2839 GIC 670 : Form_pg_attribute att = TupleDescAttr(oldslot->tts_tupleDescriptor, attnums[i] - 1);
2840 :
2841 670 : if (!datum_image_eq(oldvalue, newvalue, att->attbyval, att->attlen))
2842 360 : return false;
2843 : }
2844 : else
2845 ECB : {
2846 : /*
2847 : * For the FK table, compare with the appropriate equality
2848 : * operator. Changes that compare equal will still satisfy the
2849 : * constraint after the update.
2850 : */
2851 GIC 370 : if (!ri_AttributesEqual(riinfo->ff_eq_oprs[i], RIAttType(rel, attnums[i]),
2852 : oldvalue, newvalue))
2853 135 : return false;
2854 : }
2855 : }
2856 :
2857 CBC 485 : return true;
2858 : }
2859 ECB :
2860 :
2861 : /*
2862 : * ri_AttributesEqual -
2863 : *
2864 : * Call the appropriate equality comparison operator for two values.
2865 : *
2866 : * NB: we have already checked that neither value is null.
2867 : */
2868 : static bool
2869 GIC 370 : ri_AttributesEqual(Oid eq_opr, Oid typeid,
2870 : Datum oldvalue, Datum newvalue)
2871 : {
2872 370 : RI_CompareHashEntry *entry = ri_HashCompareOp(eq_opr, typeid);
2873 :
2874 : /* Do we need to cast the values? */
2875 CBC 370 : if (OidIsValid(entry->cast_func_finfo.fn_oid))
2876 : {
2877 GIC 6 : oldvalue = FunctionCall3(&entry->cast_func_finfo,
2878 ECB : oldvalue,
2879 : Int32GetDatum(-1), /* typmod */
2880 : BoolGetDatum(false)); /* implicit coercion */
2881 CBC 6 : newvalue = FunctionCall3(&entry->cast_func_finfo,
2882 : newvalue,
2883 ECB : Int32GetDatum(-1), /* typmod */
2884 : BoolGetDatum(false)); /* implicit coercion */
2885 : }
2886 :
2887 : /*
2888 : * Apply the comparison operator.
2889 : *
2890 : * Note: This function is part of a call stack that determines whether an
2891 : * update to a row is significant enough that it needs checking or action
2892 : * on the other side of a foreign-key constraint. Therefore, the
2893 : * comparison here would need to be done with the collation of the *other*
2894 : * table. For simplicity (e.g., we might not even have the other table
2895 : * open), we'll just use the default collation here, which could lead to
2896 : * some false negatives. All this would break if we ever allow
2897 : * database-wide collations to be nondeterministic.
2898 : */
2899 GIC 370 : return DatumGetBool(FunctionCall2Coll(&entry->eq_opr_finfo,
2900 : DEFAULT_COLLATION_OID,
2901 : oldvalue, newvalue));
2902 : }
2903 :
2904 : /*
2905 ECB : * ri_HashCompareOp -
2906 : *
2907 : * See if we know how to compare two values, and create a new hash entry
2908 : * if not.
2909 : */
2910 : static RI_CompareHashEntry *
2911 GIC 370 : ri_HashCompareOp(Oid eq_opr, Oid typeid)
2912 : {
2913 : RI_CompareKey key;
2914 : RI_CompareHashEntry *entry;
2915 : bool found;
2916 :
2917 ECB : /*
2918 : * On the first call initialize the hashtable
2919 : */
2920 GIC 370 : if (!ri_compare_cache)
2921 UIC 0 : ri_InitHashTables();
2922 :
2923 : /*
2924 : * Find or create a hash entry. Note we're assuming RI_CompareKey
2925 : * contains no struct padding.
2926 ECB : */
2927 GBC 370 : key.eq_opr = eq_opr;
2928 GIC 370 : key.typeid = typeid;
2929 370 : entry = (RI_CompareHashEntry *) hash_search(ri_compare_cache,
2930 : &key,
2931 : HASH_ENTER, &found);
2932 370 : if (!found)
2933 CBC 137 : entry->valid = false;
2934 ECB :
2935 : /*
2936 : * If not already initialized, do so. Since we'll keep this hash entry
2937 : * for the life of the backend, put any subsidiary info for the function
2938 : * cache structs into TopMemoryContext.
2939 : */
2940 GIC 370 : if (!entry->valid)
2941 : {
2942 : Oid lefttype,
2943 : righttype,
2944 : castfunc;
2945 : CoercionPathType pathtype;
2946 ECB :
2947 : /* We always need to know how to call the equality operator */
2948 GIC 137 : fmgr_info_cxt(get_opcode(eq_opr), &entry->eq_opr_finfo,
2949 : TopMemoryContext);
2950 :
2951 : /*
2952 : * If we chose to use a cast from FK to PK type, we may have to apply
2953 : * the cast function to get to the operator's input type.
2954 ECB : *
2955 : * XXX eventually it would be good to support array-coercion cases
2956 : * here and in ri_AttributesEqual(). At the moment there is no point
2957 : * because cases involving nonidentical array types will be rejected
2958 : * at constraint creation time.
2959 : *
2960 : * XXX perhaps also consider supporting CoerceViaIO? No need at the
2961 : * moment since that will never be generated for implicit coercions.
2962 : */
2963 GIC 137 : op_input_types(eq_opr, &lefttype, &righttype);
2964 137 : Assert(lefttype == righttype);
2965 137 : if (typeid == lefttype)
2966 134 : castfunc = InvalidOid; /* simplest case */
2967 : else
2968 : {
2969 CBC 3 : pathtype = find_coercion_pathway(lefttype, typeid,
2970 ECB : COERCION_IMPLICIT,
2971 : &castfunc);
2972 CBC 3 : if (pathtype != COERCION_PATH_FUNC &&
2973 : pathtype != COERCION_PATH_RELABELTYPE)
2974 : {
2975 ECB : /*
2976 : * The declared input type of the eq_opr might be a
2977 : * polymorphic type such as ANYARRAY or ANYENUM, or other
2978 : * special cases such as RECORD; find_coercion_pathway
2979 : * currently doesn't subsume these special cases.
2980 : */
2981 UIC 0 : if (!IsBinaryCoercible(typeid, lefttype))
2982 0 : elog(ERROR, "no conversion function from %s to %s",
2983 : format_type_be(typeid),
2984 : format_type_be(lefttype));
2985 : }
2986 : }
2987 GBC 137 : if (OidIsValid(castfunc))
2988 3 : fmgr_info_cxt(castfunc, &entry->cast_func_finfo,
2989 : TopMemoryContext);
2990 : else
2991 GIC 134 : entry->cast_func_finfo.fn_oid = InvalidOid;
2992 137 : entry->valid = true;
2993 ECB : }
2994 :
2995 GIC 370 : return entry;
2996 : }
2997 ECB :
2998 :
2999 : /*
3000 : * Given a trigger function OID, determine whether it is an RI trigger,
3001 : * and if so whether it is attached to PK or FK relation.
3002 : */
3003 : int
3004 GIC 3705 : RI_FKey_trigger_type(Oid tgfoid)
3005 : {
3006 3705 : switch (tgfoid)
3007 : {
3008 1276 : case F_RI_FKEY_CASCADE_DEL:
3009 : case F_RI_FKEY_CASCADE_UPD:
3010 ECB : case F_RI_FKEY_RESTRICT_DEL:
3011 : case F_RI_FKEY_RESTRICT_UPD:
3012 : case F_RI_FKEY_SETNULL_DEL:
3013 : case F_RI_FKEY_SETNULL_UPD:
3014 : case F_RI_FKEY_SETDEFAULT_DEL:
3015 : case F_RI_FKEY_SETDEFAULT_UPD:
3016 : case F_RI_FKEY_NOACTION_DEL:
3017 : case F_RI_FKEY_NOACTION_UPD:
3018 GIC 1276 : return RI_TRIGGER_PK;
3019 :
3020 1094 : case F_RI_FKEY_CHECK_INS:
3021 : case F_RI_FKEY_CHECK_UPD:
3022 1094 : return RI_TRIGGER_FK;
3023 : }
3024 ECB :
3025 GIC 1335 : return RI_TRIGGER_NONE;
3026 ECB : }
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