diff options
| -rw-r--r-- | src/backend/utils/adt/ri_triggers.c | 247 |
1 files changed, 243 insertions, 4 deletions
diff --git a/src/backend/utils/adt/ri_triggers.c b/src/backend/utils/adt/ri_triggers.c index e0084ca127a..f50f240fc35 100644 --- a/src/backend/utils/adt/ri_triggers.c +++ b/src/backend/utils/adt/ri_triggers.c @@ -17,7 +17,7 @@ * * Portions Copyright (c) 1996-2002, PostgreSQL Global Development Group * - * $Header: /cvsroot/pgsql/src/backend/utils/adt/ri_triggers.c,v 1.39 2002/06/21 02:59:38 momjian Exp $ + * $Header: /cvsroot/pgsql/src/backend/utils/adt/ri_triggers.c,v 1.40 2002/07/30 16:33:21 momjian Exp $ * * ---------- */ @@ -130,6 +130,10 @@ static void ri_BuildQueryKeyFull(RI_QueryKey *key, Oid constr_id, int32 constr_queryno, Relation fk_rel, Relation pk_rel, int argc, char **argv); +static void ri_BuildQueryKeyPkCheck(RI_QueryKey *key, Oid constr_id, + int32 constr_queryno, + Relation pk_rel, + int argc, char **argv); static bool ri_KeysEqual(Relation rel, HeapTuple oldtup, HeapTuple newtup, RI_QueryKey *key, int pairidx); static bool ri_AllKeysUnequal(Relation rel, HeapTuple oldtup, HeapTuple newtup, @@ -137,12 +141,13 @@ static bool ri_AllKeysUnequal(Relation rel, HeapTuple oldtup, HeapTuple newtup, static bool ri_OneKeyEqual(Relation rel, int column, HeapTuple oldtup, HeapTuple newtup, RI_QueryKey *key, int pairidx); static bool ri_AttributesEqual(Oid typeid, Datum oldvalue, Datum newvalue); +static bool ri_Check_Pk_Match(Relation pk_rel, HeapTuple old_row, + Oid tgoid, int match_type, int tgnargs, char **tgargs); static void ri_InitHashTables(void); static void *ri_FetchPreparedPlan(RI_QueryKey *key); static void ri_HashPreparedPlan(RI_QueryKey *key, void *plan); - /* ---------- * RI_FKey_check - * @@ -385,6 +390,7 @@ RI_FKey_check(PG_FUNCTION_ARGS) if (SPI_connect() != SPI_OK_CONNECT) elog(WARNING, "SPI_connect() failed in RI_FKey_check()"); + /* * Fetch or prepare a saved plan for the real check */ @@ -513,6 +519,161 @@ RI_FKey_check_upd(PG_FUNCTION_ARGS) /* ---------- + * ri_Check_Pk_Match + * + * Check for matching value of old pk row in current state for + * noaction triggers. Returns false if no row was found and a fk row + * could potentially be referencing this row, true otherwise. + * ---------- + */ +static bool +ri_Check_Pk_Match(Relation pk_rel, HeapTuple old_row, Oid tgoid, int match_type, int tgnargs, char **tgargs) { + void *qplan; + RI_QueryKey qkey; + bool isnull; + Datum check_values[RI_MAX_NUMKEYS]; + char check_nulls[RI_MAX_NUMKEYS + 1]; + int i; + Oid save_uid; + bool result; + save_uid = GetUserId(); + + ri_BuildQueryKeyPkCheck(&qkey, tgoid, + RI_PLAN_CHECK_LOOKUPPK, pk_rel, + tgnargs, tgargs); + + switch (ri_NullCheck(pk_rel, old_row, &qkey, RI_KEYPAIR_PK_IDX)) + { + case RI_KEYS_ALL_NULL: + /* + * No check - nothing could have been referencing this row anyway. + */ + return true; + + case RI_KEYS_SOME_NULL: + + /* + * This is the only case that differs between the three kinds + * of MATCH. + */ + switch (match_type) + { + case RI_MATCH_TYPE_FULL: + case RI_MATCH_TYPE_UNSPECIFIED: + + /* + * MATCH <unspecified>/FULL - if ANY column is null, we + * can't be matching to this row already. + */ + return true; + + case RI_MATCH_TYPE_PARTIAL: + + /* + * MATCH PARTIAL - all non-null columns must match. + * (not implemented, can be done by modifying the + * query below to only include non-null columns, or by + * writing a special version here) + */ + elog(ERROR, "MATCH PARTIAL not yet implemented"); + break; + } + + case RI_KEYS_NONE_NULL: + + /* + * Have a full qualified key - continue below for all three + * kinds of MATCH. + */ + break; + } + + if (SPI_connect() != SPI_OK_CONNECT) + elog(WARNING, "SPI_connect() failed in RI_FKey_check()"); + + + /* + * Fetch or prepare a saved plan for the real check + */ + if ((qplan = ri_FetchPreparedPlan(&qkey)) == NULL) + { + char querystr[MAX_QUOTED_REL_NAME_LEN + 100 + + (MAX_QUOTED_NAME_LEN + 32) * RI_MAX_NUMKEYS]; + char pkrelname[MAX_QUOTED_REL_NAME_LEN]; + char attname[MAX_QUOTED_NAME_LEN]; + const char *querysep; + Oid queryoids[RI_MAX_NUMKEYS]; + + /* ---------- + * The query string built is + * SELECT 1 FROM ONLY <pktable> WHERE pkatt1 = $1 [AND ...] + * The type id's for the $ parameters are those of the + * corresponding FK attributes. Thus, SPI_prepare could + * eventually fail if the parser cannot identify some way + * how to compare these two types by '='. + * ---------- + */ + quoteRelationName(pkrelname, pk_rel); + sprintf(querystr, "SELECT 1 FROM ONLY %s x", pkrelname); + querysep = "WHERE"; + for (i = 0; i < qkey.nkeypairs; i++) + { + quoteOneName(attname, + tgargs[RI_FIRST_ATTNAME_ARGNO + i * 2 + RI_KEYPAIR_PK_IDX]); + sprintf(querystr + strlen(querystr), " %s %s = $%d", + querysep, attname, i+1); + querysep = "AND"; + queryoids[i] = SPI_gettypeid(pk_rel->rd_att, + qkey.keypair[i][RI_KEYPAIR_PK_IDX]); + } + strcat(querystr, " FOR UPDATE OF x"); + + /* + * Prepare, save and remember the new plan. + */ + qplan = SPI_prepare(querystr, qkey.nkeypairs, queryoids); + qplan = SPI_saveplan(qplan); + ri_HashPreparedPlan(&qkey, qplan); + } + + /* + * We have a plan now. Build up the arguments for SPI_execp() from the + * key values in the new FK tuple. + */ + for (i = 0; i < qkey.nkeypairs; i++) + { + check_values[i] = SPI_getbinval(old_row, + pk_rel->rd_att, + qkey.keypair[i][RI_KEYPAIR_PK_IDX], + &isnull); + if (isnull) + check_nulls[i] = 'n'; + else + check_nulls[i] = ' '; + } + check_nulls[i] = '\0'; + + /* + * Now check that foreign key exists in PK table + */ + + SetUserId(RelationGetForm(pk_rel)->relowner); + + if (SPI_execp(qplan, check_values, check_nulls, 1) != SPI_OK_SELECT) + elog(ERROR, "SPI_execp() failed in ri_Check_Pk_Match()"); + + SetUserId(save_uid); + + result = (SPI_processed!=0); + + if (SPI_finish() != SPI_OK_FINISH) + elog(WARNING, "SPI_finish() failed in ri_Check_Pk_Match()"); + + return result; +} + + +/* ---------- * RI_FKey_noaction_del - * * Give an error and roll back the current transaction if the @@ -535,6 +696,7 @@ RI_FKey_noaction_del(PG_FUNCTION_ARGS) char del_nulls[RI_MAX_NUMKEYS + 1]; bool isnull; int i; + int match_type; Oid save_uid; save_uid = GetUserId(); @@ -581,7 +743,18 @@ RI_FKey_noaction_del(PG_FUNCTION_ARGS) pk_rel = trigdata->tg_relation; old_row = trigdata->tg_trigtuple; - switch (ri_DetermineMatchType(tgargs[RI_MATCH_TYPE_ARGNO])) + match_type = ri_DetermineMatchType(tgargs[RI_MATCH_TYPE_ARGNO]); + if (ri_Check_Pk_Match(pk_rel, old_row, trigdata->tg_trigger->tgoid, + match_type, tgnargs, tgargs)) { + /* + * There's either another row, or no row could match this + * one. In either case, we don't need to do the check. + */ + heap_close(fk_rel, RowShareLock); + return PointerGetDatum(NULL); + } + + switch (match_type) { /* ---------- * SQL3 11.9 <referential constraint definition> @@ -746,6 +919,7 @@ RI_FKey_noaction_upd(PG_FUNCTION_ARGS) char upd_nulls[RI_MAX_NUMKEYS + 1]; bool isnull; int i; + int match_type; Oid save_uid; save_uid = GetUserId(); @@ -793,7 +967,18 @@ RI_FKey_noaction_upd(PG_FUNCTION_ARGS) new_row = trigdata->tg_newtuple; old_row = trigdata->tg_trigtuple; - switch (ri_DetermineMatchType(tgargs[RI_MATCH_TYPE_ARGNO])) + match_type = ri_DetermineMatchType(tgargs[RI_MATCH_TYPE_ARGNO]); + if (ri_Check_Pk_Match(pk_rel, old_row, trigdata->tg_trigger->tgoid, + match_type, tgnargs, tgargs)) { + /* + * There's either another row, or no row could match this + * one. In either case, we don't need to do the check. + */ + heap_close(fk_rel, RowShareLock); + return PointerGetDatum(NULL); + } + + switch (match_type) { /* ---------- * SQL3 11.9 <referential constraint definition> @@ -3042,6 +3227,59 @@ ri_BuildQueryKeyFull(RI_QueryKey *key, Oid constr_id, int32 constr_queryno, } } +/* ---------- + * ri_BuildQueryKeyPkCheck - + * + * Build up a new hashtable key for a prepared SPI plan of a + * check for PK rows in noaction triggers. + * + * constr_type is FULL + * constr_id is the OID of the pg_trigger row that invoked us + * constr_queryno is an internal number of the query inside the proc + * pk_relid is the OID of referenced relation + * nkeypairs is the number of keypairs + * following are the attribute number keypairs of the trigger invocation + * + * At least for MATCH FULL this builds a unique key per plan. + * ---------- + */ +static void +ri_BuildQueryKeyPkCheck(RI_QueryKey *key, Oid constr_id, int32 constr_queryno, + Relation pk_rel, + int argc, char **argv) +{ + int i; + int j; + int fno; + + /* + * Initialize the key and fill in type, oid's and number of keypairs + */ + memset((void *) key, 0, sizeof(RI_QueryKey)); + key->constr_type = RI_MATCH_TYPE_FULL; + key->constr_id = constr_id; + key->constr_queryno = constr_queryno; + key->fk_relid = 0; + key->pk_relid = pk_rel->rd_id; + key->nkeypairs = (argc - RI_FIRST_ATTNAME_ARGNO) / 2; + + /* + * Lookup the attribute numbers of the arguments to the trigger call + * and fill in the keypairs. + */ + for (i = 0, j = RI_FIRST_ATTNAME_ARGNO + RI_KEYPAIR_PK_IDX; j < argc; i++, j += 2) + { + fno = SPI_fnumber(pk_rel->rd_att, argv[j]); + if (fno == SPI_ERROR_NOATTRIBUTE) + elog(ERROR, "constraint %s: table %s does not have an attribute %s", + argv[RI_CONSTRAINT_NAME_ARGNO], + RelationGetRelationName(pk_rel), + argv[j + 1]); + key->keypair[i][RI_KEYPAIR_PK_IDX] = fno; + key->keypair[i][RI_KEYPAIR_FK_IDX] = 0; + } +} + /* ---------- * ri_NullCheck - @@ -3378,3 +3616,4 @@ ri_AttributesEqual(Oid typeid, Datum oldvalue, Datum newvalue) return DatumGetBool(FunctionCall2(&(entry->oprfmgrinfo), oldvalue, newvalue)); } + |