LCOV - code coverage report
Current view: top level - src/backend/utils/adt - ri_triggers.c (source / functions) Hit Total Coverage
Test: PostgreSQL 15beta1 Lines: 758 830 91.3 %
Date: 2022-05-18 04:09:35 Functions: 42 42 100.0 %
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) 1996-2022, PostgreSQL Global Development Group
      18             :  *
      19             :  * src/backend/utils/adt/ri_triggers.c
      20             :  *
      21             :  *-------------------------------------------------------------------------
      22             :  */
      23             : 
      24             : #include "postgres.h"
      25             : 
      26             : #include "access/htup_details.h"
      27             : #include "access/sysattr.h"
      28             : #include "access/table.h"
      29             : #include "access/tableam.h"
      30             : #include "access/xact.h"
      31             : #include "catalog/pg_collation.h"
      32             : #include "catalog/pg_constraint.h"
      33             : #include "catalog/pg_operator.h"
      34             : #include "catalog/pg_type.h"
      35             : #include "commands/trigger.h"
      36             : #include "executor/executor.h"
      37             : #include "executor/spi.h"
      38             : #include "lib/ilist.h"
      39             : #include "miscadmin.h"
      40             : #include "parser/parse_coerce.h"
      41             : #include "parser/parse_relation.h"
      42             : #include "storage/bufmgr.h"
      43             : #include "utils/acl.h"
      44             : #include "utils/builtins.h"
      45             : #include "utils/datum.h"
      46             : #include "utils/fmgroids.h"
      47             : #include "utils/guc.h"
      48             : #include "utils/inval.h"
      49             : #include "utils/lsyscache.h"
      50             : #include "utils/memutils.h"
      51             : #include "utils/rel.h"
      52             : #include "utils/rls.h"
      53             : #include "utils/ruleutils.h"
      54             : #include "utils/snapmgr.h"
      55             : #include "utils/syscache.h"
      56             : 
      57             : /*
      58             :  * Local definitions
      59             :  */
      60             : 
      61             : #define RI_MAX_NUMKEYS                  INDEX_MAX_KEYS
      62             : 
      63             : #define RI_INIT_CONSTRAINTHASHSIZE      64
      64             : #define RI_INIT_QUERYHASHSIZE           (RI_INIT_CONSTRAINTHASHSIZE * 4)
      65             : 
      66             : #define RI_KEYS_ALL_NULL                0
      67             : #define RI_KEYS_SOME_NULL               1
      68             : #define RI_KEYS_NONE_NULL               2
      69             : 
      70             : /* RI query type codes */
      71             : /* these queries are executed against the PK (referenced) table: */
      72             : #define RI_PLAN_CHECK_LOOKUPPK          1
      73             : #define RI_PLAN_CHECK_LOOKUPPK_FROM_PK  2
      74             : #define RI_PLAN_LAST_ON_PK              RI_PLAN_CHECK_LOOKUPPK_FROM_PK
      75             : /* these queries are executed against the FK (referencing) table: */
      76             : #define RI_PLAN_CASCADE_ONDELETE        3
      77             : #define RI_PLAN_CASCADE_ONUPDATE        4
      78             : /* For RESTRICT, the same plan can be used for both ON DELETE and ON UPDATE triggers. */
      79             : #define RI_PLAN_RESTRICT                5
      80             : #define RI_PLAN_SETNULL_ONDELETE        6
      81             : #define RI_PLAN_SETNULL_ONUPDATE        7
      82             : #define RI_PLAN_SETDEFAULT_ONDELETE     8
      83             : #define RI_PLAN_SETDEFAULT_ONUPDATE     9
      84             : 
      85             : #define MAX_QUOTED_NAME_LEN  (NAMEDATALEN*2+3)
      86             : #define MAX_QUOTED_REL_NAME_LEN  (MAX_QUOTED_NAME_LEN*2)
      87             : 
      88             : #define RIAttName(rel, attnum)  NameStr(*attnumAttName(rel, attnum))
      89             : #define RIAttType(rel, attnum)  attnumTypeId(rel, attnum)
      90             : #define RIAttCollation(rel, attnum) attnumCollationId(rel, attnum)
      91             : 
      92             : #define RI_TRIGTYPE_INSERT 1
      93             : #define RI_TRIGTYPE_UPDATE 2
      94             : #define RI_TRIGTYPE_DELETE 3
      95             : 
      96             : 
      97             : /*
      98             :  * RI_ConstraintInfo
      99             :  *
     100             :  * Information extracted from an FK pg_constraint entry.  This is cached in
     101             :  * ri_constraint_cache.
     102             :  */
     103             : typedef struct RI_ConstraintInfo
     104             : {
     105             :     Oid         constraint_id;  /* OID of pg_constraint entry (hash key) */
     106             :     bool        valid;          /* successfully initialized? */
     107             :     Oid         constraint_root_id; /* OID of topmost ancestor constraint;
     108             :                                      * same as constraint_id if not inherited */
     109             :     uint32      oidHashValue;   /* hash value of constraint_id */
     110             :     uint32      rootHashValue;  /* hash value of constraint_root_id */
     111             :     NameData    conname;        /* name of the FK constraint */
     112             :     Oid         pk_relid;       /* referenced relation */
     113             :     Oid         fk_relid;       /* referencing relation */
     114             :     char        confupdtype;    /* foreign key's ON UPDATE action */
     115             :     char        confdeltype;    /* foreign key's ON DELETE action */
     116             :     int         ndelsetcols;    /* number of columns referenced in ON DELETE
     117             :                                  * SET clause */
     118             :     int16       confdelsetcols[RI_MAX_NUMKEYS]; /* attnums of cols to set on
     119             :                                                  * delete */
     120             :     char        confmatchtype;  /* foreign key's match type */
     121             :     int         nkeys;          /* number of key columns */
     122             :     int16       pk_attnums[RI_MAX_NUMKEYS]; /* attnums of referenced cols */
     123             :     int16       fk_attnums[RI_MAX_NUMKEYS]; /* attnums of referencing cols */
     124             :     Oid         pf_eq_oprs[RI_MAX_NUMKEYS]; /* equality operators (PK = FK) */
     125             :     Oid         pp_eq_oprs[RI_MAX_NUMKEYS]; /* equality operators (PK = PK) */
     126             :     Oid         ff_eq_oprs[RI_MAX_NUMKEYS]; /* equality operators (FK = FK) */
     127             :     dlist_node  valid_link;     /* Link in list of valid entries */
     128             : } RI_ConstraintInfo;
     129             : 
     130             : /*
     131             :  * RI_QueryKey
     132             :  *
     133             :  * The key identifying a prepared SPI plan in our query hashtable
     134             :  */
     135             : typedef struct RI_QueryKey
     136             : {
     137             :     Oid         constr_id;      /* OID of pg_constraint entry */
     138             :     int32       constr_queryno; /* query type ID, see RI_PLAN_XXX above */
     139             : } RI_QueryKey;
     140             : 
     141             : /*
     142             :  * RI_QueryHashEntry
     143             :  */
     144             : typedef struct RI_QueryHashEntry
     145             : {
     146             :     RI_QueryKey key;
     147             :     SPIPlanPtr  plan;
     148             : } RI_QueryHashEntry;
     149             : 
     150             : /*
     151             :  * RI_CompareKey
     152             :  *
     153             :  * The key identifying an entry showing how to compare two values
     154             :  */
     155             : typedef struct RI_CompareKey
     156             : {
     157             :     Oid         eq_opr;         /* the equality operator to apply */
     158             :     Oid         typeid;         /* the data type to apply it to */
     159             : } RI_CompareKey;
     160             : 
     161             : /*
     162             :  * RI_CompareHashEntry
     163             :  */
     164             : typedef struct RI_CompareHashEntry
     165             : {
     166             :     RI_CompareKey key;
     167             :     bool        valid;          /* successfully initialized? */
     168             :     FmgrInfo    eq_opr_finfo;   /* call info for equality fn */
     169             :     FmgrInfo    cast_func_finfo;    /* in case we must coerce input */
     170             : } RI_CompareHashEntry;
     171             : 
     172             : 
     173             : /*
     174             :  * Local data
     175             :  */
     176             : static HTAB *ri_constraint_cache = NULL;
     177             : static HTAB *ri_query_cache = NULL;
     178             : static HTAB *ri_compare_cache = NULL;
     179             : static dlist_head ri_constraint_cache_valid_list;
     180             : static int  ri_constraint_cache_valid_count = 0;
     181             : 
     182             : 
     183             : /*
     184             :  * Local function prototypes
     185             :  */
     186             : static bool ri_Check_Pk_Match(Relation pk_rel, Relation fk_rel,
     187             :                               TupleTableSlot *oldslot,
     188             :                               const RI_ConstraintInfo *riinfo);
     189             : static Datum ri_restrict(TriggerData *trigdata, bool is_no_action);
     190             : static Datum ri_set(TriggerData *trigdata, bool is_set_null, int tgkind);
     191             : static void quoteOneName(char *buffer, const char *name);
     192             : static void quoteRelationName(char *buffer, Relation rel);
     193             : static void ri_GenerateQual(StringInfo buf,
     194             :                             const char *sep,
     195             :                             const char *leftop, Oid leftoptype,
     196             :                             Oid opoid,
     197             :                             const char *rightop, Oid rightoptype);
     198             : static void ri_GenerateQualCollation(StringInfo buf, Oid collation);
     199             : static int  ri_NullCheck(TupleDesc tupdesc, TupleTableSlot *slot,
     200             :                          const RI_ConstraintInfo *riinfo, bool rel_is_pk);
     201             : static void ri_BuildQueryKey(RI_QueryKey *key,
     202             :                              const RI_ConstraintInfo *riinfo,
     203             :                              int32 constr_queryno);
     204             : static bool ri_KeysEqual(Relation rel, TupleTableSlot *oldslot, TupleTableSlot *newslot,
     205             :                          const RI_ConstraintInfo *riinfo, bool rel_is_pk);
     206             : static bool ri_AttributesEqual(Oid eq_opr, Oid typeid,
     207             :                                Datum oldvalue, Datum newvalue);
     208             : 
     209             : static void ri_InitHashTables(void);
     210             : static void InvalidateConstraintCacheCallBack(Datum arg, int cacheid, uint32 hashvalue);
     211             : static SPIPlanPtr ri_FetchPreparedPlan(RI_QueryKey *key);
     212             : static void ri_HashPreparedPlan(RI_QueryKey *key, SPIPlanPtr plan);
     213             : static RI_CompareHashEntry *ri_HashCompareOp(Oid eq_opr, Oid typeid);
     214             : 
     215             : static void ri_CheckTrigger(FunctionCallInfo fcinfo, const char *funcname,
     216             :                             int tgkind);
     217             : static const RI_ConstraintInfo *ri_FetchConstraintInfo(Trigger *trigger,
     218             :                                                        Relation trig_rel, bool rel_is_pk);
     219             : static const RI_ConstraintInfo *ri_LoadConstraintInfo(Oid constraintOid);
     220             : static Oid  get_ri_constraint_root(Oid constrOid);
     221             : static SPIPlanPtr ri_PlanCheck(const char *querystr, int nargs, Oid *argtypes,
     222             :                                RI_QueryKey *qkey, Relation fk_rel, Relation pk_rel);
     223             : static bool ri_PerformCheck(const RI_ConstraintInfo *riinfo,
     224             :                             RI_QueryKey *qkey, SPIPlanPtr qplan,
     225             :                             Relation fk_rel, Relation pk_rel,
     226             :                             TupleTableSlot *oldslot, TupleTableSlot *newslot,
     227             :                             bool detectNewRows, int expect_OK);
     228             : static void ri_ExtractValues(Relation rel, TupleTableSlot *slot,
     229             :                              const RI_ConstraintInfo *riinfo, bool rel_is_pk,
     230             :                              Datum *vals, char *nulls);
     231             : static void ri_ReportViolation(const RI_ConstraintInfo *riinfo,
     232             :                                Relation pk_rel, Relation fk_rel,
     233             :                                TupleTableSlot *violatorslot, TupleDesc tupdesc,
     234             :                                int queryno, bool partgone) pg_attribute_noreturn();
     235             : 
     236             : 
     237             : /*
     238             :  * RI_FKey_check -
     239             :  *
     240             :  * Check foreign key existence (combined for INSERT and UPDATE).
     241             :  */
     242             : static Datum
     243        4044 : RI_FKey_check(TriggerData *trigdata)
     244             : {
     245             :     const RI_ConstraintInfo *riinfo;
     246             :     Relation    fk_rel;
     247             :     Relation    pk_rel;
     248             :     TupleTableSlot *newslot;
     249             :     RI_QueryKey qkey;
     250             :     SPIPlanPtr  qplan;
     251             : 
     252        4044 :     riinfo = ri_FetchConstraintInfo(trigdata->tg_trigger,
     253             :                                     trigdata->tg_relation, false);
     254             : 
     255        4044 :     if (TRIGGER_FIRED_BY_UPDATE(trigdata->tg_event))
     256         412 :         newslot = trigdata->tg_newslot;
     257             :     else
     258        3632 :         newslot = trigdata->tg_trigslot;
     259             : 
     260             :     /*
     261             :      * We should not even consider checking the row if it is no longer valid,
     262             :      * since it was either deleted (so the deferred check should be skipped)
     263             :      * or updated (in which case only the latest version of the row should be
     264             :      * checked).  Test its liveness according to SnapshotSelf.  We need pin
     265             :      * and lock on the buffer to call HeapTupleSatisfiesVisibility.  Caller
     266             :      * should be holding pin, but not lock.
     267             :      */
     268        4044 :     if (!table_tuple_satisfies_snapshot(trigdata->tg_relation, newslot, SnapshotSelf))
     269          60 :         return PointerGetDatum(NULL);
     270             : 
     271             :     /*
     272             :      * Get the relation descriptors of the FK and PK tables.
     273             :      *
     274             :      * pk_rel is opened in RowShareLock mode since that's what our eventual
     275             :      * SELECT FOR KEY SHARE will get on it.
     276             :      */
     277        3984 :     fk_rel = trigdata->tg_relation;
     278        3984 :     pk_rel = table_open(riinfo->pk_relid, RowShareLock);
     279             : 
     280        3984 :     switch (ri_NullCheck(RelationGetDescr(fk_rel), newslot, riinfo, false))
     281             :     {
     282         132 :         case RI_KEYS_ALL_NULL:
     283             : 
     284             :             /*
     285             :              * No further check needed - an all-NULL key passes every type of
     286             :              * foreign key constraint.
     287             :              */
     288         132 :             table_close(pk_rel, RowShareLock);
     289         132 :             return PointerGetDatum(NULL);
     290             : 
     291         156 :         case RI_KEYS_SOME_NULL:
     292             : 
     293             :             /*
     294             :              * This is the only case that differs between the three kinds of
     295             :              * MATCH.
     296             :              */
     297         156 :             switch (riinfo->confmatchtype)
     298             :             {
     299          36 :                 case FKCONSTR_MATCH_FULL:
     300             : 
     301             :                     /*
     302             :                      * Not allowed - MATCH FULL says either all or none of the
     303             :                      * attributes can be NULLs
     304             :                      */
     305          36 :                     ereport(ERROR,
     306             :                             (errcode(ERRCODE_FOREIGN_KEY_VIOLATION),
     307             :                              errmsg("insert or update on table \"%s\" violates foreign key constraint \"%s\"",
     308             :                                     RelationGetRelationName(fk_rel),
     309             :                                     NameStr(riinfo->conname)),
     310             :                              errdetail("MATCH FULL does not allow mixing of null and nonnull key values."),
     311             :                              errtableconstraint(fk_rel,
     312             :                                                 NameStr(riinfo->conname))));
     313             :                     table_close(pk_rel, RowShareLock);
     314             :                     return PointerGetDatum(NULL);
     315             : 
     316         120 :                 case FKCONSTR_MATCH_SIMPLE:
     317             : 
     318             :                     /*
     319             :                      * MATCH SIMPLE - if ANY column is null, the key passes
     320             :                      * the constraint.
     321             :                      */
     322         120 :                     table_close(pk_rel, RowShareLock);
     323         120 :                     return PointerGetDatum(NULL);
     324             : 
     325             : #ifdef NOT_USED
     326             :                 case FKCONSTR_MATCH_PARTIAL:
     327             : 
     328             :                     /*
     329             :                      * MATCH PARTIAL - all non-null columns must match. (not
     330             :                      * implemented, can be done by modifying the query below
     331             :                      * to only include non-null columns, or by writing a
     332             :                      * special version here)
     333             :                      */
     334             :                     break;
     335             : #endif
     336             :             }
     337             : 
     338             :         case RI_KEYS_NONE_NULL:
     339             : 
     340             :             /*
     341             :              * Have a full qualified key - continue below for all three kinds
     342             :              * of MATCH.
     343             :              */
     344        3696 :             break;
     345             :     }
     346             : 
     347        3696 :     if (SPI_connect() != SPI_OK_CONNECT)
     348           0 :         elog(ERROR, "SPI_connect failed");
     349             : 
     350             :     /* Fetch or prepare a saved plan for the real check */
     351        3696 :     ri_BuildQueryKey(&qkey, riinfo, RI_PLAN_CHECK_LOOKUPPK);
     352             : 
     353        3696 :     if ((qplan = ri_FetchPreparedPlan(&qkey)) == NULL)
     354             :     {
     355             :         StringInfoData querybuf;
     356             :         char        pkrelname[MAX_QUOTED_REL_NAME_LEN];
     357             :         char        attname[MAX_QUOTED_NAME_LEN];
     358             :         char        paramname[16];
     359             :         const char *querysep;
     360             :         Oid         queryoids[RI_MAX_NUMKEYS];
     361             :         const char *pk_only;
     362             : 
     363             :         /* ----------
     364             :          * The query string built is
     365             :          *  SELECT 1 FROM [ONLY] <pktable> x WHERE pkatt1 = $1 [AND ...]
     366             :          *         FOR KEY SHARE OF x
     367             :          * The type id's for the $ parameters are those of the
     368             :          * corresponding FK attributes.
     369             :          * ----------
     370             :          */
     371        2012 :         initStringInfo(&querybuf);
     372        4024 :         pk_only = pk_rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE ?
     373        2012 :             "" : "ONLY ";
     374        2012 :         quoteRelationName(pkrelname, pk_rel);
     375        2012 :         appendStringInfo(&querybuf, "SELECT 1 FROM %s%s x",
     376             :                          pk_only, pkrelname);
     377        2012 :         querysep = "WHERE";
     378        4248 :         for (int i = 0; i < riinfo->nkeys; i++)
     379             :         {
     380        2236 :             Oid         pk_type = RIAttType(pk_rel, riinfo->pk_attnums[i]);
     381        2236 :             Oid         fk_type = RIAttType(fk_rel, riinfo->fk_attnums[i]);
     382             : 
     383        2236 :             quoteOneName(attname,
     384        2236 :                          RIAttName(pk_rel, riinfo->pk_attnums[i]));
     385        2236 :             sprintf(paramname, "$%d", i + 1);
     386        2236 :             ri_GenerateQual(&querybuf, querysep,
     387             :                             attname, pk_type,
     388             :                             riinfo->pf_eq_oprs[i],
     389             :                             paramname, fk_type);
     390        2236 :             querysep = "AND";
     391        2236 :             queryoids[i] = fk_type;
     392             :         }
     393        2012 :         appendStringInfoString(&querybuf, " FOR KEY SHARE OF x");
     394             : 
     395             :         /* Prepare and save the plan */
     396        2012 :         qplan = ri_PlanCheck(querybuf.data, riinfo->nkeys, queryoids,
     397             :                              &qkey, fk_rel, pk_rel);
     398             :     }
     399             : 
     400             :     /*
     401             :      * Now check that foreign key exists in PK table
     402             :      *
     403             :      * XXX detectNewRows must be true when a partitioned table is on the
     404             :      * referenced side.  The reason is that our snapshot must be fresh in
     405             :      * order for the hack in find_inheritance_children() to work.
     406             :      */
     407        3696 :     ri_PerformCheck(riinfo, &qkey, qplan,
     408             :                     fk_rel, pk_rel,
     409             :                     NULL, newslot,
     410        3696 :                     pk_rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE,
     411             :                     SPI_OK_SELECT);
     412             : 
     413        3232 :     if (SPI_finish() != SPI_OK_FINISH)
     414           0 :         elog(ERROR, "SPI_finish failed");
     415             : 
     416        3232 :     table_close(pk_rel, RowShareLock);
     417             : 
     418        3232 :     return PointerGetDatum(NULL);
     419             : }
     420             : 
     421             : 
     422             : /*
     423             :  * RI_FKey_check_ins -
     424             :  *
     425             :  * Check foreign key existence at insert event on FK table.
     426             :  */
     427             : Datum
     428        3632 : RI_FKey_check_ins(PG_FUNCTION_ARGS)
     429             : {
     430             :     /* Check that this is a valid trigger call on the right time and event. */
     431        3632 :     ri_CheckTrigger(fcinfo, "RI_FKey_check_ins", RI_TRIGTYPE_INSERT);
     432             : 
     433             :     /* Share code with UPDATE case. */
     434        3632 :     return RI_FKey_check((TriggerData *) fcinfo->context);
     435             : }
     436             : 
     437             : 
     438             : /*
     439             :  * RI_FKey_check_upd -
     440             :  *
     441             :  * Check foreign key existence at update event on FK table.
     442             :  */
     443             : Datum
     444         412 : RI_FKey_check_upd(PG_FUNCTION_ARGS)
     445             : {
     446             :     /* Check that this is a valid trigger call on the right time and event. */
     447         412 :     ri_CheckTrigger(fcinfo, "RI_FKey_check_upd", RI_TRIGTYPE_UPDATE);
     448             : 
     449             :     /* Share code with INSERT case. */
     450         412 :     return RI_FKey_check((TriggerData *) fcinfo->context);
     451             : }
     452             : 
     453             : 
     454             : /*
     455             :  * ri_Check_Pk_Match
     456             :  *
     457             :  * Check to see if another PK row has been created that provides the same
     458             :  * key values as the "oldslot" that's been modified or deleted in our trigger
     459             :  * event.  Returns true if a match is found in the PK table.
     460             :  *
     461             :  * We assume the caller checked that the oldslot contains no NULL key values,
     462             :  * since otherwise a match is impossible.
     463             :  */
     464             : static bool
     465         738 : ri_Check_Pk_Match(Relation pk_rel, Relation fk_rel,
     466             :                   TupleTableSlot *oldslot,
     467             :                   const RI_ConstraintInfo *riinfo)
     468             : {
     469             :     SPIPlanPtr  qplan;
     470             :     RI_QueryKey qkey;
     471             :     bool        result;
     472             : 
     473             :     /* Only called for non-null rows */
     474             :     Assert(ri_NullCheck(RelationGetDescr(pk_rel), oldslot, riinfo, true) == RI_KEYS_NONE_NULL);
     475             : 
     476         738 :     if (SPI_connect() != SPI_OK_CONNECT)
     477           0 :         elog(ERROR, "SPI_connect failed");
     478             : 
     479             :     /*
     480             :      * Fetch or prepare a saved plan for checking PK table with values coming
     481             :      * from a PK row
     482             :      */
     483         738 :     ri_BuildQueryKey(&qkey, riinfo, RI_PLAN_CHECK_LOOKUPPK_FROM_PK);
     484             : 
     485         738 :     if ((qplan = ri_FetchPreparedPlan(&qkey)) == NULL)
     486             :     {
     487             :         StringInfoData querybuf;
     488             :         char        pkrelname[MAX_QUOTED_REL_NAME_LEN];
     489             :         char        attname[MAX_QUOTED_NAME_LEN];
     490             :         char        paramname[16];
     491             :         const char *querysep;
     492             :         const char *pk_only;
     493             :         Oid         queryoids[RI_MAX_NUMKEYS];
     494             : 
     495             :         /* ----------
     496             :          * The query string built is
     497             :          *  SELECT 1 FROM [ONLY] <pktable> x WHERE pkatt1 = $1 [AND ...]
     498             :          *         FOR KEY SHARE OF x
     499             :          * The type id's for the $ parameters are those of the
     500             :          * PK attributes themselves.
     501             :          * ----------
     502             :          */
     503         346 :         initStringInfo(&querybuf);
     504         692 :         pk_only = pk_rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE ?
     505         346 :             "" : "ONLY ";
     506         346 :         quoteRelationName(pkrelname, pk_rel);
     507         346 :         appendStringInfo(&querybuf, "SELECT 1 FROM %s%s x",
     508             :                          pk_only, pkrelname);
     509         346 :         querysep = "WHERE";
     510         796 :         for (int i = 0; i < riinfo->nkeys; i++)
     511             :         {
     512         450 :             Oid         pk_type = RIAttType(pk_rel, riinfo->pk_attnums[i]);
     513             : 
     514         450 :             quoteOneName(attname,
     515         450 :                          RIAttName(pk_rel, riinfo->pk_attnums[i]));
     516         450 :             sprintf(paramname, "$%d", i + 1);
     517         450 :             ri_GenerateQual(&querybuf, querysep,
     518             :                             attname, pk_type,
     519             :                             riinfo->pp_eq_oprs[i],
     520             :                             paramname, pk_type);
     521         450 :             querysep = "AND";
     522         450 :             queryoids[i] = pk_type;
     523             :         }
     524         346 :         appendStringInfoString(&querybuf, " FOR KEY SHARE OF x");
     525             : 
     526             :         /* Prepare and save the plan */
     527         346 :         qplan = ri_PlanCheck(querybuf.data, riinfo->nkeys, queryoids,
     528             :                              &qkey, fk_rel, pk_rel);
     529             :     }
     530             : 
     531             :     /*
     532             :      * We have a plan now. Run it.
     533             :      */
     534         738 :     result = ri_PerformCheck(riinfo, &qkey, qplan,
     535             :                              fk_rel, pk_rel,
     536             :                              oldslot, NULL,
     537             :                              true,  /* treat like update */
     538             :                              SPI_OK_SELECT);
     539             : 
     540         738 :     if (SPI_finish() != SPI_OK_FINISH)
     541           0 :         elog(ERROR, "SPI_finish failed");
     542             : 
     543         738 :     return result;
     544             : }
     545             : 
     546             : 
     547             : /*
     548             :  * RI_FKey_noaction_del -
     549             :  *
     550             :  * Give an error and roll back the current transaction if the
     551             :  * delete has resulted in a violation of the given referential
     552             :  * integrity constraint.
     553             :  */
     554             : Datum
     555         306 : RI_FKey_noaction_del(PG_FUNCTION_ARGS)
     556             : {
     557             :     /* Check that this is a valid trigger call on the right time and event. */
     558         306 :     ri_CheckTrigger(fcinfo, "RI_FKey_noaction_del", RI_TRIGTYPE_DELETE);
     559             : 
     560             :     /* Share code with RESTRICT/UPDATE cases. */
     561         306 :     return ri_restrict((TriggerData *) fcinfo->context, true);
     562             : }
     563             : 
     564             : /*
     565             :  * RI_FKey_restrict_del -
     566             :  *
     567             :  * Restrict delete from PK table to rows unreferenced by foreign key.
     568             :  *
     569             :  * The SQL standard intends that this referential action occur exactly when
     570             :  * the delete is performed, rather than after.  This appears to be
     571             :  * the only difference between "NO ACTION" and "RESTRICT".  In Postgres
     572             :  * we still implement this as an AFTER trigger, but it's non-deferrable.
     573             :  */
     574             : Datum
     575          12 : RI_FKey_restrict_del(PG_FUNCTION_ARGS)
     576             : {
     577             :     /* Check that this is a valid trigger call on the right time and event. */
     578          12 :     ri_CheckTrigger(fcinfo, "RI_FKey_restrict_del", RI_TRIGTYPE_DELETE);
     579             : 
     580             :     /* Share code with NO ACTION/UPDATE cases. */
     581          12 :     return ri_restrict((TriggerData *) fcinfo->context, false);
     582             : }
     583             : 
     584             : /*
     585             :  * RI_FKey_noaction_upd -
     586             :  *
     587             :  * Give an error and roll back the current transaction if the
     588             :  * update has resulted in a violation of the given referential
     589             :  * integrity constraint.
     590             :  */
     591             : Datum
     592         300 : RI_FKey_noaction_upd(PG_FUNCTION_ARGS)
     593             : {
     594             :     /* Check that this is a valid trigger call on the right time and event. */
     595         300 :     ri_CheckTrigger(fcinfo, "RI_FKey_noaction_upd", RI_TRIGTYPE_UPDATE);
     596             : 
     597             :     /* Share code with RESTRICT/DELETE cases. */
     598         300 :     return ri_restrict((TriggerData *) fcinfo->context, true);
     599             : }
     600             : 
     601             : /*
     602             :  * RI_FKey_restrict_upd -
     603             :  *
     604             :  * Restrict update of PK to rows unreferenced by foreign key.
     605             :  *
     606             :  * The SQL standard intends that this referential action occur exactly when
     607             :  * the update is performed, rather than after.  This appears to be
     608             :  * the only difference between "NO ACTION" and "RESTRICT".  In Postgres
     609             :  * we still implement this as an AFTER trigger, but it's non-deferrable.
     610             :  */
     611             : Datum
     612          24 : RI_FKey_restrict_upd(PG_FUNCTION_ARGS)
     613             : {
     614             :     /* Check that this is a valid trigger call on the right time and event. */
     615          24 :     ri_CheckTrigger(fcinfo, "RI_FKey_restrict_upd", RI_TRIGTYPE_UPDATE);
     616             : 
     617             :     /* Share code with NO ACTION/DELETE cases. */
     618          24 :     return ri_restrict((TriggerData *) fcinfo->context, false);
     619             : }
     620             : 
     621             : /*
     622             :  * ri_restrict -
     623             :  *
     624             :  * Common code for ON DELETE RESTRICT, ON DELETE NO ACTION,
     625             :  * ON UPDATE RESTRICT, and ON UPDATE NO ACTION.
     626             :  */
     627             : static Datum
     628         774 : ri_restrict(TriggerData *trigdata, bool is_no_action)
     629             : {
     630             :     const RI_ConstraintInfo *riinfo;
     631             :     Relation    fk_rel;
     632             :     Relation    pk_rel;
     633             :     TupleTableSlot *oldslot;
     634             :     RI_QueryKey qkey;
     635             :     SPIPlanPtr  qplan;
     636             : 
     637         774 :     riinfo = ri_FetchConstraintInfo(trigdata->tg_trigger,
     638             :                                     trigdata->tg_relation, true);
     639             : 
     640             :     /*
     641             :      * Get the relation descriptors of the FK and PK tables and the old tuple.
     642             :      *
     643             :      * fk_rel is opened in RowShareLock mode since that's what our eventual
     644             :      * SELECT FOR KEY SHARE will get on it.
     645             :      */
     646         774 :     fk_rel = table_open(riinfo->fk_relid, RowShareLock);
     647         774 :     pk_rel = trigdata->tg_relation;
     648         774 :     oldslot = trigdata->tg_trigslot;
     649             : 
     650             :     /*
     651             :      * If another PK row now exists providing the old key values, we should
     652             :      * not do anything.  However, this check should only be made in the NO
     653             :      * ACTION case; in RESTRICT cases we don't wish to allow another row to be
     654             :      * substituted.
     655             :      */
     656        1512 :     if (is_no_action &&
     657         738 :         ri_Check_Pk_Match(pk_rel, fk_rel, oldslot, riinfo))
     658             :     {
     659          52 :         table_close(fk_rel, RowShareLock);
     660          52 :         return PointerGetDatum(NULL);
     661             :     }
     662             : 
     663         722 :     if (SPI_connect() != SPI_OK_CONNECT)
     664           0 :         elog(ERROR, "SPI_connect failed");
     665             : 
     666             :     /*
     667             :      * Fetch or prepare a saved plan for the restrict lookup (it's the same
     668             :      * query for delete and update cases)
     669             :      */
     670         722 :     ri_BuildQueryKey(&qkey, riinfo, RI_PLAN_RESTRICT);
     671             : 
     672         722 :     if ((qplan = ri_FetchPreparedPlan(&qkey)) == NULL)
     673             :     {
     674             :         StringInfoData querybuf;
     675             :         char        fkrelname[MAX_QUOTED_REL_NAME_LEN];
     676             :         char        attname[MAX_QUOTED_NAME_LEN];
     677             :         char        paramname[16];
     678             :         const char *querysep;
     679             :         Oid         queryoids[RI_MAX_NUMKEYS];
     680             :         const char *fk_only;
     681             : 
     682             :         /* ----------
     683             :          * The query string built is
     684             :          *  SELECT 1 FROM [ONLY] <fktable> x WHERE $1 = fkatt1 [AND ...]
     685             :          *         FOR KEY SHARE OF x
     686             :          * The type id's for the $ parameters are those of the
     687             :          * corresponding PK attributes.
     688             :          * ----------
     689             :          */
     690         294 :         initStringInfo(&querybuf);
     691         588 :         fk_only = fk_rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE ?
     692         294 :             "" : "ONLY ";
     693         294 :         quoteRelationName(fkrelname, fk_rel);
     694         294 :         appendStringInfo(&querybuf, "SELECT 1 FROM %s%s x",
     695             :                          fk_only, fkrelname);
     696         294 :         querysep = "WHERE";
     697         688 :         for (int i = 0; i < riinfo->nkeys; i++)
     698             :         {
     699         394 :             Oid         pk_type = RIAttType(pk_rel, riinfo->pk_attnums[i]);
     700         394 :             Oid         fk_type = RIAttType(fk_rel, riinfo->fk_attnums[i]);
     701         394 :             Oid         pk_coll = RIAttCollation(pk_rel, riinfo->pk_attnums[i]);
     702         394 :             Oid         fk_coll = RIAttCollation(fk_rel, riinfo->fk_attnums[i]);
     703             : 
     704         394 :             quoteOneName(attname,
     705         394 :                          RIAttName(fk_rel, riinfo->fk_attnums[i]));
     706         394 :             sprintf(paramname, "$%d", i + 1);
     707         394 :             ri_GenerateQual(&querybuf, querysep,
     708             :                             paramname, pk_type,
     709             :                             riinfo->pf_eq_oprs[i],
     710             :                             attname, fk_type);
     711         394 :             if (pk_coll != fk_coll && !get_collation_isdeterministic(pk_coll))
     712           0 :                 ri_GenerateQualCollation(&querybuf, pk_coll);
     713         394 :             querysep = "AND";
     714         394 :             queryoids[i] = pk_type;
     715             :         }
     716         294 :         appendStringInfoString(&querybuf, " FOR KEY SHARE OF x");
     717             : 
     718             :         /* Prepare and save the plan */
     719         294 :         qplan = ri_PlanCheck(querybuf.data, riinfo->nkeys, queryoids,
     720             :                              &qkey, fk_rel, pk_rel);
     721             :     }
     722             : 
     723             :     /*
     724             :      * We have a plan now. Run it to check for existing references.
     725             :      */
     726         722 :     ri_PerformCheck(riinfo, &qkey, qplan,
     727             :                     fk_rel, pk_rel,
     728             :                     oldslot, NULL,
     729             :                     true,       /* must detect new rows */
     730             :                     SPI_OK_SELECT);
     731             : 
     732         412 :     if (SPI_finish() != SPI_OK_FINISH)
     733           0 :         elog(ERROR, "SPI_finish failed");
     734             : 
     735         412 :     table_close(fk_rel, RowShareLock);
     736             : 
     737         412 :     return PointerGetDatum(NULL);
     738             : }
     739             : 
     740             : 
     741             : /*
     742             :  * RI_FKey_cascade_del -
     743             :  *
     744             :  * Cascaded delete foreign key references at delete event on PK table.
     745             :  */
     746             : Datum
     747         144 : RI_FKey_cascade_del(PG_FUNCTION_ARGS)
     748             : {
     749         144 :     TriggerData *trigdata = (TriggerData *) fcinfo->context;
     750             :     const RI_ConstraintInfo *riinfo;
     751             :     Relation    fk_rel;
     752             :     Relation    pk_rel;
     753             :     TupleTableSlot *oldslot;
     754             :     RI_QueryKey qkey;
     755             :     SPIPlanPtr  qplan;
     756             : 
     757             :     /* Check that this is a valid trigger call on the right time and event. */
     758         144 :     ri_CheckTrigger(fcinfo, "RI_FKey_cascade_del", RI_TRIGTYPE_DELETE);
     759             : 
     760         144 :     riinfo = ri_FetchConstraintInfo(trigdata->tg_trigger,
     761             :                                     trigdata->tg_relation, true);
     762             : 
     763             :     /*
     764             :      * Get the relation descriptors of the FK and PK tables and the old tuple.
     765             :      *
     766             :      * fk_rel is opened in RowExclusiveLock mode since that's what our
     767             :      * eventual DELETE will get on it.
     768             :      */
     769         144 :     fk_rel = table_open(riinfo->fk_relid, RowExclusiveLock);
     770         144 :     pk_rel = trigdata->tg_relation;
     771         144 :     oldslot = trigdata->tg_trigslot;
     772             : 
     773         144 :     if (SPI_connect() != SPI_OK_CONNECT)
     774           0 :         elog(ERROR, "SPI_connect failed");
     775             : 
     776             :     /* Fetch or prepare a saved plan for the cascaded delete */
     777         144 :     ri_BuildQueryKey(&qkey, riinfo, RI_PLAN_CASCADE_ONDELETE);
     778             : 
     779         144 :     if ((qplan = ri_FetchPreparedPlan(&qkey)) == NULL)
     780             :     {
     781             :         StringInfoData querybuf;
     782             :         char        fkrelname[MAX_QUOTED_REL_NAME_LEN];
     783             :         char        attname[MAX_QUOTED_NAME_LEN];
     784             :         char        paramname[16];
     785             :         const char *querysep;
     786             :         Oid         queryoids[RI_MAX_NUMKEYS];
     787             :         const char *fk_only;
     788             : 
     789             :         /* ----------
     790             :          * The query string built is
     791             :          *  DELETE FROM [ONLY] <fktable> WHERE $1 = fkatt1 [AND ...]
     792             :          * The type id's for the $ parameters are those of the
     793             :          * corresponding PK attributes.
     794             :          * ----------
     795             :          */
     796          84 :         initStringInfo(&querybuf);
     797         168 :         fk_only = fk_rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE ?
     798          84 :             "" : "ONLY ";
     799          84 :         quoteRelationName(fkrelname, fk_rel);
     800          84 :         appendStringInfo(&querybuf, "DELETE FROM %s%s",
     801             :                          fk_only, fkrelname);
     802          84 :         querysep = "WHERE";
     803         186 :         for (int i = 0; i < riinfo->nkeys; i++)
     804             :         {
     805         102 :             Oid         pk_type = RIAttType(pk_rel, riinfo->pk_attnums[i]);
     806         102 :             Oid         fk_type = RIAttType(fk_rel, riinfo->fk_attnums[i]);
     807         102 :             Oid         pk_coll = RIAttCollation(pk_rel, riinfo->pk_attnums[i]);
     808         102 :             Oid         fk_coll = RIAttCollation(fk_rel, riinfo->fk_attnums[i]);
     809             : 
     810         102 :             quoteOneName(attname,
     811         102 :                          RIAttName(fk_rel, riinfo->fk_attnums[i]));
     812         102 :             sprintf(paramname, "$%d", i + 1);
     813         102 :             ri_GenerateQual(&querybuf, querysep,
     814             :                             paramname, pk_type,
     815             :                             riinfo->pf_eq_oprs[i],
     816             :                             attname, fk_type);
     817         102 :             if (pk_coll != fk_coll && !get_collation_isdeterministic(pk_coll))
     818           0 :                 ri_GenerateQualCollation(&querybuf, pk_coll);
     819         102 :             querysep = "AND";
     820         102 :             queryoids[i] = pk_type;
     821             :         }
     822             : 
     823             :         /* Prepare and save the plan */
     824          84 :         qplan = ri_PlanCheck(querybuf.data, riinfo->nkeys, queryoids,
     825             :                              &qkey, fk_rel, pk_rel);
     826             :     }
     827             : 
     828             :     /*
     829             :      * We have a plan now. Build up the arguments from the key values in the
     830             :      * deleted PK tuple and delete the referencing rows
     831             :      */
     832         144 :     ri_PerformCheck(riinfo, &qkey, qplan,
     833             :                     fk_rel, pk_rel,
     834             :                     oldslot, NULL,
     835             :                     true,       /* must detect new rows */
     836             :                     SPI_OK_DELETE);
     837             : 
     838         144 :     if (SPI_finish() != SPI_OK_FINISH)
     839           0 :         elog(ERROR, "SPI_finish failed");
     840             : 
     841         144 :     table_close(fk_rel, RowExclusiveLock);
     842             : 
     843         144 :     return PointerGetDatum(NULL);
     844             : }
     845             : 
     846             : 
     847             : /*
     848             :  * RI_FKey_cascade_upd -
     849             :  *
     850             :  * Cascaded update foreign key references at update event on PK table.
     851             :  */
     852             : Datum
     853         198 : RI_FKey_cascade_upd(PG_FUNCTION_ARGS)
     854             : {
     855         198 :     TriggerData *trigdata = (TriggerData *) fcinfo->context;
     856             :     const RI_ConstraintInfo *riinfo;
     857             :     Relation    fk_rel;
     858             :     Relation    pk_rel;
     859             :     TupleTableSlot *newslot;
     860             :     TupleTableSlot *oldslot;
     861             :     RI_QueryKey qkey;
     862             :     SPIPlanPtr  qplan;
     863             : 
     864             :     /* Check that this is a valid trigger call on the right time and event. */
     865         198 :     ri_CheckTrigger(fcinfo, "RI_FKey_cascade_upd", RI_TRIGTYPE_UPDATE);
     866             : 
     867         198 :     riinfo = ri_FetchConstraintInfo(trigdata->tg_trigger,
     868             :                                     trigdata->tg_relation, true);
     869             : 
     870             :     /*
     871             :      * Get the relation descriptors of the FK and PK tables and the new and
     872             :      * old tuple.
     873             :      *
     874             :      * fk_rel is opened in RowExclusiveLock mode since that's what our
     875             :      * eventual UPDATE will get on it.
     876             :      */
     877         198 :     fk_rel = table_open(riinfo->fk_relid, RowExclusiveLock);
     878         198 :     pk_rel = trigdata->tg_relation;
     879         198 :     newslot = trigdata->tg_newslot;
     880         198 :     oldslot = trigdata->tg_trigslot;
     881             : 
     882         198 :     if (SPI_connect() != SPI_OK_CONNECT)
     883           0 :         elog(ERROR, "SPI_connect failed");
     884             : 
     885             :     /* Fetch or prepare a saved plan for the cascaded update */
     886         198 :     ri_BuildQueryKey(&qkey, riinfo, RI_PLAN_CASCADE_ONUPDATE);
     887             : 
     888         198 :     if ((qplan = ri_FetchPreparedPlan(&qkey)) == NULL)
     889             :     {
     890             :         StringInfoData querybuf;
     891             :         StringInfoData qualbuf;
     892             :         char        fkrelname[MAX_QUOTED_REL_NAME_LEN];
     893             :         char        attname[MAX_QUOTED_NAME_LEN];
     894             :         char        paramname[16];
     895             :         const char *querysep;
     896             :         const char *qualsep;
     897             :         Oid         queryoids[RI_MAX_NUMKEYS * 2];
     898             :         const char *fk_only;
     899             : 
     900             :         /* ----------
     901             :          * The query string built is
     902             :          *  UPDATE [ONLY] <fktable> SET fkatt1 = $1 [, ...]
     903             :          *          WHERE $n = fkatt1 [AND ...]
     904             :          * The type id's for the $ parameters are those of the
     905             :          * corresponding PK attributes.  Note that we are assuming
     906             :          * there is an assignment cast from the PK to the FK type;
     907             :          * else the parser will fail.
     908             :          * ----------
     909             :          */
     910         110 :         initStringInfo(&querybuf);
     911         110 :         initStringInfo(&qualbuf);
     912         220 :         fk_only = fk_rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE ?
     913         110 :             "" : "ONLY ";
     914         110 :         quoteRelationName(fkrelname, fk_rel);
     915         110 :         appendStringInfo(&querybuf, "UPDATE %s%s SET",
     916             :                          fk_only, fkrelname);
     917         110 :         querysep = "";
     918         110 :         qualsep = "WHERE";
     919         244 :         for (int i = 0, j = riinfo->nkeys; i < riinfo->nkeys; i++, j++)
     920             :         {
     921         134 :             Oid         pk_type = RIAttType(pk_rel, riinfo->pk_attnums[i]);
     922         134 :             Oid         fk_type = RIAttType(fk_rel, riinfo->fk_attnums[i]);
     923         134 :             Oid         pk_coll = RIAttCollation(pk_rel, riinfo->pk_attnums[i]);
     924         134 :             Oid         fk_coll = RIAttCollation(fk_rel, riinfo->fk_attnums[i]);
     925             : 
     926         134 :             quoteOneName(attname,
     927         134 :                          RIAttName(fk_rel, riinfo->fk_attnums[i]));
     928         134 :             appendStringInfo(&querybuf,
     929             :                              "%s %s = $%d",
     930             :                              querysep, attname, i + 1);
     931         134 :             sprintf(paramname, "$%d", j + 1);
     932         134 :             ri_GenerateQual(&qualbuf, qualsep,
     933             :                             paramname, pk_type,
     934             :                             riinfo->pf_eq_oprs[i],
     935             :                             attname, fk_type);
     936         134 :             if (pk_coll != fk_coll && !get_collation_isdeterministic(pk_coll))
     937           0 :                 ri_GenerateQualCollation(&querybuf, pk_coll);
     938         134 :             querysep = ",";
     939         134 :             qualsep = "AND";
     940         134 :             queryoids[i] = pk_type;
     941         134 :             queryoids[j] = pk_type;
     942             :         }
     943         110 :         appendBinaryStringInfo(&querybuf, qualbuf.data, qualbuf.len);
     944             : 
     945             :         /* Prepare and save the plan */
     946         110 :         qplan = ri_PlanCheck(querybuf.data, riinfo->nkeys * 2, queryoids,
     947             :                              &qkey, fk_rel, pk_rel);
     948             :     }
     949             : 
     950             :     /*
     951             :      * We have a plan now. Run it to update the existing references.
     952             :      */
     953         198 :     ri_PerformCheck(riinfo, &qkey, qplan,
     954             :                     fk_rel, pk_rel,
     955             :                     oldslot, newslot,
     956             :                     true,       /* must detect new rows */
     957             :                     SPI_OK_UPDATE);
     958             : 
     959         198 :     if (SPI_finish() != SPI_OK_FINISH)
     960           0 :         elog(ERROR, "SPI_finish failed");
     961             : 
     962         198 :     table_close(fk_rel, RowExclusiveLock);
     963             : 
     964         198 :     return PointerGetDatum(NULL);
     965             : }
     966             : 
     967             : 
     968             : /*
     969             :  * RI_FKey_setnull_del -
     970             :  *
     971             :  * Set foreign key references to NULL values at delete event on PK table.
     972             :  */
     973             : Datum
     974          96 : RI_FKey_setnull_del(PG_FUNCTION_ARGS)
     975             : {
     976             :     /* Check that this is a valid trigger call on the right time and event. */
     977          96 :     ri_CheckTrigger(fcinfo, "RI_FKey_setnull_del", RI_TRIGTYPE_DELETE);
     978             : 
     979             :     /* Share code with UPDATE case */
     980          96 :     return ri_set((TriggerData *) fcinfo->context, true, RI_TRIGTYPE_DELETE);
     981             : }
     982             : 
     983             : /*
     984             :  * RI_FKey_setnull_upd -
     985             :  *
     986             :  * Set foreign key references to NULL at update event on PK table.
     987             :  */
     988             : Datum
     989          30 : RI_FKey_setnull_upd(PG_FUNCTION_ARGS)
     990             : {
     991             :     /* Check that this is a valid trigger call on the right time and event. */
     992          30 :     ri_CheckTrigger(fcinfo, "RI_FKey_setnull_upd", RI_TRIGTYPE_UPDATE);
     993             : 
     994             :     /* Share code with DELETE case */
     995          30 :     return ri_set((TriggerData *) fcinfo->context, true, RI_TRIGTYPE_UPDATE);
     996             : }
     997             : 
     998             : /*
     999             :  * RI_FKey_setdefault_del -
    1000             :  *
    1001             :  * Set foreign key references to defaults at delete event on PK table.
    1002             :  */
    1003             : Datum
    1004          84 : RI_FKey_setdefault_del(PG_FUNCTION_ARGS)
    1005             : {
    1006             :     /* Check that this is a valid trigger call on the right time and event. */
    1007          84 :     ri_CheckTrigger(fcinfo, "RI_FKey_setdefault_del", RI_TRIGTYPE_DELETE);
    1008             : 
    1009             :     /* Share code with UPDATE case */
    1010          84 :     return ri_set((TriggerData *) fcinfo->context, false, RI_TRIGTYPE_DELETE);
    1011             : }
    1012             : 
    1013             : /*
    1014             :  * RI_FKey_setdefault_upd -
    1015             :  *
    1016             :  * Set foreign key references to defaults at update event on PK table.
    1017             :  */
    1018             : Datum
    1019          48 : RI_FKey_setdefault_upd(PG_FUNCTION_ARGS)
    1020             : {
    1021             :     /* Check that this is a valid trigger call on the right time and event. */
    1022          48 :     ri_CheckTrigger(fcinfo, "RI_FKey_setdefault_upd", RI_TRIGTYPE_UPDATE);
    1023             : 
    1024             :     /* Share code with DELETE case */
    1025          48 :     return ri_set((TriggerData *) fcinfo->context, false, RI_TRIGTYPE_UPDATE);
    1026             : }
    1027             : 
    1028             : /*
    1029             :  * ri_set -
    1030             :  *
    1031             :  * Common code for ON DELETE SET NULL, ON DELETE SET DEFAULT, ON UPDATE SET
    1032             :  * NULL, and ON UPDATE SET DEFAULT.
    1033             :  */
    1034             : static Datum
    1035         258 : ri_set(TriggerData *trigdata, bool is_set_null, int tgkind)
    1036             : {
    1037             :     const RI_ConstraintInfo *riinfo;
    1038             :     Relation    fk_rel;
    1039             :     Relation    pk_rel;
    1040             :     TupleTableSlot *oldslot;
    1041             :     RI_QueryKey qkey;
    1042             :     SPIPlanPtr  qplan;
    1043             :     int32       queryno;
    1044             : 
    1045         258 :     riinfo = ri_FetchConstraintInfo(trigdata->tg_trigger,
    1046             :                                     trigdata->tg_relation, true);
    1047             : 
    1048             :     /*
    1049             :      * Get the relation descriptors of the FK and PK tables and the old tuple.
    1050             :      *
    1051             :      * fk_rel is opened in RowExclusiveLock mode since that's what our
    1052             :      * eventual UPDATE will get on it.
    1053             :      */
    1054         258 :     fk_rel = table_open(riinfo->fk_relid, RowExclusiveLock);
    1055         258 :     pk_rel = trigdata->tg_relation;
    1056         258 :     oldslot = trigdata->tg_trigslot;
    1057             : 
    1058         258 :     if (SPI_connect() != SPI_OK_CONNECT)
    1059           0 :         elog(ERROR, "SPI_connect failed");
    1060             : 
    1061             :     /*
    1062             :      * Fetch or prepare a saved plan for the trigger.
    1063             :      */
    1064         258 :     switch (tgkind)
    1065             :     {
    1066          78 :         case RI_TRIGTYPE_UPDATE:
    1067          78 :             queryno = is_set_null
    1068             :                 ? RI_PLAN_SETNULL_ONUPDATE
    1069          78 :                 : RI_PLAN_SETDEFAULT_ONUPDATE;
    1070          78 :             break;
    1071         180 :         case RI_TRIGTYPE_DELETE:
    1072         180 :             queryno = is_set_null
    1073             :                 ? RI_PLAN_SETNULL_ONDELETE
    1074         180 :                 : RI_PLAN_SETDEFAULT_ONDELETE;
    1075         180 :             break;
    1076           0 :         default:
    1077           0 :             elog(ERROR, "invalid tgkind passed to ri_set");
    1078             :     }
    1079             : 
    1080         258 :     ri_BuildQueryKey(&qkey, riinfo, queryno);
    1081             : 
    1082         258 :     if ((qplan = ri_FetchPreparedPlan(&qkey)) == NULL)
    1083             :     {
    1084             :         StringInfoData querybuf;
    1085             :         char        fkrelname[MAX_QUOTED_REL_NAME_LEN];
    1086             :         char        attname[MAX_QUOTED_NAME_LEN];
    1087             :         char        paramname[16];
    1088             :         const char *querysep;
    1089             :         const char *qualsep;
    1090             :         Oid         queryoids[RI_MAX_NUMKEYS];
    1091             :         const char *fk_only;
    1092             :         int         num_cols_to_set;
    1093             :         const int16 *set_cols;
    1094             : 
    1095         154 :         switch (tgkind)
    1096             :         {
    1097          52 :             case RI_TRIGTYPE_UPDATE:
    1098          52 :                 num_cols_to_set = riinfo->nkeys;
    1099          52 :                 set_cols = riinfo->fk_attnums;
    1100          52 :                 break;
    1101         102 :             case RI_TRIGTYPE_DELETE:
    1102             : 
    1103             :                 /*
    1104             :                  * If confdelsetcols are present, then we only update the
    1105             :                  * columns specified in that array, otherwise we update all
    1106             :                  * the referencing columns.
    1107             :                  */
    1108         102 :                 if (riinfo->ndelsetcols != 0)
    1109             :                 {
    1110          24 :                     num_cols_to_set = riinfo->ndelsetcols;
    1111          24 :                     set_cols = riinfo->confdelsetcols;
    1112             :                 }
    1113             :                 else
    1114             :                 {
    1115          78 :                     num_cols_to_set = riinfo->nkeys;
    1116          78 :                     set_cols = riinfo->fk_attnums;
    1117             :                 }
    1118         102 :                 break;
    1119           0 :             default:
    1120           0 :                 elog(ERROR, "invalid tgkind passed to ri_set");
    1121             :         }
    1122             : 
    1123             :         /* ----------
    1124             :          * The query string built is
    1125             :          *  UPDATE [ONLY] <fktable> SET fkatt1 = {NULL|DEFAULT} [, ...]
    1126             :          *          WHERE $1 = fkatt1 [AND ...]
    1127             :          * The type id's for the $ parameters are those of the
    1128             :          * corresponding PK attributes.
    1129             :          * ----------
    1130             :          */
    1131         154 :         initStringInfo(&querybuf);
    1132         308 :         fk_only = fk_rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE ?
    1133         154 :             "" : "ONLY ";
    1134         154 :         quoteRelationName(fkrelname, fk_rel);
    1135         154 :         appendStringInfo(&querybuf, "UPDATE %s%s SET",
    1136             :                          fk_only, fkrelname);
    1137             : 
    1138             :         /*
    1139             :          * Add assignment clauses
    1140             :          */
    1141         154 :         querysep = "";
    1142         414 :         for (int i = 0; i < num_cols_to_set; i++)
    1143             :         {
    1144         260 :             quoteOneName(attname, RIAttName(fk_rel, set_cols[i]));
    1145         260 :             appendStringInfo(&querybuf,
    1146             :                              "%s %s = %s",
    1147             :                              querysep, attname,
    1148             :                              is_set_null ? "NULL" : "DEFAULT");
    1149         260 :             querysep = ",";
    1150             :         }
    1151             : 
    1152             :         /*
    1153             :          * Add WHERE clause
    1154             :          */
    1155         154 :         qualsep = "WHERE";
    1156         438 :         for (int i = 0; i < riinfo->nkeys; i++)
    1157             :         {
    1158         284 :             Oid         pk_type = RIAttType(pk_rel, riinfo->pk_attnums[i]);
    1159         284 :             Oid         fk_type = RIAttType(fk_rel, riinfo->fk_attnums[i]);
    1160         284 :             Oid         pk_coll = RIAttCollation(pk_rel, riinfo->pk_attnums[i]);
    1161         284 :             Oid         fk_coll = RIAttCollation(fk_rel, riinfo->fk_attnums[i]);
    1162             : 
    1163         284 :             quoteOneName(attname,
    1164         284 :                          RIAttName(fk_rel, riinfo->fk_attnums[i]));
    1165             : 
    1166         284 :             sprintf(paramname, "$%d", i + 1);
    1167         284 :             ri_GenerateQual(&querybuf, qualsep,
    1168             :                             paramname, pk_type,
    1169             :                             riinfo->pf_eq_oprs[i],
    1170             :                             attname, fk_type);
    1171         284 :             if (pk_coll != fk_coll && !get_collation_isdeterministic(pk_coll))
    1172           0 :                 ri_GenerateQualCollation(&querybuf, pk_coll);
    1173         284 :             qualsep = "AND";
    1174         284 :             queryoids[i] = pk_type;
    1175             :         }
    1176             : 
    1177             :         /* Prepare and save the plan */
    1178         154 :         qplan = ri_PlanCheck(querybuf.data, riinfo->nkeys, queryoids,
    1179             :                              &qkey, fk_rel, pk_rel);
    1180             :     }
    1181             : 
    1182             :     /*
    1183             :      * We have a plan now. Run it to update the existing references.
    1184             :      */
    1185         258 :     ri_PerformCheck(riinfo, &qkey, qplan,
    1186             :                     fk_rel, pk_rel,
    1187             :                     oldslot, NULL,
    1188             :                     true,       /* must detect new rows */
    1189             :                     SPI_OK_UPDATE);
    1190             : 
    1191         258 :     if (SPI_finish() != SPI_OK_FINISH)
    1192           0 :         elog(ERROR, "SPI_finish failed");
    1193             : 
    1194         258 :     table_close(fk_rel, RowExclusiveLock);
    1195             : 
    1196         258 :     if (is_set_null)
    1197         126 :         return PointerGetDatum(NULL);
    1198             :     else
    1199             :     {
    1200             :         /*
    1201             :          * If we just deleted or updated the PK row whose key was equal to the
    1202             :          * FK columns' default values, and a referencing row exists in the FK
    1203             :          * table, we would have updated that row to the same values it already
    1204             :          * had --- and RI_FKey_fk_upd_check_required would hence believe no
    1205             :          * check is necessary.  So we need to do another lookup now and in
    1206             :          * case a reference still exists, abort the operation.  That is
    1207             :          * already implemented in the NO ACTION trigger, so just run it. (This
    1208             :          * recheck is only needed in the SET DEFAULT case, since CASCADE would
    1209             :          * remove such rows in case of a DELETE operation or would change the
    1210             :          * FK key values in case of an UPDATE, while SET NULL is certain to
    1211             :          * result in rows that satisfy the FK constraint.)
    1212             :          */
    1213         132 :         return ri_restrict(trigdata, true);
    1214             :     }
    1215             : }
    1216             : 
    1217             : 
    1218             : /*
    1219             :  * RI_FKey_pk_upd_check_required -
    1220             :  *
    1221             :  * Check if we really need to fire the RI trigger for an update or delete to a PK
    1222             :  * relation.  This is called by the AFTER trigger queue manager to see if
    1223             :  * it can skip queuing an instance of an RI trigger.  Returns true if the
    1224             :  * trigger must be fired, false if we can prove the constraint will still
    1225             :  * be satisfied.
    1226             :  *
    1227             :  * newslot will be NULL if this is called for a delete.
    1228             :  */
    1229             : bool
    1230        1958 : RI_FKey_pk_upd_check_required(Trigger *trigger, Relation pk_rel,
    1231             :                               TupleTableSlot *oldslot, TupleTableSlot *newslot)
    1232             : {
    1233             :     const RI_ConstraintInfo *riinfo;
    1234             : 
    1235        1958 :     riinfo = ri_FetchConstraintInfo(trigger, pk_rel, true);
    1236             : 
    1237             :     /*
    1238             :      * If any old key value is NULL, the row could not have been referenced by
    1239             :      * an FK row, so no check is needed.
    1240             :      */
    1241        1958 :     if (ri_NullCheck(RelationGetDescr(pk_rel), oldslot, riinfo, true) != RI_KEYS_NONE_NULL)
    1242           6 :         return false;
    1243             : 
    1244             :     /* If all old and new key values are equal, no check is needed */
    1245        1952 :     if (newslot && ri_KeysEqual(pk_rel, oldslot, newslot, riinfo, true))
    1246         536 :         return false;
    1247             : 
    1248             :     /* Else we need to fire the trigger. */
    1249        1416 :     return true;
    1250             : }
    1251             : 
    1252             : /*
    1253             :  * RI_FKey_fk_upd_check_required -
    1254             :  *
    1255             :  * Check if we really need to fire the RI trigger for an update to an FK
    1256             :  * relation.  This is called by the AFTER trigger queue manager to see if
    1257             :  * it can skip queuing an instance of an RI trigger.  Returns true if the
    1258             :  * trigger must be fired, false if we can prove the constraint will still
    1259             :  * be satisfied.
    1260             :  */
    1261             : bool
    1262        1002 : RI_FKey_fk_upd_check_required(Trigger *trigger, Relation fk_rel,
    1263             :                               TupleTableSlot *oldslot, TupleTableSlot *newslot)
    1264             : {
    1265             :     const RI_ConstraintInfo *riinfo;
    1266             :     int         ri_nullcheck;
    1267             :     Datum       xminDatum;
    1268             :     TransactionId xmin;
    1269             :     bool        isnull;
    1270             : 
    1271             :     /*
    1272             :      * AfterTriggerSaveEvent() handles things such that this function is never
    1273             :      * called for partitioned tables.
    1274             :      */
    1275             :     Assert(fk_rel->rd_rel->relkind != RELKIND_PARTITIONED_TABLE);
    1276             : 
    1277        1002 :     riinfo = ri_FetchConstraintInfo(trigger, fk_rel, false);
    1278             : 
    1279        1002 :     ri_nullcheck = ri_NullCheck(RelationGetDescr(fk_rel), newslot, riinfo, false);
    1280             : 
    1281             :     /*
    1282             :      * If all new key values are NULL, the row satisfies the constraint, so no
    1283             :      * check is needed.
    1284             :      */
    1285        1002 :     if (ri_nullcheck == RI_KEYS_ALL_NULL)
    1286         126 :         return false;
    1287             : 
    1288             :     /*
    1289             :      * If some new key values are NULL, the behavior depends on the match
    1290             :      * type.
    1291             :      */
    1292         876 :     else if (ri_nullcheck == RI_KEYS_SOME_NULL)
    1293             :     {
    1294          30 :         switch (riinfo->confmatchtype)
    1295             :         {
    1296          24 :             case FKCONSTR_MATCH_SIMPLE:
    1297             : 
    1298             :                 /*
    1299             :                  * If any new key value is NULL, the row must satisfy the
    1300             :                  * constraint, so no check is needed.
    1301             :                  */
    1302          24 :                 return false;
    1303             : 
    1304           0 :             case FKCONSTR_MATCH_PARTIAL:
    1305             : 
    1306             :                 /*
    1307             :                  * Don't know, must run full check.
    1308             :                  */
    1309           0 :                 break;
    1310             : 
    1311           6 :             case FKCONSTR_MATCH_FULL:
    1312             : 
    1313             :                 /*
    1314             :                  * If some new key values are NULL, the row fails the
    1315             :                  * constraint.  We must not throw error here, because the row
    1316             :                  * might get invalidated before the constraint is to be
    1317             :                  * checked, but we should queue the event to apply the check
    1318             :                  * later.
    1319             :                  */
    1320           6 :                 return true;
    1321             :         }
    1322         846 :     }
    1323             : 
    1324             :     /*
    1325             :      * Continues here for no new key values are NULL, or we couldn't decide
    1326             :      * yet.
    1327             :      */
    1328             : 
    1329             :     /*
    1330             :      * If the original row was inserted by our own transaction, we must fire
    1331             :      * the trigger whether or not the keys are equal.  This is because our
    1332             :      * UPDATE will invalidate the INSERT so that the INSERT RI trigger will
    1333             :      * not do anything; so we had better do the UPDATE check.  (We could skip
    1334             :      * this if we knew the INSERT trigger already fired, but there is no easy
    1335             :      * way to know that.)
    1336             :      */
    1337         846 :     xminDatum = slot_getsysattr(oldslot, MinTransactionIdAttributeNumber, &isnull);
    1338             :     Assert(!isnull);
    1339         846 :     xmin = DatumGetTransactionId(xminDatum);
    1340         846 :     if (TransactionIdIsCurrentTransactionId(xmin))
    1341         124 :         return true;
    1342             : 
    1343             :     /* If all old and new key values are equal, no check is needed */
    1344         722 :     if (ri_KeysEqual(fk_rel, oldslot, newslot, riinfo, false))
    1345         434 :         return false;
    1346             : 
    1347             :     /* Else we need to fire the trigger. */
    1348         288 :     return true;
    1349             : }
    1350             : 
    1351             : /*
    1352             :  * RI_Initial_Check -
    1353             :  *
    1354             :  * Check an entire table for non-matching values using a single query.
    1355             :  * This is not a trigger procedure, but is called during ALTER TABLE
    1356             :  * ADD FOREIGN KEY to validate the initial table contents.
    1357             :  *
    1358             :  * We expect that the caller has made provision to prevent any problems
    1359             :  * caused by concurrent actions. This could be either by locking rel and
    1360             :  * pkrel at ShareRowExclusiveLock or higher, or by otherwise ensuring
    1361             :  * that triggers implementing the checks are already active.
    1362             :  * Hence, we do not need to lock individual rows for the check.
    1363             :  *
    1364             :  * If the check fails because the current user doesn't have permissions
    1365             :  * to read both tables, return false to let our caller know that they will
    1366             :  * need to do something else to check the constraint.
    1367             :  */
    1368             : bool
    1369         900 : RI_Initial_Check(Trigger *trigger, Relation fk_rel, Relation pk_rel)
    1370             : {
    1371             :     const RI_ConstraintInfo *riinfo;
    1372             :     StringInfoData querybuf;
    1373             :     char        pkrelname[MAX_QUOTED_REL_NAME_LEN];
    1374             :     char        fkrelname[MAX_QUOTED_REL_NAME_LEN];
    1375             :     char        pkattname[MAX_QUOTED_NAME_LEN + 3];
    1376             :     char        fkattname[MAX_QUOTED_NAME_LEN + 3];
    1377             :     RangeTblEntry *pkrte;
    1378             :     RangeTblEntry *fkrte;
    1379             :     const char *sep;
    1380             :     const char *fk_only;
    1381             :     const char *pk_only;
    1382             :     int         save_nestlevel;
    1383             :     char        workmembuf[32];
    1384             :     int         spi_result;
    1385             :     SPIPlanPtr  qplan;
    1386             : 
    1387         900 :     riinfo = ri_FetchConstraintInfo(trigger, fk_rel, false);
    1388             : 
    1389             :     /*
    1390             :      * Check to make sure current user has enough permissions to do the test
    1391             :      * query.  (If not, caller can fall back to the trigger method, which
    1392             :      * works because it changes user IDs on the fly.)
    1393             :      *
    1394             :      * XXX are there any other show-stopper conditions to check?
    1395             :      */
    1396         900 :     pkrte = makeNode(RangeTblEntry);
    1397         900 :     pkrte->rtekind = RTE_RELATION;
    1398         900 :     pkrte->relid = RelationGetRelid(pk_rel);
    1399         900 :     pkrte->relkind = pk_rel->rd_rel->relkind;
    1400         900 :     pkrte->rellockmode = AccessShareLock;
    1401         900 :     pkrte->requiredPerms = ACL_SELECT;
    1402             : 
    1403         900 :     fkrte = makeNode(RangeTblEntry);
    1404         900 :     fkrte->rtekind = RTE_RELATION;
    1405         900 :     fkrte->relid = RelationGetRelid(fk_rel);
    1406         900 :     fkrte->relkind = fk_rel->rd_rel->relkind;
    1407         900 :     fkrte->rellockmode = AccessShareLock;
    1408         900 :     fkrte->requiredPerms = ACL_SELECT;
    1409             : 
    1410        2108 :     for (int i = 0; i < riinfo->nkeys; i++)
    1411             :     {
    1412             :         int         attno;
    1413             : 
    1414        1208 :         attno = riinfo->pk_attnums[i] - FirstLowInvalidHeapAttributeNumber;
    1415        1208 :         pkrte->selectedCols = bms_add_member(pkrte->selectedCols, attno);
    1416             : 
    1417        1208 :         attno = riinfo->fk_attnums[i] - FirstLowInvalidHeapAttributeNumber;
    1418        1208 :         fkrte->selectedCols = bms_add_member(fkrte->selectedCols, attno);
    1419             :     }
    1420             : 
    1421         900 :     if (!ExecCheckRTPerms(list_make2(fkrte, pkrte), false))
    1422          12 :         return false;
    1423             : 
    1424             :     /*
    1425             :      * Also punt if RLS is enabled on either table unless this role has the
    1426             :      * bypassrls right or is the table owner of the table(s) involved which
    1427             :      * have RLS enabled.
    1428             :      */
    1429         888 :     if (!has_bypassrls_privilege(GetUserId()) &&
    1430           0 :         ((pk_rel->rd_rel->relrowsecurity &&
    1431           0 :           !pg_class_ownercheck(pkrte->relid, GetUserId())) ||
    1432           0 :          (fk_rel->rd_rel->relrowsecurity &&
    1433           0 :           !pg_class_ownercheck(fkrte->relid, GetUserId()))))
    1434           0 :         return false;
    1435             : 
    1436             :     /*----------
    1437             :      * The query string built is:
    1438             :      *  SELECT fk.keycols FROM [ONLY] relname fk
    1439             :      *   LEFT OUTER JOIN [ONLY] pkrelname pk
    1440             :      *   ON (pk.pkkeycol1=fk.keycol1 [AND ...])
    1441             :      *   WHERE pk.pkkeycol1 IS NULL AND
    1442             :      * For MATCH SIMPLE:
    1443             :      *   (fk.keycol1 IS NOT NULL [AND ...])
    1444             :      * For MATCH FULL:
    1445             :      *   (fk.keycol1 IS NOT NULL [OR ...])
    1446             :      *
    1447             :      * We attach COLLATE clauses to the operators when comparing columns
    1448             :      * that have different collations.
    1449             :      *----------
    1450             :      */
    1451         888 :     initStringInfo(&querybuf);
    1452         888 :     appendStringInfoString(&querybuf, "SELECT ");
    1453         888 :     sep = "";
    1454        2072 :     for (int i = 0; i < riinfo->nkeys; i++)
    1455             :     {
    1456        1184 :         quoteOneName(fkattname,
    1457        1184 :                      RIAttName(fk_rel, riinfo->fk_attnums[i]));
    1458        1184 :         appendStringInfo(&querybuf, "%sfk.%s", sep, fkattname);
    1459        1184 :         sep = ", ";
    1460             :     }
    1461             : 
    1462         888 :     quoteRelationName(pkrelname, pk_rel);
    1463         888 :     quoteRelationName(fkrelname, fk_rel);
    1464        1776 :     fk_only = fk_rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE ?
    1465         888 :         "" : "ONLY ";
    1466        1776 :     pk_only = pk_rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE ?
    1467         888 :         "" : "ONLY ";
    1468         888 :     appendStringInfo(&querybuf,
    1469             :                      " FROM %s%s fk LEFT OUTER JOIN %s%s pk ON",
    1470             :                      fk_only, fkrelname, pk_only, pkrelname);
    1471             : 
    1472         888 :     strcpy(pkattname, "pk.");
    1473         888 :     strcpy(fkattname, "fk.");
    1474         888 :     sep = "(";
    1475        2072 :     for (int i = 0; i < riinfo->nkeys; i++)
    1476             :     {
    1477        1184 :         Oid         pk_type = RIAttType(pk_rel, riinfo->pk_attnums[i]);
    1478        1184 :         Oid         fk_type = RIAttType(fk_rel, riinfo->fk_attnums[i]);
    1479        1184 :         Oid         pk_coll = RIAttCollation(pk_rel, riinfo->pk_attnums[i]);
    1480        1184 :         Oid         fk_coll = RIAttCollation(fk_rel, riinfo->fk_attnums[i]);
    1481             : 
    1482        1184 :         quoteOneName(pkattname + 3,
    1483        1184 :                      RIAttName(pk_rel, riinfo->pk_attnums[i]));
    1484        1184 :         quoteOneName(fkattname + 3,
    1485        1184 :                      RIAttName(fk_rel, riinfo->fk_attnums[i]));
    1486        1184 :         ri_GenerateQual(&querybuf, sep,
    1487             :                         pkattname, pk_type,
    1488             :                         riinfo->pf_eq_oprs[i],
    1489             :                         fkattname, fk_type);
    1490        1184 :         if (pk_coll != fk_coll)
    1491          12 :             ri_GenerateQualCollation(&querybuf, pk_coll);
    1492        1184 :         sep = "AND";
    1493             :     }
    1494             : 
    1495             :     /*
    1496             :      * It's sufficient to test any one pk attribute for null to detect a join
    1497             :      * failure.
    1498             :      */
    1499         888 :     quoteOneName(pkattname, RIAttName(pk_rel, riinfo->pk_attnums[0]));
    1500         888 :     appendStringInfo(&querybuf, ") WHERE pk.%s IS NULL AND (", pkattname);
    1501             : 
    1502         888 :     sep = "";
    1503        2072 :     for (int i = 0; i < riinfo->nkeys; i++)
    1504             :     {
    1505        1184 :         quoteOneName(fkattname, RIAttName(fk_rel, riinfo->fk_attnums[i]));
    1506        1184 :         appendStringInfo(&querybuf,
    1507             :                          "%sfk.%s IS NOT NULL",
    1508             :                          sep, fkattname);
    1509        1184 :         switch (riinfo->confmatchtype)
    1510             :         {
    1511        1084 :             case FKCONSTR_MATCH_SIMPLE:
    1512        1084 :                 sep = " AND ";
    1513        1084 :                 break;
    1514         100 :             case FKCONSTR_MATCH_FULL:
    1515         100 :                 sep = " OR ";
    1516         100 :                 break;
    1517             :         }
    1518        1184 :     }
    1519         888 :     appendStringInfoChar(&querybuf, ')');
    1520             : 
    1521             :     /*
    1522             :      * Temporarily increase work_mem so that the check query can be executed
    1523             :      * more efficiently.  It seems okay to do this because the query is simple
    1524             :      * enough to not use a multiple of work_mem, and one typically would not
    1525             :      * have many large foreign-key validations happening concurrently.  So
    1526             :      * this seems to meet the criteria for being considered a "maintenance"
    1527             :      * operation, and accordingly we use maintenance_work_mem.  However, we
    1528             :      * must also set hash_mem_multiplier to 1, since it is surely not okay to
    1529             :      * let that get applied to the maintenance_work_mem value.
    1530             :      *
    1531             :      * We use the equivalent of a function SET option to allow the setting to
    1532             :      * persist for exactly the duration of the check query.  guc.c also takes
    1533             :      * care of undoing the setting on error.
    1534             :      */
    1535         888 :     save_nestlevel = NewGUCNestLevel();
    1536             : 
    1537         888 :     snprintf(workmembuf, sizeof(workmembuf), "%d", maintenance_work_mem);
    1538         888 :     (void) set_config_option("work_mem", workmembuf,
    1539             :                              PGC_USERSET, PGC_S_SESSION,
    1540             :                              GUC_ACTION_SAVE, true, 0, false);
    1541         888 :     (void) set_config_option("hash_mem_multiplier", "1",
    1542             :                              PGC_USERSET, PGC_S_SESSION,
    1543             :                              GUC_ACTION_SAVE, true, 0, false);
    1544             : 
    1545         888 :     if (SPI_connect() != SPI_OK_CONNECT)
    1546           0 :         elog(ERROR, "SPI_connect failed");
    1547             : 
    1548             :     /*
    1549             :      * Generate the plan.  We don't need to cache it, and there are no
    1550             :      * arguments to the plan.
    1551             :      */
    1552         888 :     qplan = SPI_prepare(querybuf.data, 0, NULL);
    1553             : 
    1554         888 :     if (qplan == NULL)
    1555           0 :         elog(ERROR, "SPI_prepare returned %s for %s",
    1556             :              SPI_result_code_string(SPI_result), querybuf.data);
    1557             : 
    1558             :     /*
    1559             :      * Run the plan.  For safety we force a current snapshot to be used. (In
    1560             :      * transaction-snapshot mode, this arguably violates transaction isolation
    1561             :      * rules, but we really haven't got much choice.) We don't need to
    1562             :      * register the snapshot, because SPI_execute_snapshot will see to it. We
    1563             :      * need at most one tuple returned, so pass limit = 1.
    1564             :      */
    1565         888 :     spi_result = SPI_execute_snapshot(qplan,
    1566             :                                       NULL, NULL,
    1567             :                                       GetLatestSnapshot(),
    1568             :                                       InvalidSnapshot,
    1569             :                                       true, false, 1);
    1570             : 
    1571             :     /* Check result */
    1572         888 :     if (spi_result != SPI_OK_SELECT)
    1573           0 :         elog(ERROR, "SPI_execute_snapshot returned %s", SPI_result_code_string(spi_result));
    1574             : 
    1575             :     /* Did we find a tuple violating the constraint? */
    1576         888 :     if (SPI_processed > 0)
    1577             :     {
    1578             :         TupleTableSlot *slot;
    1579          56 :         HeapTuple   tuple = SPI_tuptable->vals[0];
    1580          56 :         TupleDesc   tupdesc = SPI_tuptable->tupdesc;
    1581             :         RI_ConstraintInfo fake_riinfo;
    1582             : 
    1583          56 :         slot = MakeSingleTupleTableSlot(tupdesc, &TTSOpsVirtual);
    1584             : 
    1585          56 :         heap_deform_tuple(tuple, tupdesc,
    1586             :                           slot->tts_values, slot->tts_isnull);
    1587          56 :         ExecStoreVirtualTuple(slot);
    1588             : 
    1589             :         /*
    1590             :          * The columns to look at in the result tuple are 1..N, not whatever
    1591             :          * they are in the fk_rel.  Hack up riinfo so that the subroutines
    1592             :          * called here will behave properly.
    1593             :          *
    1594             :          * In addition to this, we have to pass the correct tupdesc to
    1595             :          * ri_ReportViolation, overriding its normal habit of using the pk_rel
    1596             :          * or fk_rel's tupdesc.
    1597             :          */
    1598          56 :         memcpy(&fake_riinfo, riinfo, sizeof(RI_ConstraintInfo));
    1599         130 :         for (int i = 0; i < fake_riinfo.nkeys; i++)
    1600          74 :             fake_riinfo.fk_attnums[i] = i + 1;
    1601             : 
    1602             :         /*
    1603             :          * If it's MATCH FULL, and there are any nulls in the FK keys,
    1604             :          * complain about that rather than the lack of a match.  MATCH FULL
    1605             :          * disallows partially-null FK rows.
    1606             :          */
    1607          80 :         if (fake_riinfo.confmatchtype == FKCONSTR_MATCH_FULL &&
    1608          24 :             ri_NullCheck(tupdesc, slot, &fake_riinfo, false) != RI_KEYS_NONE_NULL)
    1609          12 :             ereport(ERROR,
    1610             :                     (errcode(ERRCODE_FOREIGN_KEY_VIOLATION),
    1611             :                      errmsg("insert or update on table \"%s\" violates foreign key constraint \"%s\"",
    1612             :                             RelationGetRelationName(fk_rel),
    1613             :                             NameStr(fake_riinfo.conname)),
    1614             :                      errdetail("MATCH FULL does not allow mixing of null and nonnull key values."),
    1615             :                      errtableconstraint(fk_rel,
    1616             :                                         NameStr(fake_riinfo.conname))));
    1617             : 
    1618             :         /*
    1619             :          * We tell ri_ReportViolation we were doing the RI_PLAN_CHECK_LOOKUPPK
    1620             :          * query, which isn't true, but will cause it to use
    1621             :          * fake_riinfo.fk_attnums as we need.
    1622             :          */
    1623          44 :         ri_ReportViolation(&fake_riinfo,
    1624             :                            pk_rel, fk_rel,
    1625             :                            slot, tupdesc,
    1626             :                            RI_PLAN_CHECK_LOOKUPPK, false);
    1627             : 
    1628             :         ExecDropSingleTupleTableSlot(slot);
    1629             :     }
    1630             : 
    1631         832 :     if (SPI_finish() != SPI_OK_FINISH)
    1632           0 :         elog(ERROR, "SPI_finish failed");
    1633             : 
    1634             :     /*
    1635             :      * Restore work_mem and hash_mem_multiplier.
    1636             :      */
    1637         832 :     AtEOXact_GUC(true, save_nestlevel);
    1638             : 
    1639         832 :     return true;
    1640             : }
    1641             : 
    1642             : /*
    1643             :  * RI_PartitionRemove_Check -
    1644             :  *
    1645             :  * Verify no referencing values exist, when a partition is detached on
    1646             :  * the referenced side of a foreign key constraint.
    1647             :  */
    1648             : void
    1649          86 : RI_PartitionRemove_Check(Trigger *trigger, Relation fk_rel, Relation pk_rel)
    1650             : {
    1651             :     const RI_ConstraintInfo *riinfo;
    1652             :     StringInfoData querybuf;
    1653             :     char       *constraintDef;
    1654             :     char        pkrelname[MAX_QUOTED_REL_NAME_LEN];
    1655             :     char        fkrelname[MAX_QUOTED_REL_NAME_LEN];
    1656             :     char        pkattname[MAX_QUOTED_NAME_LEN + 3];
    1657             :     char        fkattname[MAX_QUOTED_NAME_LEN + 3];
    1658             :     const char *sep;
    1659             :     const char *fk_only;
    1660             :     int         save_nestlevel;
    1661             :     char        workmembuf[32];
    1662             :     int         spi_result;
    1663             :     SPIPlanPtr  qplan;
    1664             :     int         i;
    1665             : 
    1666          86 :     riinfo = ri_FetchConstraintInfo(trigger, fk_rel, false);
    1667             : 
    1668             :     /*
    1669             :      * We don't check permissions before displaying the error message, on the
    1670             :      * assumption that the user detaching the partition must have enough
    1671             :      * privileges to examine the table contents anyhow.
    1672             :      */
    1673             : 
    1674             :     /*----------
    1675             :      * The query string built is:
    1676             :      *  SELECT fk.keycols FROM [ONLY] relname fk
    1677             :      *    JOIN pkrelname pk
    1678             :      *    ON (pk.pkkeycol1=fk.keycol1 [AND ...])
    1679             :      *    WHERE (<partition constraint>) AND
    1680             :      * For MATCH SIMPLE:
    1681             :      *   (fk.keycol1 IS NOT NULL [AND ...])
    1682             :      * For MATCH FULL:
    1683             :      *   (fk.keycol1 IS NOT NULL [OR ...])
    1684             :      *
    1685             :      * We attach COLLATE clauses to the operators when comparing columns
    1686             :      * that have different collations.
    1687             :      *----------
    1688             :      */
    1689          86 :     initStringInfo(&querybuf);
    1690          86 :     appendStringInfoString(&querybuf, "SELECT ");
    1691          86 :     sep = "";
    1692         172 :     for (i = 0; i < riinfo->nkeys; i++)
    1693             :     {
    1694          86 :         quoteOneName(fkattname,
    1695          86 :                      RIAttName(fk_rel, riinfo->fk_attnums[i]));
    1696          86 :         appendStringInfo(&querybuf, "%sfk.%s", sep, fkattname);
    1697          86 :         sep = ", ";
    1698             :     }
    1699             : 
    1700          86 :     quoteRelationName(pkrelname, pk_rel);
    1701          86 :     quoteRelationName(fkrelname, fk_rel);
    1702         172 :     fk_only = fk_rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE ?
    1703          86 :         "" : "ONLY ";
    1704          86 :     appendStringInfo(&querybuf,
    1705             :                      " FROM %s%s fk JOIN %s pk ON",
    1706             :                      fk_only, fkrelname, pkrelname);
    1707          86 :     strcpy(pkattname, "pk.");
    1708          86 :     strcpy(fkattname, "fk.");
    1709          86 :     sep = "(";
    1710         172 :     for (i = 0; i < riinfo->nkeys; i++)
    1711             :     {
    1712          86 :         Oid         pk_type = RIAttType(pk_rel, riinfo->pk_attnums[i]);
    1713          86 :         Oid         fk_type = RIAttType(fk_rel, riinfo->fk_attnums[i]);
    1714          86 :         Oid         pk_coll = RIAttCollation(pk_rel, riinfo->pk_attnums[i]);
    1715          86 :         Oid         fk_coll = RIAttCollation(fk_rel, riinfo->fk_attnums[i]);
    1716             : 
    1717          86 :         quoteOneName(pkattname + 3,
    1718          86 :                      RIAttName(pk_rel, riinfo->pk_attnums[i]));
    1719          86 :         quoteOneName(fkattname + 3,
    1720          86 :                      RIAttName(fk_rel, riinfo->fk_attnums[i]));
    1721          86 :         ri_GenerateQual(&querybuf, sep,
    1722             :                         pkattname, pk_type,
    1723             :                         riinfo->pf_eq_oprs[i],
    1724             :                         fkattname, fk_type);
    1725          86 :         if (pk_coll != fk_coll)
    1726           0 :             ri_GenerateQualCollation(&querybuf, pk_coll);
    1727          86 :         sep = "AND";
    1728             :     }
    1729             : 
    1730             :     /*
    1731             :      * Start the WHERE clause with the partition constraint (except if this is
    1732             :      * the default partition and there's no other partition, because the
    1733             :      * partition constraint is the empty string in that case.)
    1734             :      */
    1735          86 :     constraintDef = pg_get_partconstrdef_string(RelationGetRelid(pk_rel), "pk");
    1736          86 :     if (constraintDef && constraintDef[0] != '\0')
    1737          86 :         appendStringInfo(&querybuf, ") WHERE %s AND (",
    1738             :                          constraintDef);
    1739             :     else
    1740           0 :         appendStringInfoString(&querybuf, ") WHERE (");
    1741             : 
    1742          86 :     sep = "";
    1743         172 :     for (i = 0; i < riinfo->nkeys; i++)
    1744             :     {
    1745          86 :         quoteOneName(fkattname, RIAttName(fk_rel, riinfo->fk_attnums[i]));
    1746          86 :         appendStringInfo(&querybuf,
    1747             :                          "%sfk.%s IS NOT NULL",
    1748             :                          sep, fkattname);
    1749          86 :         switch (riinfo->confmatchtype)
    1750             :         {
    1751          86 :             case FKCONSTR_MATCH_SIMPLE:
    1752          86 :                 sep = " AND ";
    1753          86 :                 break;
    1754           0 :             case FKCONSTR_MATCH_FULL:
    1755           0 :                 sep = " OR ";
    1756           0 :                 break;
    1757             :         }
    1758          86 :     }
    1759          86 :     appendStringInfoChar(&querybuf, ')');
    1760             : 
    1761             :     /*
    1762             :      * Temporarily increase work_mem so that the check query can be executed
    1763             :      * more efficiently.  It seems okay to do this because the query is simple
    1764             :      * enough to not use a multiple of work_mem, and one typically would not
    1765             :      * have many large foreign-key validations happening concurrently.  So
    1766             :      * this seems to meet the criteria for being considered a "maintenance"
    1767             :      * operation, and accordingly we use maintenance_work_mem.  However, we
    1768             :      * must also set hash_mem_multiplier to 1, since it is surely not okay to
    1769             :      * let that get applied to the maintenance_work_mem value.
    1770             :      *
    1771             :      * We use the equivalent of a function SET option to allow the setting to
    1772             :      * persist for exactly the duration of the check query.  guc.c also takes
    1773             :      * care of undoing the setting on error.
    1774             :      */
    1775          86 :     save_nestlevel = NewGUCNestLevel();
    1776             : 
    1777          86 :     snprintf(workmembuf, sizeof(workmembuf), "%d", maintenance_work_mem);
    1778          86 :     (void) set_config_option("work_mem", workmembuf,
    1779             :                              PGC_USERSET, PGC_S_SESSION,
    1780             :                              GUC_ACTION_SAVE, true, 0, false);
    1781          86 :     (void) set_config_option("hash_mem_multiplier", "1",
    1782             :                              PGC_USERSET, PGC_S_SESSION,
    1783             :                              GUC_ACTION_SAVE, true, 0, false);
    1784             : 
    1785          86 :     if (SPI_connect() != SPI_OK_CONNECT)
    1786           0 :         elog(ERROR, "SPI_connect failed");
    1787             : 
    1788             :     /*
    1789             :      * Generate the plan.  We don't need to cache it, and there are no
    1790             :      * arguments to the plan.
    1791             :      */
    1792          86 :     qplan = SPI_prepare(querybuf.data, 0, NULL);
    1793             : 
    1794          86 :     if (qplan == NULL)
    1795           0 :         elog(ERROR, "SPI_prepare returned %s for %s",
    1796             :              SPI_result_code_string(SPI_result), querybuf.data);
    1797             : 
    1798             :     /*
    1799             :      * Run the plan.  For safety we force a current snapshot to be used. (In
    1800             :      * transaction-snapshot mode, this arguably violates transaction isolation
    1801             :      * rules, but we really haven't got much choice.) We don't need to
    1802             :      * register the snapshot, because SPI_execute_snapshot will see to it. We
    1803             :      * need at most one tuple returned, so pass limit = 1.
    1804             :      */
    1805          86 :     spi_result = SPI_execute_snapshot(qplan,
    1806             :                                       NULL, NULL,
    1807             :                                       GetLatestSnapshot(),
    1808             :                                       InvalidSnapshot,
    1809             :                                       true, false, 1);
    1810             : 
    1811             :     /* Check result */
    1812          86 :     if (spi_result != SPI_OK_SELECT)
    1813           0 :         elog(ERROR, "SPI_execute_snapshot returned %s", SPI_result_code_string(spi_result));
    1814             : 
    1815             :     /* Did we find a tuple that would violate the constraint? */
    1816          86 :     if (SPI_processed > 0)
    1817             :     {
    1818             :         TupleTableSlot *slot;
    1819          34 :         HeapTuple   tuple = SPI_tuptable->vals[0];
    1820          34 :         TupleDesc   tupdesc = SPI_tuptable->tupdesc;
    1821             :         RI_ConstraintInfo fake_riinfo;
    1822             : 
    1823          34 :         slot = MakeSingleTupleTableSlot(tupdesc, &TTSOpsVirtual);
    1824             : 
    1825          34 :         heap_deform_tuple(tuple, tupdesc,
    1826             :                           slot->tts_values, slot->tts_isnull);
    1827          34 :         ExecStoreVirtualTuple(slot);
    1828             : 
    1829             :         /*
    1830             :          * The columns to look at in the result tuple are 1..N, not whatever
    1831             :          * they are in the fk_rel.  Hack up riinfo so that ri_ReportViolation
    1832             :          * will behave properly.
    1833             :          *
    1834             :          * In addition to this, we have to pass the correct tupdesc to
    1835             :          * ri_ReportViolation, overriding its normal habit of using the pk_rel
    1836             :          * or fk_rel's tupdesc.
    1837             :          */
    1838          34 :         memcpy(&fake_riinfo, riinfo, sizeof(RI_ConstraintInfo));
    1839          68 :         for (i = 0; i < fake_riinfo.nkeys; i++)
    1840          34 :             fake_riinfo.pk_attnums[i] = i + 1;
    1841             : 
    1842          34 :         ri_ReportViolation(&fake_riinfo, pk_rel, fk_rel,
    1843             :                            slot, tupdesc, 0, true);
    1844             :     }
    1845             : 
    1846          52 :     if (SPI_finish() != SPI_OK_FINISH)
    1847           0 :         elog(ERROR, "SPI_finish failed");
    1848             : 
    1849             :     /*
    1850             :      * Restore work_mem and hash_mem_multiplier.
    1851             :      */
    1852          52 :     AtEOXact_GUC(true, save_nestlevel);
    1853          52 : }
    1854             : 
    1855             : 
    1856             : /* ----------
    1857             :  * Local functions below
    1858             :  * ----------
    1859             :  */
    1860             : 
    1861             : 
    1862             : /*
    1863             :  * quoteOneName --- safely quote a single SQL name
    1864             :  *
    1865             :  * buffer must be MAX_QUOTED_NAME_LEN long (includes room for \0)
    1866             :  */
    1867             : static void
    1868       19748 : quoteOneName(char *buffer, const char *name)
    1869             : {
    1870             :     /* Rather than trying to be smart, just always quote it. */
    1871       19748 :     *buffer++ = '"';
    1872      117296 :     while (*name)
    1873             :     {
    1874       97548 :         if (*name == '"')
    1875           0 :             *buffer++ = '"';
    1876       97548 :         *buffer++ = *name++;
    1877             :     }
    1878       19748 :     *buffer++ = '"';
    1879       19748 :     *buffer = '\0';
    1880       19748 : }
    1881             : 
    1882             : /*
    1883             :  * quoteRelationName --- safely quote a fully qualified relation name
    1884             :  *
    1885             :  * buffer must be MAX_QUOTED_REL_NAME_LEN long (includes room for \0)
    1886             :  */
    1887             : static void
    1888        4948 : quoteRelationName(char *buffer, Relation rel)
    1889             : {
    1890        4948 :     quoteOneName(buffer, get_namespace_name(RelationGetNamespace(rel)));
    1891        4948 :     buffer += strlen(buffer);
    1892        4948 :     *buffer++ = '.';
    1893        4948 :     quoteOneName(buffer, RelationGetRelationName(rel));
    1894        4948 : }
    1895             : 
    1896             : /*
    1897             :  * ri_GenerateQual --- generate a WHERE clause equating two variables
    1898             :  *
    1899             :  * This basically appends " sep leftop op rightop" to buf, adding casts
    1900             :  * and schema qualification as needed to ensure that the parser will select
    1901             :  * the operator we specify.  leftop and rightop should be parenthesized
    1902             :  * if they aren't variables or parameters.
    1903             :  */
    1904             : static void
    1905        4870 : ri_GenerateQual(StringInfo buf,
    1906             :                 const char *sep,
    1907             :                 const char *leftop, Oid leftoptype,
    1908             :                 Oid opoid,
    1909             :                 const char *rightop, Oid rightoptype)
    1910             : {
    1911        4870 :     appendStringInfo(buf, " %s ", sep);
    1912        4870 :     generate_operator_clause(buf, leftop, leftoptype, opoid,
    1913             :                              rightop, rightoptype);
    1914        4870 : }
    1915             : 
    1916             : /*
    1917             :  * ri_GenerateQualCollation --- add a COLLATE spec to a WHERE clause
    1918             :  *
    1919             :  * At present, we intentionally do not use this function for RI queries that
    1920             :  * compare a variable to a $n parameter.  Since parameter symbols always have
    1921             :  * default collation, the effect will be to use the variable's collation.
    1922             :  * Now that is only strictly correct when testing the referenced column, since
    1923             :  * the SQL standard specifies that RI comparisons should use the referenced
    1924             :  * column's collation.  However, so long as all collations have the same
    1925             :  * notion of equality (which they do, because texteq reduces to bitwise
    1926             :  * equality), there's no visible semantic impact from using the referencing
    1927             :  * column's collation when testing it, and this is a good thing to do because
    1928             :  * it lets us use a normal index on the referencing column.  However, we do
    1929             :  * have to use this function when directly comparing the referencing and
    1930             :  * referenced columns, if they are of different collations; else the parser
    1931             :  * will fail to resolve the collation to use.
    1932             :  */
    1933             : static void
    1934          12 : ri_GenerateQualCollation(StringInfo buf, Oid collation)
    1935             : {
    1936             :     HeapTuple   tp;
    1937             :     Form_pg_collation colltup;
    1938             :     char       *collname;
    1939             :     char        onename[MAX_QUOTED_NAME_LEN];
    1940             : 
    1941             :     /* Nothing to do if it's a noncollatable data type */
    1942          12 :     if (!OidIsValid(collation))
    1943           0 :         return;
    1944             : 
    1945          12 :     tp = SearchSysCache1(COLLOID, ObjectIdGetDatum(collation));
    1946          12 :     if (!HeapTupleIsValid(tp))
    1947           0 :         elog(ERROR, "cache lookup failed for collation %u", collation);
    1948          12 :     colltup = (Form_pg_collation) GETSTRUCT(tp);
    1949          12 :     collname = NameStr(colltup->collname);
    1950             : 
    1951             :     /*
    1952             :      * We qualify the name always, for simplicity and to ensure the query is
    1953             :      * not search-path-dependent.
    1954             :      */
    1955          12 :     quoteOneName(onename, get_namespace_name(colltup->collnamespace));
    1956          12 :     appendStringInfo(buf, " COLLATE %s", onename);
    1957          12 :     quoteOneName(onename, collname);
    1958          12 :     appendStringInfo(buf, ".%s", onename);
    1959             : 
    1960          12 :     ReleaseSysCache(tp);
    1961             : }
    1962             : 
    1963             : /* ----------
    1964             :  * ri_BuildQueryKey -
    1965             :  *
    1966             :  *  Construct a hashtable key for a prepared SPI plan of an FK constraint.
    1967             :  *
    1968             :  *      key: output argument, *key is filled in based on the other arguments
    1969             :  *      riinfo: info derived from pg_constraint entry
    1970             :  *      constr_queryno: an internal number identifying the query type
    1971             :  *          (see RI_PLAN_XXX constants at head of file)
    1972             :  * ----------
    1973             :  */
    1974             : static void
    1975        5756 : ri_BuildQueryKey(RI_QueryKey *key, const RI_ConstraintInfo *riinfo,
    1976             :                  int32 constr_queryno)
    1977             : {
    1978             :     /*
    1979             :      * Inherited constraints with a common ancestor can share ri_query_cache
    1980             :      * entries for all query types except RI_PLAN_CHECK_LOOKUPPK_FROM_PK.
    1981             :      * Except in that case, the query processes the other table involved in
    1982             :      * the FK constraint (i.e., not the table on which the trigger has been
    1983             :      * fired), and so it will be the same for all members of the inheritance
    1984             :      * tree.  So we may use the root constraint's OID in the hash key, rather
    1985             :      * than the constraint's own OID.  This avoids creating duplicate SPI
    1986             :      * plans, saving lots of work and memory when there are many partitions
    1987             :      * with similar FK constraints.
    1988             :      *
    1989             :      * (Note that we must still have a separate RI_ConstraintInfo for each
    1990             :      * constraint, because partitions can have different column orders,
    1991             :      * resulting in different pk_attnums[] or fk_attnums[] array contents.)
    1992             :      *
    1993             :      * We assume struct RI_QueryKey contains no padding bytes, else we'd need
    1994             :      * to use memset to clear them.
    1995             :      */
    1996        5756 :     if (constr_queryno != RI_PLAN_CHECK_LOOKUPPK_FROM_PK)
    1997        5018 :         key->constr_id = riinfo->constraint_root_id;
    1998             :     else
    1999         738 :         key->constr_id = riinfo->constraint_id;
    2000        5756 :     key->constr_queryno = constr_queryno;
    2001        5756 : }
    2002             : 
    2003             : /*
    2004             :  * Check that RI trigger function was called in expected context
    2005             :  */
    2006             : static void
    2007        5286 : ri_CheckTrigger(FunctionCallInfo fcinfo, const char *funcname, int tgkind)
    2008             : {
    2009        5286 :     TriggerData *trigdata = (TriggerData *) fcinfo->context;
    2010             : 
    2011        5286 :     if (!CALLED_AS_TRIGGER(fcinfo))
    2012           0 :         ereport(ERROR,
    2013             :                 (errcode(ERRCODE_E_R_I_E_TRIGGER_PROTOCOL_VIOLATED),
    2014             :                  errmsg("function \"%s\" was not called by trigger manager", funcname)));
    2015             : 
    2016             :     /*
    2017             :      * Check proper event
    2018             :      */
    2019        5286 :     if (!TRIGGER_FIRED_AFTER(trigdata->tg_event) ||
    2020        5286 :         !TRIGGER_FIRED_FOR_ROW(trigdata->tg_event))
    2021           0 :         ereport(ERROR,
    2022             :                 (errcode(ERRCODE_E_R_I_E_TRIGGER_PROTOCOL_VIOLATED),
    2023             :                  errmsg("function \"%s\" must be fired AFTER ROW", funcname)));
    2024             : 
    2025        5286 :     switch (tgkind)
    2026             :     {
    2027        3632 :         case RI_TRIGTYPE_INSERT:
    2028        3632 :             if (!TRIGGER_FIRED_BY_INSERT(trigdata->tg_event))
    2029           0 :                 ereport(ERROR,
    2030             :                         (errcode(ERRCODE_E_R_I_E_TRIGGER_PROTOCOL_VIOLATED),
    2031             :                          errmsg("function \"%s\" must be fired for INSERT", funcname)));
    2032        3632 :             break;
    2033        1012 :         case RI_TRIGTYPE_UPDATE:
    2034        1012 :             if (!TRIGGER_FIRED_BY_UPDATE(trigdata->tg_event))
    2035           0 :                 ereport(ERROR,
    2036             :                         (errcode(ERRCODE_E_R_I_E_TRIGGER_PROTOCOL_VIOLATED),
    2037             :                          errmsg("function \"%s\" must be fired for UPDATE", funcname)));
    2038        1012 :             break;
    2039         642 :         case RI_TRIGTYPE_DELETE:
    2040         642 :             if (!TRIGGER_FIRED_BY_DELETE(trigdata->tg_event))
    2041           0 :                 ereport(ERROR,
    2042             :                         (errcode(ERRCODE_E_R_I_E_TRIGGER_PROTOCOL_VIOLATED),
    2043             :                          errmsg("function \"%s\" must be fired for DELETE", funcname)));
    2044         642 :             break;
    2045             :     }
    2046        5286 : }
    2047             : 
    2048             : 
    2049             : /*
    2050             :  * Fetch the RI_ConstraintInfo struct for the trigger's FK constraint.
    2051             :  */
    2052             : static const RI_ConstraintInfo *
    2053        9364 : ri_FetchConstraintInfo(Trigger *trigger, Relation trig_rel, bool rel_is_pk)
    2054             : {
    2055        9364 :     Oid         constraintOid = trigger->tgconstraint;
    2056             :     const RI_ConstraintInfo *riinfo;
    2057             : 
    2058             :     /*
    2059             :      * Check that the FK constraint's OID is available; it might not be if
    2060             :      * we've been invoked via an ordinary trigger or an old-style "constraint
    2061             :      * trigger".
    2062             :      */
    2063        9364 :     if (!OidIsValid(constraintOid))
    2064           0 :         ereport(ERROR,
    2065             :                 (errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
    2066             :                  errmsg("no pg_constraint entry for trigger \"%s\" on table \"%s\"",
    2067             :                         trigger->tgname, RelationGetRelationName(trig_rel)),
    2068             :                  errhint("Remove this referential integrity trigger and its mates, then do ALTER TABLE ADD CONSTRAINT.")));
    2069             : 
    2070             :     /* Find or create a hashtable entry for the constraint */
    2071        9364 :     riinfo = ri_LoadConstraintInfo(constraintOid);
    2072             : 
    2073             :     /* Do some easy cross-checks against the trigger call data */
    2074        9364 :     if (rel_is_pk)
    2075             :     {
    2076        3332 :         if (riinfo->fk_relid != trigger->tgconstrrelid ||
    2077        3332 :             riinfo->pk_relid != RelationGetRelid(trig_rel))
    2078           0 :             elog(ERROR, "wrong pg_constraint entry for trigger \"%s\" on table \"%s\"",
    2079             :                  trigger->tgname, RelationGetRelationName(trig_rel));
    2080             :     }
    2081             :     else
    2082             :     {
    2083        6032 :         if (riinfo->fk_relid != RelationGetRelid(trig_rel) ||
    2084        6032 :             riinfo->pk_relid != trigger->tgconstrrelid)
    2085           0 :             elog(ERROR, "wrong pg_constraint entry for trigger \"%s\" on table \"%s\"",
    2086             :                  trigger->tgname, RelationGetRelationName(trig_rel));
    2087             :     }
    2088             : 
    2089        9364 :     if (riinfo->confmatchtype != FKCONSTR_MATCH_FULL &&
    2090        8900 :         riinfo->confmatchtype != FKCONSTR_MATCH_PARTIAL &&
    2091        8900 :         riinfo->confmatchtype != FKCONSTR_MATCH_SIMPLE)
    2092           0 :         elog(ERROR, "unrecognized confmatchtype: %d",
    2093             :              riinfo->confmatchtype);
    2094             : 
    2095        9364 :     if (riinfo->confmatchtype == FKCONSTR_MATCH_PARTIAL)
    2096           0 :         ereport(ERROR,
    2097             :                 (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
    2098             :                  errmsg("MATCH PARTIAL not yet implemented")));
    2099             : 
    2100        9364 :     return riinfo;
    2101             : }
    2102             : 
    2103             : /*
    2104             :  * Fetch or create the RI_ConstraintInfo struct for an FK constraint.
    2105             :  */
    2106             : static const RI_ConstraintInfo *
    2107        9364 : ri_LoadConstraintInfo(Oid constraintOid)
    2108             : {
    2109             :     RI_ConstraintInfo *riinfo;
    2110             :     bool        found;
    2111             :     HeapTuple   tup;
    2112             :     Form_pg_constraint conForm;
    2113             : 
    2114             :     /*
    2115             :      * On the first call initialize the hashtable
    2116             :      */
    2117        9364 :     if (!ri_constraint_cache)
    2118         402 :         ri_InitHashTables();
    2119             : 
    2120             :     /*
    2121             :      * Find or create a hash entry.  If we find a valid one, just return it.
    2122             :      */
    2123        9364 :     riinfo = (RI_ConstraintInfo *) hash_search(ri_constraint_cache,
    2124             :                                                (void *) &constraintOid,
    2125             :                                                HASH_ENTER, &found);
    2126        9364 :     if (!found)
    2127        3580 :         riinfo->valid = false;
    2128        5784 :     else if (riinfo->valid)
    2129        5598 :         return riinfo;
    2130             : 
    2131             :     /*
    2132             :      * Fetch the pg_constraint row so we can fill in the entry.
    2133             :      */
    2134        3766 :     tup = SearchSysCache1(CONSTROID, ObjectIdGetDatum(constraintOid));
    2135        3766 :     if (!HeapTupleIsValid(tup)) /* should not happen */
    2136           0 :         elog(ERROR, "cache lookup failed for constraint %u", constraintOid);
    2137        3766 :     conForm = (Form_pg_constraint) GETSTRUCT(tup);
    2138             : 
    2139        3766 :     if (conForm->contype != CONSTRAINT_FOREIGN) /* should not happen */
    2140           0 :         elog(ERROR, "constraint %u is not a foreign key constraint",
    2141             :              constraintOid);
    2142             : 
    2143             :     /* And extract data */
    2144             :     Assert(riinfo->constraint_id == constraintOid);
    2145        3766 :     if (OidIsValid(conForm->conparentid))
    2146        1294 :         riinfo->constraint_root_id =
    2147        1294 :             get_ri_constraint_root(conForm->conparentid);
    2148             :     else
    2149        2472 :         riinfo->constraint_root_id = constraintOid;
    2150        3766 :     riinfo->oidHashValue = GetSysCacheHashValue1(CONSTROID,
    2151             :                                                  ObjectIdGetDatum(constraintOid));
    2152        3766 :     riinfo->rootHashValue = GetSysCacheHashValue1(CONSTROID,
    2153             :                                                   ObjectIdGetDatum(riinfo->constraint_root_id));
    2154        3766 :     memcpy(&riinfo->conname, &conForm->conname, sizeof(NameData));
    2155        3766 :     riinfo->pk_relid = conForm->confrelid;
    2156        3766 :     riinfo->fk_relid = conForm->conrelid;
    2157        3766 :     riinfo->confupdtype = conForm->confupdtype;
    2158        3766 :     riinfo->confdeltype = conForm->confdeltype;
    2159        3766 :     riinfo->confmatchtype = conForm->confmatchtype;
    2160             : 
    2161        3766 :     DeconstructFkConstraintRow(tup,
    2162             :                                &riinfo->nkeys,
    2163        3766 :                                riinfo->fk_attnums,
    2164        3766 :                                riinfo->pk_attnums,
    2165        3766 :                                riinfo->pf_eq_oprs,
    2166        3766 :                                riinfo->pp_eq_oprs,
    2167        3766 :                                riinfo->ff_eq_oprs,
    2168             :                                &riinfo->ndelsetcols,
    2169        3766 :                                riinfo->confdelsetcols);
    2170             : 
    2171        3766 :     ReleaseSysCache(tup);
    2172             : 
    2173             :     /*
    2174             :      * For efficient processing of invalidation messages below, we keep a
    2175             :      * doubly-linked list, and a count, of all currently valid entries.
    2176             :      */
    2177        3766 :     dlist_push_tail(&ri_constraint_cache_valid_list, &riinfo->valid_link);
    2178        3766 :     ri_constraint_cache_valid_count++;
    2179             : 
    2180        3766 :     riinfo->valid = true;
    2181             : 
    2182        3766 :     return riinfo;
    2183             : }
    2184             : 
    2185             : /*
    2186             :  * get_ri_constraint_root
    2187             :  *      Returns the OID of the constraint's root parent
    2188             :  */
    2189             : static Oid
    2190        1570 : get_ri_constraint_root(Oid constrOid)
    2191             : {
    2192             :     for (;;)
    2193         276 :     {
    2194             :         HeapTuple   tuple;
    2195             :         Oid         constrParentOid;
    2196             : 
    2197        1570 :         tuple = SearchSysCache1(CONSTROID, ObjectIdGetDatum(constrOid));
    2198        1570 :         if (!HeapTupleIsValid(tuple))
    2199           0 :             elog(ERROR, "cache lookup failed for constraint %u", constrOid);
    2200        1570 :         constrParentOid = ((Form_pg_constraint) GETSTRUCT(tuple))->conparentid;
    2201        1570 :         ReleaseSysCache(tuple);
    2202        1570 :         if (!OidIsValid(constrParentOid))
    2203        1294 :             break;              /* we reached the root constraint */
    2204         276 :         constrOid = constrParentOid;
    2205             :     }
    2206        1294 :     return constrOid;
    2207             : }
    2208             : 
    2209             : /*
    2210             :  * Callback for pg_constraint inval events
    2211             :  *
    2212             :  * While most syscache callbacks just flush all their entries, pg_constraint
    2213             :  * gets enough update traffic that it's probably worth being smarter.
    2214             :  * Invalidate any ri_constraint_cache entry associated with the syscache
    2215             :  * entry with the specified hash value, or all entries if hashvalue == 0.
    2216             :  *
    2217             :  * Note: at the time a cache invalidation message is processed there may be
    2218             :  * active references to the cache.  Because of this we never remove entries
    2219             :  * from the cache, but only mark them invalid, which is harmless to active
    2220             :  * uses.  (Any query using an entry should hold a lock sufficient to keep that
    2221             :  * data from changing under it --- but we may get cache flushes anyway.)
    2222             :  */
    2223             : static void
    2224       33796 : InvalidateConstraintCacheCallBack(Datum arg, int cacheid, uint32 hashvalue)
    2225             : {
    2226             :     dlist_mutable_iter iter;
    2227             : 
    2228             :     Assert(ri_constraint_cache != NULL);
    2229             : 
    2230             :     /*
    2231             :      * If the list of currently valid entries gets excessively large, we mark
    2232             :      * them all invalid so we can empty the list.  This arrangement avoids
    2233             :      * O(N^2) behavior in situations where a session touches many foreign keys
    2234             :      * and also does many ALTER TABLEs, such as a restore from pg_dump.
    2235             :      */
    2236       33796 :     if (ri_constraint_cache_valid_count > 1000)
    2237           0 :         hashvalue = 0;          /* pretend it's a cache reset */
    2238             : 
    2239      141238 :     dlist_foreach_modify(iter, &ri_constraint_cache_valid_list)
    2240             :     {
    2241      107442 :         RI_ConstraintInfo *riinfo = dlist_container(RI_ConstraintInfo,
    2242             :                                                     valid_link, iter.cur);
    2243             : 
    2244             :         /*
    2245             :          * We must invalidate not only entries directly matching the given
    2246             :          * hash value, but also child entries, in case the invalidation
    2247             :          * affects a root constraint.
    2248             :          */
    2249      107442 :         if (hashvalue == 0 ||
    2250      107440 :             riinfo->oidHashValue == hashvalue ||
    2251      105262 :             riinfo->rootHashValue == hashvalue)
    2252             :         {
    2253        2440 :             riinfo->valid = false;
    2254             :             /* Remove invalidated entries from the list, too */
    2255        2440 :             dlist_delete(iter.cur);
    2256        2440 :             ri_constraint_cache_valid_count--;
    2257             :         }
    2258             :     }
    2259       33796 : }
    2260             : 
    2261             : 
    2262             : /*
    2263             :  * Prepare execution plan for a query to enforce an RI restriction
    2264             :  */
    2265             : static SPIPlanPtr
    2266        3000 : ri_PlanCheck(const char *querystr, int nargs, Oid *argtypes,
    2267             :              RI_QueryKey *qkey, Relation fk_rel, Relation pk_rel)
    2268             : {
    2269             :     SPIPlanPtr  qplan;
    2270             :     Relation    query_rel;
    2271             :     Oid         save_userid;
    2272             :     int         save_sec_context;
    2273             : 
    2274             :     /*
    2275             :      * Use the query type code to determine whether the query is run against
    2276             :      * the PK or FK table; we'll do the check as that table's owner
    2277             :      */
    2278        3000 :     if (qkey->constr_queryno <= RI_PLAN_LAST_ON_PK)
    2279        2358 :         query_rel = pk_rel;
    2280             :     else
    2281         642 :         query_rel = fk_rel;
    2282             : 
    2283             :     /* Switch to proper UID to perform check as */
    2284        3000 :     GetUserIdAndSecContext(&save_userid, &save_sec_context);
    2285        3000 :     SetUserIdAndSecContext(RelationGetForm(query_rel)->relowner,
    2286             :                            save_sec_context | SECURITY_LOCAL_USERID_CHANGE |
    2287             :                            SECURITY_NOFORCE_RLS);
    2288             : 
    2289             :     /* Create the plan */
    2290        3000 :     qplan = SPI_prepare(querystr, nargs, argtypes);
    2291             : 
    2292        3000 :     if (qplan == NULL)
    2293           0 :         elog(ERROR, "SPI_prepare returned %s for %s", SPI_result_code_string(SPI_result), querystr);
    2294             : 
    2295             :     /* Restore UID and security context */
    2296        3000 :     SetUserIdAndSecContext(save_userid, save_sec_context);
    2297             : 
    2298             :     /* Save the plan */
    2299        3000 :     SPI_keepplan(qplan);
    2300        3000 :     ri_HashPreparedPlan(qkey, qplan);
    2301             : 
    2302        3000 :     return qplan;
    2303             : }
    2304             : 
    2305             : /*
    2306             :  * Perform a query to enforce an RI restriction
    2307             :  */
    2308             : static bool
    2309        5756 : ri_PerformCheck(const RI_ConstraintInfo *riinfo,
    2310             :                 RI_QueryKey *qkey, SPIPlanPtr qplan,
    2311             :                 Relation fk_rel, Relation pk_rel,
    2312             :                 TupleTableSlot *oldslot, TupleTableSlot *newslot,
    2313             :                 bool detectNewRows, int expect_OK)
    2314             : {
    2315             :     Relation    query_rel,
    2316             :                 source_rel;
    2317             :     bool        source_is_pk;
    2318             :     Snapshot    test_snapshot;
    2319             :     Snapshot    crosscheck_snapshot;
    2320             :     int         limit;
    2321             :     int         spi_result;
    2322             :     Oid         save_userid;
    2323             :     int         save_sec_context;
    2324             :     Datum       vals[RI_MAX_NUMKEYS * 2];
    2325             :     char        nulls[RI_MAX_NUMKEYS * 2];
    2326             : 
    2327             :     /*
    2328             :      * Use the query type code to determine whether the query is run against
    2329             :      * the PK or FK table; we'll do the check as that table's owner
    2330             :      */
    2331        5756 :     if (qkey->constr_queryno <= RI_PLAN_LAST_ON_PK)
    2332        4434 :         query_rel = pk_rel;
    2333             :     else
    2334        1322 :         query_rel = fk_rel;
    2335             : 
    2336             :     /*
    2337             :      * The values for the query are taken from the table on which the trigger
    2338             :      * is called - it is normally the other one with respect to query_rel. An
    2339             :      * exception is ri_Check_Pk_Match(), which uses the PK table for both (and
    2340             :      * sets queryno to RI_PLAN_CHECK_LOOKUPPK_FROM_PK).  We might eventually
    2341             :      * need some less klugy way to determine this.
    2342             :      */
    2343        5756 :     if (qkey->constr_queryno == RI_PLAN_CHECK_LOOKUPPK)
    2344             :     {
    2345        3696 :         source_rel = fk_rel;
    2346        3696 :         source_is_pk = false;
    2347             :     }
    2348             :     else
    2349             :     {
    2350        2060 :         source_rel = pk_rel;
    2351        2060 :         source_is_pk = true;
    2352             :     }
    2353             : 
    2354             :     /* Extract the parameters to be passed into the query */
    2355        5756 :     if (newslot)
    2356             :     {
    2357        3894 :         ri_ExtractValues(source_rel, newslot, riinfo, source_is_pk,
    2358             :                          vals, nulls);
    2359        3894 :         if (oldslot)
    2360         198 :             ri_ExtractValues(source_rel, oldslot, riinfo, source_is_pk,
    2361         198 :                              vals + riinfo->nkeys, nulls + riinfo->nkeys);
    2362             :     }
    2363             :     else
    2364             :     {
    2365        1862 :         ri_ExtractValues(source_rel, oldslot, riinfo, source_is_pk,
    2366             :                          vals, nulls);
    2367             :     }
    2368             : 
    2369             :     /*
    2370             :      * In READ COMMITTED mode, we just need to use an up-to-date regular
    2371             :      * snapshot, and we will see all rows that could be interesting. But in
    2372             :      * transaction-snapshot mode, we can't change the transaction snapshot. If
    2373             :      * the caller passes detectNewRows == false then it's okay to do the query
    2374             :      * with the transaction snapshot; otherwise we use a current snapshot, and
    2375             :      * tell the executor to error out if it finds any rows under the current
    2376             :      * snapshot that wouldn't be visible per the transaction snapshot.  Note
    2377             :      * that SPI_execute_snapshot will register the snapshots, so we don't need
    2378             :      * to bother here.
    2379             :      */
    2380        5756 :     if (IsolationUsesXactSnapshot() && detectNewRows)
    2381             :     {
    2382          26 :         CommandCounterIncrement();  /* be sure all my own work is visible */
    2383          26 :         test_snapshot = GetLatestSnapshot();
    2384          26 :         crosscheck_snapshot = GetTransactionSnapshot();
    2385             :     }
    2386             :     else
    2387             :     {
    2388             :         /* the default SPI behavior is okay */
    2389        5730 :         test_snapshot = InvalidSnapshot;
    2390        5730 :         crosscheck_snapshot = InvalidSnapshot;
    2391             :     }
    2392             : 
    2393             :     /*
    2394             :      * If this is a select query (e.g., for a 'no action' or 'restrict'
    2395             :      * trigger), we only need to see if there is a single row in the table,
    2396             :      * matching the key.  Otherwise, limit = 0 - because we want the query to
    2397             :      * affect ALL the matching rows.
    2398             :      */
    2399        5756 :     limit = (expect_OK == SPI_OK_SELECT) ? 1 : 0;
    2400             : 
    2401             :     /* Switch to proper UID to perform check as */
    2402        5756 :     GetUserIdAndSecContext(&save_userid, &save_sec_context);
    2403        5756 :     SetUserIdAndSecContext(RelationGetForm(query_rel)->relowner,
    2404             :                            save_sec_context | SECURITY_LOCAL_USERID_CHANGE |
    2405             :                            SECURITY_NOFORCE_RLS);
    2406             : 
    2407             :     /* Finally we can run the query. */
    2408        5756 :     spi_result = SPI_execute_snapshot(qplan,
    2409             :                                       vals, nulls,
    2410             :                                       test_snapshot, crosscheck_snapshot,
    2411             :                                       false, false, limit);
    2412             : 
    2413             :     /* Restore UID and security context */
    2414        5746 :     SetUserIdAndSecContext(save_userid, save_sec_context);
    2415             : 
    2416             :     /* Check result */
    2417        5746 :     if (spi_result < 0)
    2418           0 :         elog(ERROR, "SPI_execute_snapshot returned %s", SPI_result_code_string(spi_result));
    2419             : 
    2420        5746 :     if (expect_OK >= 0 && spi_result != expect_OK)
    2421           0 :         ereport(ERROR,
    2422             :                 (errcode(ERRCODE_INTERNAL_ERROR),
    2423             :                  errmsg("referential integrity query on \"%s\" from constraint \"%s\" on \"%s\" gave unexpected result",
    2424             :                         RelationGetRelationName(pk_rel),
    2425             :                         NameStr(riinfo->conname),
    2426             :                         RelationGetRelationName(fk_rel)),
    2427             :                  errhint("This is most likely due to a rule having rewritten the query.")));
    2428             : 
    2429             :     /* XXX wouldn't it be clearer to do this part at the caller? */
    2430        5746 :     if (qkey->constr_queryno != RI_PLAN_CHECK_LOOKUPPK_FROM_PK &&
    2431        4408 :         expect_OK == SPI_OK_SELECT &&
    2432        4408 :         (SPI_processed == 0) == (qkey->constr_queryno == RI_PLAN_CHECK_LOOKUPPK))
    2433         764 :         ri_ReportViolation(riinfo,
    2434             :                            pk_rel, fk_rel,
    2435             :                            newslot ? newslot : oldslot,
    2436             :                            NULL,
    2437             :                            qkey->constr_queryno, false);
    2438             : 
    2439        4982 :     return SPI_processed != 0;
    2440             : }
    2441             : 
    2442             : /*
    2443             :  * Extract fields from a tuple into Datum/nulls arrays
    2444             :  */
    2445             : static void
    2446        5954 : ri_ExtractValues(Relation rel, TupleTableSlot *slot,
    2447             :                  const RI_ConstraintInfo *riinfo, bool rel_is_pk,
    2448             :                  Datum *vals, char *nulls)
    2449             : {
    2450             :     const int16 *attnums;
    2451             :     bool        isnull;
    2452             : 
    2453        5954 :     if (rel_is_pk)
    2454        2258 :         attnums = riinfo->pk_attnums;
    2455             :     else
    2456        3696 :         attnums = riinfo->fk_attnums;
    2457             : 
    2458       13510 :     for (int i = 0; i < riinfo->nkeys; i++)
    2459             :     {
    2460        7556 :         vals[i] = slot_getattr(slot, attnums[i], &isnull);
    2461        7556 :         nulls[i] = isnull ? 'n' : ' ';
    2462             :     }
    2463        5954 : }
    2464             : 
    2465             : /*
    2466             :  * Produce an error report
    2467             :  *
    2468             :  * If the failed constraint was on insert/update to the FK table,
    2469             :  * we want the key names and values extracted from there, and the error
    2470             :  * message to look like 'key blah is not present in PK'.
    2471             :  * Otherwise, the attr names and values come from the PK table and the
    2472             :  * message looks like 'key blah is still referenced from FK'.
    2473             :  */
    2474             : static void
    2475         842 : ri_ReportViolation(const RI_ConstraintInfo *riinfo,
    2476             :                    Relation pk_rel, Relation fk_rel,
    2477             :                    TupleTableSlot *violatorslot, TupleDesc tupdesc,
    2478             :                    int queryno, bool partgone)
    2479             : {
    2480             :     StringInfoData key_names;
    2481             :     StringInfoData key_values;
    2482             :     bool        onfk;
    2483             :     const int16 *attnums;
    2484             :     Oid         rel_oid;
    2485             :     AclResult   aclresult;
    2486         842 :     bool        has_perm = true;
    2487             : 
    2488             :     /*
    2489             :      * Determine which relation to complain about.  If tupdesc wasn't passed
    2490             :      * by caller, assume the violator tuple came from there.
    2491             :      */
    2492         842 :     onfk = (queryno == RI_PLAN_CHECK_LOOKUPPK);
    2493         842 :     if (onfk)
    2494             :     {
    2495         498 :         attnums = riinfo->fk_attnums;
    2496         498 :         rel_oid = fk_rel->rd_id;
    2497         498 :         if (tupdesc == NULL)
    2498         454 :             tupdesc = fk_rel->rd_att;
    2499             :     }
    2500             :     else
    2501             :     {
    2502         344 :         attnums = riinfo->pk_attnums;
    2503         344 :         rel_oid = pk_rel->rd_id;
    2504         344 :         if (tupdesc == NULL)
    2505         310 :             tupdesc = pk_rel->rd_att;
    2506             :     }
    2507             : 
    2508             :     /*
    2509             :      * Check permissions- if the user does not have access to view the data in
    2510             :      * any of the key columns then we don't include the errdetail() below.
    2511             :      *
    2512             :      * Check if RLS is enabled on the relation first.  If so, we don't return
    2513             :      * any specifics to avoid leaking data.
    2514             :      *
    2515             :      * Check table-level permissions next and, failing that, column-level
    2516             :      * privileges.
    2517             :      *
    2518             :      * When a partition at the referenced side is being detached/dropped, we
    2519             :      * needn't check, since the user must be the table owner anyway.
    2520             :      */
    2521         842 :     if (partgone)
    2522          34 :         has_perm = true;
    2523         808 :     else if (check_enable_rls(rel_oid, InvalidOid, true) != RLS_ENABLED)
    2524             :     {
    2525         802 :         aclresult = pg_class_aclcheck(rel_oid, GetUserId(), ACL_SELECT);
    2526         802 :         if (aclresult != ACLCHECK_OK)
    2527             :         {
    2528             :             /* Try for column-level permissions */
    2529           0 :             for (int idx = 0; idx < riinfo->nkeys; idx++)
    2530             :             {
    2531           0 :                 aclresult = pg_attribute_aclcheck(rel_oid, attnums[idx],
    2532             :                                                   GetUserId(),
    2533             :                                                   ACL_SELECT);
    2534             : 
    2535             :                 /* No access to the key */
    2536           0 :                 if (aclresult != ACLCHECK_OK)
    2537             :                 {
    2538           0 :                     has_perm = false;
    2539           0 :                     break;
    2540             :                 }
    2541             :             }
    2542             :         }
    2543             :     }
    2544             :     else
    2545           6 :         has_perm = false;
    2546             : 
    2547         842 :     if (has_perm)
    2548             :     {
    2549             :         /* Get printable versions of the keys involved */
    2550         836 :         initStringInfo(&key_names);
    2551         836 :         initStringInfo(&key_values);
    2552        1966 :         for (int idx = 0; idx < riinfo->nkeys; idx++)
    2553             :         {
    2554        1130 :             int         fnum = attnums[idx];
    2555        1130 :             Form_pg_attribute att = TupleDescAttr(tupdesc, fnum - 1);
    2556             :             char       *name,
    2557             :                        *val;
    2558             :             Datum       datum;
    2559             :             bool        isnull;
    2560             : 
    2561        1130 :             name = NameStr(att->attname);
    2562             : 
    2563        1130 :             datum = slot_getattr(violatorslot, fnum, &isnull);
    2564        1130 :             if (!isnull)
    2565             :             {
    2566             :                 Oid         foutoid;
    2567             :                 bool        typisvarlena;
    2568             : 
    2569        1130 :                 getTypeOutputInfo(att->atttypid, &foutoid, &typisvarlena);
    2570        1130 :                 val = OidOutputFunctionCall(foutoid, datum);
    2571             :             }
    2572             :             else
    2573           0 :                 val = "null";
    2574             : 
    2575        1130 :             if (idx > 0)
    2576             :             {
    2577         294 :                 appendStringInfoString(&key_names, ", ");
    2578         294 :                 appendStringInfoString(&key_values, ", ");
    2579             :             }
    2580        1130 :             appendStringInfoString(&key_names, name);
    2581        1130 :             appendStringInfoString(&key_values, val);
    2582             :         }
    2583             :     }
    2584             : 
    2585         842 :     if (partgone)
    2586          34 :         ereport(ERROR,
    2587             :                 (errcode(ERRCODE_FOREIGN_KEY_VIOLATION),
    2588             :                  errmsg("removing partition \"%s\" violates foreign key constraint \"%s\"",
    2589             :                         RelationGetRelationName(pk_rel),
    2590             :                         NameStr(riinfo->conname)),
    2591             :                  errdetail("Key (%s)=(%s) is still referenced from table \"%s\".",
    2592             :                            key_names.data, key_values.data,
    2593             :                            RelationGetRelationName(fk_rel)),
    2594             :                  errtableconstraint(fk_rel, NameStr(riinfo->conname))));
    2595         808 :     else if (onfk)
    2596         498 :         ereport(ERROR,
    2597             :                 (errcode(ERRCODE_FOREIGN_KEY_VIOLATION),
    2598             :                  errmsg("insert or update on table \"%s\" violates foreign key constraint \"%s\"",
    2599             :                         RelationGetRelationName(fk_rel),
    2600             :                         NameStr(riinfo->conname)),
    2601             :                  has_perm ?
    2602             :                  errdetail("Key (%s)=(%s) is not present in table \"%s\".",
    2603             :                            key_names.data, key_values.data,
    2604             :                            RelationGetRelationName(pk_rel)) :
    2605             :                  errdetail("Key is not present in table \"%s\".",
    2606             :                            RelationGetRelationName(pk_rel)),
    2607             :                  errtableconstraint(fk_rel, NameStr(riinfo->conname))));
    2608             :     else
    2609         310 :         ereport(ERROR,
    2610             :                 (errcode(ERRCODE_FOREIGN_KEY_VIOLATION),
    2611             :                  errmsg("update or delete on table \"%s\" violates foreign key constraint \"%s\" on table \"%s\"",
    2612             :                         RelationGetRelationName(pk_rel),
    2613             :                         NameStr(riinfo->conname),
    2614             :                         RelationGetRelationName(fk_rel)),
    2615             :                  has_perm ?
    2616             :                  errdetail("Key (%s)=(%s) is still referenced from table \"%s\".",
    2617             :                            key_names.data, key_values.data,
    2618             :                            RelationGetRelationName(fk_rel)) :
    2619             :                  errdetail("Key is still referenced from table \"%s\".",
    2620             :                            RelationGetRelationName(fk_rel)),
    2621             :                  errtableconstraint(fk_rel, NameStr(riinfo->conname))));
    2622             : }
    2623             : 
    2624             : 
    2625             : /*
    2626             :  * ri_NullCheck -
    2627             :  *
    2628             :  * Determine the NULL state of all key values in a tuple
    2629             :  *
    2630             :  * Returns one of RI_KEYS_ALL_NULL, RI_KEYS_NONE_NULL or RI_KEYS_SOME_NULL.
    2631             :  */
    2632             : static int
    2633        6968 : ri_NullCheck(TupleDesc tupDesc,
    2634             :              TupleTableSlot *slot,
    2635             :              const RI_ConstraintInfo *riinfo, bool rel_is_pk)
    2636             : {
    2637             :     const int16 *attnums;
    2638        6968 :     bool        allnull = true;
    2639        6968 :     bool        nonenull = true;
    2640             : 
    2641        6968 :     if (rel_is_pk)
    2642        1958 :         attnums = riinfo->pk_attnums;
    2643             :     else
    2644        5010 :         attnums = riinfo->fk_attnums;
    2645             : 
    2646       15616 :     for (int i = 0; i < riinfo->nkeys; i++)
    2647             :     {
    2648        8648 :         if (slot_attisnull(slot, attnums[i]))
    2649         534 :             nonenull = false;
    2650             :         else
    2651        8114 :             allnull = false;
    2652             :     }
    2653             : 
    2654        6968 :     if (allnull)
    2655         258 :         return RI_KEYS_ALL_NULL;
    2656             : 
    2657        6710 :     if (nonenull)
    2658        6506 :         return RI_KEYS_NONE_NULL;
    2659             : 
    2660         204 :     return RI_KEYS_SOME_NULL;
    2661             : }
    2662             : 
    2663             : 
    2664             : /*
    2665             :  * ri_InitHashTables -
    2666             :  *
    2667             :  * Initialize our internal hash tables.
    2668             :  */
    2669             : static void
    2670         402 : ri_InitHashTables(void)
    2671             : {
    2672             :     HASHCTL     ctl;
    2673             : 
    2674         402 :     ctl.keysize = sizeof(Oid);
    2675         402 :     ctl.entrysize = sizeof(RI_ConstraintInfo);
    2676         402 :     ri_constraint_cache = hash_create("RI constraint cache",
    2677             :                                       RI_INIT_CONSTRAINTHASHSIZE,
    2678             :                                       &ctl, HASH_ELEM | HASH_BLOBS);
    2679             : 
    2680             :     /* Arrange to flush cache on pg_constraint changes */
    2681         402 :     CacheRegisterSyscacheCallback(CONSTROID,
    2682             :                                   InvalidateConstraintCacheCallBack,
    2683             :                                   (Datum) 0);
    2684             : 
    2685         402 :     ctl.keysize = sizeof(RI_QueryKey);
    2686         402 :     ctl.entrysize = sizeof(RI_QueryHashEntry);
    2687         402 :     ri_query_cache = hash_create("RI query cache",
    2688             :                                  RI_INIT_QUERYHASHSIZE,
    2689             :                                  &ctl, HASH_ELEM | HASH_BLOBS);
    2690             : 
    2691         402 :     ctl.keysize = sizeof(RI_CompareKey);
    2692         402 :     ctl.entrysize = sizeof(RI_CompareHashEntry);
    2693         402 :     ri_compare_cache = hash_create("RI compare cache",
    2694             :                                    RI_INIT_QUERYHASHSIZE,
    2695             :                                    &ctl, HASH_ELEM | HASH_BLOBS);
    2696         402 : }
    2697             : 
    2698             : 
    2699             : /*
    2700             :  * ri_FetchPreparedPlan -
    2701             :  *
    2702             :  * Lookup for a query key in our private hash table of prepared
    2703             :  * and saved SPI execution plans. Return the plan if found or NULL.
    2704             :  */
    2705             : static SPIPlanPtr
    2706        5756 : ri_FetchPreparedPlan(RI_QueryKey *key)
    2707             : {
    2708             :     RI_QueryHashEntry *entry;
    2709             :     SPIPlanPtr  plan;
    2710             : 
    2711             :     /*
    2712             :      * On the first call initialize the hashtable
    2713             :      */
    2714        5756 :     if (!ri_query_cache)
    2715           0 :         ri_InitHashTables();
    2716             : 
    2717             :     /*
    2718             :      * Lookup for the key
    2719             :      */
    2720        5756 :     entry = (RI_QueryHashEntry *) hash_search(ri_query_cache,
    2721             :                                               (void *) key,
    2722             :                                               HASH_FIND, NULL);
    2723        5756 :     if (entry == NULL)
    2724        2718 :         return NULL;
    2725             : 
    2726             :     /*
    2727             :      * Check whether the plan is still valid.  If it isn't, we don't want to
    2728             :      * simply rely on plancache.c to regenerate it; rather we should start
    2729             :      * from scratch and rebuild the query text too.  This is to cover cases
    2730             :      * such as table/column renames.  We depend on the plancache machinery to
    2731             :      * detect possible invalidations, though.
    2732             :      *
    2733             :      * CAUTION: this check is only trustworthy if the caller has already
    2734             :      * locked both FK and PK rels.
    2735             :      */
    2736        3038 :     plan = entry->plan;
    2737        3038 :     if (plan && SPI_plan_is_valid(plan))
    2738        2756 :         return plan;
    2739             : 
    2740             :     /*
    2741             :      * Otherwise we might as well flush the cached plan now, to free a little
    2742             :      * memory space before we make a new one.
    2743             :      */
    2744         282 :     entry->plan = NULL;
    2745         282 :     if (plan)
    2746         282 :         SPI_freeplan(plan);
    2747             : 
    2748         282 :     return NULL;
    2749             : }
    2750             : 
    2751             : 
    2752             : /*
    2753             :  * ri_HashPreparedPlan -
    2754             :  *
    2755             :  * Add another plan to our private SPI query plan hashtable.
    2756             :  */
    2757             : static void
    2758        3000 : ri_HashPreparedPlan(RI_QueryKey *key, SPIPlanPtr plan)
    2759             : {
    2760             :     RI_QueryHashEntry *entry;
    2761             :     bool        found;
    2762             : 
    2763             :     /*
    2764             :      * On the first call initialize the hashtable
    2765             :      */
    2766        3000 :     if (!ri_query_cache)
    2767           0 :         ri_InitHashTables();
    2768             : 
    2769             :     /*
    2770             :      * Add the new plan.  We might be overwriting an entry previously found
    2771             :      * invalid by ri_FetchPreparedPlan.
    2772             :      */
    2773        3000 :     entry = (RI_QueryHashEntry *) hash_search(ri_query_cache,
    2774             :                                               (void *) key,
    2775             :                                               HASH_ENTER, &found);
    2776             :     Assert(!found || entry->plan == NULL);
    2777        3000 :     entry->plan = plan;
    2778        3000 : }
    2779             : 
    2780             : 
    2781             : /*
    2782             :  * ri_KeysEqual -
    2783             :  *
    2784             :  * Check if all key values in OLD and NEW are equal.
    2785             :  *
    2786             :  * Note: at some point we might wish to redefine this as checking for
    2787             :  * "IS NOT DISTINCT" rather than "=", that is, allow two nulls to be
    2788             :  * considered equal.  Currently there is no need since all callers have
    2789             :  * previously found at least one of the rows to contain no nulls.
    2790             :  */
    2791             : static bool
    2792        1972 : ri_KeysEqual(Relation rel, TupleTableSlot *oldslot, TupleTableSlot *newslot,
    2793             :              const RI_ConstraintInfo *riinfo, bool rel_is_pk)
    2794             : {
    2795             :     const int16 *attnums;
    2796             : 
    2797        1972 :     if (rel_is_pk)
    2798        1250 :         attnums = riinfo->pk_attnums;
    2799             :     else
    2800         722 :         attnums = riinfo->fk_attnums;
    2801             : 
    2802             :     /* XXX: could be worthwhile to fetch all necessary attrs at once */
    2803        3062 :     for (int i = 0; i < riinfo->nkeys; i++)
    2804             :     {
    2805             :         Datum       oldvalue;
    2806             :         Datum       newvalue;
    2807             :         bool        isnull;
    2808             : 
    2809             :         /*
    2810             :          * Get one attribute's oldvalue. If it is NULL - they're not equal.
    2811             :          */
    2812        2092 :         oldvalue = slot_getattr(oldslot, attnums[i], &isnull);
    2813        2092 :         if (isnull)
    2814        1002 :             return false;
    2815             : 
    2816             :         /*
    2817             :          * Get one attribute's newvalue. If it is NULL - they're not equal.
    2818             :          */
    2819        2062 :         newvalue = slot_getattr(newslot, attnums[i], &isnull);
    2820        2062 :         if (isnull)
    2821           0 :             return false;
    2822             : 
    2823        2062 :         if (rel_is_pk)
    2824             :         {
    2825             :             /*
    2826             :              * If we are looking at the PK table, then do a bytewise
    2827             :              * comparison.  We must propagate PK changes if the value is
    2828             :              * changed to one that "looks" different but would compare as
    2829             :              * equal using the equality operator.  This only makes a
    2830             :              * difference for ON UPDATE CASCADE, but for consistency we treat
    2831             :              * all changes to the PK the same.
    2832             :              */
    2833        1334 :             Form_pg_attribute att = TupleDescAttr(oldslot->tts_tupleDescriptor, attnums[i] - 1);
    2834             : 
    2835        1334 :             if (!datum_image_eq(oldvalue, newvalue, att->attbyval, att->attlen))
    2836         714 :                 return false;
    2837             :         }
    2838             :         else
    2839             :         {
    2840             :             /*
    2841             :              * For the FK table, compare with the appropriate equality
    2842             :              * operator.  Changes that compare equal will still satisfy the
    2843             :              * constraint after the update.
    2844             :              */
    2845         728 :             if (!ri_AttributesEqual(riinfo->ff_eq_oprs[i], RIAttType(rel, attnums[i]),
    2846             :                                     oldvalue, newvalue))
    2847         258 :                 return false;
    2848             :         }
    2849             :     }
    2850             : 
    2851         970 :     return true;
    2852             : }
    2853             : 
    2854             : 
    2855             : /*
    2856             :  * ri_AttributesEqual -
    2857             :  *
    2858             :  * Call the appropriate equality comparison operator for two values.
    2859             :  *
    2860             :  * NB: we have already checked that neither value is null.
    2861             :  */
    2862             : static bool
    2863         728 : ri_AttributesEqual(Oid eq_opr, Oid typeid,
    2864             :                    Datum oldvalue, Datum newvalue)
    2865             : {
    2866         728 :     RI_CompareHashEntry *entry = ri_HashCompareOp(eq_opr, typeid);
    2867             : 
    2868             :     /* Do we need to cast the values? */
    2869         728 :     if (OidIsValid(entry->cast_func_finfo.fn_oid))
    2870             :     {
    2871          12 :         oldvalue = FunctionCall3(&entry->cast_func_finfo,
    2872             :                                  oldvalue,
    2873             :                                  Int32GetDatum(-1), /* typmod */
    2874             :                                  BoolGetDatum(false));  /* implicit coercion */
    2875          12 :         newvalue = FunctionCall3(&entry->cast_func_finfo,
    2876             :                                  newvalue,
    2877             :                                  Int32GetDatum(-1), /* typmod */
    2878             :                                  BoolGetDatum(false));  /* implicit coercion */
    2879             :     }
    2880             : 
    2881             :     /*
    2882             :      * Apply the comparison operator.
    2883             :      *
    2884             :      * Note: This function is part of a call stack that determines whether an
    2885             :      * update to a row is significant enough that it needs checking or action
    2886             :      * on the other side of a foreign-key constraint.  Therefore, the
    2887             :      * comparison here would need to be done with the collation of the *other*
    2888             :      * table.  For simplicity (e.g., we might not even have the other table
    2889             :      * open), we'll just use the default collation here, which could lead to
    2890             :      * some false negatives.  All this would break if we ever allow
    2891             :      * database-wide collations to be nondeterministic.
    2892             :      */
    2893         728 :     return DatumGetBool(FunctionCall2Coll(&entry->eq_opr_finfo,
    2894             :                                           DEFAULT_COLLATION_OID,
    2895             :                                           oldvalue, newvalue));
    2896             : }
    2897             : 
    2898             : /*
    2899             :  * ri_HashCompareOp -
    2900             :  *
    2901             :  * See if we know how to compare two values, and create a new hash entry
    2902             :  * if not.
    2903             :  */
    2904             : static RI_CompareHashEntry *
    2905         728 : ri_HashCompareOp(Oid eq_opr, Oid typeid)
    2906             : {
    2907             :     RI_CompareKey key;
    2908             :     RI_CompareHashEntry *entry;
    2909             :     bool        found;
    2910             : 
    2911             :     /*
    2912             :      * On the first call initialize the hashtable
    2913             :      */
    2914         728 :     if (!ri_compare_cache)
    2915           0 :         ri_InitHashTables();
    2916             : 
    2917             :     /*
    2918             :      * Find or create a hash entry.  Note we're assuming RI_CompareKey
    2919             :      * contains no struct padding.
    2920             :      */
    2921         728 :     key.eq_opr = eq_opr;
    2922         728 :     key.typeid = typeid;
    2923         728 :     entry = (RI_CompareHashEntry *) hash_search(ri_compare_cache,
    2924             :                                                 (void *) &key,
    2925             :                                                 HASH_ENTER, &found);
    2926         728 :     if (!found)
    2927         268 :         entry->valid = false;
    2928             : 
    2929             :     /*
    2930             :      * If not already initialized, do so.  Since we'll keep this hash entry
    2931             :      * for the life of the backend, put any subsidiary info for the function
    2932             :      * cache structs into TopMemoryContext.
    2933             :      */
    2934         728 :     if (!entry->valid)
    2935             :     {
    2936             :         Oid         lefttype,
    2937             :                     righttype,
    2938             :                     castfunc;
    2939             :         CoercionPathType pathtype;
    2940             : 
    2941             :         /* We always need to know how to call the equality operator */
    2942         268 :         fmgr_info_cxt(get_opcode(eq_opr), &entry->eq_opr_finfo,
    2943             :                       TopMemoryContext);
    2944             : 
    2945             :         /*
    2946             :          * If we chose to use a cast from FK to PK type, we may have to apply
    2947             :          * the cast function to get to the operator's input type.
    2948             :          *
    2949             :          * XXX eventually it would be good to support array-coercion cases
    2950             :          * here and in ri_AttributesEqual().  At the moment there is no point
    2951             :          * because cases involving nonidentical array types will be rejected
    2952             :          * at constraint creation time.
    2953             :          *
    2954             :          * XXX perhaps also consider supporting CoerceViaIO?  No need at the
    2955             :          * moment since that will never be generated for implicit coercions.
    2956             :          */
    2957         268 :         op_input_types(eq_opr, &lefttype, &righttype);
    2958             :         Assert(lefttype == righttype);
    2959         268 :         if (typeid == lefttype)
    2960         262 :             castfunc = InvalidOid;  /* simplest case */
    2961             :         else
    2962             :         {
    2963           6 :             pathtype = find_coercion_pathway(lefttype, typeid,
    2964             :                                              COERCION_IMPLICIT,
    2965             :                                              &castfunc);
    2966           6 :             if (pathtype != COERCION_PATH_FUNC &&
    2967             :                 pathtype != COERCION_PATH_RELABELTYPE)
    2968             :             {
    2969             :                 /*
    2970             :                  * The declared input type of the eq_opr might be a
    2971             :                  * polymorphic type such as ANYARRAY or ANYENUM, or other
    2972             :                  * special cases such as RECORD; find_coercion_pathway
    2973             :                  * currently doesn't subsume these special cases.
    2974             :                  */
    2975           0 :                 if (!IsBinaryCoercible(typeid, lefttype))
    2976           0 :                     elog(ERROR, "no conversion function from %s to %s",
    2977             :                          format_type_be(typeid),
    2978             :                          format_type_be(lefttype));
    2979             :             }
    2980             :         }
    2981         268 :         if (OidIsValid(castfunc))
    2982           6 :             fmgr_info_cxt(castfunc, &entry->cast_func_finfo,
    2983             :                           TopMemoryContext);
    2984             :         else
    2985         262 :             entry->cast_func_finfo.fn_oid = InvalidOid;
    2986         268 :         entry->valid = true;
    2987             :     }
    2988             : 
    2989         728 :     return entry;
    2990             : }
    2991             : 
    2992             : 
    2993             : /*
    2994             :  * Given a trigger function OID, determine whether it is an RI trigger,
    2995             :  * and if so whether it is attached to PK or FK relation.
    2996             :  */
    2997             : int
    2998        5936 : RI_FKey_trigger_type(Oid tgfoid)
    2999             : {
    3000        5936 :     switch (tgfoid)
    3001             :     {
    3002        2210 :         case F_RI_FKEY_CASCADE_DEL:
    3003             :         case F_RI_FKEY_CASCADE_UPD:
    3004             :         case F_RI_FKEY_RESTRICT_DEL:
    3005             :         case F_RI_FKEY_RESTRICT_UPD:
    3006             :         case F_RI_FKEY_SETNULL_DEL:
    3007             :         case F_RI_FKEY_SETNULL_UPD:
    3008             :         case F_RI_FKEY_SETDEFAULT_DEL:
    3009             :         case F_RI_FKEY_SETDEFAULT_UPD:
    3010             :         case F_RI_FKEY_NOACTION_DEL:
    3011             :         case F_RI_FKEY_NOACTION_UPD:
    3012        2210 :             return RI_TRIGGER_PK;
    3013             : 
    3014        1068 :         case F_RI_FKEY_CHECK_INS:
    3015             :         case F_RI_FKEY_CHECK_UPD:
    3016        1068 :             return RI_TRIGGER_FK;
    3017             :     }
    3018             : 
    3019        2658 :     return RI_TRIGGER_NONE;
    3020             : }

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