LCOV - code coverage report
Current view: top level - src/backend/utils/adt - ri_triggers.c (source / functions) Hit Total Coverage
Test: PostgreSQL 12beta2 Lines: 698 766 91.1 %
Date: 2019-06-19 14:06:47 Functions: 41 41 100.0 %
Legend: Lines: hit not hit

          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) 1996-2019, 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 "parser/parse_coerce.h"
      40             : #include "parser/parse_relation.h"
      41             : #include "miscadmin.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             : /*
      59             :  * Local definitions
      60             :  */
      61             : 
      62             : #define RI_MAX_NUMKEYS                  INDEX_MAX_KEYS
      63             : 
      64             : #define RI_INIT_CONSTRAINTHASHSIZE      64
      65             : #define RI_INIT_QUERYHASHSIZE           (RI_INIT_CONSTRAINTHASHSIZE * 4)
      66             : 
      67             : #define RI_KEYS_ALL_NULL                0
      68             : #define RI_KEYS_SOME_NULL               1
      69             : #define RI_KEYS_NONE_NULL               2
      70             : 
      71             : /* RI query type codes */
      72             : /* these queries are executed against the PK (referenced) table: */
      73             : #define RI_PLAN_CHECK_LOOKUPPK          1
      74             : #define RI_PLAN_CHECK_LOOKUPPK_FROM_PK  2
      75             : #define RI_PLAN_LAST_ON_PK              RI_PLAN_CHECK_LOOKUPPK_FROM_PK
      76             : /* these queries are executed against the FK (referencing) table: */
      77             : #define RI_PLAN_CASCADE_DEL_DODELETE    3
      78             : #define RI_PLAN_CASCADE_UPD_DOUPDATE    4
      79             : #define RI_PLAN_RESTRICT_CHECKREF       5
      80             : #define RI_PLAN_SETNULL_DOUPDATE        6
      81             : #define RI_PLAN_SETDEFAULT_DOUPDATE     7
      82             : 
      83             : #define MAX_QUOTED_NAME_LEN  (NAMEDATALEN*2+3)
      84             : #define MAX_QUOTED_REL_NAME_LEN  (MAX_QUOTED_NAME_LEN*2)
      85             : 
      86             : #define RIAttName(rel, attnum)  NameStr(*attnumAttName(rel, attnum))
      87             : #define RIAttType(rel, attnum)  attnumTypeId(rel, attnum)
      88             : #define RIAttCollation(rel, attnum) attnumCollationId(rel, attnum)
      89             : 
      90             : #define RI_TRIGTYPE_INSERT 1
      91             : #define RI_TRIGTYPE_UPDATE 2
      92             : #define RI_TRIGTYPE_DELETE 3
      93             : 
      94             : 
      95             : /*
      96             :  * RI_ConstraintInfo
      97             :  *
      98             :  * Information extracted from an FK pg_constraint entry.  This is cached in
      99             :  * ri_constraint_cache.
     100             :  */
     101             : typedef struct RI_ConstraintInfo
     102             : {
     103             :     Oid         constraint_id;  /* OID of pg_constraint entry (hash key) */
     104             :     bool        valid;          /* successfully initialized? */
     105             :     uint32      oidHashValue;   /* hash value of pg_constraint OID */
     106             :     NameData    conname;        /* name of the FK constraint */
     107             :     Oid         pk_relid;       /* referenced relation */
     108             :     Oid         fk_relid;       /* referencing relation */
     109             :     char        confupdtype;    /* foreign key's ON UPDATE action */
     110             :     char        confdeltype;    /* foreign key's ON DELETE action */
     111             :     char        confmatchtype;  /* foreign key's match type */
     112             :     int         nkeys;          /* number of key columns */
     113             :     int16       pk_attnums[RI_MAX_NUMKEYS]; /* attnums of referenced cols */
     114             :     int16       fk_attnums[RI_MAX_NUMKEYS]; /* attnums of referencing cols */
     115             :     Oid         pf_eq_oprs[RI_MAX_NUMKEYS]; /* equality operators (PK = FK) */
     116             :     Oid         pp_eq_oprs[RI_MAX_NUMKEYS]; /* equality operators (PK = PK) */
     117             :     Oid         ff_eq_oprs[RI_MAX_NUMKEYS]; /* equality operators (FK = FK) */
     118             :     dlist_node  valid_link;     /* Link in list of valid entries */
     119             : } RI_ConstraintInfo;
     120             : 
     121             : /*
     122             :  * RI_QueryKey
     123             :  *
     124             :  * The key identifying a prepared SPI plan in our query hashtable
     125             :  */
     126             : typedef struct RI_QueryKey
     127             : {
     128             :     Oid         constr_id;      /* OID of pg_constraint entry */
     129             :     int32       constr_queryno; /* query type ID, see RI_PLAN_XXX above */
     130             : } RI_QueryKey;
     131             : 
     132             : /*
     133             :  * RI_QueryHashEntry
     134             :  */
     135             : typedef struct RI_QueryHashEntry
     136             : {
     137             :     RI_QueryKey key;
     138             :     SPIPlanPtr  plan;
     139             : } RI_QueryHashEntry;
     140             : 
     141             : /*
     142             :  * RI_CompareKey
     143             :  *
     144             :  * The key identifying an entry showing how to compare two values
     145             :  */
     146             : typedef struct RI_CompareKey
     147             : {
     148             :     Oid         eq_opr;         /* the equality operator to apply */
     149             :     Oid         typeid;         /* the data type to apply it to */
     150             : } RI_CompareKey;
     151             : 
     152             : /*
     153             :  * RI_CompareHashEntry
     154             :  */
     155             : typedef struct RI_CompareHashEntry
     156             : {
     157             :     RI_CompareKey key;
     158             :     bool        valid;          /* successfully initialized? */
     159             :     FmgrInfo    eq_opr_finfo;   /* call info for equality fn */
     160             :     FmgrInfo    cast_func_finfo;    /* in case we must coerce input */
     161             : } RI_CompareHashEntry;
     162             : 
     163             : 
     164             : /*
     165             :  * Local data
     166             :  */
     167             : static HTAB *ri_constraint_cache = NULL;
     168             : static HTAB *ri_query_cache = NULL;
     169             : static HTAB *ri_compare_cache = NULL;
     170             : static dlist_head ri_constraint_cache_valid_list;
     171             : static int  ri_constraint_cache_valid_count = 0;
     172             : 
     173             : 
     174             : /*
     175             :  * Local function prototypes
     176             :  */
     177             : static bool ri_Check_Pk_Match(Relation pk_rel, Relation fk_rel,
     178             :                               TupleTableSlot *oldslot,
     179             :                               const RI_ConstraintInfo *riinfo);
     180             : static Datum ri_restrict(TriggerData *trigdata, bool is_no_action);
     181             : static Datum ri_set(TriggerData *trigdata, bool is_set_null);
     182             : static void quoteOneName(char *buffer, const char *name);
     183             : static void quoteRelationName(char *buffer, Relation rel);
     184             : static void ri_GenerateQual(StringInfo buf,
     185             :                             const char *sep,
     186             :                             const char *leftop, Oid leftoptype,
     187             :                             Oid opoid,
     188             :                             const char *rightop, Oid rightoptype);
     189             : static void ri_GenerateQualCollation(StringInfo buf, Oid collation);
     190             : static int  ri_NullCheck(TupleDesc tupdesc, TupleTableSlot *slot,
     191             :                          const RI_ConstraintInfo *riinfo, bool rel_is_pk);
     192             : static void ri_BuildQueryKey(RI_QueryKey *key,
     193             :                              const RI_ConstraintInfo *riinfo,
     194             :                              int32 constr_queryno);
     195             : static bool ri_KeysEqual(Relation rel, TupleTableSlot *oldslot, TupleTableSlot *newslot,
     196             :                          const RI_ConstraintInfo *riinfo, bool rel_is_pk);
     197             : static bool ri_AttributesEqual(Oid eq_opr, Oid typeid,
     198             :                                Datum oldvalue, Datum newvalue);
     199             : 
     200             : static void ri_InitHashTables(void);
     201             : static void InvalidateConstraintCacheCallBack(Datum arg, int cacheid, uint32 hashvalue);
     202             : static SPIPlanPtr ri_FetchPreparedPlan(RI_QueryKey *key);
     203             : static void ri_HashPreparedPlan(RI_QueryKey *key, SPIPlanPtr plan);
     204             : static RI_CompareHashEntry *ri_HashCompareOp(Oid eq_opr, Oid typeid);
     205             : 
     206             : static void ri_CheckTrigger(FunctionCallInfo fcinfo, const char *funcname,
     207             :                             int tgkind);
     208             : static const RI_ConstraintInfo *ri_FetchConstraintInfo(Trigger *trigger,
     209             :                                                        Relation trig_rel, bool rel_is_pk);
     210             : static const RI_ConstraintInfo *ri_LoadConstraintInfo(Oid constraintOid);
     211             : static SPIPlanPtr ri_PlanCheck(const char *querystr, int nargs, Oid *argtypes,
     212             :                                RI_QueryKey *qkey, Relation fk_rel, Relation pk_rel,
     213             :                                bool cache_plan);
     214             : static bool ri_PerformCheck(const RI_ConstraintInfo *riinfo,
     215             :                             RI_QueryKey *qkey, SPIPlanPtr qplan,
     216             :                             Relation fk_rel, Relation pk_rel,
     217             :                             TupleTableSlot *oldslot, TupleTableSlot *newslot,
     218             :                             bool detectNewRows, int expect_OK);
     219             : static void ri_ExtractValues(Relation rel, TupleTableSlot *slot,
     220             :                              const RI_ConstraintInfo *riinfo, bool rel_is_pk,
     221             :                              Datum *vals, char *nulls);
     222             : static void ri_ReportViolation(const RI_ConstraintInfo *riinfo,
     223             :                                Relation pk_rel, Relation fk_rel,
     224             :                                TupleTableSlot *violatorslot, TupleDesc tupdesc,
     225             :                                int queryno, bool partgone) pg_attribute_noreturn();
     226             : 
     227             : 
     228             : /*
     229             :  * RI_FKey_check -
     230             :  *
     231             :  * Check foreign key existence (combined for INSERT and UPDATE).
     232             :  */
     233             : static Datum
     234        2738 : RI_FKey_check(TriggerData *trigdata)
     235             : {
     236             :     const RI_ConstraintInfo *riinfo;
     237             :     Relation    fk_rel;
     238             :     Relation    pk_rel;
     239             :     TupleTableSlot *newslot;
     240             :     RI_QueryKey qkey;
     241             :     SPIPlanPtr  qplan;
     242             : 
     243        2738 :     riinfo = ri_FetchConstraintInfo(trigdata->tg_trigger,
     244             :                                     trigdata->tg_relation, false);
     245             : 
     246        2738 :     if (TRIGGER_FIRED_BY_UPDATE(trigdata->tg_event))
     247         214 :         newslot = trigdata->tg_newslot;
     248             :     else
     249        2524 :         newslot = trigdata->tg_trigslot;
     250             : 
     251             :     /*
     252             :      * We should not even consider checking the row if it is no longer valid,
     253             :      * since it was either deleted (so the deferred check should be skipped)
     254             :      * or updated (in which case only the latest version of the row should be
     255             :      * checked).  Test its liveness according to SnapshotSelf.  We need pin
     256             :      * and lock on the buffer to call HeapTupleSatisfiesVisibility.  Caller
     257             :      * should be holding pin, but not lock.
     258             :      */
     259        2738 :     if (!table_tuple_satisfies_snapshot(trigdata->tg_relation, newslot, SnapshotSelf))
     260          40 :         return PointerGetDatum(NULL);
     261             : 
     262             :     /*
     263             :      * Get the relation descriptors of the FK and PK tables.
     264             :      *
     265             :      * pk_rel is opened in RowShareLock mode since that's what our eventual
     266             :      * SELECT FOR KEY SHARE will get on it.
     267             :      */
     268        2698 :     fk_rel = trigdata->tg_relation;
     269        2698 :     pk_rel = table_open(riinfo->pk_relid, RowShareLock);
     270             : 
     271        2698 :     switch (ri_NullCheck(RelationGetDescr(fk_rel), newslot, riinfo, false))
     272             :     {
     273             :         case RI_KEYS_ALL_NULL:
     274             : 
     275             :             /*
     276             :              * No further check needed - an all-NULL key passes every type of
     277             :              * foreign key constraint.
     278             :              */
     279          92 :             table_close(pk_rel, RowShareLock);
     280          92 :             return PointerGetDatum(NULL);
     281             : 
     282             :         case RI_KEYS_SOME_NULL:
     283             : 
     284             :             /*
     285             :              * This is the only case that differs between the three kinds of
     286             :              * MATCH.
     287             :              */
     288          92 :             switch (riinfo->confmatchtype)
     289             :             {
     290             :                 case FKCONSTR_MATCH_FULL:
     291             : 
     292             :                     /*
     293             :                      * Not allowed - MATCH FULL says either all or none of the
     294             :                      * attributes can be NULLs
     295             :                      */
     296          24 :                     ereport(ERROR,
     297             :                             (errcode(ERRCODE_FOREIGN_KEY_VIOLATION),
     298             :                              errmsg("insert or update on table \"%s\" violates foreign key constraint \"%s\"",
     299             :                                     RelationGetRelationName(fk_rel),
     300             :                                     NameStr(riinfo->conname)),
     301             :                              errdetail("MATCH FULL does not allow mixing of null and nonnull key values."),
     302             :                              errtableconstraint(fk_rel,
     303             :                                                 NameStr(riinfo->conname))));
     304             :                     table_close(pk_rel, RowShareLock);
     305             :                     return PointerGetDatum(NULL);
     306             : 
     307             :                 case FKCONSTR_MATCH_SIMPLE:
     308             : 
     309             :                     /*
     310             :                      * MATCH SIMPLE - if ANY column is null, the key passes
     311             :                      * the constraint.
     312             :                      */
     313          68 :                     table_close(pk_rel, RowShareLock);
     314          68 :                     return PointerGetDatum(NULL);
     315             : 
     316             : #ifdef NOT_USED
     317             :                 case FKCONSTR_MATCH_PARTIAL:
     318             : 
     319             :                     /*
     320             :                      * MATCH PARTIAL - all non-null columns must match. (not
     321             :                      * implemented, can be done by modifying the query below
     322             :                      * to only include non-null columns, or by writing a
     323             :                      * special version here)
     324             :                      */
     325             :                     break;
     326             : #endif
     327             :             }
     328             : 
     329             :         case RI_KEYS_NONE_NULL:
     330             : 
     331             :             /*
     332             :              * Have a full qualified key - continue below for all three kinds
     333             :              * of MATCH.
     334             :              */
     335        2514 :             break;
     336             :     }
     337             : 
     338        2514 :     if (SPI_connect() != SPI_OK_CONNECT)
     339           0 :         elog(ERROR, "SPI_connect failed");
     340             : 
     341             :     /* Fetch or prepare a saved plan for the real check */
     342        2514 :     ri_BuildQueryKey(&qkey, riinfo, RI_PLAN_CHECK_LOOKUPPK);
     343             : 
     344        2514 :     if ((qplan = ri_FetchPreparedPlan(&qkey)) == NULL)
     345             :     {
     346             :         StringInfoData querybuf;
     347             :         char        pkrelname[MAX_QUOTED_REL_NAME_LEN];
     348             :         char        attname[MAX_QUOTED_NAME_LEN];
     349             :         char        paramname[16];
     350             :         const char *querysep;
     351             :         Oid         queryoids[RI_MAX_NUMKEYS];
     352             :         const char *pk_only;
     353             : 
     354             :         /* ----------
     355             :          * The query string built is
     356             :          *  SELECT 1 FROM [ONLY] <pktable> x WHERE pkatt1 = $1 [AND ...]
     357             :          *         FOR KEY SHARE OF x
     358             :          * The type id's for the $ parameters are those of the
     359             :          * corresponding FK attributes.
     360             :          * ----------
     361             :          */
     362        1590 :         initStringInfo(&querybuf);
     363        3180 :         pk_only = pk_rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE ?
     364        1590 :             "" : "ONLY ";
     365        1590 :         quoteRelationName(pkrelname, pk_rel);
     366        1590 :         appendStringInfo(&querybuf, "SELECT 1 FROM %s%s x",
     367             :                          pk_only, pkrelname);
     368        1590 :         querysep = "WHERE";
     369        3308 :         for (int i = 0; i < riinfo->nkeys; i++)
     370             :         {
     371        1718 :             Oid         pk_type = RIAttType(pk_rel, riinfo->pk_attnums[i]);
     372        1718 :             Oid         fk_type = RIAttType(fk_rel, riinfo->fk_attnums[i]);
     373             : 
     374        1718 :             quoteOneName(attname,
     375        1718 :                          RIAttName(pk_rel, riinfo->pk_attnums[i]));
     376        1718 :             sprintf(paramname, "$%d", i + 1);
     377        1718 :             ri_GenerateQual(&querybuf, querysep,
     378             :                             attname, pk_type,
     379             :                             riinfo->pf_eq_oprs[i],
     380             :                             paramname, fk_type);
     381        1718 :             querysep = "AND";
     382        1718 :             queryoids[i] = fk_type;
     383             :         }
     384        1590 :         appendStringInfoString(&querybuf, " FOR KEY SHARE OF x");
     385             : 
     386             :         /* Prepare and save the plan */
     387        1590 :         qplan = ri_PlanCheck(querybuf.data, riinfo->nkeys, queryoids,
     388             :                              &qkey, fk_rel, pk_rel, true);
     389             :     }
     390             : 
     391             :     /*
     392             :      * Now check that foreign key exists in PK table
     393             :      */
     394        2514 :     ri_PerformCheck(riinfo, &qkey, qplan,
     395             :                     fk_rel, pk_rel,
     396             :                     NULL, newslot,
     397             :                     false,
     398             :                     SPI_OK_SELECT);
     399             : 
     400        2242 :     if (SPI_finish() != SPI_OK_FINISH)
     401           0 :         elog(ERROR, "SPI_finish failed");
     402             : 
     403        2242 :     table_close(pk_rel, RowShareLock);
     404             : 
     405        2242 :     return PointerGetDatum(NULL);
     406             : }
     407             : 
     408             : 
     409             : /*
     410             :  * RI_FKey_check_ins -
     411             :  *
     412             :  * Check foreign key existence at insert event on FK table.
     413             :  */
     414             : Datum
     415        2524 : RI_FKey_check_ins(PG_FUNCTION_ARGS)
     416             : {
     417             :     /* Check that this is a valid trigger call on the right time and event. */
     418        2524 :     ri_CheckTrigger(fcinfo, "RI_FKey_check_ins", RI_TRIGTYPE_INSERT);
     419             : 
     420             :     /* Share code with UPDATE case. */
     421        2524 :     return RI_FKey_check((TriggerData *) fcinfo->context);
     422             : }
     423             : 
     424             : 
     425             : /*
     426             :  * RI_FKey_check_upd -
     427             :  *
     428             :  * Check foreign key existence at update event on FK table.
     429             :  */
     430             : Datum
     431         214 : RI_FKey_check_upd(PG_FUNCTION_ARGS)
     432             : {
     433             :     /* Check that this is a valid trigger call on the right time and event. */
     434         214 :     ri_CheckTrigger(fcinfo, "RI_FKey_check_upd", RI_TRIGTYPE_UPDATE);
     435             : 
     436             :     /* Share code with INSERT case. */
     437         214 :     return RI_FKey_check((TriggerData *) fcinfo->context);
     438             : }
     439             : 
     440             : 
     441             : /*
     442             :  * ri_Check_Pk_Match
     443             :  *
     444             :  * Check to see if another PK row has been created that provides the same
     445             :  * key values as the "oldslot" that's been modified or deleted in our trigger
     446             :  * event.  Returns true if a match is found in the PK table.
     447             :  *
     448             :  * We assume the caller checked that the oldslot contains no NULL key values,
     449             :  * since otherwise a match is impossible.
     450             :  */
     451             : static bool
     452         432 : ri_Check_Pk_Match(Relation pk_rel, Relation fk_rel,
     453             :                   TupleTableSlot *oldslot,
     454             :                   const RI_ConstraintInfo *riinfo)
     455             : {
     456             :     SPIPlanPtr  qplan;
     457             :     RI_QueryKey qkey;
     458             :     bool        result;
     459             : 
     460             :     /* Only called for non-null rows */
     461             :     Assert(ri_NullCheck(RelationGetDescr(pk_rel), oldslot, riinfo, true) == RI_KEYS_NONE_NULL);
     462             : 
     463         432 :     if (SPI_connect() != SPI_OK_CONNECT)
     464           0 :         elog(ERROR, "SPI_connect failed");
     465             : 
     466             :     /*
     467             :      * Fetch or prepare a saved plan for checking PK table with values coming
     468             :      * from a PK row
     469             :      */
     470         432 :     ri_BuildQueryKey(&qkey, riinfo, RI_PLAN_CHECK_LOOKUPPK_FROM_PK);
     471             : 
     472         432 :     if ((qplan = ri_FetchPreparedPlan(&qkey)) == NULL)
     473             :     {
     474             :         StringInfoData querybuf;
     475             :         char        pkrelname[MAX_QUOTED_REL_NAME_LEN];
     476             :         char        attname[MAX_QUOTED_NAME_LEN];
     477             :         char        paramname[16];
     478             :         const char *querysep;
     479             :         const char *pk_only;
     480             :         Oid         queryoids[RI_MAX_NUMKEYS];
     481             : 
     482             :         /* ----------
     483             :          * The query string built is
     484             :          *  SELECT 1 FROM [ONLY] <pktable> x WHERE pkatt1 = $1 [AND ...]
     485             :          *         FOR KEY SHARE OF x
     486             :          * The type id's for the $ parameters are those of the
     487             :          * PK attributes themselves.
     488             :          * ----------
     489             :          */
     490         200 :         initStringInfo(&querybuf);
     491         400 :         pk_only = pk_rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE ?
     492         200 :             "" : "ONLY ";
     493         200 :         quoteRelationName(pkrelname, pk_rel);
     494         200 :         appendStringInfo(&querybuf, "SELECT 1 FROM %s%s x",
     495             :                          pk_only, pkrelname);
     496         200 :         querysep = "WHERE";
     497         466 :         for (int i = 0; i < riinfo->nkeys; i++)
     498             :         {
     499         266 :             Oid         pk_type = RIAttType(pk_rel, riinfo->pk_attnums[i]);
     500             : 
     501         266 :             quoteOneName(attname,
     502         266 :                          RIAttName(pk_rel, riinfo->pk_attnums[i]));
     503         266 :             sprintf(paramname, "$%d", i + 1);
     504         266 :             ri_GenerateQual(&querybuf, querysep,
     505             :                             attname, pk_type,
     506             :                             riinfo->pp_eq_oprs[i],
     507             :                             paramname, pk_type);
     508         266 :             querysep = "AND";
     509         266 :             queryoids[i] = pk_type;
     510             :         }
     511         200 :         appendStringInfoString(&querybuf, " FOR KEY SHARE OF x");
     512             : 
     513             :         /* Prepare and save the plan */
     514         200 :         qplan = ri_PlanCheck(querybuf.data, riinfo->nkeys, queryoids,
     515             :                              &qkey, fk_rel, pk_rel, true);
     516             :     }
     517             : 
     518             :     /*
     519             :      * We have a plan now. Run it.
     520             :      */
     521         432 :     result = ri_PerformCheck(riinfo, &qkey, qplan,
     522             :                              fk_rel, pk_rel,
     523             :                              oldslot, NULL,
     524             :                              true,  /* treat like update */
     525             :                              SPI_OK_SELECT);
     526             : 
     527         432 :     if (SPI_finish() != SPI_OK_FINISH)
     528           0 :         elog(ERROR, "SPI_finish failed");
     529             : 
     530         432 :     return result;
     531             : }
     532             : 
     533             : 
     534             : /*
     535             :  * RI_FKey_noaction_del -
     536             :  *
     537             :  * Give an error and roll back the current transaction if the
     538             :  * delete has resulted in a violation of the given referential
     539             :  * integrity constraint.
     540             :  */
     541             : Datum
     542         212 : RI_FKey_noaction_del(PG_FUNCTION_ARGS)
     543             : {
     544             :     /* Check that this is a valid trigger call on the right time and event. */
     545         212 :     ri_CheckTrigger(fcinfo, "RI_FKey_noaction_del", RI_TRIGTYPE_DELETE);
     546             : 
     547             :     /* Share code with RESTRICT/UPDATE cases. */
     548         212 :     return ri_restrict((TriggerData *) fcinfo->context, true);
     549             : }
     550             : 
     551             : /*
     552             :  * RI_FKey_restrict_del -
     553             :  *
     554             :  * Restrict delete from PK table to rows unreferenced by foreign key.
     555             :  *
     556             :  * The SQL standard intends that this referential action occur exactly when
     557             :  * the delete is performed, rather than after.  This appears to be
     558             :  * the only difference between "NO ACTION" and "RESTRICT".  In Postgres
     559             :  * we still implement this as an AFTER trigger, but it's non-deferrable.
     560             :  */
     561             : Datum
     562          12 : RI_FKey_restrict_del(PG_FUNCTION_ARGS)
     563             : {
     564             :     /* Check that this is a valid trigger call on the right time and event. */
     565          12 :     ri_CheckTrigger(fcinfo, "RI_FKey_restrict_del", RI_TRIGTYPE_DELETE);
     566             : 
     567             :     /* Share code with NO ACTION/UPDATE cases. */
     568          12 :     return ri_restrict((TriggerData *) fcinfo->context, false);
     569             : }
     570             : 
     571             : /*
     572             :  * RI_FKey_noaction_upd -
     573             :  *
     574             :  * Give an error and roll back the current transaction if the
     575             :  * update has resulted in a violation of the given referential
     576             :  * integrity constraint.
     577             :  */
     578             : Datum
     579         152 : RI_FKey_noaction_upd(PG_FUNCTION_ARGS)
     580             : {
     581             :     /* Check that this is a valid trigger call on the right time and event. */
     582         152 :     ri_CheckTrigger(fcinfo, "RI_FKey_noaction_upd", RI_TRIGTYPE_UPDATE);
     583             : 
     584             :     /* Share code with RESTRICT/DELETE cases. */
     585         152 :     return ri_restrict((TriggerData *) fcinfo->context, true);
     586             : }
     587             : 
     588             : /*
     589             :  * RI_FKey_restrict_upd -
     590             :  *
     591             :  * Restrict update of PK to rows unreferenced by foreign key.
     592             :  *
     593             :  * The SQL standard intends that this referential action occur exactly when
     594             :  * the update is performed, rather than after.  This appears to be
     595             :  * the only difference between "NO ACTION" and "RESTRICT".  In Postgres
     596             :  * we still implement this as an AFTER trigger, but it's non-deferrable.
     597             :  */
     598             : Datum
     599          12 : RI_FKey_restrict_upd(PG_FUNCTION_ARGS)
     600             : {
     601             :     /* Check that this is a valid trigger call on the right time and event. */
     602          12 :     ri_CheckTrigger(fcinfo, "RI_FKey_restrict_upd", RI_TRIGTYPE_UPDATE);
     603             : 
     604             :     /* Share code with NO ACTION/DELETE cases. */
     605          12 :     return ri_restrict((TriggerData *) fcinfo->context, false);
     606             : }
     607             : 
     608             : /*
     609             :  * ri_restrict -
     610             :  *
     611             :  * Common code for ON DELETE RESTRICT, ON DELETE NO ACTION,
     612             :  * ON UPDATE RESTRICT, and ON UPDATE NO ACTION.
     613             :  */
     614             : static Datum
     615         456 : ri_restrict(TriggerData *trigdata, bool is_no_action)
     616             : {
     617             :     const RI_ConstraintInfo *riinfo;
     618             :     Relation    fk_rel;
     619             :     Relation    pk_rel;
     620             :     TupleTableSlot *oldslot;
     621             :     RI_QueryKey qkey;
     622             :     SPIPlanPtr  qplan;
     623             : 
     624         456 :     riinfo = ri_FetchConstraintInfo(trigdata->tg_trigger,
     625             :                                     trigdata->tg_relation, true);
     626             : 
     627             :     /*
     628             :      * Get the relation descriptors of the FK and PK tables and the old tuple.
     629             :      *
     630             :      * fk_rel is opened in RowShareLock mode since that's what our eventual
     631             :      * SELECT FOR KEY SHARE will get on it.
     632             :      */
     633         456 :     fk_rel = table_open(riinfo->fk_relid, RowShareLock);
     634         456 :     pk_rel = trigdata->tg_relation;
     635         456 :     oldslot = trigdata->tg_trigslot;
     636             : 
     637             :     /*
     638             :      * If another PK row now exists providing the old key values, we should
     639             :      * not do anything.  However, this check should only be made in the NO
     640             :      * ACTION case; in RESTRICT cases we don't wish to allow another row to be
     641             :      * substituted.
     642             :      */
     643         888 :     if (is_no_action &&
     644         432 :         ri_Check_Pk_Match(pk_rel, fk_rel, oldslot, riinfo))
     645             :     {
     646          12 :         table_close(fk_rel, RowShareLock);
     647          12 :         return PointerGetDatum(NULL);
     648             :     }
     649             : 
     650         444 :     if (SPI_connect() != SPI_OK_CONNECT)
     651           0 :         elog(ERROR, "SPI_connect failed");
     652             : 
     653             :     /*
     654             :      * Fetch or prepare a saved plan for the restrict lookup (it's the same
     655             :      * query for delete and update cases)
     656             :      */
     657         444 :     ri_BuildQueryKey(&qkey, riinfo, RI_PLAN_RESTRICT_CHECKREF);
     658             : 
     659         444 :     if ((qplan = ri_FetchPreparedPlan(&qkey)) == NULL)
     660             :     {
     661             :         StringInfoData querybuf;
     662             :         char        fkrelname[MAX_QUOTED_REL_NAME_LEN];
     663             :         char        attname[MAX_QUOTED_NAME_LEN];
     664             :         char        paramname[16];
     665             :         const char *querysep;
     666             :         Oid         queryoids[RI_MAX_NUMKEYS];
     667             :         const char *fk_only;
     668             : 
     669             :         /* ----------
     670             :          * The query string built is
     671             :          *  SELECT 1 FROM [ONLY] <fktable> x WHERE $1 = fkatt1 [AND ...]
     672             :          *         FOR KEY SHARE OF x
     673             :          * The type id's for the $ parameters are those of the
     674             :          * corresponding PK attributes.
     675             :          * ----------
     676             :          */
     677         210 :         initStringInfo(&querybuf);
     678         420 :         fk_only = fk_rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE ?
     679         210 :             "" : "ONLY ";
     680         210 :         quoteRelationName(fkrelname, fk_rel);
     681         210 :         appendStringInfo(&querybuf, "SELECT 1 FROM %s%s x",
     682             :                          fk_only, fkrelname);
     683         210 :         querysep = "WHERE";
     684         484 :         for (int i = 0; i < riinfo->nkeys; i++)
     685             :         {
     686         274 :             Oid         pk_type = RIAttType(pk_rel, riinfo->pk_attnums[i]);
     687         274 :             Oid         fk_type = RIAttType(fk_rel, riinfo->fk_attnums[i]);
     688         274 :             Oid         pk_coll = RIAttCollation(pk_rel, riinfo->pk_attnums[i]);
     689         274 :             Oid         fk_coll = RIAttCollation(fk_rel, riinfo->fk_attnums[i]);
     690             : 
     691         274 :             quoteOneName(attname,
     692         274 :                          RIAttName(fk_rel, riinfo->fk_attnums[i]));
     693         274 :             sprintf(paramname, "$%d", i + 1);
     694         274 :             ri_GenerateQual(&querybuf, querysep,
     695             :                             paramname, pk_type,
     696             :                             riinfo->pf_eq_oprs[i],
     697             :                             attname, fk_type);
     698         274 :             if (pk_coll != fk_coll && !get_collation_isdeterministic(pk_coll))
     699           0 :                 ri_GenerateQualCollation(&querybuf, pk_coll);
     700         274 :             querysep = "AND";
     701         274 :             queryoids[i] = pk_type;
     702             :         }
     703         210 :         appendStringInfoString(&querybuf, " FOR KEY SHARE OF x");
     704             : 
     705             :         /* Prepare and save the plan */
     706         210 :         qplan = ri_PlanCheck(querybuf.data, riinfo->nkeys, queryoids,
     707             :                              &qkey, fk_rel, pk_rel, true);
     708             :     }
     709             : 
     710             :     /*
     711             :      * We have a plan now. Run it to check for existing references.
     712             :      */
     713         444 :     ri_PerformCheck(riinfo, &qkey, qplan,
     714             :                     fk_rel, pk_rel,
     715             :                     oldslot, NULL,
     716             :                     true,       /* must detect new rows */
     717             :                     SPI_OK_SELECT);
     718             : 
     719         242 :     if (SPI_finish() != SPI_OK_FINISH)
     720           0 :         elog(ERROR, "SPI_finish failed");
     721             : 
     722         242 :     table_close(fk_rel, RowShareLock);
     723             : 
     724         242 :     return PointerGetDatum(NULL);
     725             : }
     726             : 
     727             : 
     728             : /*
     729             :  * RI_FKey_cascade_del -
     730             :  *
     731             :  * Cascaded delete foreign key references at delete event on PK table.
     732             :  */
     733             : Datum
     734          80 : RI_FKey_cascade_del(PG_FUNCTION_ARGS)
     735             : {
     736          80 :     TriggerData *trigdata = (TriggerData *) fcinfo->context;
     737             :     const RI_ConstraintInfo *riinfo;
     738             :     Relation    fk_rel;
     739             :     Relation    pk_rel;
     740             :     TupleTableSlot *oldslot;
     741             :     RI_QueryKey qkey;
     742             :     SPIPlanPtr  qplan;
     743             : 
     744             :     /* Check that this is a valid trigger call on the right time and event. */
     745          80 :     ri_CheckTrigger(fcinfo, "RI_FKey_cascade_del", RI_TRIGTYPE_DELETE);
     746             : 
     747          80 :     riinfo = ri_FetchConstraintInfo(trigdata->tg_trigger,
     748             :                                     trigdata->tg_relation, true);
     749             : 
     750             :     /*
     751             :      * Get the relation descriptors of the FK and PK tables and the old tuple.
     752             :      *
     753             :      * fk_rel is opened in RowExclusiveLock mode since that's what our
     754             :      * eventual DELETE will get on it.
     755             :      */
     756          80 :     fk_rel = table_open(riinfo->fk_relid, RowExclusiveLock);
     757          80 :     pk_rel = trigdata->tg_relation;
     758          80 :     oldslot = trigdata->tg_trigslot;
     759             : 
     760          80 :     if (SPI_connect() != SPI_OK_CONNECT)
     761           0 :         elog(ERROR, "SPI_connect failed");
     762             : 
     763             :     /* Fetch or prepare a saved plan for the cascaded delete */
     764          80 :     ri_BuildQueryKey(&qkey, riinfo, RI_PLAN_CASCADE_DEL_DODELETE);
     765             : 
     766          80 :     if ((qplan = ri_FetchPreparedPlan(&qkey)) == NULL)
     767             :     {
     768             :         StringInfoData querybuf;
     769             :         char        fkrelname[MAX_QUOTED_REL_NAME_LEN];
     770             :         char        attname[MAX_QUOTED_NAME_LEN];
     771             :         char        paramname[16];
     772             :         const char *querysep;
     773             :         Oid         queryoids[RI_MAX_NUMKEYS];
     774             :         const char *fk_only;
     775             : 
     776             :         /* ----------
     777             :          * The query string built is
     778             :          *  DELETE FROM [ONLY] <fktable> WHERE $1 = fkatt1 [AND ...]
     779             :          * The type id's for the $ parameters are those of the
     780             :          * corresponding PK attributes.
     781             :          * ----------
     782             :          */
     783          44 :         initStringInfo(&querybuf);
     784          88 :         fk_only = fk_rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE ?
     785          44 :             "" : "ONLY ";
     786          44 :         quoteRelationName(fkrelname, fk_rel);
     787          44 :         appendStringInfo(&querybuf, "DELETE FROM %s%s",
     788             :                          fk_only, fkrelname);
     789          44 :         querysep = "WHERE";
     790         100 :         for (int i = 0; i < riinfo->nkeys; i++)
     791             :         {
     792          56 :             Oid         pk_type = RIAttType(pk_rel, riinfo->pk_attnums[i]);
     793          56 :             Oid         fk_type = RIAttType(fk_rel, riinfo->fk_attnums[i]);
     794          56 :             Oid         pk_coll = RIAttCollation(pk_rel, riinfo->pk_attnums[i]);
     795          56 :             Oid         fk_coll = RIAttCollation(fk_rel, riinfo->fk_attnums[i]);
     796             : 
     797          56 :             quoteOneName(attname,
     798          56 :                          RIAttName(fk_rel, riinfo->fk_attnums[i]));
     799          56 :             sprintf(paramname, "$%d", i + 1);
     800          56 :             ri_GenerateQual(&querybuf, querysep,
     801             :                             paramname, pk_type,
     802             :                             riinfo->pf_eq_oprs[i],
     803             :                             attname, fk_type);
     804          56 :             if (pk_coll != fk_coll && !get_collation_isdeterministic(pk_coll))
     805           0 :                 ri_GenerateQualCollation(&querybuf, pk_coll);
     806          56 :             querysep = "AND";
     807          56 :             queryoids[i] = pk_type;
     808             :         }
     809             : 
     810             :         /* Prepare and save the plan */
     811          44 :         qplan = ri_PlanCheck(querybuf.data, riinfo->nkeys, queryoids,
     812             :                              &qkey, fk_rel, pk_rel, true);
     813             :     }
     814             : 
     815             :     /*
     816             :      * We have a plan now. Build up the arguments from the key values in the
     817             :      * deleted PK tuple and delete the referencing rows
     818             :      */
     819          80 :     ri_PerformCheck(riinfo, &qkey, qplan,
     820             :                     fk_rel, pk_rel,
     821             :                     oldslot, NULL,
     822             :                     true,       /* must detect new rows */
     823             :                     SPI_OK_DELETE);
     824             : 
     825          80 :     if (SPI_finish() != SPI_OK_FINISH)
     826           0 :         elog(ERROR, "SPI_finish failed");
     827             : 
     828          80 :     table_close(fk_rel, RowExclusiveLock);
     829             : 
     830          80 :     return PointerGetDatum(NULL);
     831             : }
     832             : 
     833             : 
     834             : /*
     835             :  * RI_FKey_cascade_upd -
     836             :  *
     837             :  * Cascaded update foreign key references at update event on PK table.
     838             :  */
     839             : Datum
     840          56 : RI_FKey_cascade_upd(PG_FUNCTION_ARGS)
     841             : {
     842          56 :     TriggerData *trigdata = (TriggerData *) fcinfo->context;
     843             :     const RI_ConstraintInfo *riinfo;
     844             :     Relation    fk_rel;
     845             :     Relation    pk_rel;
     846             :     TupleTableSlot *newslot;
     847             :     TupleTableSlot *oldslot;
     848             :     RI_QueryKey qkey;
     849             :     SPIPlanPtr  qplan;
     850             : 
     851             :     /* Check that this is a valid trigger call on the right time and event. */
     852          56 :     ri_CheckTrigger(fcinfo, "RI_FKey_cascade_upd", RI_TRIGTYPE_UPDATE);
     853             : 
     854          56 :     riinfo = ri_FetchConstraintInfo(trigdata->tg_trigger,
     855             :                                     trigdata->tg_relation, true);
     856             : 
     857             :     /*
     858             :      * Get the relation descriptors of the FK and PK tables and the new and
     859             :      * old tuple.
     860             :      *
     861             :      * fk_rel is opened in RowExclusiveLock mode since that's what our
     862             :      * eventual UPDATE will get on it.
     863             :      */
     864          56 :     fk_rel = table_open(riinfo->fk_relid, RowExclusiveLock);
     865          56 :     pk_rel = trigdata->tg_relation;
     866          56 :     newslot = trigdata->tg_newslot;
     867          56 :     oldslot = trigdata->tg_trigslot;
     868             : 
     869          56 :     if (SPI_connect() != SPI_OK_CONNECT)
     870           0 :         elog(ERROR, "SPI_connect failed");
     871             : 
     872             :     /* Fetch or prepare a saved plan for the cascaded update */
     873          56 :     ri_BuildQueryKey(&qkey, riinfo, RI_PLAN_CASCADE_UPD_DOUPDATE);
     874             : 
     875          56 :     if ((qplan = ri_FetchPreparedPlan(&qkey)) == NULL)
     876             :     {
     877             :         StringInfoData querybuf;
     878             :         StringInfoData qualbuf;
     879             :         char        fkrelname[MAX_QUOTED_REL_NAME_LEN];
     880             :         char        attname[MAX_QUOTED_NAME_LEN];
     881             :         char        paramname[16];
     882             :         const char *querysep;
     883             :         const char *qualsep;
     884             :         Oid         queryoids[RI_MAX_NUMKEYS * 2];
     885             :         const char *fk_only;
     886             : 
     887             :         /* ----------
     888             :          * The query string built is
     889             :          *  UPDATE [ONLY] <fktable> SET fkatt1 = $1 [, ...]
     890             :          *          WHERE $n = fkatt1 [AND ...]
     891             :          * The type id's for the $ parameters are those of the
     892             :          * corresponding PK attributes.  Note that we are assuming
     893             :          * there is an assignment cast from the PK to the FK type;
     894             :          * else the parser will fail.
     895             :          * ----------
     896             :          */
     897          44 :         initStringInfo(&querybuf);
     898          44 :         initStringInfo(&qualbuf);
     899          88 :         fk_only = fk_rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE ?
     900          44 :             "" : "ONLY ";
     901          44 :         quoteRelationName(fkrelname, fk_rel);
     902          44 :         appendStringInfo(&querybuf, "UPDATE %s%s SET",
     903             :                          fk_only, fkrelname);
     904          44 :         querysep = "";
     905          44 :         qualsep = "WHERE";
     906         104 :         for (int i = 0, j = riinfo->nkeys; i < riinfo->nkeys; i++, j++)
     907             :         {
     908          60 :             Oid         pk_type = RIAttType(pk_rel, riinfo->pk_attnums[i]);
     909          60 :             Oid         fk_type = RIAttType(fk_rel, riinfo->fk_attnums[i]);
     910          60 :             Oid         pk_coll = RIAttCollation(pk_rel, riinfo->pk_attnums[i]);
     911          60 :             Oid         fk_coll = RIAttCollation(fk_rel, riinfo->fk_attnums[i]);
     912             : 
     913          60 :             quoteOneName(attname,
     914          60 :                          RIAttName(fk_rel, riinfo->fk_attnums[i]));
     915          60 :             appendStringInfo(&querybuf,
     916             :                              "%s %s = $%d",
     917             :                              querysep, attname, i + 1);
     918          60 :             sprintf(paramname, "$%d", j + 1);
     919          60 :             ri_GenerateQual(&qualbuf, qualsep,
     920             :                             paramname, pk_type,
     921             :                             riinfo->pf_eq_oprs[i],
     922             :                             attname, fk_type);
     923          60 :             if (pk_coll != fk_coll && !get_collation_isdeterministic(pk_coll))
     924           0 :                 ri_GenerateQualCollation(&querybuf, pk_coll);
     925          60 :             querysep = ",";
     926          60 :             qualsep = "AND";
     927          60 :             queryoids[i] = pk_type;
     928          60 :             queryoids[j] = pk_type;
     929             :         }
     930          44 :         appendStringInfoString(&querybuf, qualbuf.data);
     931             : 
     932             :         /* Prepare and save the plan */
     933          44 :         qplan = ri_PlanCheck(querybuf.data, riinfo->nkeys * 2, queryoids,
     934             :                              &qkey, fk_rel, pk_rel, true);
     935             :     }
     936             : 
     937             :     /*
     938             :      * We have a plan now. Run it to update the existing references.
     939             :      */
     940          56 :     ri_PerformCheck(riinfo, &qkey, qplan,
     941             :                     fk_rel, pk_rel,
     942             :                     oldslot, newslot,
     943             :                     true,       /* must detect new rows */
     944             :                     SPI_OK_UPDATE);
     945             : 
     946          56 :     if (SPI_finish() != SPI_OK_FINISH)
     947           0 :         elog(ERROR, "SPI_finish failed");
     948             : 
     949          56 :     table_close(fk_rel, RowExclusiveLock);
     950             : 
     951          56 :     return PointerGetDatum(NULL);
     952             : }
     953             : 
     954             : 
     955             : /*
     956             :  * RI_FKey_setnull_del -
     957             :  *
     958             :  * Set foreign key references to NULL values at delete event on PK table.
     959             :  */
     960             : Datum
     961          52 : RI_FKey_setnull_del(PG_FUNCTION_ARGS)
     962             : {
     963             :     /* Check that this is a valid trigger call on the right time and event. */
     964          52 :     ri_CheckTrigger(fcinfo, "RI_FKey_setnull_del", RI_TRIGTYPE_DELETE);
     965             : 
     966             :     /* Share code with UPDATE case */
     967          52 :     return ri_set((TriggerData *) fcinfo->context, true);
     968             : }
     969             : 
     970             : /*
     971             :  * RI_FKey_setnull_upd -
     972             :  *
     973             :  * Set foreign key references to NULL at update event on PK table.
     974             :  */
     975             : Datum
     976          20 : RI_FKey_setnull_upd(PG_FUNCTION_ARGS)
     977             : {
     978             :     /* Check that this is a valid trigger call on the right time and event. */
     979          20 :     ri_CheckTrigger(fcinfo, "RI_FKey_setnull_upd", RI_TRIGTYPE_UPDATE);
     980             : 
     981             :     /* Share code with DELETE case */
     982          20 :     return ri_set((TriggerData *) fcinfo->context, true);
     983             : }
     984             : 
     985             : /*
     986             :  * RI_FKey_setdefault_del -
     987             :  *
     988             :  * Set foreign key references to defaults at delete event on PK table.
     989             :  */
     990             : Datum
     991          40 : RI_FKey_setdefault_del(PG_FUNCTION_ARGS)
     992             : {
     993             :     /* Check that this is a valid trigger call on the right time and event. */
     994          40 :     ri_CheckTrigger(fcinfo, "RI_FKey_setdefault_del", RI_TRIGTYPE_DELETE);
     995             : 
     996             :     /* Share code with UPDATE case */
     997          40 :     return ri_set((TriggerData *) fcinfo->context, false);
     998             : }
     999             : 
    1000             : /*
    1001             :  * RI_FKey_setdefault_upd -
    1002             :  *
    1003             :  * Set foreign key references to defaults at update event on PK table.
    1004             :  */
    1005             : Datum
    1006          28 : RI_FKey_setdefault_upd(PG_FUNCTION_ARGS)
    1007             : {
    1008             :     /* Check that this is a valid trigger call on the right time and event. */
    1009          28 :     ri_CheckTrigger(fcinfo, "RI_FKey_setdefault_upd", RI_TRIGTYPE_UPDATE);
    1010             : 
    1011             :     /* Share code with DELETE case */
    1012          28 :     return ri_set((TriggerData *) fcinfo->context, false);
    1013             : }
    1014             : 
    1015             : /*
    1016             :  * ri_set -
    1017             :  *
    1018             :  * Common code for ON DELETE SET NULL, ON DELETE SET DEFAULT, ON UPDATE SET
    1019             :  * NULL, and ON UPDATE SET DEFAULT.
    1020             :  */
    1021             : static Datum
    1022         140 : ri_set(TriggerData *trigdata, bool is_set_null)
    1023             : {
    1024             :     const RI_ConstraintInfo *riinfo;
    1025             :     Relation    fk_rel;
    1026             :     Relation    pk_rel;
    1027             :     TupleTableSlot *oldslot;
    1028             :     RI_QueryKey qkey;
    1029             :     SPIPlanPtr  qplan;
    1030             : 
    1031         140 :     riinfo = ri_FetchConstraintInfo(trigdata->tg_trigger,
    1032             :                                     trigdata->tg_relation, true);
    1033             : 
    1034             :     /*
    1035             :      * Get the relation descriptors of the FK and PK tables and the old tuple.
    1036             :      *
    1037             :      * fk_rel is opened in RowExclusiveLock mode since that's what our
    1038             :      * eventual UPDATE will get on it.
    1039             :      */
    1040         140 :     fk_rel = table_open(riinfo->fk_relid, RowExclusiveLock);
    1041         140 :     pk_rel = trigdata->tg_relation;
    1042         140 :     oldslot = trigdata->tg_trigslot;
    1043             : 
    1044         140 :     if (SPI_connect() != SPI_OK_CONNECT)
    1045           0 :         elog(ERROR, "SPI_connect failed");
    1046             : 
    1047             :     /*
    1048             :      * Fetch or prepare a saved plan for the set null/default operation (it's
    1049             :      * the same query for delete and update cases)
    1050             :      */
    1051         140 :     ri_BuildQueryKey(&qkey, riinfo,
    1052             :                      (is_set_null
    1053             :                       ? RI_PLAN_SETNULL_DOUPDATE
    1054             :                       : RI_PLAN_SETDEFAULT_DOUPDATE));
    1055             : 
    1056         140 :     if ((qplan = ri_FetchPreparedPlan(&qkey)) == NULL)
    1057             :     {
    1058             :         StringInfoData querybuf;
    1059             :         StringInfoData qualbuf;
    1060             :         char        fkrelname[MAX_QUOTED_REL_NAME_LEN];
    1061             :         char        attname[MAX_QUOTED_NAME_LEN];
    1062             :         char        paramname[16];
    1063             :         const char *querysep;
    1064             :         const char *qualsep;
    1065             :         Oid         queryoids[RI_MAX_NUMKEYS];
    1066             :         const char *fk_only;
    1067             : 
    1068             :         /* ----------
    1069             :          * The query string built is
    1070             :          *  UPDATE [ONLY] <fktable> SET fkatt1 = {NULL|DEFAULT} [, ...]
    1071             :          *          WHERE $1 = fkatt1 [AND ...]
    1072             :          * The type id's for the $ parameters are those of the
    1073             :          * corresponding PK attributes.
    1074             :          * ----------
    1075             :          */
    1076          64 :         initStringInfo(&querybuf);
    1077          64 :         initStringInfo(&qualbuf);
    1078         128 :         fk_only = fk_rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE ?
    1079          64 :             "" : "ONLY ";
    1080          64 :         quoteRelationName(fkrelname, fk_rel);
    1081          64 :         appendStringInfo(&querybuf, "UPDATE %s%s SET",
    1082             :                          fk_only, fkrelname);
    1083          64 :         querysep = "";
    1084          64 :         qualsep = "WHERE";
    1085         176 :         for (int i = 0; i < riinfo->nkeys; i++)
    1086             :         {
    1087         112 :             Oid         pk_type = RIAttType(pk_rel, riinfo->pk_attnums[i]);
    1088         112 :             Oid         fk_type = RIAttType(fk_rel, riinfo->fk_attnums[i]);
    1089         112 :             Oid         pk_coll = RIAttCollation(pk_rel, riinfo->pk_attnums[i]);
    1090         112 :             Oid         fk_coll = RIAttCollation(fk_rel, riinfo->fk_attnums[i]);
    1091             : 
    1092         112 :             quoteOneName(attname,
    1093         112 :                          RIAttName(fk_rel, riinfo->fk_attnums[i]));
    1094         112 :             appendStringInfo(&querybuf,
    1095             :                              "%s %s = %s",
    1096             :                              querysep, attname,
    1097             :                              is_set_null ? "NULL" : "DEFAULT");
    1098         112 :             sprintf(paramname, "$%d", i + 1);
    1099         112 :             ri_GenerateQual(&qualbuf, qualsep,
    1100             :                             paramname, pk_type,
    1101             :                             riinfo->pf_eq_oprs[i],
    1102             :                             attname, fk_type);
    1103         112 :             if (pk_coll != fk_coll && !get_collation_isdeterministic(pk_coll))
    1104           0 :                 ri_GenerateQualCollation(&querybuf, pk_coll);
    1105         112 :             querysep = ",";
    1106         112 :             qualsep = "AND";
    1107         112 :             queryoids[i] = pk_type;
    1108             :         }
    1109          64 :         appendStringInfoString(&querybuf, qualbuf.data);
    1110             : 
    1111             :         /* Prepare and save the plan */
    1112          64 :         qplan = ri_PlanCheck(querybuf.data, riinfo->nkeys, queryoids,
    1113             :                              &qkey, fk_rel, pk_rel, true);
    1114             :     }
    1115             : 
    1116             :     /*
    1117             :      * We have a plan now. Run it to update the existing references.
    1118             :      */
    1119         140 :     ri_PerformCheck(riinfo, &qkey, qplan,
    1120             :                     fk_rel, pk_rel,
    1121             :                     oldslot, NULL,
    1122             :                     true,       /* must detect new rows */
    1123             :                     SPI_OK_UPDATE);
    1124             : 
    1125         140 :     if (SPI_finish() != SPI_OK_FINISH)
    1126           0 :         elog(ERROR, "SPI_finish failed");
    1127             : 
    1128         140 :     table_close(fk_rel, RowExclusiveLock);
    1129             : 
    1130         140 :     if (is_set_null)
    1131          72 :         return PointerGetDatum(NULL);
    1132             :     else
    1133             :     {
    1134             :         /*
    1135             :          * If we just deleted or updated the PK row whose key was equal to the
    1136             :          * FK columns' default values, and a referencing row exists in the FK
    1137             :          * table, we would have updated that row to the same values it already
    1138             :          * had --- and RI_FKey_fk_upd_check_required would hence believe no
    1139             :          * check is necessary.  So we need to do another lookup now and in
    1140             :          * case a reference still exists, abort the operation.  That is
    1141             :          * already implemented in the NO ACTION trigger, so just run it. (This
    1142             :          * recheck is only needed in the SET DEFAULT case, since CASCADE would
    1143             :          * remove such rows in case of a DELETE operation or would change the
    1144             :          * FK key values in case of an UPDATE, while SET NULL is certain to
    1145             :          * result in rows that satisfy the FK constraint.)
    1146             :          */
    1147          68 :         return ri_restrict(trigdata, true);
    1148             :     }
    1149             : }
    1150             : 
    1151             : 
    1152             : /*
    1153             :  * RI_FKey_pk_upd_check_required -
    1154             :  *
    1155             :  * Check if we really need to fire the RI trigger for an update or delete to a PK
    1156             :  * relation.  This is called by the AFTER trigger queue manager to see if
    1157             :  * it can skip queuing an instance of an RI trigger.  Returns true if the
    1158             :  * trigger must be fired, false if we can prove the constraint will still
    1159             :  * be satisfied.
    1160             :  *
    1161             :  * newslot will be NULL if this is called for a delete.
    1162             :  */
    1163             : bool
    1164        1172 : RI_FKey_pk_upd_check_required(Trigger *trigger, Relation pk_rel,
    1165             :                               TupleTableSlot *oldslot, TupleTableSlot *newslot)
    1166             : {
    1167             :     const RI_ConstraintInfo *riinfo;
    1168             : 
    1169        1172 :     riinfo = ri_FetchConstraintInfo(trigger, pk_rel, true);
    1170             : 
    1171             :     /*
    1172             :      * If any old key value is NULL, the row could not have been referenced by
    1173             :      * an FK row, so no check is needed.
    1174             :      */
    1175        1172 :     if (ri_NullCheck(RelationGetDescr(pk_rel), oldslot, riinfo, true) != RI_KEYS_NONE_NULL)
    1176           4 :         return false;
    1177             : 
    1178             :     /* If all old and new key values are equal, no check is needed */
    1179        1168 :     if (newslot && ri_KeysEqual(pk_rel, oldslot, newslot, riinfo, true))
    1180         472 :         return false;
    1181             : 
    1182             :     /* Else we need to fire the trigger. */
    1183         696 :     return true;
    1184             : }
    1185             : 
    1186             : /*
    1187             :  * RI_FKey_fk_upd_check_required -
    1188             :  *
    1189             :  * Check if we really need to fire the RI trigger for an update to an FK
    1190             :  * relation.  This is called by the AFTER trigger queue manager to see if
    1191             :  * it can skip queuing an instance of an RI trigger.  Returns true if the
    1192             :  * trigger must be fired, false if we can prove the constraint will still
    1193             :  * be satisfied.
    1194             :  */
    1195             : bool
    1196         678 : RI_FKey_fk_upd_check_required(Trigger *trigger, Relation fk_rel,
    1197             :                               TupleTableSlot *oldslot, TupleTableSlot *newslot)
    1198             : {
    1199             :     const RI_ConstraintInfo *riinfo;
    1200             :     int         ri_nullcheck;
    1201             :     Datum       xminDatum;
    1202             :     TransactionId xmin;
    1203             :     bool        isnull;
    1204             : 
    1205         678 :     riinfo = ri_FetchConstraintInfo(trigger, fk_rel, false);
    1206             : 
    1207         678 :     ri_nullcheck = ri_NullCheck(RelationGetDescr(fk_rel), newslot, riinfo, false);
    1208             : 
    1209             :     /*
    1210             :      * If all new key values are NULL, the row satisfies the constraint, so no
    1211             :      * check is needed.
    1212             :      */
    1213         678 :     if (ri_nullcheck == RI_KEYS_ALL_NULL)
    1214          84 :         return false;
    1215             : 
    1216             :     /*
    1217             :      * If some new key values are NULL, the behavior depends on the match
    1218             :      * type.
    1219             :      */
    1220         594 :     else if (ri_nullcheck == RI_KEYS_SOME_NULL)
    1221             :     {
    1222           8 :         switch (riinfo->confmatchtype)
    1223             :         {
    1224             :             case FKCONSTR_MATCH_SIMPLE:
    1225             : 
    1226             :                 /*
    1227             :                  * If any new key value is NULL, the row must satisfy the
    1228             :                  * constraint, so no check is needed.
    1229             :                  */
    1230           4 :                 return false;
    1231             : 
    1232             :             case FKCONSTR_MATCH_PARTIAL:
    1233             : 
    1234             :                 /*
    1235             :                  * Don't know, must run full check.
    1236             :                  */
    1237           0 :                 break;
    1238             : 
    1239             :             case FKCONSTR_MATCH_FULL:
    1240             : 
    1241             :                 /*
    1242             :                  * If some new key values are NULL, the row fails the
    1243             :                  * constraint.  We must not throw error here, because the row
    1244             :                  * might get invalidated before the constraint is to be
    1245             :                  * checked, but we should queue the event to apply the check
    1246             :                  * later.
    1247             :                  */
    1248           4 :                 return true;
    1249             :         }
    1250             :     }
    1251             : 
    1252             :     /*
    1253             :      * Continues here for no new key values are NULL, or we couldn't decide
    1254             :      * yet.
    1255             :      */
    1256             : 
    1257             :     /*
    1258             :      * If the original row was inserted by our own transaction, we must fire
    1259             :      * the trigger whether or not the keys are equal.  This is because our
    1260             :      * UPDATE will invalidate the INSERT so that the INSERT RI trigger will
    1261             :      * not do anything; so we had better do the UPDATE check.  (We could skip
    1262             :      * this if we knew the INSERT trigger already fired, but there is no easy
    1263             :      * way to know that.)
    1264             :      */
    1265         586 :     xminDatum = slot_getsysattr(oldslot, MinTransactionIdAttributeNumber, &isnull);
    1266             :     Assert(!isnull);
    1267         586 :     xmin = DatumGetTransactionId(xminDatum);
    1268         586 :     if (TransactionIdIsCurrentTransactionId(xmin))
    1269          94 :         return true;
    1270             : 
    1271             :     /* If all old and new key values are equal, no check is needed */
    1272         492 :     if (ri_KeysEqual(fk_rel, oldslot, newslot, riinfo, false))
    1273         372 :         return false;
    1274             : 
    1275             :     /* Else we need to fire the trigger. */
    1276         120 :     return true;
    1277             : }
    1278             : 
    1279             : /*
    1280             :  * RI_Initial_Check -
    1281             :  *
    1282             :  * Check an entire table for non-matching values using a single query.
    1283             :  * This is not a trigger procedure, but is called during ALTER TABLE
    1284             :  * ADD FOREIGN KEY to validate the initial table contents.
    1285             :  *
    1286             :  * We expect that the caller has made provision to prevent any problems
    1287             :  * caused by concurrent actions. This could be either by locking rel and
    1288             :  * pkrel at ShareRowExclusiveLock or higher, or by otherwise ensuring
    1289             :  * that triggers implementing the checks are already active.
    1290             :  * Hence, we do not need to lock individual rows for the check.
    1291             :  *
    1292             :  * If the check fails because the current user doesn't have permissions
    1293             :  * to read both tables, return false to let our caller know that they will
    1294             :  * need to do something else to check the constraint.
    1295             :  */
    1296             : bool
    1297         632 : RI_Initial_Check(Trigger *trigger, Relation fk_rel, Relation pk_rel)
    1298             : {
    1299             :     const RI_ConstraintInfo *riinfo;
    1300             :     StringInfoData querybuf;
    1301             :     char        pkrelname[MAX_QUOTED_REL_NAME_LEN];
    1302             :     char        fkrelname[MAX_QUOTED_REL_NAME_LEN];
    1303             :     char        pkattname[MAX_QUOTED_NAME_LEN + 3];
    1304             :     char        fkattname[MAX_QUOTED_NAME_LEN + 3];
    1305             :     RangeTblEntry *pkrte;
    1306             :     RangeTblEntry *fkrte;
    1307             :     const char *sep;
    1308             :     const char *fk_only;
    1309             :     const char *pk_only;
    1310             :     int         save_nestlevel;
    1311             :     char        workmembuf[32];
    1312             :     int         spi_result;
    1313             :     SPIPlanPtr  qplan;
    1314             : 
    1315         632 :     riinfo = ri_FetchConstraintInfo(trigger, fk_rel, false);
    1316             : 
    1317             :     /*
    1318             :      * Check to make sure current user has enough permissions to do the test
    1319             :      * query.  (If not, caller can fall back to the trigger method, which
    1320             :      * works because it changes user IDs on the fly.)
    1321             :      *
    1322             :      * XXX are there any other show-stopper conditions to check?
    1323             :      */
    1324         632 :     pkrte = makeNode(RangeTblEntry);
    1325         632 :     pkrte->rtekind = RTE_RELATION;
    1326         632 :     pkrte->relid = RelationGetRelid(pk_rel);
    1327         632 :     pkrte->relkind = pk_rel->rd_rel->relkind;
    1328         632 :     pkrte->rellockmode = AccessShareLock;
    1329         632 :     pkrte->requiredPerms = ACL_SELECT;
    1330             : 
    1331         632 :     fkrte = makeNode(RangeTblEntry);
    1332         632 :     fkrte->rtekind = RTE_RELATION;
    1333         632 :     fkrte->relid = RelationGetRelid(fk_rel);
    1334         632 :     fkrte->relkind = fk_rel->rd_rel->relkind;
    1335         632 :     fkrte->rellockmode = AccessShareLock;
    1336         632 :     fkrte->requiredPerms = ACL_SELECT;
    1337             : 
    1338        1422 :     for (int i = 0; i < riinfo->nkeys; i++)
    1339             :     {
    1340             :         int         attno;
    1341             : 
    1342         790 :         attno = riinfo->pk_attnums[i] - FirstLowInvalidHeapAttributeNumber;
    1343         790 :         pkrte->selectedCols = bms_add_member(pkrte->selectedCols, attno);
    1344             : 
    1345         790 :         attno = riinfo->fk_attnums[i] - FirstLowInvalidHeapAttributeNumber;
    1346         790 :         fkrte->selectedCols = bms_add_member(fkrte->selectedCols, attno);
    1347             :     }
    1348             : 
    1349         632 :     if (!ExecCheckRTPerms(list_make2(fkrte, pkrte), false))
    1350           8 :         return false;
    1351             : 
    1352             :     /*
    1353             :      * Also punt if RLS is enabled on either table unless this role has the
    1354             :      * bypassrls right or is the table owner of the table(s) involved which
    1355             :      * have RLS enabled.
    1356             :      */
    1357         624 :     if (!has_bypassrls_privilege(GetUserId()) &&
    1358           0 :         ((pk_rel->rd_rel->relrowsecurity &&
    1359           0 :           !pg_class_ownercheck(pkrte->relid, GetUserId())) ||
    1360           0 :          (fk_rel->rd_rel->relrowsecurity &&
    1361           0 :           !pg_class_ownercheck(fkrte->relid, GetUserId()))))
    1362           0 :         return false;
    1363             : 
    1364             :     /*----------
    1365             :      * The query string built is:
    1366             :      *  SELECT fk.keycols FROM [ONLY] relname fk
    1367             :      *   LEFT OUTER JOIN [ONLY] pkrelname pk
    1368             :      *   ON (pk.pkkeycol1=fk.keycol1 [AND ...])
    1369             :      *   WHERE pk.pkkeycol1 IS NULL AND
    1370             :      * For MATCH SIMPLE:
    1371             :      *   (fk.keycol1 IS NOT NULL [AND ...])
    1372             :      * For MATCH FULL:
    1373             :      *   (fk.keycol1 IS NOT NULL [OR ...])
    1374             :      *
    1375             :      * We attach COLLATE clauses to the operators when comparing columns
    1376             :      * that have different collations.
    1377             :      *----------
    1378             :      */
    1379         624 :     initStringInfo(&querybuf);
    1380         624 :     appendStringInfoString(&querybuf, "SELECT ");
    1381         624 :     sep = "";
    1382        1398 :     for (int i = 0; i < riinfo->nkeys; i++)
    1383             :     {
    1384         774 :         quoteOneName(fkattname,
    1385         774 :                      RIAttName(fk_rel, riinfo->fk_attnums[i]));
    1386         774 :         appendStringInfo(&querybuf, "%sfk.%s", sep, fkattname);
    1387         774 :         sep = ", ";
    1388             :     }
    1389             : 
    1390         624 :     quoteRelationName(pkrelname, pk_rel);
    1391         624 :     quoteRelationName(fkrelname, fk_rel);
    1392        1248 :     fk_only = fk_rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE ?
    1393         624 :         "" : "ONLY ";
    1394        1248 :     pk_only = pk_rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE ?
    1395         624 :         "" : "ONLY ";
    1396         624 :     appendStringInfo(&querybuf,
    1397             :                      " FROM %s%s fk LEFT OUTER JOIN %s%s pk ON",
    1398             :                      fk_only, fkrelname, pk_only, pkrelname);
    1399             : 
    1400         624 :     strcpy(pkattname, "pk.");
    1401         624 :     strcpy(fkattname, "fk.");
    1402         624 :     sep = "(";
    1403        1398 :     for (int i = 0; i < riinfo->nkeys; i++)
    1404             :     {
    1405         774 :         Oid         pk_type = RIAttType(pk_rel, riinfo->pk_attnums[i]);
    1406         774 :         Oid         fk_type = RIAttType(fk_rel, riinfo->fk_attnums[i]);
    1407         774 :         Oid         pk_coll = RIAttCollation(pk_rel, riinfo->pk_attnums[i]);
    1408         774 :         Oid         fk_coll = RIAttCollation(fk_rel, riinfo->fk_attnums[i]);
    1409             : 
    1410         774 :         quoteOneName(pkattname + 3,
    1411         774 :                      RIAttName(pk_rel, riinfo->pk_attnums[i]));
    1412         774 :         quoteOneName(fkattname + 3,
    1413         774 :                      RIAttName(fk_rel, riinfo->fk_attnums[i]));
    1414         774 :         ri_GenerateQual(&querybuf, sep,
    1415             :                         pkattname, pk_type,
    1416             :                         riinfo->pf_eq_oprs[i],
    1417             :                         fkattname, fk_type);
    1418         774 :         if (pk_coll != fk_coll)
    1419           8 :             ri_GenerateQualCollation(&querybuf, pk_coll);
    1420         774 :         sep = "AND";
    1421             :     }
    1422             : 
    1423             :     /*
    1424             :      * It's sufficient to test any one pk attribute for null to detect a join
    1425             :      * failure.
    1426             :      */
    1427         624 :     quoteOneName(pkattname, RIAttName(pk_rel, riinfo->pk_attnums[0]));
    1428         624 :     appendStringInfo(&querybuf, ") WHERE pk.%s IS NULL AND (", pkattname);
    1429             : 
    1430         624 :     sep = "";
    1431        1398 :     for (int i = 0; i < riinfo->nkeys; i++)
    1432             :     {
    1433         774 :         quoteOneName(fkattname, RIAttName(fk_rel, riinfo->fk_attnums[i]));
    1434         774 :         appendStringInfo(&querybuf,
    1435             :                          "%sfk.%s IS NOT NULL",
    1436             :                          sep, fkattname);
    1437         774 :         switch (riinfo->confmatchtype)
    1438             :         {
    1439             :             case FKCONSTR_MATCH_SIMPLE:
    1440         706 :                 sep = " AND ";
    1441         706 :                 break;
    1442             :             case FKCONSTR_MATCH_FULL:
    1443          68 :                 sep = " OR ";
    1444          68 :                 break;
    1445             :         }
    1446             :     }
    1447         624 :     appendStringInfoChar(&querybuf, ')');
    1448             : 
    1449             :     /*
    1450             :      * Temporarily increase work_mem so that the check query can be executed
    1451             :      * more efficiently.  It seems okay to do this because the query is simple
    1452             :      * enough to not use a multiple of work_mem, and one typically would not
    1453             :      * have many large foreign-key validations happening concurrently.  So
    1454             :      * this seems to meet the criteria for being considered a "maintenance"
    1455             :      * operation, and accordingly we use maintenance_work_mem.
    1456             :      *
    1457             :      * We use the equivalent of a function SET option to allow the setting to
    1458             :      * persist for exactly the duration of the check query.  guc.c also takes
    1459             :      * care of undoing the setting on error.
    1460             :      */
    1461         624 :     save_nestlevel = NewGUCNestLevel();
    1462             : 
    1463         624 :     snprintf(workmembuf, sizeof(workmembuf), "%d", maintenance_work_mem);
    1464         624 :     (void) set_config_option("work_mem", workmembuf,
    1465             :                              PGC_USERSET, PGC_S_SESSION,
    1466             :                              GUC_ACTION_SAVE, true, 0, false);
    1467             : 
    1468         624 :     if (SPI_connect() != SPI_OK_CONNECT)
    1469           0 :         elog(ERROR, "SPI_connect failed");
    1470             : 
    1471             :     /*
    1472             :      * Generate the plan.  We don't need to cache it, and there are no
    1473             :      * arguments to the plan.
    1474             :      */
    1475         624 :     qplan = SPI_prepare(querybuf.data, 0, NULL);
    1476             : 
    1477         624 :     if (qplan == NULL)
    1478           0 :         elog(ERROR, "SPI_prepare returned %s for %s",
    1479             :              SPI_result_code_string(SPI_result), querybuf.data);
    1480             : 
    1481             :     /*
    1482             :      * Run the plan.  For safety we force a current snapshot to be used. (In
    1483             :      * transaction-snapshot mode, this arguably violates transaction isolation
    1484             :      * rules, but we really haven't got much choice.) We don't need to
    1485             :      * register the snapshot, because SPI_execute_snapshot will see to it. We
    1486             :      * need at most one tuple returned, so pass limit = 1.
    1487             :      */
    1488         624 :     spi_result = SPI_execute_snapshot(qplan,
    1489             :                                       NULL, NULL,
    1490             :                                       GetLatestSnapshot(),
    1491             :                                       InvalidSnapshot,
    1492             :                                       true, false, 1);
    1493             : 
    1494             :     /* Check result */
    1495         624 :     if (spi_result != SPI_OK_SELECT)
    1496           0 :         elog(ERROR, "SPI_execute_snapshot returned %s", SPI_result_code_string(spi_result));
    1497             : 
    1498             :     /* Did we find a tuple violating the constraint? */
    1499         624 :     if (SPI_processed > 0)
    1500             :     {
    1501             :         TupleTableSlot *slot;
    1502          42 :         HeapTuple   tuple = SPI_tuptable->vals[0];
    1503          42 :         TupleDesc   tupdesc = SPI_tuptable->tupdesc;
    1504             :         RI_ConstraintInfo fake_riinfo;
    1505             : 
    1506          42 :         slot = MakeSingleTupleTableSlot(tupdesc, &TTSOpsVirtual);
    1507             : 
    1508          42 :         heap_deform_tuple(tuple, tupdesc,
    1509             :                           slot->tts_values, slot->tts_isnull);
    1510          42 :         ExecStoreVirtualTuple(slot);
    1511             : 
    1512             :         /*
    1513             :          * The columns to look at in the result tuple are 1..N, not whatever
    1514             :          * they are in the fk_rel.  Hack up riinfo so that the subroutines
    1515             :          * called here will behave properly.
    1516             :          *
    1517             :          * In addition to this, we have to pass the correct tupdesc to
    1518             :          * ri_ReportViolation, overriding its normal habit of using the pk_rel
    1519             :          * or fk_rel's tupdesc.
    1520             :          */
    1521          42 :         memcpy(&fake_riinfo, riinfo, sizeof(RI_ConstraintInfo));
    1522          96 :         for (int i = 0; i < fake_riinfo.nkeys; i++)
    1523          54 :             fake_riinfo.fk_attnums[i] = i + 1;
    1524             : 
    1525             :         /*
    1526             :          * If it's MATCH FULL, and there are any nulls in the FK keys,
    1527             :          * complain about that rather than the lack of a match.  MATCH FULL
    1528             :          * disallows partially-null FK rows.
    1529             :          */
    1530          58 :         if (fake_riinfo.confmatchtype == FKCONSTR_MATCH_FULL &&
    1531          16 :             ri_NullCheck(tupdesc, slot, &fake_riinfo, false) != RI_KEYS_NONE_NULL)
    1532           8 :             ereport(ERROR,
    1533             :                     (errcode(ERRCODE_FOREIGN_KEY_VIOLATION),
    1534             :                      errmsg("insert or update on table \"%s\" violates foreign key constraint \"%s\"",
    1535             :                             RelationGetRelationName(fk_rel),
    1536             :                             NameStr(fake_riinfo.conname)),
    1537             :                      errdetail("MATCH FULL does not allow mixing of null and nonnull key values."),
    1538             :                      errtableconstraint(fk_rel,
    1539             :                                         NameStr(fake_riinfo.conname))));
    1540             : 
    1541             :         /*
    1542             :          * We tell ri_ReportViolation we were doing the RI_PLAN_CHECK_LOOKUPPK
    1543             :          * query, which isn't true, but will cause it to use
    1544             :          * fake_riinfo.fk_attnums as we need.
    1545             :          */
    1546          34 :         ri_ReportViolation(&fake_riinfo,
    1547             :                            pk_rel, fk_rel,
    1548             :                            slot, tupdesc,
    1549             :                            RI_PLAN_CHECK_LOOKUPPK, false);
    1550             : 
    1551             :         ExecDropSingleTupleTableSlot(slot);
    1552             :     }
    1553             : 
    1554         582 :     if (SPI_finish() != SPI_OK_FINISH)
    1555           0 :         elog(ERROR, "SPI_finish failed");
    1556             : 
    1557             :     /*
    1558             :      * Restore work_mem.
    1559             :      */
    1560         582 :     AtEOXact_GUC(true, save_nestlevel);
    1561             : 
    1562         582 :     return true;
    1563             : }
    1564             : 
    1565             : /*
    1566             :  * RI_PartitionRemove_Check -
    1567             :  *
    1568             :  * Verify no referencing values exist, when a partition is detached on
    1569             :  * the referenced side of a foreign key constraint.
    1570             :  */
    1571             : void
    1572          24 : RI_PartitionRemove_Check(Trigger *trigger, Relation fk_rel, Relation pk_rel)
    1573             : {
    1574             :     const RI_ConstraintInfo *riinfo;
    1575             :     StringInfoData querybuf;
    1576             :     char       *constraintDef;
    1577             :     char        pkrelname[MAX_QUOTED_REL_NAME_LEN];
    1578             :     char        fkrelname[MAX_QUOTED_REL_NAME_LEN];
    1579             :     char        pkattname[MAX_QUOTED_NAME_LEN + 3];
    1580             :     char        fkattname[MAX_QUOTED_NAME_LEN + 3];
    1581             :     const char *sep;
    1582             :     const char *fk_only;
    1583             :     int         save_nestlevel;
    1584             :     char        workmembuf[32];
    1585             :     int         spi_result;
    1586             :     SPIPlanPtr  qplan;
    1587             :     int         i;
    1588             : 
    1589          24 :     riinfo = ri_FetchConstraintInfo(trigger, fk_rel, false);
    1590             : 
    1591             :     /*
    1592             :      * We don't check permissions before displaying the error message, on the
    1593             :      * assumption that the user detaching the partition must have enough
    1594             :      * privileges to examine the table contents anyhow.
    1595             :      */
    1596             : 
    1597             :     /*----------
    1598             :      * The query string built is:
    1599             :      *  SELECT fk.keycols FROM [ONLY] relname fk
    1600             :      *    JOIN pkrelname pk
    1601             :      *    ON (pk.pkkeycol1=fk.keycol1 [AND ...])
    1602             :      *    WHERE (<partition constraint>) AND
    1603             :      * For MATCH SIMPLE:
    1604             :      *   (fk.keycol1 IS NOT NULL [AND ...])
    1605             :      * For MATCH FULL:
    1606             :      *   (fk.keycol1 IS NOT NULL [OR ...])
    1607             :      *
    1608             :      * We attach COLLATE clauses to the operators when comparing columns
    1609             :      * that have different collations.
    1610             :      *----------
    1611             :      */
    1612          24 :     initStringInfo(&querybuf);
    1613          24 :     appendStringInfoString(&querybuf, "SELECT ");
    1614          24 :     sep = "";
    1615          48 :     for (i = 0; i < riinfo->nkeys; i++)
    1616             :     {
    1617          24 :         quoteOneName(fkattname,
    1618          24 :                      RIAttName(fk_rel, riinfo->fk_attnums[i]));
    1619          24 :         appendStringInfo(&querybuf, "%sfk.%s", sep, fkattname);
    1620          24 :         sep = ", ";
    1621             :     }
    1622             : 
    1623          24 :     quoteRelationName(pkrelname, pk_rel);
    1624          24 :     quoteRelationName(fkrelname, fk_rel);
    1625          48 :     fk_only = fk_rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE ?
    1626          24 :         "" : "ONLY ";
    1627          24 :     appendStringInfo(&querybuf,
    1628             :                      " FROM %s%s fk JOIN %s pk ON",
    1629             :                      fk_only, fkrelname, pkrelname);
    1630          24 :     strcpy(pkattname, "pk.");
    1631          24 :     strcpy(fkattname, "fk.");
    1632          24 :     sep = "(";
    1633          48 :     for (i = 0; i < riinfo->nkeys; i++)
    1634             :     {
    1635          24 :         Oid         pk_type = RIAttType(pk_rel, riinfo->pk_attnums[i]);
    1636          24 :         Oid         fk_type = RIAttType(fk_rel, riinfo->fk_attnums[i]);
    1637          24 :         Oid         pk_coll = RIAttCollation(pk_rel, riinfo->pk_attnums[i]);
    1638          24 :         Oid         fk_coll = RIAttCollation(fk_rel, riinfo->fk_attnums[i]);
    1639             : 
    1640          24 :         quoteOneName(pkattname + 3,
    1641          24 :                      RIAttName(pk_rel, riinfo->pk_attnums[i]));
    1642          24 :         quoteOneName(fkattname + 3,
    1643          24 :                      RIAttName(fk_rel, riinfo->fk_attnums[i]));
    1644          24 :         ri_GenerateQual(&querybuf, sep,
    1645             :                         pkattname, pk_type,
    1646             :                         riinfo->pf_eq_oprs[i],
    1647             :                         fkattname, fk_type);
    1648          24 :         if (pk_coll != fk_coll)
    1649           0 :             ri_GenerateQualCollation(&querybuf, pk_coll);
    1650          24 :         sep = "AND";
    1651             :     }
    1652             : 
    1653             :     /*
    1654             :      * Start the WHERE clause with the partition constraint (except if this is
    1655             :      * the default partition and there's no other partition, because the
    1656             :      * partition constraint is the empty string in that case.)
    1657             :      */
    1658          24 :     constraintDef = pg_get_partconstrdef_string(RelationGetRelid(pk_rel), "pk");
    1659          24 :     if (constraintDef && constraintDef[0] != '\0')
    1660          24 :         appendStringInfo(&querybuf, ") WHERE %s AND (",
    1661             :                          constraintDef);
    1662             :     else
    1663           0 :         appendStringInfo(&querybuf, ") WHERE (");
    1664             : 
    1665          24 :     sep = "";
    1666          48 :     for (i = 0; i < riinfo->nkeys; i++)
    1667             :     {
    1668          24 :         quoteOneName(fkattname, RIAttName(fk_rel, riinfo->fk_attnums[i]));
    1669          24 :         appendStringInfo(&querybuf,
    1670             :                          "%sfk.%s IS NOT NULL",
    1671             :                          sep, fkattname);
    1672          24 :         switch (riinfo->confmatchtype)
    1673             :         {
    1674             :             case FKCONSTR_MATCH_SIMPLE:
    1675          24 :                 sep = " AND ";
    1676          24 :                 break;
    1677             :             case FKCONSTR_MATCH_FULL:
    1678           0 :                 sep = " OR ";
    1679           0 :                 break;
    1680             :         }
    1681             :     }
    1682          24 :     appendStringInfoChar(&querybuf, ')');
    1683             : 
    1684             :     /*
    1685             :      * Temporarily increase work_mem so that the check query can be executed
    1686             :      * more efficiently.  It seems okay to do this because the query is simple
    1687             :      * enough to not use a multiple of work_mem, and one typically would not
    1688             :      * have many large foreign-key validations happening concurrently.  So
    1689             :      * this seems to meet the criteria for being considered a "maintenance"
    1690             :      * operation, and accordingly we use maintenance_work_mem.
    1691             :      *
    1692             :      * We use the equivalent of a function SET option to allow the setting to
    1693             :      * persist for exactly the duration of the check query.  guc.c also takes
    1694             :      * care of undoing the setting on error.
    1695             :      */
    1696          24 :     save_nestlevel = NewGUCNestLevel();
    1697             : 
    1698          24 :     snprintf(workmembuf, sizeof(workmembuf), "%d", maintenance_work_mem);
    1699          24 :     (void) set_config_option("work_mem", workmembuf,
    1700             :                              PGC_USERSET, PGC_S_SESSION,
    1701             :                              GUC_ACTION_SAVE, true, 0, false);
    1702             : 
    1703          24 :     if (SPI_connect() != SPI_OK_CONNECT)
    1704           0 :         elog(ERROR, "SPI_connect failed");
    1705             : 
    1706             :     /*
    1707             :      * Generate the plan.  We don't need to cache it, and there are no
    1708             :      * arguments to the plan.
    1709             :      */
    1710          24 :     qplan = SPI_prepare(querybuf.data, 0, NULL);
    1711             : 
    1712          24 :     if (qplan == NULL)
    1713           0 :         elog(ERROR, "SPI_prepare returned %s for %s",
    1714             :              SPI_result_code_string(SPI_result), querybuf.data);
    1715             : 
    1716             :     /*
    1717             :      * Run the plan.  For safety we force a current snapshot to be used. (In
    1718             :      * transaction-snapshot mode, this arguably violates transaction isolation
    1719             :      * rules, but we really haven't got much choice.) We don't need to
    1720             :      * register the snapshot, because SPI_execute_snapshot will see to it. We
    1721             :      * need at most one tuple returned, so pass limit = 1.
    1722             :      */
    1723          24 :     spi_result = SPI_execute_snapshot(qplan,
    1724             :                                       NULL, NULL,
    1725             :                                       GetLatestSnapshot(),
    1726             :                                       InvalidSnapshot,
    1727             :                                       true, false, 1);
    1728             : 
    1729             :     /* Check result */
    1730          24 :     if (spi_result != SPI_OK_SELECT)
    1731           0 :         elog(ERROR, "SPI_execute_snapshot returned %s", SPI_result_code_string(spi_result));
    1732             : 
    1733             :     /* Did we find a tuple that would violate the constraint? */
    1734          24 :     if (SPI_processed > 0)
    1735             :     {
    1736             :         TupleTableSlot *slot;
    1737          20 :         HeapTuple   tuple = SPI_tuptable->vals[0];
    1738          20 :         TupleDesc   tupdesc = SPI_tuptable->tupdesc;
    1739             :         RI_ConstraintInfo fake_riinfo;
    1740             : 
    1741          20 :         slot = MakeSingleTupleTableSlot(tupdesc, &TTSOpsVirtual);
    1742             : 
    1743          20 :         heap_deform_tuple(tuple, tupdesc,
    1744             :                           slot->tts_values, slot->tts_isnull);
    1745          20 :         ExecStoreVirtualTuple(slot);
    1746             : 
    1747             :         /*
    1748             :          * The columns to look at in the result tuple are 1..N, not whatever
    1749             :          * they are in the fk_rel.  Hack up riinfo so that ri_ReportViolation
    1750             :          * will behave properly.
    1751             :          *
    1752             :          * In addition to this, we have to pass the correct tupdesc to
    1753             :          * ri_ReportViolation, overriding its normal habit of using the pk_rel
    1754             :          * or fk_rel's tupdesc.
    1755             :          */
    1756          20 :         memcpy(&fake_riinfo, riinfo, sizeof(RI_ConstraintInfo));
    1757          40 :         for (i = 0; i < fake_riinfo.nkeys; i++)
    1758          20 :             fake_riinfo.pk_attnums[i] = i + 1;
    1759             : 
    1760          20 :         ri_ReportViolation(&fake_riinfo, pk_rel, fk_rel,
    1761             :                            slot, tupdesc, 0, true);
    1762             :     }
    1763             : 
    1764           4 :     if (SPI_finish() != SPI_OK_FINISH)
    1765           0 :         elog(ERROR, "SPI_finish failed");
    1766             : 
    1767             :     /*
    1768             :      * Restore work_mem.
    1769             :      */
    1770           4 :     AtEOXact_GUC(true, save_nestlevel);
    1771           4 : }
    1772             : 
    1773             : 
    1774             : /* ----------
    1775             :  * Local functions below
    1776             :  * ----------
    1777             :  */
    1778             : 
    1779             : 
    1780             : /*
    1781             :  * quoteOneName --- safely quote a single SQL name
    1782             :  *
    1783             :  * buffer must be MAX_QUOTED_NAME_LEN long (includes room for \0)
    1784             :  */
    1785             : static void
    1786       13214 : quoteOneName(char *buffer, const char *name)
    1787             : {
    1788             :     /* Rather than trying to be smart, just always quote it. */
    1789       13214 :     *buffer++ = '"';
    1790       92308 :     while (*name)
    1791             :     {
    1792       65880 :         if (*name == '"')
    1793           0 :             *buffer++ = '"';
    1794       65880 :         *buffer++ = *name++;
    1795             :     }
    1796       13214 :     *buffer++ = '"';
    1797       13214 :     *buffer = '\0';
    1798       13214 : }
    1799             : 
    1800             : /*
    1801             :  * quoteRelationName --- safely quote a fully qualified relation name
    1802             :  *
    1803             :  * buffer must be MAX_QUOTED_REL_NAME_LEN long (includes room for \0)
    1804             :  */
    1805             : static void
    1806        3448 : quoteRelationName(char *buffer, Relation rel)
    1807             : {
    1808        3448 :     quoteOneName(buffer, get_namespace_name(RelationGetNamespace(rel)));
    1809        3448 :     buffer += strlen(buffer);
    1810        3448 :     *buffer++ = '.';
    1811        3448 :     quoteOneName(buffer, RelationGetRelationName(rel));
    1812        3448 : }
    1813             : 
    1814             : /*
    1815             :  * ri_GenerateQual --- generate a WHERE clause equating two variables
    1816             :  *
    1817             :  * This basically appends " sep leftop op rightop" to buf, adding casts
    1818             :  * and schema qualification as needed to ensure that the parser will select
    1819             :  * the operator we specify.  leftop and rightop should be parenthesized
    1820             :  * if they aren't variables or parameters.
    1821             :  */
    1822             : static void
    1823        3284 : ri_GenerateQual(StringInfo buf,
    1824             :                 const char *sep,
    1825             :                 const char *leftop, Oid leftoptype,
    1826             :                 Oid opoid,
    1827             :                 const char *rightop, Oid rightoptype)
    1828             : {
    1829        3284 :     appendStringInfo(buf, " %s ", sep);
    1830        3284 :     generate_operator_clause(buf, leftop, leftoptype, opoid,
    1831             :                              rightop, rightoptype);
    1832        3284 : }
    1833             : 
    1834             : /*
    1835             :  * ri_GenerateQualCollation --- add a COLLATE spec to a WHERE clause
    1836             :  *
    1837             :  * At present, we intentionally do not use this function for RI queries that
    1838             :  * compare a variable to a $n parameter.  Since parameter symbols always have
    1839             :  * default collation, the effect will be to use the variable's collation.
    1840             :  * Now that is only strictly correct when testing the referenced column, since
    1841             :  * the SQL standard specifies that RI comparisons should use the referenced
    1842             :  * column's collation.  However, so long as all collations have the same
    1843             :  * notion of equality (which they do, because texteq reduces to bitwise
    1844             :  * equality), there's no visible semantic impact from using the referencing
    1845             :  * column's collation when testing it, and this is a good thing to do because
    1846             :  * it lets us use a normal index on the referencing column.  However, we do
    1847             :  * have to use this function when directly comparing the referencing and
    1848             :  * referenced columns, if they are of different collations; else the parser
    1849             :  * will fail to resolve the collation to use.
    1850             :  */
    1851             : static void
    1852           8 : ri_GenerateQualCollation(StringInfo buf, Oid collation)
    1853             : {
    1854             :     HeapTuple   tp;
    1855             :     Form_pg_collation colltup;
    1856             :     char       *collname;
    1857             :     char        onename[MAX_QUOTED_NAME_LEN];
    1858             : 
    1859             :     /* Nothing to do if it's a noncollatable data type */
    1860           8 :     if (!OidIsValid(collation))
    1861           0 :         return;
    1862             : 
    1863           8 :     tp = SearchSysCache1(COLLOID, ObjectIdGetDatum(collation));
    1864           8 :     if (!HeapTupleIsValid(tp))
    1865           0 :         elog(ERROR, "cache lookup failed for collation %u", collation);
    1866           8 :     colltup = (Form_pg_collation) GETSTRUCT(tp);
    1867           8 :     collname = NameStr(colltup->collname);
    1868             : 
    1869             :     /*
    1870             :      * We qualify the name always, for simplicity and to ensure the query is
    1871             :      * not search-path-dependent.
    1872             :      */
    1873           8 :     quoteOneName(onename, get_namespace_name(colltup->collnamespace));
    1874           8 :     appendStringInfo(buf, " COLLATE %s", onename);
    1875           8 :     quoteOneName(onename, collname);
    1876           8 :     appendStringInfo(buf, ".%s", onename);
    1877             : 
    1878           8 :     ReleaseSysCache(tp);
    1879             : }
    1880             : 
    1881             : /* ----------
    1882             :  * ri_BuildQueryKey -
    1883             :  *
    1884             :  *  Construct a hashtable key for a prepared SPI plan of an FK constraint.
    1885             :  *
    1886             :  *      key: output argument, *key is filled in based on the other arguments
    1887             :  *      riinfo: info from pg_constraint entry
    1888             :  *      constr_queryno: an internal number identifying the query type
    1889             :  *          (see RI_PLAN_XXX constants at head of file)
    1890             :  * ----------
    1891             :  */
    1892             : static void
    1893        3666 : ri_BuildQueryKey(RI_QueryKey *key, const RI_ConstraintInfo *riinfo,
    1894             :                  int32 constr_queryno)
    1895             : {
    1896             :     /*
    1897             :      * We assume struct RI_QueryKey contains no padding bytes, else we'd need
    1898             :      * to use memset to clear them.
    1899             :      */
    1900        3666 :     key->constr_id = riinfo->constraint_id;
    1901        3666 :     key->constr_queryno = constr_queryno;
    1902        3666 : }
    1903             : 
    1904             : /*
    1905             :  * Check that RI trigger function was called in expected context
    1906             :  */
    1907             : static void
    1908        3402 : ri_CheckTrigger(FunctionCallInfo fcinfo, const char *funcname, int tgkind)
    1909             : {
    1910        3402 :     TriggerData *trigdata = (TriggerData *) fcinfo->context;
    1911             : 
    1912        3402 :     if (!CALLED_AS_TRIGGER(fcinfo))
    1913           0 :         ereport(ERROR,
    1914             :                 (errcode(ERRCODE_E_R_I_E_TRIGGER_PROTOCOL_VIOLATED),
    1915             :                  errmsg("function \"%s\" was not called by trigger manager", funcname)));
    1916             : 
    1917             :     /*
    1918             :      * Check proper event
    1919             :      */
    1920        6804 :     if (!TRIGGER_FIRED_AFTER(trigdata->tg_event) ||
    1921        3402 :         !TRIGGER_FIRED_FOR_ROW(trigdata->tg_event))
    1922           0 :         ereport(ERROR,
    1923             :                 (errcode(ERRCODE_E_R_I_E_TRIGGER_PROTOCOL_VIOLATED),
    1924             :                  errmsg("function \"%s\" must be fired AFTER ROW", funcname)));
    1925             : 
    1926        3402 :     switch (tgkind)
    1927             :     {
    1928             :         case RI_TRIGTYPE_INSERT:
    1929        2524 :             if (!TRIGGER_FIRED_BY_INSERT(trigdata->tg_event))
    1930           0 :                 ereport(ERROR,
    1931             :                         (errcode(ERRCODE_E_R_I_E_TRIGGER_PROTOCOL_VIOLATED),
    1932             :                          errmsg("function \"%s\" must be fired for INSERT", funcname)));
    1933        2524 :             break;
    1934             :         case RI_TRIGTYPE_UPDATE:
    1935         482 :             if (!TRIGGER_FIRED_BY_UPDATE(trigdata->tg_event))
    1936           0 :                 ereport(ERROR,
    1937             :                         (errcode(ERRCODE_E_R_I_E_TRIGGER_PROTOCOL_VIOLATED),
    1938             :                          errmsg("function \"%s\" must be fired for UPDATE", funcname)));
    1939         482 :             break;
    1940             :         case RI_TRIGTYPE_DELETE:
    1941         396 :             if (!TRIGGER_FIRED_BY_DELETE(trigdata->tg_event))
    1942           0 :                 ereport(ERROR,
    1943             :                         (errcode(ERRCODE_E_R_I_E_TRIGGER_PROTOCOL_VIOLATED),
    1944             :                          errmsg("function \"%s\" must be fired for DELETE", funcname)));
    1945         396 :             break;
    1946             :     }
    1947        3402 : }
    1948             : 
    1949             : 
    1950             : /*
    1951             :  * Fetch the RI_ConstraintInfo struct for the trigger's FK constraint.
    1952             :  */
    1953             : static const RI_ConstraintInfo *
    1954        5976 : ri_FetchConstraintInfo(Trigger *trigger, Relation trig_rel, bool rel_is_pk)
    1955             : {
    1956        5976 :     Oid         constraintOid = trigger->tgconstraint;
    1957             :     const RI_ConstraintInfo *riinfo;
    1958             : 
    1959             :     /*
    1960             :      * Check that the FK constraint's OID is available; it might not be if
    1961             :      * we've been invoked via an ordinary trigger or an old-style "constraint
    1962             :      * trigger".
    1963             :      */
    1964        5976 :     if (!OidIsValid(constraintOid))
    1965           0 :         ereport(ERROR,
    1966             :                 (errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
    1967             :                  errmsg("no pg_constraint entry for trigger \"%s\" on table \"%s\"",
    1968             :                         trigger->tgname, RelationGetRelationName(trig_rel)),
    1969             :                  errhint("Remove this referential integrity trigger and its mates, then do ALTER TABLE ADD CONSTRAINT.")));
    1970             : 
    1971             :     /* Find or create a hashtable entry for the constraint */
    1972        5976 :     riinfo = ri_LoadConstraintInfo(constraintOid);
    1973             : 
    1974             :     /* Do some easy cross-checks against the trigger call data */
    1975        5976 :     if (rel_is_pk)
    1976             :     {
    1977        3808 :         if (riinfo->fk_relid != trigger->tgconstrrelid ||
    1978        1904 :             riinfo->pk_relid != RelationGetRelid(trig_rel))
    1979           0 :             elog(ERROR, "wrong pg_constraint entry for trigger \"%s\" on table \"%s\"",
    1980             :                  trigger->tgname, RelationGetRelationName(trig_rel));
    1981             :     }
    1982             :     else
    1983             :     {
    1984        8144 :         if (riinfo->fk_relid != RelationGetRelid(trig_rel) ||
    1985        4072 :             riinfo->pk_relid != trigger->tgconstrrelid)
    1986           0 :             elog(ERROR, "wrong pg_constraint entry for trigger \"%s\" on table \"%s\"",
    1987             :                  trigger->tgname, RelationGetRelationName(trig_rel));
    1988             :     }
    1989             : 
    1990       11642 :     if (riinfo->confmatchtype != FKCONSTR_MATCH_FULL &&
    1991       11332 :         riinfo->confmatchtype != FKCONSTR_MATCH_PARTIAL &&
    1992        5666 :         riinfo->confmatchtype != FKCONSTR_MATCH_SIMPLE)
    1993           0 :         elog(ERROR, "unrecognized confmatchtype: %d",
    1994             :              riinfo->confmatchtype);
    1995             : 
    1996        5976 :     if (riinfo->confmatchtype == FKCONSTR_MATCH_PARTIAL)
    1997           0 :         ereport(ERROR,
    1998             :                 (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
    1999             :                  errmsg("MATCH PARTIAL not yet implemented")));
    2000             : 
    2001        5976 :     return riinfo;
    2002             : }
    2003             : 
    2004             : /*
    2005             :  * Fetch or create the RI_ConstraintInfo struct for an FK constraint.
    2006             :  */
    2007             : static const RI_ConstraintInfo *
    2008        5976 : ri_LoadConstraintInfo(Oid constraintOid)
    2009             : {
    2010             :     RI_ConstraintInfo *riinfo;
    2011             :     bool        found;
    2012             :     HeapTuple   tup;
    2013             :     Form_pg_constraint conForm;
    2014             : 
    2015             :     /*
    2016             :      * On the first call initialize the hashtable
    2017             :      */
    2018        5976 :     if (!ri_constraint_cache)
    2019         344 :         ri_InitHashTables();
    2020             : 
    2021             :     /*
    2022             :      * Find or create a hash entry.  If we find a valid one, just return it.
    2023             :      */
    2024        5976 :     riinfo = (RI_ConstraintInfo *) hash_search(ri_constraint_cache,
    2025             :                                                (void *) &constraintOid,
    2026             :                                                HASH_ENTER, &found);
    2027        5976 :     if (!found)
    2028        2494 :         riinfo->valid = false;
    2029        3482 :     else if (riinfo->valid)
    2030        3398 :         return riinfo;
    2031             : 
    2032             :     /*
    2033             :      * Fetch the pg_constraint row so we can fill in the entry.
    2034             :      */
    2035        2578 :     tup = SearchSysCache1(CONSTROID, ObjectIdGetDatum(constraintOid));
    2036        2578 :     if (!HeapTupleIsValid(tup)) /* should not happen */
    2037           0 :         elog(ERROR, "cache lookup failed for constraint %u", constraintOid);
    2038        2578 :     conForm = (Form_pg_constraint) GETSTRUCT(tup);
    2039             : 
    2040        2578 :     if (conForm->contype != CONSTRAINT_FOREIGN) /* should not happen */
    2041           0 :         elog(ERROR, "constraint %u is not a foreign key constraint",
    2042             :              constraintOid);
    2043             : 
    2044             :     /* And extract data */
    2045             :     Assert(riinfo->constraint_id == constraintOid);
    2046        2578 :     riinfo->oidHashValue = GetSysCacheHashValue1(CONSTROID,
    2047             :                                                  ObjectIdGetDatum(constraintOid));
    2048        2578 :     memcpy(&riinfo->conname, &conForm->conname, sizeof(NameData));
    2049        2578 :     riinfo->pk_relid = conForm->confrelid;
    2050        2578 :     riinfo->fk_relid = conForm->conrelid;
    2051        2578 :     riinfo->confupdtype = conForm->confupdtype;
    2052        2578 :     riinfo->confdeltype = conForm->confdeltype;
    2053        2578 :     riinfo->confmatchtype = conForm->confmatchtype;
    2054             : 
    2055        2578 :     DeconstructFkConstraintRow(tup,
    2056             :                                &riinfo->nkeys,
    2057        2578 :                                riinfo->fk_attnums,
    2058        2578 :                                riinfo->pk_attnums,
    2059        2578 :                                riinfo->pf_eq_oprs,
    2060        2578 :                                riinfo->pp_eq_oprs,
    2061        2578 :                                riinfo->ff_eq_oprs);
    2062             : 
    2063        2578 :     ReleaseSysCache(tup);
    2064             : 
    2065             :     /*
    2066             :      * For efficient processing of invalidation messages below, we keep a
    2067             :      * doubly-linked list, and a count, of all currently valid entries.
    2068             :      */
    2069        2578 :     dlist_push_tail(&ri_constraint_cache_valid_list, &riinfo->valid_link);
    2070        2578 :     ri_constraint_cache_valid_count++;
    2071             : 
    2072        2578 :     riinfo->valid = true;
    2073             : 
    2074        2578 :     return riinfo;
    2075             : }
    2076             : 
    2077             : /*
    2078             :  * Callback for pg_constraint inval events
    2079             :  *
    2080             :  * While most syscache callbacks just flush all their entries, pg_constraint
    2081             :  * gets enough update traffic that it's probably worth being smarter.
    2082             :  * Invalidate any ri_constraint_cache entry associated with the syscache
    2083             :  * entry with the specified hash value, or all entries if hashvalue == 0.
    2084             :  *
    2085             :  * Note: at the time a cache invalidation message is processed there may be
    2086             :  * active references to the cache.  Because of this we never remove entries
    2087             :  * from the cache, but only mark them invalid, which is harmless to active
    2088             :  * uses.  (Any query using an entry should hold a lock sufficient to keep that
    2089             :  * data from changing under it --- but we may get cache flushes anyway.)
    2090             :  */
    2091             : static void
    2092       17654 : InvalidateConstraintCacheCallBack(Datum arg, int cacheid, uint32 hashvalue)
    2093             : {
    2094             :     dlist_mutable_iter iter;
    2095             : 
    2096             :     Assert(ri_constraint_cache != NULL);
    2097             : 
    2098             :     /*
    2099             :      * If the list of currently valid entries gets excessively large, we mark
    2100             :      * them all invalid so we can empty the list.  This arrangement avoids
    2101             :      * O(N^2) behavior in situations where a session touches many foreign keys
    2102             :      * and also does many ALTER TABLEs, such as a restore from pg_dump.
    2103             :      */
    2104       17654 :     if (ri_constraint_cache_valid_count > 1000)
    2105           0 :         hashvalue = 0;          /* pretend it's a cache reset */
    2106             : 
    2107       50028 :     dlist_foreach_modify(iter, &ri_constraint_cache_valid_list)
    2108             :     {
    2109       32374 :         RI_ConstraintInfo *riinfo = dlist_container(RI_ConstraintInfo,
    2110             :                                                     valid_link, iter.cur);
    2111             : 
    2112       32374 :         if (hashvalue == 0 || riinfo->oidHashValue == hashvalue)
    2113             :         {
    2114        1552 :             riinfo->valid = false;
    2115             :             /* Remove invalidated entries from the list, too */
    2116        1552 :             dlist_delete(iter.cur);
    2117        1552 :             ri_constraint_cache_valid_count--;
    2118             :         }
    2119             :     }
    2120       17654 : }
    2121             : 
    2122             : 
    2123             : /*
    2124             :  * Prepare execution plan for a query to enforce an RI restriction
    2125             :  *
    2126             :  * If cache_plan is true, the plan is saved into our plan hashtable
    2127             :  * so that we don't need to plan it again.
    2128             :  */
    2129             : static SPIPlanPtr
    2130        2152 : ri_PlanCheck(const char *querystr, int nargs, Oid *argtypes,
    2131             :              RI_QueryKey *qkey, Relation fk_rel, Relation pk_rel,
    2132             :              bool cache_plan)
    2133             : {
    2134             :     SPIPlanPtr  qplan;
    2135             :     Relation    query_rel;
    2136             :     Oid         save_userid;
    2137             :     int         save_sec_context;
    2138             : 
    2139             :     /*
    2140             :      * Use the query type code to determine whether the query is run against
    2141             :      * the PK or FK table; we'll do the check as that table's owner
    2142             :      */
    2143        2152 :     if (qkey->constr_queryno <= RI_PLAN_LAST_ON_PK)
    2144        1790 :         query_rel = pk_rel;
    2145             :     else
    2146         362 :         query_rel = fk_rel;
    2147             : 
    2148             :     /* Switch to proper UID to perform check as */
    2149        2152 :     GetUserIdAndSecContext(&save_userid, &save_sec_context);
    2150        2152 :     SetUserIdAndSecContext(RelationGetForm(query_rel)->relowner,
    2151             :                            save_sec_context | SECURITY_LOCAL_USERID_CHANGE |
    2152             :                            SECURITY_NOFORCE_RLS);
    2153             : 
    2154             :     /* Create the plan */
    2155        2152 :     qplan = SPI_prepare(querystr, nargs, argtypes);
    2156             : 
    2157        2152 :     if (qplan == NULL)
    2158           0 :         elog(ERROR, "SPI_prepare returned %s for %s", SPI_result_code_string(SPI_result), querystr);
    2159             : 
    2160             :     /* Restore UID and security context */
    2161        2152 :     SetUserIdAndSecContext(save_userid, save_sec_context);
    2162             : 
    2163             :     /* Save the plan if requested */
    2164        2152 :     if (cache_plan)
    2165             :     {
    2166        2152 :         SPI_keepplan(qplan);
    2167        2152 :         ri_HashPreparedPlan(qkey, qplan);
    2168             :     }
    2169             : 
    2170        2152 :     return qplan;
    2171             : }
    2172             : 
    2173             : /*
    2174             :  * Perform a query to enforce an RI restriction
    2175             :  */
    2176             : static bool
    2177        3666 : ri_PerformCheck(const RI_ConstraintInfo *riinfo,
    2178             :                 RI_QueryKey *qkey, SPIPlanPtr qplan,
    2179             :                 Relation fk_rel, Relation pk_rel,
    2180             :                 TupleTableSlot *oldslot, TupleTableSlot *newslot,
    2181             :                 bool detectNewRows, int expect_OK)
    2182             : {
    2183             :     Relation    query_rel,
    2184             :                 source_rel;
    2185             :     bool        source_is_pk;
    2186             :     Snapshot    test_snapshot;
    2187             :     Snapshot    crosscheck_snapshot;
    2188             :     int         limit;
    2189             :     int         spi_result;
    2190             :     Oid         save_userid;
    2191             :     int         save_sec_context;
    2192             :     Datum       vals[RI_MAX_NUMKEYS * 2];
    2193             :     char        nulls[RI_MAX_NUMKEYS * 2];
    2194             : 
    2195             :     /*
    2196             :      * Use the query type code to determine whether the query is run against
    2197             :      * the PK or FK table; we'll do the check as that table's owner
    2198             :      */
    2199        3666 :     if (qkey->constr_queryno <= RI_PLAN_LAST_ON_PK)
    2200        2946 :         query_rel = pk_rel;
    2201             :     else
    2202         720 :         query_rel = fk_rel;
    2203             : 
    2204             :     /*
    2205             :      * The values for the query are taken from the table on which the trigger
    2206             :      * is called - it is normally the other one with respect to query_rel. An
    2207             :      * exception is ri_Check_Pk_Match(), which uses the PK table for both (and
    2208             :      * sets queryno to RI_PLAN_CHECK_LOOKUPPK_FROM_PK).  We might eventually
    2209             :      * need some less klugy way to determine this.
    2210             :      */
    2211        3666 :     if (qkey->constr_queryno == RI_PLAN_CHECK_LOOKUPPK)
    2212             :     {
    2213        2514 :         source_rel = fk_rel;
    2214        2514 :         source_is_pk = false;
    2215             :     }
    2216             :     else
    2217             :     {
    2218        1152 :         source_rel = pk_rel;
    2219        1152 :         source_is_pk = true;
    2220             :     }
    2221             : 
    2222             :     /* Extract the parameters to be passed into the query */
    2223        3666 :     if (newslot)
    2224             :     {
    2225        2570 :         ri_ExtractValues(source_rel, newslot, riinfo, source_is_pk,
    2226             :                          vals, nulls);
    2227        2570 :         if (oldslot)
    2228         112 :             ri_ExtractValues(source_rel, oldslot, riinfo, source_is_pk,
    2229         112 :                              vals + riinfo->nkeys, nulls + riinfo->nkeys);
    2230             :     }
    2231             :     else
    2232             :     {
    2233        1096 :         ri_ExtractValues(source_rel, oldslot, riinfo, source_is_pk,
    2234             :                          vals, nulls);
    2235             :     }
    2236             : 
    2237             :     /*
    2238             :      * In READ COMMITTED mode, we just need to use an up-to-date regular
    2239             :      * snapshot, and we will see all rows that could be interesting. But in
    2240             :      * transaction-snapshot mode, we can't change the transaction snapshot. If
    2241             :      * the caller passes detectNewRows == false then it's okay to do the query
    2242             :      * with the transaction snapshot; otherwise we use a current snapshot, and
    2243             :      * tell the executor to error out if it finds any rows under the current
    2244             :      * snapshot that wouldn't be visible per the transaction snapshot.  Note
    2245             :      * that SPI_execute_snapshot will register the snapshots, so we don't need
    2246             :      * to bother here.
    2247             :      */
    2248        3666 :     if (IsolationUsesXactSnapshot() && detectNewRows)
    2249             :     {
    2250           0 :         CommandCounterIncrement();  /* be sure all my own work is visible */
    2251           0 :         test_snapshot = GetLatestSnapshot();
    2252           0 :         crosscheck_snapshot = GetTransactionSnapshot();
    2253             :     }
    2254             :     else
    2255             :     {
    2256             :         /* the default SPI behavior is okay */
    2257        3666 :         test_snapshot = InvalidSnapshot;
    2258        3666 :         crosscheck_snapshot = InvalidSnapshot;
    2259             :     }
    2260             : 
    2261             :     /*
    2262             :      * If this is a select query (e.g., for a 'no action' or 'restrict'
    2263             :      * trigger), we only need to see if there is a single row in the table,
    2264             :      * matching the key.  Otherwise, limit = 0 - because we want the query to
    2265             :      * affect ALL the matching rows.
    2266             :      */
    2267        3666 :     limit = (expect_OK == SPI_OK_SELECT) ? 1 : 0;
    2268             : 
    2269             :     /* Switch to proper UID to perform check as */
    2270        3666 :     GetUserIdAndSecContext(&save_userid, &save_sec_context);
    2271        3666 :     SetUserIdAndSecContext(RelationGetForm(query_rel)->relowner,
    2272             :                            save_sec_context | SECURITY_LOCAL_USERID_CHANGE |
    2273             :                            SECURITY_NOFORCE_RLS);
    2274             : 
    2275             :     /* Finally we can run the query. */
    2276        3666 :     spi_result = SPI_execute_snapshot(qplan,
    2277             :                                       vals, nulls,
    2278             :                                       test_snapshot, crosscheck_snapshot,
    2279             :                                       false, false, limit);
    2280             : 
    2281             :     /* Restore UID and security context */
    2282        3656 :     SetUserIdAndSecContext(save_userid, save_sec_context);
    2283             : 
    2284             :     /* Check result */
    2285        3656 :     if (spi_result < 0)
    2286           0 :         elog(ERROR, "SPI_execute_snapshot returned %s", SPI_result_code_string(spi_result));
    2287             : 
    2288        3656 :     if (expect_OK >= 0 && spi_result != expect_OK)
    2289           0 :         ereport(ERROR,
    2290             :                 (errcode(ERRCODE_INTERNAL_ERROR),
    2291             :                  errmsg("referential integrity query on \"%s\" from constraint \"%s\" on \"%s\" gave unexpected result",
    2292             :                         RelationGetRelationName(pk_rel),
    2293             :                         NameStr(riinfo->conname),
    2294             :                         RelationGetRelationName(fk_rel)),
    2295             :                  errhint("This is most likely due to a rule having rewritten the query.")));
    2296             : 
    2297             :     /* XXX wouldn't it be clearer to do this part at the caller? */
    2298        3656 :     if (qkey->constr_queryno != RI_PLAN_CHECK_LOOKUPPK_FROM_PK &&
    2299        2948 :         expect_OK == SPI_OK_SELECT &&
    2300        2948 :         (SPI_processed == 0) == (qkey->constr_queryno == RI_PLAN_CHECK_LOOKUPPK))
    2301         464 :         ri_ReportViolation(riinfo,
    2302             :                            pk_rel, fk_rel,
    2303             :                            newslot ? newslot : oldslot,
    2304             :                            NULL,
    2305             :                            qkey->constr_queryno, false);
    2306             : 
    2307        3192 :     return SPI_processed != 0;
    2308             : }
    2309             : 
    2310             : /*
    2311             :  * Extract fields from a tuple into Datum/nulls arrays
    2312             :  */
    2313             : static void
    2314        3722 : ri_ExtractValues(Relation rel, TupleTableSlot *slot,
    2315             :                  const RI_ConstraintInfo *riinfo, bool rel_is_pk,
    2316             :                  Datum *vals, char *nulls)
    2317             : {
    2318             :     const int16 *attnums;
    2319             :     bool        isnull;
    2320             : 
    2321        3722 :     if (rel_is_pk)
    2322        1208 :         attnums = riinfo->pk_attnums;
    2323             :     else
    2324        2514 :         attnums = riinfo->fk_attnums;
    2325             : 
    2326        8404 :     for (int i = 0; i < riinfo->nkeys; i++)
    2327             :     {
    2328        4682 :         vals[i] = slot_getattr(slot, attnums[i], &isnull);
    2329        4682 :         nulls[i] = isnull ? 'n' : ' ';
    2330             :     }
    2331        3722 : }
    2332             : 
    2333             : /*
    2334             :  * Produce an error report
    2335             :  *
    2336             :  * If the failed constraint was on insert/update to the FK table,
    2337             :  * we want the key names and values extracted from there, and the error
    2338             :  * message to look like 'key blah is not present in PK'.
    2339             :  * Otherwise, the attr names and values come from the PK table and the
    2340             :  * message looks like 'key blah is still referenced from FK'.
    2341             :  */
    2342             : static void
    2343         518 : ri_ReportViolation(const RI_ConstraintInfo *riinfo,
    2344             :                    Relation pk_rel, Relation fk_rel,
    2345             :                    TupleTableSlot *violatorslot, TupleDesc tupdesc,
    2346             :                    int queryno, bool partgone)
    2347             : {
    2348             :     StringInfoData key_names;
    2349             :     StringInfoData key_values;
    2350             :     bool        onfk;
    2351             :     const int16 *attnums;
    2352             :     Oid         rel_oid;
    2353             :     AclResult   aclresult;
    2354         518 :     bool        has_perm = true;
    2355             : 
    2356             :     /*
    2357             :      * Determine which relation to complain about.  If tupdesc wasn't passed
    2358             :      * by caller, assume the violator tuple came from there.
    2359             :      */
    2360         518 :     onfk = (queryno == RI_PLAN_CHECK_LOOKUPPK);
    2361         518 :     if (onfk)
    2362             :     {
    2363         296 :         attnums = riinfo->fk_attnums;
    2364         296 :         rel_oid = fk_rel->rd_id;
    2365         296 :         if (tupdesc == NULL)
    2366         262 :             tupdesc = fk_rel->rd_att;
    2367             :     }
    2368             :     else
    2369             :     {
    2370         222 :         attnums = riinfo->pk_attnums;
    2371         222 :         rel_oid = pk_rel->rd_id;
    2372         222 :         if (tupdesc == NULL)
    2373         202 :             tupdesc = pk_rel->rd_att;
    2374             :     }
    2375             : 
    2376             :     /*
    2377             :      * Check permissions- if the user does not have access to view the data in
    2378             :      * any of the key columns then we don't include the errdetail() below.
    2379             :      *
    2380             :      * Check if RLS is enabled on the relation first.  If so, we don't return
    2381             :      * any specifics to avoid leaking data.
    2382             :      *
    2383             :      * Check table-level permissions next and, failing that, column-level
    2384             :      * privileges.
    2385             :      *
    2386             :      * When a partition at the referenced side is being detached/dropped, we
    2387             :      * needn't check, since the user must be the table owner anyway.
    2388             :      */
    2389         518 :     if (partgone)
    2390          20 :         has_perm = true;
    2391         498 :     else if (check_enable_rls(rel_oid, InvalidOid, true) != RLS_ENABLED)
    2392             :     {
    2393         494 :         aclresult = pg_class_aclcheck(rel_oid, GetUserId(), ACL_SELECT);
    2394         494 :         if (aclresult != ACLCHECK_OK)
    2395             :         {
    2396             :             /* Try for column-level permissions */
    2397           0 :             for (int idx = 0; idx < riinfo->nkeys; idx++)
    2398             :             {
    2399           0 :                 aclresult = pg_attribute_aclcheck(rel_oid, attnums[idx],
    2400             :                                                   GetUserId(),
    2401             :                                                   ACL_SELECT);
    2402             : 
    2403             :                 /* No access to the key */
    2404           0 :                 if (aclresult != ACLCHECK_OK)
    2405             :                 {
    2406           0 :                     has_perm = false;
    2407           0 :                     break;
    2408             :                 }
    2409             :             }
    2410             :         }
    2411             :     }
    2412             :     else
    2413           4 :         has_perm = false;
    2414             : 
    2415         518 :     if (has_perm)
    2416             :     {
    2417             :         /* Get printable versions of the keys involved */
    2418         514 :         initStringInfo(&key_names);
    2419         514 :         initStringInfo(&key_values);
    2420        1224 :         for (int idx = 0; idx < riinfo->nkeys; idx++)
    2421             :         {
    2422         710 :             int         fnum = attnums[idx];
    2423         710 :             Form_pg_attribute att = TupleDescAttr(tupdesc, fnum - 1);
    2424             :             char       *name,
    2425             :                        *val;
    2426             :             Datum       datum;
    2427             :             bool        isnull;
    2428             : 
    2429         710 :             name = NameStr(att->attname);
    2430             : 
    2431         710 :             datum = slot_getattr(violatorslot, fnum, &isnull);
    2432         710 :             if (!isnull)
    2433             :             {
    2434             :                 Oid         foutoid;
    2435             :                 bool        typisvarlena;
    2436             : 
    2437         710 :                 getTypeOutputInfo(att->atttypid, &foutoid, &typisvarlena);
    2438         710 :                 val = OidOutputFunctionCall(foutoid, datum);
    2439             :             }
    2440             :             else
    2441           0 :                 val = "null";
    2442             : 
    2443         710 :             if (idx > 0)
    2444             :             {
    2445         196 :                 appendStringInfoString(&key_names, ", ");
    2446         196 :                 appendStringInfoString(&key_values, ", ");
    2447             :             }
    2448         710 :             appendStringInfoString(&key_names, name);
    2449         710 :             appendStringInfoString(&key_values, val);
    2450             :         }
    2451             :     }
    2452             : 
    2453         518 :     if (partgone)
    2454          20 :         ereport(ERROR,
    2455             :                 (errcode(ERRCODE_FOREIGN_KEY_VIOLATION),
    2456             :                  errmsg("removing partition \"%s\" violates foreign key constraint \"%s\"",
    2457             :                         RelationGetRelationName(pk_rel),
    2458             :                         NameStr(riinfo->conname)),
    2459             :                  errdetail("Key (%s)=(%s) still referenced from table \"%s\".",
    2460             :                            key_names.data, key_values.data,
    2461             :                            RelationGetRelationName(fk_rel))));
    2462         498 :     else if (onfk)
    2463         296 :         ereport(ERROR,
    2464             :                 (errcode(ERRCODE_FOREIGN_KEY_VIOLATION),
    2465             :                  errmsg("insert or update on table \"%s\" violates foreign key constraint \"%s\"",
    2466             :                         RelationGetRelationName(fk_rel),
    2467             :                         NameStr(riinfo->conname)),
    2468             :                  has_perm ?
    2469             :                  errdetail("Key (%s)=(%s) is not present in table \"%s\".",
    2470             :                            key_names.data, key_values.data,
    2471             :                            RelationGetRelationName(pk_rel)) :
    2472             :                  errdetail("Key is not present in table \"%s\".",
    2473             :                            RelationGetRelationName(pk_rel)),
    2474             :                  errtableconstraint(fk_rel, NameStr(riinfo->conname))));
    2475             :     else
    2476         202 :         ereport(ERROR,
    2477             :                 (errcode(ERRCODE_FOREIGN_KEY_VIOLATION),
    2478             :                  errmsg("update or delete on table \"%s\" violates foreign key constraint \"%s\" on table \"%s\"",
    2479             :                         RelationGetRelationName(pk_rel),
    2480             :                         NameStr(riinfo->conname),
    2481             :                         RelationGetRelationName(fk_rel)),
    2482             :                  has_perm ?
    2483             :                  errdetail("Key (%s)=(%s) is still referenced from table \"%s\".",
    2484             :                            key_names.data, key_values.data,
    2485             :                            RelationGetRelationName(fk_rel)) :
    2486             :                  errdetail("Key is still referenced from table \"%s\".",
    2487             :                            RelationGetRelationName(fk_rel)),
    2488             :                  errtableconstraint(fk_rel, NameStr(riinfo->conname))));
    2489             : }
    2490             : 
    2491             : 
    2492             : /*
    2493             :  * ri_NullCheck -
    2494             :  *
    2495             :  * Determine the NULL state of all key values in a tuple
    2496             :  *
    2497             :  * Returns one of RI_KEYS_ALL_NULL, RI_KEYS_NONE_NULL or RI_KEYS_SOME_NULL.
    2498             :  */
    2499             : static int
    2500        4564 : ri_NullCheck(TupleDesc tupDesc,
    2501             :              TupleTableSlot *slot,
    2502             :              const RI_ConstraintInfo *riinfo, bool rel_is_pk)
    2503             : {
    2504             :     const int16 *attnums;
    2505        4564 :     bool        allnull = true;
    2506        4564 :     bool        nonenull = true;
    2507             : 
    2508        4564 :     if (rel_is_pk)
    2509        1172 :         attnums = riinfo->pk_attnums;
    2510             :     else
    2511        3392 :         attnums = riinfo->fk_attnums;
    2512             : 
    2513       10136 :     for (int i = 0; i < riinfo->nkeys; i++)
    2514             :     {
    2515        5572 :         if (slot_attisnull(slot, attnums[i]))
    2516         336 :             nonenull = false;
    2517             :         else
    2518        5236 :             allnull = false;
    2519             :     }
    2520             : 
    2521        4564 :     if (allnull)
    2522         176 :         return RI_KEYS_ALL_NULL;
    2523             : 
    2524        4388 :     if (nonenull)
    2525        4276 :         return RI_KEYS_NONE_NULL;
    2526             : 
    2527         112 :     return RI_KEYS_SOME_NULL;
    2528             : }
    2529             : 
    2530             : 
    2531             : /*
    2532             :  * ri_InitHashTables -
    2533             :  *
    2534             :  * Initialize our internal hash tables.
    2535             :  */
    2536             : static void
    2537         344 : ri_InitHashTables(void)
    2538             : {
    2539             :     HASHCTL     ctl;
    2540             : 
    2541         344 :     memset(&ctl, 0, sizeof(ctl));
    2542         344 :     ctl.keysize = sizeof(Oid);
    2543         344 :     ctl.entrysize = sizeof(RI_ConstraintInfo);
    2544         344 :     ri_constraint_cache = hash_create("RI constraint cache",
    2545             :                                       RI_INIT_CONSTRAINTHASHSIZE,
    2546             :                                       &ctl, HASH_ELEM | HASH_BLOBS);
    2547             : 
    2548             :     /* Arrange to flush cache on pg_constraint changes */
    2549         344 :     CacheRegisterSyscacheCallback(CONSTROID,
    2550             :                                   InvalidateConstraintCacheCallBack,
    2551             :                                   (Datum) 0);
    2552             : 
    2553         344 :     memset(&ctl, 0, sizeof(ctl));
    2554         344 :     ctl.keysize = sizeof(RI_QueryKey);
    2555         344 :     ctl.entrysize = sizeof(RI_QueryHashEntry);
    2556         344 :     ri_query_cache = hash_create("RI query cache",
    2557             :                                  RI_INIT_QUERYHASHSIZE,
    2558             :                                  &ctl, HASH_ELEM | HASH_BLOBS);
    2559             : 
    2560         344 :     memset(&ctl, 0, sizeof(ctl));
    2561         344 :     ctl.keysize = sizeof(RI_CompareKey);
    2562         344 :     ctl.entrysize = sizeof(RI_CompareHashEntry);
    2563         344 :     ri_compare_cache = hash_create("RI compare cache",
    2564             :                                    RI_INIT_QUERYHASHSIZE,
    2565             :                                    &ctl, HASH_ELEM | HASH_BLOBS);
    2566         344 : }
    2567             : 
    2568             : 
    2569             : /*
    2570             :  * ri_FetchPreparedPlan -
    2571             :  *
    2572             :  * Lookup for a query key in our private hash table of prepared
    2573             :  * and saved SPI execution plans. Return the plan if found or NULL.
    2574             :  */
    2575             : static SPIPlanPtr
    2576        3666 : ri_FetchPreparedPlan(RI_QueryKey *key)
    2577             : {
    2578             :     RI_QueryHashEntry *entry;
    2579             :     SPIPlanPtr  plan;
    2580             : 
    2581             :     /*
    2582             :      * On the first call initialize the hashtable
    2583             :      */
    2584        3666 :     if (!ri_query_cache)
    2585           0 :         ri_InitHashTables();
    2586             : 
    2587             :     /*
    2588             :      * Lookup for the key
    2589             :      */
    2590        3666 :     entry = (RI_QueryHashEntry *) hash_search(ri_query_cache,
    2591             :                                               (void *) key,
    2592             :                                               HASH_FIND, NULL);
    2593        3666 :     if (entry == NULL)
    2594        1990 :         return NULL;
    2595             : 
    2596             :     /*
    2597             :      * Check whether the plan is still valid.  If it isn't, we don't want to
    2598             :      * simply rely on plancache.c to regenerate it; rather we should start
    2599             :      * from scratch and rebuild the query text too.  This is to cover cases
    2600             :      * such as table/column renames.  We depend on the plancache machinery to
    2601             :      * detect possible invalidations, though.
    2602             :      *
    2603             :      * CAUTION: this check is only trustworthy if the caller has already
    2604             :      * locked both FK and PK rels.
    2605             :      */
    2606        1676 :     plan = entry->plan;
    2607        1676 :     if (plan && SPI_plan_is_valid(plan))
    2608        1514 :         return plan;
    2609             : 
    2610             :     /*
    2611             :      * Otherwise we might as well flush the cached plan now, to free a little
    2612             :      * memory space before we make a new one.
    2613             :      */
    2614         162 :     entry->plan = NULL;
    2615         162 :     if (plan)
    2616         162 :         SPI_freeplan(plan);
    2617             : 
    2618         162 :     return NULL;
    2619             : }
    2620             : 
    2621             : 
    2622             : /*
    2623             :  * ri_HashPreparedPlan -
    2624             :  *
    2625             :  * Add another plan to our private SPI query plan hashtable.
    2626             :  */
    2627             : static void
    2628        2152 : ri_HashPreparedPlan(RI_QueryKey *key, SPIPlanPtr plan)
    2629             : {
    2630             :     RI_QueryHashEntry *entry;
    2631             :     bool        found;
    2632             : 
    2633             :     /*
    2634             :      * On the first call initialize the hashtable
    2635             :      */
    2636        2152 :     if (!ri_query_cache)
    2637           0 :         ri_InitHashTables();
    2638             : 
    2639             :     /*
    2640             :      * Add the new plan.  We might be overwriting an entry previously found
    2641             :      * invalid by ri_FetchPreparedPlan.
    2642             :      */
    2643        2152 :     entry = (RI_QueryHashEntry *) hash_search(ri_query_cache,
    2644             :                                               (void *) key,
    2645             :                                               HASH_ENTER, &found);
    2646             :     Assert(!found || entry->plan == NULL);
    2647        2152 :     entry->plan = plan;
    2648        2152 : }
    2649             : 
    2650             : 
    2651             : /*
    2652             :  * ri_KeysEqual -
    2653             :  *
    2654             :  * Check if all key values in OLD and NEW are equal.
    2655             :  *
    2656             :  * Note: at some point we might wish to redefine this as checking for
    2657             :  * "IS NOT DISTINCT" rather than "=", that is, allow two nulls to be
    2658             :  * considered equal.  Currently there is no need since all callers have
    2659             :  * previously found at least one of the rows to contain no nulls.
    2660             :  */
    2661             : static bool
    2662        1240 : ri_KeysEqual(Relation rel, TupleTableSlot *oldslot, TupleTableSlot *newslot,
    2663             :              const RI_ConstraintInfo *riinfo, bool rel_is_pk)
    2664             : {
    2665             :     const int16 *attnums;
    2666             : 
    2667        1240 :     if (rel_is_pk)
    2668         748 :         attnums = riinfo->pk_attnums;
    2669             :     else
    2670         492 :         attnums = riinfo->fk_attnums;
    2671             : 
    2672             :     /* XXX: could be worthwhile to fetch all necessary attrs at once */
    2673        4320 :     for (int i = 0; i < riinfo->nkeys; i++)
    2674             :     {
    2675             :         Datum       oldvalue;
    2676             :         Datum       newvalue;
    2677             :         bool        isnull;
    2678             : 
    2679             :         /*
    2680             :          * Get one attribute's oldvalue. If it is NULL - they're not equal.
    2681             :          */
    2682        1316 :         oldvalue = slot_getattr(oldslot, attnums[i], &isnull);
    2683        1316 :         if (isnull)
    2684         420 :             return false;
    2685             : 
    2686             :         /*
    2687             :          * Get one attribute's newvalue. If it is NULL - they're not equal.
    2688             :          */
    2689        1292 :         newvalue = slot_getattr(newslot, attnums[i], &isnull);
    2690        1292 :         if (isnull)
    2691           0 :             return false;
    2692             : 
    2693        1292 :         if (rel_is_pk)
    2694             :         {
    2695             :             /*
    2696             :              * If we are looking at the PK table, then do a bytewise
    2697             :              * comparison.  We must propagate PK changes if the value is
    2698             :              * changed to one that "looks" different but would compare as
    2699             :              * equal using the equality operator.  This only makes a
    2700             :              * difference for ON UPDATE CASCADE, but for consistency we treat
    2701             :              * all changes to the PK the same.
    2702             :              */
    2703         804 :             Form_pg_attribute att = TupleDescAttr(oldslot->tts_tupleDescriptor, attnums[i] - 1);
    2704             : 
    2705         804 :             if (!datum_image_eq(oldvalue, newvalue, att->attbyval, att->attlen))
    2706         276 :                 return false;
    2707             :         }
    2708             :         else
    2709             :         {
    2710             :             /*
    2711             :              * For the FK table, compare with the appropriate equality
    2712             :              * operator.  Changes that compare equal will still satisfy the
    2713             :              * constraint after the update.
    2714             :              */
    2715         488 :             if (!ri_AttributesEqual(riinfo->ff_eq_oprs[i], RIAttType(rel, attnums[i]),
    2716             :                                     oldvalue, newvalue))
    2717          96 :                 return false;
    2718             :         }
    2719             :     }
    2720             : 
    2721         844 :     return true;
    2722             : }
    2723             : 
    2724             : 
    2725             : /*
    2726             :  * ri_AttributesEqual -
    2727             :  *
    2728             :  * Call the appropriate equality comparison operator for two values.
    2729             :  *
    2730             :  * NB: we have already checked that neither value is null.
    2731             :  */
    2732             : static bool
    2733         488 : ri_AttributesEqual(Oid eq_opr, Oid typeid,
    2734             :                    Datum oldvalue, Datum newvalue)
    2735             : {
    2736         488 :     RI_CompareHashEntry *entry = ri_HashCompareOp(eq_opr, typeid);
    2737             : 
    2738             :     /* Do we need to cast the values? */
    2739         488 :     if (OidIsValid(entry->cast_func_finfo.fn_oid))
    2740             :     {
    2741           8 :         oldvalue = FunctionCall3(&entry->cast_func_finfo,
    2742             :                                  oldvalue,
    2743             :                                  Int32GetDatum(-1), /* typmod */
    2744             :                                  BoolGetDatum(false));  /* implicit coercion */
    2745           8 :         newvalue = FunctionCall3(&entry->cast_func_finfo,
    2746             :                                  newvalue,
    2747             :                                  Int32GetDatum(-1), /* typmod */
    2748             :                                  BoolGetDatum(false));  /* implicit coercion */
    2749             :     }
    2750             : 
    2751             :     /*
    2752             :      * Apply the comparison operator.
    2753             :      *
    2754             :      * Note: This function is part of a call stack that determines whether an
    2755             :      * update to a row is significant enough that it needs checking or action
    2756             :      * on the other side of a foreign-key constraint.  Therefore, the
    2757             :      * comparison here would need to be done with the collation of the *other*
    2758             :      * table.  For simplicity (e.g., we might not even have the other table
    2759             :      * open), we'll just use the default collation here, which could lead to
    2760             :      * some false negatives.  All this would break if we ever allow
    2761             :      * database-wide collations to be nondeterministic.
    2762             :      */
    2763         488 :     return DatumGetBool(FunctionCall2Coll(&entry->eq_opr_finfo,
    2764             :                                           DEFAULT_COLLATION_OID,
    2765             :                                           oldvalue, newvalue));
    2766             : }
    2767             : 
    2768             : /*
    2769             :  * ri_HashCompareOp -
    2770             :  *
    2771             :  * See if we know how to compare two values, and create a new hash entry
    2772             :  * if not.
    2773             :  */
    2774             : static RI_CompareHashEntry *
    2775         488 : ri_HashCompareOp(Oid eq_opr, Oid typeid)
    2776             : {
    2777             :     RI_CompareKey key;
    2778             :     RI_CompareHashEntry *entry;
    2779             :     bool        found;
    2780             : 
    2781             :     /*
    2782             :      * On the first call initialize the hashtable
    2783             :      */
    2784         488 :     if (!ri_compare_cache)
    2785           0 :         ri_InitHashTables();
    2786             : 
    2787             :     /*
    2788             :      * Find or create a hash entry.  Note we're assuming RI_CompareKey
    2789             :      * contains no struct padding.
    2790             :      */
    2791         488 :     key.eq_opr = eq_opr;
    2792         488 :     key.typeid = typeid;
    2793         488 :     entry = (RI_CompareHashEntry *) hash_search(ri_compare_cache,
    2794             :                                                 (void *) &key,
    2795             :                                                 HASH_ENTER, &found);
    2796         488 :     if (!found)
    2797         248 :         entry->valid = false;
    2798             : 
    2799             :     /*
    2800             :      * If not already initialized, do so.  Since we'll keep this hash entry
    2801             :      * for the life of the backend, put any subsidiary info for the function
    2802             :      * cache structs into TopMemoryContext.
    2803             :      */
    2804         488 :     if (!entry->valid)
    2805             :     {
    2806             :         Oid         lefttype,
    2807             :                     righttype,
    2808             :                     castfunc;
    2809             :         CoercionPathType pathtype;
    2810             : 
    2811             :         /* We always need to know how to call the equality operator */
    2812         248 :         fmgr_info_cxt(get_opcode(eq_opr), &entry->eq_opr_finfo,
    2813             :                       TopMemoryContext);
    2814             : 
    2815             :         /*
    2816             :          * If we chose to use a cast from FK to PK type, we may have to apply
    2817             :          * the cast function to get to the operator's input type.
    2818             :          *
    2819             :          * XXX eventually it would be good to support array-coercion cases
    2820             :          * here and in ri_AttributesEqual().  At the moment there is no point
    2821             :          * because cases involving nonidentical array types will be rejected
    2822             :          * at constraint creation time.
    2823             :          *
    2824             :          * XXX perhaps also consider supporting CoerceViaIO?  No need at the
    2825             :          * moment since that will never be generated for implicit coercions.
    2826             :          */
    2827         248 :         op_input_types(eq_opr, &lefttype, &righttype);
    2828             :         Assert(lefttype == righttype);
    2829         248 :         if (typeid == lefttype)
    2830         244 :             castfunc = InvalidOid;  /* simplest case */
    2831             :         else
    2832             :         {
    2833           4 :             pathtype = find_coercion_pathway(lefttype, typeid,
    2834             :                                              COERCION_IMPLICIT,
    2835             :                                              &castfunc);
    2836           4 :             if (pathtype != COERCION_PATH_FUNC &&
    2837             :                 pathtype != COERCION_PATH_RELABELTYPE)
    2838             :             {
    2839             :                 /*
    2840             :                  * The declared input type of the eq_opr might be a
    2841             :                  * polymorphic type such as ANYARRAY or ANYENUM, or other
    2842             :                  * special cases such as RECORD; find_coercion_pathway
    2843             :                  * currently doesn't subsume these special cases.
    2844             :                  */
    2845           0 :                 if (!IsBinaryCoercible(typeid, lefttype))
    2846           0 :                     elog(ERROR, "no conversion function from %s to %s",
    2847             :                          format_type_be(typeid),
    2848             :                          format_type_be(lefttype));
    2849             :             }
    2850             :         }
    2851         248 :         if (OidIsValid(castfunc))
    2852           4 :             fmgr_info_cxt(castfunc, &entry->cast_func_finfo,
    2853             :                           TopMemoryContext);
    2854             :         else
    2855         244 :             entry->cast_func_finfo.fn_oid = InvalidOid;
    2856         248 :         entry->valid = true;
    2857             :     }
    2858             : 
    2859         488 :     return entry;
    2860             : }
    2861             : 
    2862             : 
    2863             : /*
    2864             :  * Given a trigger function OID, determine whether it is an RI trigger,
    2865             :  * and if so whether it is attached to PK or FK relation.
    2866             :  */
    2867             : int
    2868        3388 : RI_FKey_trigger_type(Oid tgfoid)
    2869             : {
    2870        3388 :     switch (tgfoid)
    2871             :     {
    2872             :         case F_RI_FKEY_CASCADE_DEL:
    2873             :         case F_RI_FKEY_CASCADE_UPD:
    2874             :         case F_RI_FKEY_RESTRICT_DEL:
    2875             :         case F_RI_FKEY_RESTRICT_UPD:
    2876             :         case F_RI_FKEY_SETNULL_DEL:
    2877             :         case F_RI_FKEY_SETNULL_UPD:
    2878             :         case F_RI_FKEY_SETDEFAULT_DEL:
    2879             :         case F_RI_FKEY_SETDEFAULT_UPD:
    2880             :         case F_RI_FKEY_NOACTION_DEL:
    2881             :         case F_RI_FKEY_NOACTION_UPD:
    2882        1172 :             return RI_TRIGGER_PK;
    2883             : 
    2884             :         case F_RI_FKEY_CHECK_INS:
    2885             :         case F_RI_FKEY_CHECK_UPD:
    2886         678 :             return RI_TRIGGER_FK;
    2887             :     }
    2888             : 
    2889        1538 :     return RI_TRIGGER_NONE;
    2890             : }

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