#include "postgres.h"
#include "access/htup_details.h"
#include "access/sysattr.h"
#include "access/table.h"
#include "access/tableam.h"
#include "access/xact.h"
#include "catalog/pg_collation.h"
#include "catalog/pg_constraint.h"
#include "catalog/pg_proc.h"
#include "commands/trigger.h"
#include "executor/executor.h"
#include "executor/spi.h"
#include "lib/ilist.h"
#include "miscadmin.h"
#include "parser/parse_coerce.h"
#include "parser/parse_relation.h"
#include "utils/acl.h"
#include "utils/builtins.h"
#include "utils/datum.h"
#include "utils/fmgroids.h"
#include "utils/guc.h"
#include "utils/inval.h"
#include "utils/lsyscache.h"
#include "utils/memutils.h"
#include "utils/rangetypes.h"
#include "utils/rel.h"
#include "utils/rls.h"
#include "utils/ruleutils.h"
#include "utils/snapmgr.h"
#include "utils/syscache.h"

Include dependency graph for ri_triggers.c:

Data Structures
struct	RI_ConstraintInfo

struct	RI_QueryKey

struct	RI_QueryHashEntry

struct	RI_CompareKey

struct	RI_CompareHashEntry

Macros
#define	RI_MAX_NUMKEYS INDEX_MAX_KEYS

#define	RI_INIT_CONSTRAINTHASHSIZE 64

#define	RI_INIT_QUERYHASHSIZE (RI_INIT_CONSTRAINTHASHSIZE * 4)

#define	RI_KEYS_ALL_NULL 0

#define	RI_KEYS_SOME_NULL 1

#define	RI_KEYS_NONE_NULL 2

#define	RI_PLAN_CHECK_LOOKUPPK 1

#define	RI_PLAN_CHECK_LOOKUPPK_FROM_PK 2

#define	RI_PLAN_LAST_ON_PK RI_PLAN_CHECK_LOOKUPPK_FROM_PK

#define	RI_PLAN_CASCADE_ONDELETE 3

#define	RI_PLAN_CASCADE_ONUPDATE 4

#define	RI_PLAN_NO_ACTION 5

#define	RI_PLAN_RESTRICT 6

#define	RI_PLAN_SETNULL_ONDELETE 7

#define	RI_PLAN_SETNULL_ONUPDATE 8

#define	RI_PLAN_SETDEFAULT_ONDELETE 9

#define	RI_PLAN_SETDEFAULT_ONUPDATE 10

#define	MAX_QUOTED_NAME_LEN (NAMEDATALEN*2+3)

#define	MAX_QUOTED_REL_NAME_LEN (MAX_QUOTED_NAME_LEN*2)

#define	RIAttName(rel, attnum) NameStr(*attnumAttName(rel, attnum))

#define	RIAttType(rel, attnum) attnumTypeId(rel, attnum)

#define	RIAttCollation(rel, attnum) attnumCollationId(rel, attnum)

#define	RI_TRIGTYPE_INSERT 1

#define	RI_TRIGTYPE_UPDATE 2

#define	RI_TRIGTYPE_DELETE 3

Typedefs
typedef struct RI_ConstraintInfo	RI_ConstraintInfo

typedef struct RI_QueryKey	RI_QueryKey

typedef struct RI_QueryHashEntry	RI_QueryHashEntry

typedef struct RI_CompareKey	RI_CompareKey

typedef struct RI_CompareHashEntry	RI_CompareHashEntry

Functions
static bool	ri_Check_Pk_Match (Relation pk_rel, Relation fk_rel, TupleTableSlot oldslot, const RI_ConstraintInfo riinfo)

static Datum	ri_restrict (TriggerData *trigdata, bool is_no_action)

static Datum	ri_set (TriggerData *trigdata, bool is_set_null, int tgkind)

static void	quoteOneName (char buffer, const char name)

static void	quoteRelationName (char *buffer, Relation rel)

static void	ri_GenerateQual (StringInfo buf, const char sep, const char leftop, Oid leftoptype, Oid opoid, const char *rightop, Oid rightoptype)

static void	ri_GenerateQualCollation (StringInfo buf, Oid collation)

static int	ri_NullCheck (TupleDesc tupDesc, TupleTableSlot slot, const RI_ConstraintInfo riinfo, bool rel_is_pk)

static void	ri_BuildQueryKey (RI_QueryKey key, const RI_ConstraintInfo riinfo, int32 constr_queryno)

static bool	ri_KeysEqual (Relation rel, TupleTableSlot oldslot, TupleTableSlot newslot, const RI_ConstraintInfo *riinfo, bool rel_is_pk)

static bool	ri_CompareWithCast (Oid eq_opr, Oid typeid, Oid collid, Datum lhs, Datum rhs)

static void	ri_InitHashTables (void)

static void	InvalidateConstraintCacheCallBack (Datum arg, int cacheid, uint32 hashvalue)

static SPIPlanPtr	ri_FetchPreparedPlan (RI_QueryKey *key)

static void	ri_HashPreparedPlan (RI_QueryKey *key, SPIPlanPtr plan)

static RI_CompareHashEntry *	ri_HashCompareOp (Oid eq_opr, Oid typeid)

static void	ri_CheckTrigger (FunctionCallInfo fcinfo, const char *funcname, int tgkind)

static const RI_ConstraintInfo *	ri_FetchConstraintInfo (Trigger *trigger, Relation trig_rel, bool rel_is_pk)

static const RI_ConstraintInfo *	ri_LoadConstraintInfo (Oid constraintOid)

static Oid	get_ri_constraint_root (Oid constrOid)

static SPIPlanPtr	ri_PlanCheck (const char querystr, int nargs, Oid argtypes, RI_QueryKey *qkey, Relation fk_rel, Relation pk_rel)

static bool	ri_PerformCheck (const RI_ConstraintInfo riinfo, RI_QueryKey qkey, SPIPlanPtr qplan, Relation fk_rel, Relation pk_rel, TupleTableSlot oldslot, TupleTableSlot newslot, bool is_restrict, bool detectNewRows, int expect_OK)

static void	ri_ExtractValues (Relation rel, TupleTableSlot slot, const RI_ConstraintInfo riinfo, bool rel_is_pk, Datum vals, char nulls)

static pg_noreturn void	ri_ReportViolation (const RI_ConstraintInfo riinfo, Relation pk_rel, Relation fk_rel, TupleTableSlot violatorslot, TupleDesc tupdesc, int queryno, bool is_restrict, bool partgone)

static Datum	RI_FKey_check (TriggerData *trigdata)

Datum	RI_FKey_check_ins (PG_FUNCTION_ARGS)

Datum	RI_FKey_check_upd (PG_FUNCTION_ARGS)

Datum	RI_FKey_noaction_del (PG_FUNCTION_ARGS)

Datum	RI_FKey_restrict_del (PG_FUNCTION_ARGS)

Datum	RI_FKey_noaction_upd (PG_FUNCTION_ARGS)

Datum	RI_FKey_restrict_upd (PG_FUNCTION_ARGS)

Datum	RI_FKey_cascade_del (PG_FUNCTION_ARGS)

Datum	RI_FKey_cascade_upd (PG_FUNCTION_ARGS)

Datum	RI_FKey_setnull_del (PG_FUNCTION_ARGS)

Datum	RI_FKey_setnull_upd (PG_FUNCTION_ARGS)

Datum	RI_FKey_setdefault_del (PG_FUNCTION_ARGS)

Datum	RI_FKey_setdefault_upd (PG_FUNCTION_ARGS)

bool	RI_FKey_pk_upd_check_required (Trigger trigger, Relation pk_rel, TupleTableSlot oldslot, TupleTableSlot *newslot)

bool	RI_FKey_fk_upd_check_required (Trigger trigger, Relation fk_rel, TupleTableSlot oldslot, TupleTableSlot *newslot)

bool	RI_Initial_Check (Trigger *trigger, Relation fk_rel, Relation pk_rel)

void	RI_PartitionRemove_Check (Trigger *trigger, Relation fk_rel, Relation pk_rel)

int	RI_FKey_trigger_type (Oid tgfoid)

Variables
static HTAB *	ri_constraint_cache = NULL

static HTAB *	ri_query_cache = NULL

static HTAB *	ri_compare_cache = NULL

static dclist_head	ri_constraint_cache_valid_list

Macro Definition Documentation

◆ MAX_QUOTED_NAME_LEN

#define MAX_QUOTED_NAME_LEN (NAMEDATALEN*2+3)

Definition at line 85 of file ri_triggers.c.

◆ MAX_QUOTED_REL_NAME_LEN

#define MAX_QUOTED_REL_NAME_LEN (MAX_QUOTED_NAME_LEN*2)

Definition at line 86 of file ri_triggers.c.

◆ RI_INIT_CONSTRAINTHASHSIZE

#define RI_INIT_CONSTRAINTHASHSIZE 64

Definition at line 62 of file ri_triggers.c.

◆ RI_INIT_QUERYHASHSIZE

#define RI_INIT_QUERYHASHSIZE (RI_INIT_CONSTRAINTHASHSIZE * 4)

Definition at line 63 of file ri_triggers.c.

◆ RI_KEYS_ALL_NULL

#define RI_KEYS_ALL_NULL 0

Definition at line 65 of file ri_triggers.c.

◆ RI_KEYS_NONE_NULL

#define RI_KEYS_NONE_NULL 2

Definition at line 67 of file ri_triggers.c.

◆ RI_KEYS_SOME_NULL

#define RI_KEYS_SOME_NULL 1

Definition at line 66 of file ri_triggers.c.

◆ RI_MAX_NUMKEYS

#define RI_MAX_NUMKEYS INDEX_MAX_KEYS

Definition at line 60 of file ri_triggers.c.

◆ RI_PLAN_CASCADE_ONDELETE

#define RI_PLAN_CASCADE_ONDELETE 3

Definition at line 75 of file ri_triggers.c.

◆ RI_PLAN_CASCADE_ONUPDATE

#define RI_PLAN_CASCADE_ONUPDATE 4

Definition at line 76 of file ri_triggers.c.

◆ RI_PLAN_CHECK_LOOKUPPK

#define RI_PLAN_CHECK_LOOKUPPK 1

Definition at line 71 of file ri_triggers.c.

◆ RI_PLAN_CHECK_LOOKUPPK_FROM_PK

#define RI_PLAN_CHECK_LOOKUPPK_FROM_PK 2

Definition at line 72 of file ri_triggers.c.

◆ RI_PLAN_LAST_ON_PK

#define RI_PLAN_LAST_ON_PK RI_PLAN_CHECK_LOOKUPPK_FROM_PK

Definition at line 73 of file ri_triggers.c.

◆ RI_PLAN_NO_ACTION

#define RI_PLAN_NO_ACTION 5

Definition at line 77 of file ri_triggers.c.

◆ RI_PLAN_RESTRICT

#define RI_PLAN_RESTRICT 6

Definition at line 79 of file ri_triggers.c.

◆ RI_PLAN_SETDEFAULT_ONDELETE

#define RI_PLAN_SETDEFAULT_ONDELETE 9

Definition at line 82 of file ri_triggers.c.

◆ RI_PLAN_SETDEFAULT_ONUPDATE

#define RI_PLAN_SETDEFAULT_ONUPDATE 10

Definition at line 83 of file ri_triggers.c.

◆ RI_PLAN_SETNULL_ONDELETE

#define RI_PLAN_SETNULL_ONDELETE 7

Definition at line 80 of file ri_triggers.c.

◆ RI_PLAN_SETNULL_ONUPDATE

#define RI_PLAN_SETNULL_ONUPDATE 8

Definition at line 81 of file ri_triggers.c.

◆ RI_TRIGTYPE_DELETE

#define RI_TRIGTYPE_DELETE 3

Definition at line 94 of file ri_triggers.c.

◆ RI_TRIGTYPE_INSERT

#define RI_TRIGTYPE_INSERT 1

Definition at line 92 of file ri_triggers.c.

◆ RI_TRIGTYPE_UPDATE

#define RI_TRIGTYPE_UPDATE 2

Definition at line 93 of file ri_triggers.c.

◆ RIAttCollation

#define RIAttCollation	(	rel,
		attnum
	)	attnumCollationId(rel, attnum)

Definition at line 90 of file ri_triggers.c.

◆ RIAttName

#define RIAttName	(	rel,
		attnum
	)	NameStr(*attnumAttName(rel, attnum))

Definition at line 88 of file ri_triggers.c.

◆ RIAttType

#define RIAttType	(	rel,
		attnum
	)	attnumTypeId(rel, attnum)

Definition at line 89 of file ri_triggers.c.

Typedef Documentation

◆ RI_CompareHashEntry

typedef struct RI_CompareHashEntry RI_CompareHashEntry

◆ RI_CompareKey

typedef struct RI_CompareKey RI_CompareKey

◆ RI_ConstraintInfo

typedef struct RI_ConstraintInfo RI_ConstraintInfo

◆ RI_QueryHashEntry

typedef struct RI_QueryHashEntry RI_QueryHashEntry

◆ RI_QueryKey

typedef struct RI_QueryKey RI_QueryKey

Function Documentation

◆ get_ri_constraint_root()

static Oid get_ri_constraint_root ( Oid constrOid )

static

Definition at line 2366 of file ri_triggers.c.

{
    for (;;)
    {
        HeapTuple   tuple;
        Oid         constrParentOid;
 
        tuple = SearchSysCache1(CONSTROID, ObjectIdGetDatum(constrOid));
        if (!HeapTupleIsValid(tuple))
            elog(ERROR, "cache lookup failed for constraint %u", constrOid);
        constrParentOid = ((Form_pg_constraint) GETSTRUCT(tuple))->conparentid;
        ReleaseSysCache(tuple);
        if (!OidIsValid(constrParentOid))
            break;              /* we reached the root constraint */
        constrOid = constrParentOid;
    }
    return constrOid;
}

References elog, ERROR, GETSTRUCT(), HeapTupleIsValid, ObjectIdGetDatum(), OidIsValid, ReleaseSysCache(), and SearchSysCache1().

Referenced by ri_LoadConstraintInfo().

◆ InvalidateConstraintCacheCallBack()

static void InvalidateConstraintCacheCallBack	(	Datum	arg,
		int	cacheid,
		uint32	hashvalue
	)

static

Definition at line 2400 of file ri_triggers.c.

{
    dlist_mutable_iter iter;
 
    Assert(ri_constraint_cache != NULL);
 
    /*
     * If the list of currently valid entries gets excessively large, we mark
     * them all invalid so we can empty the list.  This arrangement avoids
     * O(N^2) behavior in situations where a session touches many foreign keys
     * and also does many ALTER TABLEs, such as a restore from pg_dump.
     */
    if (dclist_count(&ri_constraint_cache_valid_list) > 1000)
        hashvalue = 0;          /* pretend it's a cache reset */
 
    dclist_foreach_modify(iter, &ri_constraint_cache_valid_list)
    {
        RI_ConstraintInfo *riinfo = dclist_container(RI_ConstraintInfo,
                                                     valid_link, iter.cur);
 
        /*
         * We must invalidate not only entries directly matching the given
         * hash value, but also child entries, in case the invalidation
         * affects a root constraint.
         */
        if (hashvalue == 0 ||
            riinfo->oidHashValue == hashvalue ||
            riinfo->rootHashValue == hashvalue)
        {
            riinfo->valid = false;
            /* Remove invalidated entries from the list, too */
            dclist_delete_from(&ri_constraint_cache_valid_list, iter.cur);
        }
    }
}

References Assert(), dlist_mutable_iter::cur, dclist_container, dclist_count(), dclist_delete_from(), dclist_foreach_modify, RI_ConstraintInfo::oidHashValue, ri_constraint_cache, ri_constraint_cache_valid_list, RI_ConstraintInfo::rootHashValue, and RI_ConstraintInfo::valid.

Referenced by ri_InitHashTables().

◆ quoteOneName()

static void quoteOneName	(	char *	buffer,
		const char *	name
	)

static

Definition at line 2031 of file ri_triggers.c.

{
    /* Rather than trying to be smart, just always quote it. */
    *buffer++ = '"';
    while (*name)
    {
        if (*name == '"')
            *buffer++ = '"';
        *buffer++ = *name++;
    }
    *buffer++ = '"';
    *buffer = '\0';
}

References name.

Referenced by quoteRelationName(), ri_Check_Pk_Match(), RI_FKey_cascade_del(), RI_FKey_cascade_upd(), RI_FKey_check(), ri_GenerateQualCollation(), RI_Initial_Check(), RI_PartitionRemove_Check(), ri_restrict(), and ri_set().

◆ quoteRelationName()

static void quoteRelationName	(	char *	buffer,
		Relation	rel
	)

static

Definition at line 2051 of file ri_triggers.c.

{
    quoteOneName(buffer, get_namespace_name(RelationGetNamespace(rel)));
    buffer += strlen(buffer);
    *buffer++ = '.';
    quoteOneName(buffer, RelationGetRelationName(rel));
}

References get_namespace_name(), quoteOneName(), RelationGetNamespace, and RelationGetRelationName.

Referenced by ri_Check_Pk_Match(), RI_FKey_cascade_del(), RI_FKey_cascade_upd(), RI_FKey_check(), RI_Initial_Check(), RI_PartitionRemove_Check(), ri_restrict(), and ri_set().

◆ ri_BuildQueryKey()

static void ri_BuildQueryKey	(	RI_QueryKey *	key,
		const RI_ConstraintInfo *	riinfo,
		int32	constr_queryno
	)

static

Definition at line 2136 of file ri_triggers.c.

{
    /*
     * Inherited constraints with a common ancestor can share ri_query_cache
     * entries for all query types except RI_PLAN_CHECK_LOOKUPPK_FROM_PK.
     * Except in that case, the query processes the other table involved in
     * the FK constraint (i.e., not the table on which the trigger has been
     * fired), and so it will be the same for all members of the inheritance
     * tree.  So we may use the root constraint's OID in the hash key, rather
     * than the constraint's own OID.  This avoids creating duplicate SPI
     * plans, saving lots of work and memory when there are many partitions
     * with similar FK constraints.
     *
     * (Note that we must still have a separate RI_ConstraintInfo for each
     * constraint, because partitions can have different column orders,
     * resulting in different pk_attnums[] or fk_attnums[] array contents.)
     *
     * We assume struct RI_QueryKey contains no padding bytes, else we'd need
     * to use memset to clear them.
     */
    if (constr_queryno != RI_PLAN_CHECK_LOOKUPPK_FROM_PK)
        key->constr_id = riinfo->constraint_root_id;
    else
        key->constr_id = riinfo->constraint_id;
    key->constr_queryno = constr_queryno;
}

References RI_ConstraintInfo::constraint_id, RI_ConstraintInfo::constraint_root_id, sort-test::key, and RI_PLAN_CHECK_LOOKUPPK_FROM_PK.

Referenced by ri_Check_Pk_Match(), RI_FKey_cascade_del(), RI_FKey_cascade_upd(), RI_FKey_check(), ri_restrict(), and ri_set().

◆ ri_Check_Pk_Match()

static bool ri_Check_Pk_Match	(	Relation	pk_rel,
		Relation	fk_rel,
		TupleTableSlot *	oldslot,
		const RI_ConstraintInfo *	riinfo
	)

static

Definition at line 511 of file ri_triggers.c.

{
    SPIPlanPtr  qplan;
    RI_QueryKey qkey;
    bool        result;
 
    /* Only called for non-null rows */
    Assert(ri_NullCheck(RelationGetDescr(pk_rel), oldslot, riinfo, true) == RI_KEYS_NONE_NULL);
 
    SPI_connect();
 
    /*
     * Fetch or prepare a saved plan for checking PK table with values coming
     * from a PK row
     */
    ri_BuildQueryKey(&qkey, riinfo, RI_PLAN_CHECK_LOOKUPPK_FROM_PK);
 
    if ((qplan = ri_FetchPreparedPlan(&qkey)) == NULL)
    {
        StringInfoData querybuf;
        char        pkrelname[MAX_QUOTED_REL_NAME_LEN];
        char        attname[MAX_QUOTED_NAME_LEN];
        char        paramname[16];
        const char *querysep;
        const char *pk_only;
        Oid         queryoids[RI_MAX_NUMKEYS];
 
        /* ----------
         * The query string built is
         *  SELECT 1 FROM [ONLY] <pktable> x WHERE pkatt1 = $1 [AND ...]
         *         FOR KEY SHARE OF x
         * The type id's for the $ parameters are those of the
         * PK attributes themselves.
         *
         * But for temporal FKs we need to make sure
         * the old PK's range is completely covered.
         * So we use this query instead:
         *  SELECT 1
         *  FROM    (
         *    SELECT pkperiodatt AS r
         *    FROM   [ONLY] pktable x
         *    WHERE  pkatt1 = $1 [AND ...]
         *    AND    pkperiodatt && $n
         *    FOR KEY SHARE OF x
         *  ) x1
         *  HAVING $n <@ range_agg(x1.r)
         * Note if FOR KEY SHARE ever allows GROUP BY and HAVING
         * we can make this a bit simpler.
         * ----------
         */
        initStringInfo(&querybuf);
        pk_only = pk_rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE ?
            "" : "ONLY ";
        quoteRelationName(pkrelname, pk_rel);
        if (riinfo->hasperiod)
        {
            quoteOneName(attname, RIAttName(pk_rel, riinfo->pk_attnums[riinfo->nkeys - 1]));
 
            appendStringInfo(&querybuf,
                             "SELECT 1 FROM (SELECT %s AS r FROM %s%s x",
                             attname, pk_only, pkrelname);
        }
        else
        {
            appendStringInfo(&querybuf, "SELECT 1 FROM %s%s x",
                             pk_only, pkrelname);
        }
        querysep = "WHERE";
        for (int i = 0; i < riinfo->nkeys; i++)
        {
            Oid         pk_type = RIAttType(pk_rel, riinfo->pk_attnums[i]);
 
            quoteOneName(attname,
                         RIAttName(pk_rel, riinfo->pk_attnums[i]));
            sprintf(paramname, "$%d", i + 1);
            ri_GenerateQual(&querybuf, querysep,
                            attname, pk_type,
                            riinfo->pp_eq_oprs[i],
                            paramname, pk_type);
            querysep = "AND";
            queryoids[i] = pk_type;
        }
        appendStringInfoString(&querybuf, " FOR KEY SHARE OF x");
        if (riinfo->hasperiod)
        {
            Oid         fk_type = RIAttType(fk_rel, riinfo->fk_attnums[riinfo->nkeys - 1]);
 
            appendStringInfoString(&querybuf, ") x1 HAVING ");
            sprintf(paramname, "$%d", riinfo->nkeys);
            ri_GenerateQual(&querybuf, "",
                            paramname, fk_type,
                            riinfo->agged_period_contained_by_oper,
                            "pg_catalog.range_agg", ANYMULTIRANGEOID);
            appendStringInfoString(&querybuf, "(x1.r)");
        }
 
        /* Prepare and save the plan */
        qplan = ri_PlanCheck(querybuf.data, riinfo->nkeys, queryoids,
                             &qkey, fk_rel, pk_rel);
    }
 
    /*
     * We have a plan now. Run it.
     */
    result = ri_PerformCheck(riinfo, &qkey, qplan,
                             fk_rel, pk_rel,
                             oldslot, NULL,
                             false,
                             true,  /* treat like update */
                             SPI_OK_SELECT);
 
    if (SPI_finish() != SPI_OK_FINISH)
        elog(ERROR, "SPI_finish failed");
 
    return result;
}

References RI_ConstraintInfo::agged_period_contained_by_oper, appendStringInfo(), appendStringInfoString(), Assert(), attname, StringInfoData::data, elog, ERROR, RI_ConstraintInfo::fk_attnums, RI_ConstraintInfo::hasperiod, i, initStringInfo(), MAX_QUOTED_NAME_LEN, MAX_QUOTED_REL_NAME_LEN, RI_ConstraintInfo::nkeys, RI_ConstraintInfo::pk_attnums, RI_ConstraintInfo::pp_eq_oprs, quoteOneName(), quoteRelationName(), RelationData::rd_rel, RelationGetDescr, ri_BuildQueryKey(), ri_FetchPreparedPlan(), ri_GenerateQual(), RI_KEYS_NONE_NULL, RI_MAX_NUMKEYS, ri_NullCheck(), ri_PerformCheck(), RI_PLAN_CHECK_LOOKUPPK_FROM_PK, ri_PlanCheck(), RIAttName, RIAttType, SPI_connect(), SPI_finish(), SPI_OK_FINISH, SPI_OK_SELECT, and sprintf.

Referenced by ri_restrict().

◆ ri_CheckTrigger()

static void ri_CheckTrigger	(	FunctionCallInfo	fcinfo,
		const char *	funcname,
		int	tgkind
	)

static

Definition at line 2168 of file ri_triggers.c.

{
    TriggerData *trigdata = (TriggerData *) fcinfo->context;
 
    if (!CALLED_AS_TRIGGER(fcinfo))
        ereport(ERROR,
                (errcode(ERRCODE_E_R_I_E_TRIGGER_PROTOCOL_VIOLATED),
                 errmsg("function \"%s\" was not called by trigger manager", funcname)));
 
    /*
     * Check proper event
     */
    if (!TRIGGER_FIRED_AFTER(trigdata->tg_event) ||
        !TRIGGER_FIRED_FOR_ROW(trigdata->tg_event))
        ereport(ERROR,
                (errcode(ERRCODE_E_R_I_E_TRIGGER_PROTOCOL_VIOLATED),
                 errmsg("function \"%s\" must be fired AFTER ROW", funcname)));
 
    switch (tgkind)
    {
        case RI_TRIGTYPE_INSERT:
            if (!TRIGGER_FIRED_BY_INSERT(trigdata->tg_event))
                ereport(ERROR,
                        (errcode(ERRCODE_E_R_I_E_TRIGGER_PROTOCOL_VIOLATED),
                         errmsg("function \"%s\" must be fired for INSERT", funcname)));
            break;
        case RI_TRIGTYPE_UPDATE:
            if (!TRIGGER_FIRED_BY_UPDATE(trigdata->tg_event))
                ereport(ERROR,
                        (errcode(ERRCODE_E_R_I_E_TRIGGER_PROTOCOL_VIOLATED),
                         errmsg("function \"%s\" must be fired for UPDATE", funcname)));
            break;
        case RI_TRIGTYPE_DELETE:
            if (!TRIGGER_FIRED_BY_DELETE(trigdata->tg_event))
                ereport(ERROR,
                        (errcode(ERRCODE_E_R_I_E_TRIGGER_PROTOCOL_VIOLATED),
                         errmsg("function \"%s\" must be fired for DELETE", funcname)));
            break;
    }
}

References CALLED_AS_TRIGGER, FunctionCallInfoBaseData::context, ereport, errcode(), errmsg(), ERROR, funcname, if(), RI_TRIGTYPE_DELETE, RI_TRIGTYPE_INSERT, RI_TRIGTYPE_UPDATE, TriggerData::tg_event, TRIGGER_FIRED_AFTER, TRIGGER_FIRED_BY_DELETE, TRIGGER_FIRED_BY_INSERT, TRIGGER_FIRED_BY_UPDATE, and TRIGGER_FIRED_FOR_ROW.

Referenced by RI_FKey_cascade_del(), RI_FKey_cascade_upd(), RI_FKey_check_ins(), RI_FKey_check_upd(), RI_FKey_noaction_del(), RI_FKey_noaction_upd(), RI_FKey_restrict_del(), RI_FKey_restrict_upd(), RI_FKey_setdefault_del(), RI_FKey_setdefault_upd(), RI_FKey_setnull_del(), and RI_FKey_setnull_upd().

◆ ri_CompareWithCast()

static bool ri_CompareWithCast	(	Oid	eq_opr,
		Oid	typeid,
		Oid	collid,
		Datum	lhs,
		Datum	rhs
	)

static

Definition at line 3071 of file ri_triggers.c.

{
    RI_CompareHashEntry *entry = ri_HashCompareOp(eq_opr, typeid);
 
    /* Do we need to cast the values? */
    if (OidIsValid(entry->cast_func_finfo.fn_oid))
    {
        lhs = FunctionCall3(&entry->cast_func_finfo,
                            lhs,
                            Int32GetDatum(-1),  /* typmod */
                            BoolGetDatum(false));   /* implicit coercion */
        rhs = FunctionCall3(&entry->cast_func_finfo,
                            rhs,
                            Int32GetDatum(-1),  /* typmod */
                            BoolGetDatum(false));   /* implicit coercion */
    }
 
    /*
     * Apply the comparison operator.
     *
     * Note: This function is part of a call stack that determines whether an
     * update to a row is significant enough that it needs checking or action
     * on the other side of a foreign-key constraint.  Therefore, the
     * comparison here would need to be done with the collation of the *other*
     * table.  For simplicity (e.g., we might not even have the other table
     * open), we'll use our own collation.  This is fine because we require
     * that both collations have the same notion of equality (either they are
     * both deterministic or else they are both the same).
     *
     * With range/multirangetypes, the collation of the base type is stored as
     * part of the rangetype (pg_range.rngcollation), and always used, so
     * there is no danger of inconsistency even using a non-equals operator.
     * But if we support arbitrary types with PERIOD, we should perhaps just
     * always force a re-check.
     */
    return DatumGetBool(FunctionCall2Coll(&entry->eq_opr_finfo, collid, lhs, rhs));
}

References BoolGetDatum(), RI_CompareHashEntry::cast_func_finfo, collid, DatumGetBool(), RI_CompareHashEntry::eq_opr_finfo, FmgrInfo::fn_oid, FunctionCall2Coll(), FunctionCall3, Int32GetDatum(), OidIsValid, and ri_HashCompareOp().

Referenced by ri_KeysEqual().

◆ ri_ExtractValues()

static void ri_ExtractValues	(	Relation	rel,
		TupleTableSlot *	slot,
		const RI_ConstraintInfo *	riinfo,
		bool	rel_is_pk,
		Datum *	vals,
		char *	nulls
	)

static

Definition at line 2622 of file ri_triggers.c.

{
    const int16 *attnums;
    bool        isnull;
 
    if (rel_is_pk)
        attnums = riinfo->pk_attnums;
    else
        attnums = riinfo->fk_attnums;
 
    for (int i = 0; i < riinfo->nkeys; i++)
    {
        vals[i] = slot_getattr(slot, attnums[i], &isnull);
        nulls[i] = isnull ? 'n' : ' ';
    }
}

References RI_ConstraintInfo::fk_attnums, i, RI_ConstraintInfo::nkeys, RI_ConstraintInfo::pk_attnums, and slot_getattr().

Referenced by ri_PerformCheck().

◆ ri_FetchConstraintInfo()

static const RI_ConstraintInfo * ri_FetchConstraintInfo	(	Trigger *	trigger,
		Relation	trig_rel,
		bool	rel_is_pk
	)

static

Definition at line 2214 of file ri_triggers.c.

{
    Oid         constraintOid = trigger->tgconstraint;
    const RI_ConstraintInfo *riinfo;
 
    /*
     * Check that the FK constraint's OID is available; it might not be if
     * we've been invoked via an ordinary trigger or an old-style "constraint
     * trigger".
     */
    if (!OidIsValid(constraintOid))
        ereport(ERROR,
                (errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
                 errmsg("no pg_constraint entry for trigger \"%s\" on table \"%s\"",
                        trigger->tgname, RelationGetRelationName(trig_rel)),
                 errhint("Remove this referential integrity trigger and its mates, then do ALTER TABLE ADD CONSTRAINT.")));
 
    /* Find or create a hashtable entry for the constraint */
    riinfo = ri_LoadConstraintInfo(constraintOid);
 
    /* Do some easy cross-checks against the trigger call data */
    if (rel_is_pk)
    {
        if (riinfo->fk_relid != trigger->tgconstrrelid ||
            riinfo->pk_relid != RelationGetRelid(trig_rel))
            elog(ERROR, "wrong pg_constraint entry for trigger \"%s\" on table \"%s\"",
                 trigger->tgname, RelationGetRelationName(trig_rel));
    }
    else
    {
        if (riinfo->fk_relid != RelationGetRelid(trig_rel) ||
            riinfo->pk_relid != trigger->tgconstrrelid)
            elog(ERROR, "wrong pg_constraint entry for trigger \"%s\" on table \"%s\"",
                 trigger->tgname, RelationGetRelationName(trig_rel));
    }
 
    if (riinfo->confmatchtype != FKCONSTR_MATCH_FULL &&
        riinfo->confmatchtype != FKCONSTR_MATCH_PARTIAL &&
        riinfo->confmatchtype != FKCONSTR_MATCH_SIMPLE)
        elog(ERROR, "unrecognized confmatchtype: %d",
             riinfo->confmatchtype);
 
    if (riinfo->confmatchtype == FKCONSTR_MATCH_PARTIAL)
        ereport(ERROR,
                (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
                 errmsg("MATCH PARTIAL not yet implemented")));
 
    return riinfo;
}

References RI_ConstraintInfo::confmatchtype, elog, ereport, errcode(), errhint(), errmsg(), ERROR, RI_ConstraintInfo::fk_relid, FKCONSTR_MATCH_FULL, FKCONSTR_MATCH_PARTIAL, FKCONSTR_MATCH_SIMPLE, OidIsValid, RI_ConstraintInfo::pk_relid, RelationGetRelationName, RelationGetRelid, ri_LoadConstraintInfo(), Trigger::tgconstraint, Trigger::tgconstrrelid, and Trigger::tgname.

Referenced by RI_FKey_cascade_del(), RI_FKey_cascade_upd(), RI_FKey_check(), RI_FKey_fk_upd_check_required(), RI_FKey_pk_upd_check_required(), RI_Initial_Check(), RI_PartitionRemove_Check(), ri_restrict(), and ri_set().

◆ ri_FetchPreparedPlan()

static SPIPlanPtr ri_FetchPreparedPlan ( RI_QueryKey * key )

static

Definition at line 2896 of file ri_triggers.c.

{
    RI_QueryHashEntry *entry;
    SPIPlanPtr  plan;
 
    /*
     * On the first call initialize the hashtable
     */
    if (!ri_query_cache)
        ri_InitHashTables();
 
    /*
     * Lookup for the key
     */
    entry = (RI_QueryHashEntry *) hash_search(ri_query_cache,
                                              key,
                                              HASH_FIND, NULL);
    if (entry == NULL)
        return NULL;
 
    /*
     * Check whether the plan is still valid.  If it isn't, we don't want to
     * simply rely on plancache.c to regenerate it; rather we should start
     * from scratch and rebuild the query text too.  This is to cover cases
     * such as table/column renames.  We depend on the plancache machinery to
     * detect possible invalidations, though.
     *
     * CAUTION: this check is only trustworthy if the caller has already
     * locked both FK and PK rels.
     */
    plan = entry->plan;
    if (plan && SPI_plan_is_valid(plan))
        return plan;
 
    /*
     * Otherwise we might as well flush the cached plan now, to free a little
     * memory space before we make a new one.
     */
    entry->plan = NULL;
    if (plan)
        SPI_freeplan(plan);
 
    return NULL;
}

References HASH_FIND, hash_search(), sort-test::key, RI_QueryHashEntry::plan, plan, ri_InitHashTables(), ri_query_cache, SPI_freeplan(), and SPI_plan_is_valid().

Referenced by ri_Check_Pk_Match(), RI_FKey_cascade_del(), RI_FKey_cascade_upd(), RI_FKey_check(), ri_restrict(), and ri_set().

◆ RI_FKey_cascade_del()

Datum RI_FKey_cascade_del ( PG_FUNCTION_ARGS )

Definition at line 915 of file ri_triggers.c.

{
    TriggerData *trigdata = (TriggerData *) fcinfo->context;
    const RI_ConstraintInfo *riinfo;
    Relation    fk_rel;
    Relation    pk_rel;
    TupleTableSlot *oldslot;
    RI_QueryKey qkey;
    SPIPlanPtr  qplan;
 
    /* Check that this is a valid trigger call on the right time and event. */
    ri_CheckTrigger(fcinfo, "RI_FKey_cascade_del", RI_TRIGTYPE_DELETE);
 
    riinfo = ri_FetchConstraintInfo(trigdata->tg_trigger,
                                    trigdata->tg_relation, true);
 
    /*
     * Get the relation descriptors of the FK and PK tables and the old tuple.
     *
     * fk_rel is opened in RowExclusiveLock mode since that's what our
     * eventual DELETE will get on it.
     */
    fk_rel = table_open(riinfo->fk_relid, RowExclusiveLock);
    pk_rel = trigdata->tg_relation;
    oldslot = trigdata->tg_trigslot;
 
    SPI_connect();
 
    /* Fetch or prepare a saved plan for the cascaded delete */
    ri_BuildQueryKey(&qkey, riinfo, RI_PLAN_CASCADE_ONDELETE);
 
    if ((qplan = ri_FetchPreparedPlan(&qkey)) == NULL)
    {
        StringInfoData querybuf;
        char        fkrelname[MAX_QUOTED_REL_NAME_LEN];
        char        attname[MAX_QUOTED_NAME_LEN];
        char        paramname[16];
        const char *querysep;
        Oid         queryoids[RI_MAX_NUMKEYS];
        const char *fk_only;
 
        /* ----------
         * The query string built is
         *  DELETE FROM [ONLY] <fktable> WHERE $1 = fkatt1 [AND ...]
         * The type id's for the $ parameters are those of the
         * corresponding PK attributes.
         * ----------
         */
        initStringInfo(&querybuf);
        fk_only = fk_rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE ?
            "" : "ONLY ";
        quoteRelationName(fkrelname, fk_rel);
        appendStringInfo(&querybuf, "DELETE FROM %s%s",
                         fk_only, fkrelname);
        querysep = "WHERE";
        for (int i = 0; i < riinfo->nkeys; i++)
        {
            Oid         pk_type = RIAttType(pk_rel, riinfo->pk_attnums[i]);
            Oid         fk_type = RIAttType(fk_rel, riinfo->fk_attnums[i]);
 
            quoteOneName(attname,
                         RIAttName(fk_rel, riinfo->fk_attnums[i]));
            sprintf(paramname, "$%d", i + 1);
            ri_GenerateQual(&querybuf, querysep,
                            paramname, pk_type,
                            riinfo->pf_eq_oprs[i],
                            attname, fk_type);
            querysep = "AND";
            queryoids[i] = pk_type;
        }
 
        /* Prepare and save the plan */
        qplan = ri_PlanCheck(querybuf.data, riinfo->nkeys, queryoids,
                             &qkey, fk_rel, pk_rel);
    }
 
    /*
     * We have a plan now. Build up the arguments from the key values in the
     * deleted PK tuple and delete the referencing rows
     */
    ri_PerformCheck(riinfo, &qkey, qplan,
                    fk_rel, pk_rel,
                    oldslot, NULL,
                    false,
                    true,       /* must detect new rows */
                    SPI_OK_DELETE);
 
    if (SPI_finish() != SPI_OK_FINISH)
        elog(ERROR, "SPI_finish failed");
 
    table_close(fk_rel, RowExclusiveLock);
 
    return PointerGetDatum(NULL);
}

References appendStringInfo(), attname, StringInfoData::data, elog, ERROR, i, initStringInfo(), MAX_QUOTED_NAME_LEN, MAX_QUOTED_REL_NAME_LEN, PointerGetDatum(), quoteOneName(), quoteRelationName(), ri_BuildQueryKey(), ri_CheckTrigger(), ri_FetchConstraintInfo(), ri_FetchPreparedPlan(), ri_GenerateQual(), RI_MAX_NUMKEYS, ri_PerformCheck(), RI_PLAN_CASCADE_ONDELETE, ri_PlanCheck(), RI_TRIGTYPE_DELETE, RIAttName, RIAttType, RowExclusiveLock, SPI_connect(), SPI_finish(), SPI_OK_DELETE, SPI_OK_FINISH, sprintf, table_close(), table_open(), TriggerData::tg_relation, TriggerData::tg_trigger, and TriggerData::tg_trigslot.

◆ RI_FKey_cascade_upd()

Datum RI_FKey_cascade_upd ( PG_FUNCTION_ARGS )

Definition at line 1017 of file ri_triggers.c.

{
    TriggerData *trigdata = (TriggerData *) fcinfo->context;
    const RI_ConstraintInfo *riinfo;
    Relation    fk_rel;
    Relation    pk_rel;
    TupleTableSlot *newslot;
    TupleTableSlot *oldslot;
    RI_QueryKey qkey;
    SPIPlanPtr  qplan;
 
    /* Check that this is a valid trigger call on the right time and event. */
    ri_CheckTrigger(fcinfo, "RI_FKey_cascade_upd", RI_TRIGTYPE_UPDATE);
 
    riinfo = ri_FetchConstraintInfo(trigdata->tg_trigger,
                                    trigdata->tg_relation, true);
 
    /*
     * Get the relation descriptors of the FK and PK tables and the new and
     * old tuple.
     *
     * fk_rel is opened in RowExclusiveLock mode since that's what our
     * eventual UPDATE will get on it.
     */
    fk_rel = table_open(riinfo->fk_relid, RowExclusiveLock);
    pk_rel = trigdata->tg_relation;
    newslot = trigdata->tg_newslot;
    oldslot = trigdata->tg_trigslot;
 
    SPI_connect();
 
    /* Fetch or prepare a saved plan for the cascaded update */
    ri_BuildQueryKey(&qkey, riinfo, RI_PLAN_CASCADE_ONUPDATE);
 
    if ((qplan = ri_FetchPreparedPlan(&qkey)) == NULL)
    {
        StringInfoData querybuf;
        StringInfoData qualbuf;
        char        fkrelname[MAX_QUOTED_REL_NAME_LEN];
        char        attname[MAX_QUOTED_NAME_LEN];
        char        paramname[16];
        const char *querysep;
        const char *qualsep;
        Oid         queryoids[RI_MAX_NUMKEYS * 2];
        const char *fk_only;
 
        /* ----------
         * The query string built is
         *  UPDATE [ONLY] <fktable> SET fkatt1 = $1 [, ...]
         *          WHERE $n = fkatt1 [AND ...]
         * The type id's for the $ parameters are those of the
         * corresponding PK attributes.  Note that we are assuming
         * there is an assignment cast from the PK to the FK type;
         * else the parser will fail.
         * ----------
         */
        initStringInfo(&querybuf);
        initStringInfo(&qualbuf);
        fk_only = fk_rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE ?
            "" : "ONLY ";
        quoteRelationName(fkrelname, fk_rel);
        appendStringInfo(&querybuf, "UPDATE %s%s SET",
                         fk_only, fkrelname);
        querysep = "";
        qualsep = "WHERE";
        for (int i = 0, j = riinfo->nkeys; i < riinfo->nkeys; i++, j++)
        {
            Oid         pk_type = RIAttType(pk_rel, riinfo->pk_attnums[i]);
            Oid         fk_type = RIAttType(fk_rel, riinfo->fk_attnums[i]);
 
            quoteOneName(attname,
                         RIAttName(fk_rel, riinfo->fk_attnums[i]));
            appendStringInfo(&querybuf,
                             "%s %s = $%d",
                             querysep, attname, i + 1);
            sprintf(paramname, "$%d", j + 1);
            ri_GenerateQual(&qualbuf, qualsep,
                            paramname, pk_type,
                            riinfo->pf_eq_oprs[i],
                            attname, fk_type);
            querysep = ",";
            qualsep = "AND";
            queryoids[i] = pk_type;
            queryoids[j] = pk_type;
        }
        appendBinaryStringInfo(&querybuf, qualbuf.data, qualbuf.len);
 
        /* Prepare and save the plan */
        qplan = ri_PlanCheck(querybuf.data, riinfo->nkeys * 2, queryoids,
                             &qkey, fk_rel, pk_rel);
    }
 
    /*
     * We have a plan now. Run it to update the existing references.
     */
    ri_PerformCheck(riinfo, &qkey, qplan,
                    fk_rel, pk_rel,
                    oldslot, newslot,
                    false,
                    true,       /* must detect new rows */
                    SPI_OK_UPDATE);
 
    if (SPI_finish() != SPI_OK_FINISH)
        elog(ERROR, "SPI_finish failed");
 
    table_close(fk_rel, RowExclusiveLock);
 
    return PointerGetDatum(NULL);
}

References appendBinaryStringInfo(), appendStringInfo(), attname, StringInfoData::data, elog, ERROR, i, initStringInfo(), j, StringInfoData::len, MAX_QUOTED_NAME_LEN, MAX_QUOTED_REL_NAME_LEN, PointerGetDatum(), quoteOneName(), quoteRelationName(), ri_BuildQueryKey(), ri_CheckTrigger(), ri_FetchConstraintInfo(), ri_FetchPreparedPlan(), ri_GenerateQual(), RI_MAX_NUMKEYS, ri_PerformCheck(), RI_PLAN_CASCADE_ONUPDATE, ri_PlanCheck(), RI_TRIGTYPE_UPDATE, RIAttName, RIAttType, RowExclusiveLock, SPI_connect(), SPI_finish(), SPI_OK_FINISH, SPI_OK_UPDATE, sprintf, table_close(), table_open(), TriggerData::tg_newslot, TriggerData::tg_relation, TriggerData::tg_trigger, and TriggerData::tg_trigslot.

◆ RI_FKey_check()

static Datum RI_FKey_check ( TriggerData * trigdata )

static

Definition at line 250 of file ri_triggers.c.

{
    const RI_ConstraintInfo *riinfo;
    Relation    fk_rel;
    Relation    pk_rel;
    TupleTableSlot *newslot;
    RI_QueryKey qkey;
    SPIPlanPtr  qplan;
 
    riinfo = ri_FetchConstraintInfo(trigdata->tg_trigger,
                                    trigdata->tg_relation, false);
 
    if (TRIGGER_FIRED_BY_UPDATE(trigdata->tg_event))
        newslot = trigdata->tg_newslot;
    else
        newslot = trigdata->tg_trigslot;
 
    /*
     * We should not even consider checking the row if it is no longer valid,
     * since it was either deleted (so the deferred check should be skipped)
     * or updated (in which case only the latest version of the row should be
     * checked).  Test its liveness according to SnapshotSelf.  We need pin
     * and lock on the buffer to call HeapTupleSatisfiesVisibility.  Caller
     * should be holding pin, but not lock.
     */
    if (!table_tuple_satisfies_snapshot(trigdata->tg_relation, newslot, SnapshotSelf))
        return PointerGetDatum(NULL);
 
    /*
     * Get the relation descriptors of the FK and PK tables.
     *
     * pk_rel is opened in RowShareLock mode since that's what our eventual
     * SELECT FOR KEY SHARE will get on it.
     */
    fk_rel = trigdata->tg_relation;
    pk_rel = table_open(riinfo->pk_relid, RowShareLock);
 
    switch (ri_NullCheck(RelationGetDescr(fk_rel), newslot, riinfo, false))
    {
        case RI_KEYS_ALL_NULL:
 
            /*
             * No further check needed - an all-NULL key passes every type of
             * foreign key constraint.
             */
            table_close(pk_rel, RowShareLock);
            return PointerGetDatum(NULL);
 
        case RI_KEYS_SOME_NULL:
 
            /*
             * This is the only case that differs between the three kinds of
             * MATCH.
             */
            switch (riinfo->confmatchtype)
            {
                case FKCONSTR_MATCH_FULL:
 
                    /*
                     * Not allowed - MATCH FULL says either all or none of the
                     * attributes can be NULLs
                     */
                    ereport(ERROR,
                            (errcode(ERRCODE_FOREIGN_KEY_VIOLATION),
                             errmsg("insert or update on table \"%s\" violates foreign key constraint \"%s\"",
                                    RelationGetRelationName(fk_rel),
                                    NameStr(riinfo->conname)),
                             errdetail("MATCH FULL does not allow mixing of null and nonnull key values."),
                             errtableconstraint(fk_rel,
                                                NameStr(riinfo->conname))));
                    table_close(pk_rel, RowShareLock);
                    return PointerGetDatum(NULL);
 
                case FKCONSTR_MATCH_SIMPLE:
 
                    /*
                     * MATCH SIMPLE - if ANY column is null, the key passes
                     * the constraint.
                     */
                    table_close(pk_rel, RowShareLock);
                    return PointerGetDatum(NULL);
 
#ifdef NOT_USED
                case FKCONSTR_MATCH_PARTIAL:
 
                    /*
                     * MATCH PARTIAL - all non-null columns must match. (not
                     * implemented, can be done by modifying the query below
                     * to only include non-null columns, or by writing a
                     * special version here)
                     */
                    break;
#endif
            }
 
        case RI_KEYS_NONE_NULL:
 
            /*
             * Have a full qualified key - continue below for all three kinds
             * of MATCH.
             */
            break;
    }
 
    SPI_connect();
 
    /* Fetch or prepare a saved plan for the real check */
    ri_BuildQueryKey(&qkey, riinfo, RI_PLAN_CHECK_LOOKUPPK);
 
    if ((qplan = ri_FetchPreparedPlan(&qkey)) == NULL)
    {
        StringInfoData querybuf;
        char        pkrelname[MAX_QUOTED_REL_NAME_LEN];
        char        attname[MAX_QUOTED_NAME_LEN];
        char        paramname[16];
        const char *querysep;
        Oid         queryoids[RI_MAX_NUMKEYS];
        const char *pk_only;
 
        /* ----------
         * The query string built is
         *  SELECT 1 FROM [ONLY] <pktable> x WHERE pkatt1 = $1 [AND ...]
         *         FOR KEY SHARE OF x
         * The type id's for the $ parameters are those of the
         * corresponding FK attributes.
         *
         * But for temporal FKs we need to make sure
         * the FK's range is completely covered.
         * So we use this query instead:
         *  SELECT 1
         *  FROM    (
         *      SELECT pkperiodatt AS r
         *      FROM   [ONLY] pktable x
         *      WHERE  pkatt1 = $1 [AND ...]
         *      AND    pkperiodatt && $n
         *      FOR KEY SHARE OF x
         *  ) x1
         *  HAVING $n <@ range_agg(x1.r)
         * Note if FOR KEY SHARE ever allows GROUP BY and HAVING
         * we can make this a bit simpler.
         * ----------
         */
        initStringInfo(&querybuf);
        pk_only = pk_rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE ?
            "" : "ONLY ";
        quoteRelationName(pkrelname, pk_rel);
        if (riinfo->hasperiod)
        {
            quoteOneName(attname,
                         RIAttName(pk_rel, riinfo->pk_attnums[riinfo->nkeys - 1]));
 
            appendStringInfo(&querybuf,
                             "SELECT 1 FROM (SELECT %s AS r FROM %s%s x",
                             attname, pk_only, pkrelname);
        }
        else
        {
            appendStringInfo(&querybuf, "SELECT 1 FROM %s%s x",
                             pk_only, pkrelname);
        }
        querysep = "WHERE";
        for (int i = 0; i < riinfo->nkeys; i++)
        {
            Oid         pk_type = RIAttType(pk_rel, riinfo->pk_attnums[i]);
            Oid         fk_type = RIAttType(fk_rel, riinfo->fk_attnums[i]);
 
            quoteOneName(attname,
                         RIAttName(pk_rel, riinfo->pk_attnums[i]));
            sprintf(paramname, "$%d", i + 1);
            ri_GenerateQual(&querybuf, querysep,
                            attname, pk_type,
                            riinfo->pf_eq_oprs[i],
                            paramname, fk_type);
            querysep = "AND";
            queryoids[i] = fk_type;
        }
        appendStringInfoString(&querybuf, " FOR KEY SHARE OF x");
        if (riinfo->hasperiod)
        {
            Oid         fk_type = RIAttType(fk_rel, riinfo->fk_attnums[riinfo->nkeys - 1]);
 
            appendStringInfoString(&querybuf, ") x1 HAVING ");
            sprintf(paramname, "$%d", riinfo->nkeys);
            ri_GenerateQual(&querybuf, "",
                            paramname, fk_type,
                            riinfo->agged_period_contained_by_oper,
                            "pg_catalog.range_agg", ANYMULTIRANGEOID);
            appendStringInfoString(&querybuf, "(x1.r)");
        }
 
        /* Prepare and save the plan */
        qplan = ri_PlanCheck(querybuf.data, riinfo->nkeys, queryoids,
                             &qkey, fk_rel, pk_rel);
    }
 
    /*
     * Now check that foreign key exists in PK table
     *
     * XXX detectNewRows must be true when a partitioned table is on the
     * referenced side.  The reason is that our snapshot must be fresh in
     * order for the hack in find_inheritance_children() to work.
     */
    ri_PerformCheck(riinfo, &qkey, qplan,
                    fk_rel, pk_rel,
                    NULL, newslot,
                    false,
                    pk_rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE,
                    SPI_OK_SELECT);
 
    if (SPI_finish() != SPI_OK_FINISH)
        elog(ERROR, "SPI_finish failed");
 
    table_close(pk_rel, RowShareLock);
 
    return PointerGetDatum(NULL);
}

Referenced by RI_FKey_check_ins(), and RI_FKey_check_upd().

◆ RI_FKey_check_ins()

Datum RI_FKey_check_ins ( PG_FUNCTION_ARGS )

Definition at line 474 of file ri_triggers.c.

{
    /* Check that this is a valid trigger call on the right time and event. */
    ri_CheckTrigger(fcinfo, "RI_FKey_check_ins", RI_TRIGTYPE_INSERT);
 
    /* Share code with UPDATE case. */
    return RI_FKey_check((TriggerData *) fcinfo->context);
}

References ri_CheckTrigger(), RI_FKey_check(), and RI_TRIGTYPE_INSERT.

Referenced by validateForeignKeyConstraint().

◆ RI_FKey_check_upd()

Datum RI_FKey_check_upd ( PG_FUNCTION_ARGS )

Definition at line 490 of file ri_triggers.c.

{
    /* Check that this is a valid trigger call on the right time and event. */
    ri_CheckTrigger(fcinfo, "RI_FKey_check_upd", RI_TRIGTYPE_UPDATE);
 
    /* Share code with INSERT case. */
    return RI_FKey_check((TriggerData *) fcinfo->context);
}

References ri_CheckTrigger(), RI_FKey_check(), and RI_TRIGTYPE_UPDATE.

◆ RI_FKey_fk_upd_check_required()

bool RI_FKey_fk_upd_check_required	(	Trigger *	trigger,
		Relation	fk_rel,
		TupleTableSlot *	oldslot,
		TupleTableSlot *	newslot
	)

Definition at line 1418 of file ri_triggers.c.

{
    const RI_ConstraintInfo *riinfo;
    int         ri_nullcheck;
 
    /*
     * AfterTriggerSaveEvent() handles things such that this function is never
     * called for partitioned tables.
     */
    Assert(fk_rel->rd_rel->relkind != RELKIND_PARTITIONED_TABLE);
 
    riinfo = ri_FetchConstraintInfo(trigger, fk_rel, false);
 
    ri_nullcheck = ri_NullCheck(RelationGetDescr(fk_rel), newslot, riinfo, false);
 
    /*
     * If all new key values are NULL, the row satisfies the constraint, so no
     * check is needed.
     */
    if (ri_nullcheck == RI_KEYS_ALL_NULL)
        return false;
 
    /*
     * If some new key values are NULL, the behavior depends on the match
     * type.
     */
    else if (ri_nullcheck == RI_KEYS_SOME_NULL)
    {
        switch (riinfo->confmatchtype)
        {
            case FKCONSTR_MATCH_SIMPLE:
 
                /*
                 * If any new key value is NULL, the row must satisfy the
                 * constraint, so no check is needed.
                 */
                return false;
 
            case FKCONSTR_MATCH_PARTIAL:
 
                /*
                 * Don't know, must run full check.
                 */
                break;
 
            case FKCONSTR_MATCH_FULL:
 
                /*
                 * If some new key values are NULL, the row fails the
                 * constraint.  We must not throw error here, because the row
                 * might get invalidated before the constraint is to be
                 * checked, but we should queue the event to apply the check
                 * later.
                 */
                return true;
        }
    }
 
    /*
     * Continues here for no new key values are NULL, or we couldn't decide
     * yet.
     */
 
    /*
     * If the original row was inserted by our own transaction, we must fire
     * the trigger whether or not the keys are equal.  This is because our
     * UPDATE will invalidate the INSERT so that the INSERT RI trigger will
     * not do anything; so we had better do the UPDATE check.  (We could skip
     * this if we knew the INSERT trigger already fired, but there is no easy
     * way to know that.)
     */
    if (slot_is_current_xact_tuple(oldslot))
        return true;
 
    /* If all old and new key values are equal, no check is needed */
    if (ri_KeysEqual(fk_rel, oldslot, newslot, riinfo, false))
        return false;
 
    /* Else we need to fire the trigger. */
    return true;
}

References Assert(), RI_ConstraintInfo::confmatchtype, FKCONSTR_MATCH_FULL, FKCONSTR_MATCH_PARTIAL, FKCONSTR_MATCH_SIMPLE, RelationData::rd_rel, RelationGetDescr, ri_FetchConstraintInfo(), RI_KEYS_ALL_NULL, RI_KEYS_SOME_NULL, ri_KeysEqual(), ri_NullCheck(), and slot_is_current_xact_tuple().

Referenced by AfterTriggerSaveEvent().

◆ RI_FKey_noaction_del()

Datum RI_FKey_noaction_del ( PG_FUNCTION_ARGS )

Definition at line 639 of file ri_triggers.c.

{
    /* Check that this is a valid trigger call on the right time and event. */
    ri_CheckTrigger(fcinfo, "RI_FKey_noaction_del", RI_TRIGTYPE_DELETE);
 
    /* Share code with RESTRICT/UPDATE cases. */
    return ri_restrict((TriggerData *) fcinfo->context, true);
}

References ri_CheckTrigger(), ri_restrict(), and RI_TRIGTYPE_DELETE.

◆ RI_FKey_noaction_upd()

Datum RI_FKey_noaction_upd ( PG_FUNCTION_ARGS )

Definition at line 676 of file ri_triggers.c.

{
    /* Check that this is a valid trigger call on the right time and event. */
    ri_CheckTrigger(fcinfo, "RI_FKey_noaction_upd", RI_TRIGTYPE_UPDATE);
 
    /* Share code with RESTRICT/DELETE cases. */
    return ri_restrict((TriggerData *) fcinfo->context, true);
}

References ri_CheckTrigger(), ri_restrict(), and RI_TRIGTYPE_UPDATE.

◆ RI_FKey_pk_upd_check_required()

bool RI_FKey_pk_upd_check_required	(	Trigger *	trigger,
		Relation	pk_rel,
		TupleTableSlot *	oldslot,
		TupleTableSlot *	newslot
	)

Definition at line 1386 of file ri_triggers.c.

{
    const RI_ConstraintInfo *riinfo;
 
    riinfo = ri_FetchConstraintInfo(trigger, pk_rel, true);
 
    /*
     * If any old key value is NULL, the row could not have been referenced by
     * an FK row, so no check is needed.
     */
    if (ri_NullCheck(RelationGetDescr(pk_rel), oldslot, riinfo, true) != RI_KEYS_NONE_NULL)
        return false;
 
    /* If all old and new key values are equal, no check is needed */
    if (newslot && ri_KeysEqual(pk_rel, oldslot, newslot, riinfo, true))
        return false;
 
    /* Else we need to fire the trigger. */
    return true;
}

References RelationGetDescr, ri_FetchConstraintInfo(), RI_KEYS_NONE_NULL, ri_KeysEqual(), and ri_NullCheck().

Referenced by AfterTriggerSaveEvent().

◆ RI_FKey_restrict_del()

Datum RI_FKey_restrict_del ( PG_FUNCTION_ARGS )

Definition at line 659 of file ri_triggers.c.

{
    /* Check that this is a valid trigger call on the right time and event. */
    ri_CheckTrigger(fcinfo, "RI_FKey_restrict_del", RI_TRIGTYPE_DELETE);
 
    /* Share code with NO ACTION/UPDATE cases. */
    return ri_restrict((TriggerData *) fcinfo->context, false);
}

References ri_CheckTrigger(), ri_restrict(), and RI_TRIGTYPE_DELETE.

◆ RI_FKey_restrict_upd()

Datum RI_FKey_restrict_upd ( PG_FUNCTION_ARGS )

Definition at line 696 of file ri_triggers.c.

{
    /* Check that this is a valid trigger call on the right time and event. */
    ri_CheckTrigger(fcinfo, "RI_FKey_restrict_upd", RI_TRIGTYPE_UPDATE);
 
    /* Share code with NO ACTION/DELETE cases. */
    return ri_restrict((TriggerData *) fcinfo->context, false);
}

References ri_CheckTrigger(), ri_restrict(), and RI_TRIGTYPE_UPDATE.

◆ RI_FKey_setdefault_del()

Datum RI_FKey_setdefault_del ( PG_FUNCTION_ARGS )

Definition at line 1164 of file ri_triggers.c.

{
    /* Check that this is a valid trigger call on the right time and event. */
    ri_CheckTrigger(fcinfo, "RI_FKey_setdefault_del", RI_TRIGTYPE_DELETE);
 
    /* Share code with UPDATE case */
    return ri_set((TriggerData *) fcinfo->context, false, RI_TRIGTYPE_DELETE);
}

References ri_CheckTrigger(), ri_set(), and RI_TRIGTYPE_DELETE.

◆ RI_FKey_setdefault_upd()

Datum RI_FKey_setdefault_upd ( PG_FUNCTION_ARGS )

Definition at line 1179 of file ri_triggers.c.

{
    /* Check that this is a valid trigger call on the right time and event. */
    ri_CheckTrigger(fcinfo, "RI_FKey_setdefault_upd", RI_TRIGTYPE_UPDATE);
 
    /* Share code with DELETE case */
    return ri_set((TriggerData *) fcinfo->context, false, RI_TRIGTYPE_UPDATE);
}

References ri_CheckTrigger(), ri_set(), and RI_TRIGTYPE_UPDATE.

◆ RI_FKey_setnull_del()

Datum RI_FKey_setnull_del ( PG_FUNCTION_ARGS )

Definition at line 1134 of file ri_triggers.c.

{
    /* Check that this is a valid trigger call on the right time and event. */
    ri_CheckTrigger(fcinfo, "RI_FKey_setnull_del", RI_TRIGTYPE_DELETE);
 
    /* Share code with UPDATE case */
    return ri_set((TriggerData *) fcinfo->context, true, RI_TRIGTYPE_DELETE);
}

References ri_CheckTrigger(), ri_set(), and RI_TRIGTYPE_DELETE.

◆ RI_FKey_setnull_upd()

Datum RI_FKey_setnull_upd ( PG_FUNCTION_ARGS )

Definition at line 1149 of file ri_triggers.c.

{
    /* Check that this is a valid trigger call on the right time and event. */
    ri_CheckTrigger(fcinfo, "RI_FKey_setnull_upd", RI_TRIGTYPE_UPDATE);
 
    /* Share code with DELETE case */
    return ri_set((TriggerData *) fcinfo->context, true, RI_TRIGTYPE_UPDATE);
}

References ri_CheckTrigger(), ri_set(), and RI_TRIGTYPE_UPDATE.

◆ RI_FKey_trigger_type()

int RI_FKey_trigger_type ( Oid tgfoid )

Definition at line 3210 of file ri_triggers.c.

{
    switch (tgfoid)
    {
        case F_RI_FKEY_CASCADE_DEL:
        case F_RI_FKEY_CASCADE_UPD:
        case F_RI_FKEY_RESTRICT_DEL:
        case F_RI_FKEY_RESTRICT_UPD:
        case F_RI_FKEY_SETNULL_DEL:
        case F_RI_FKEY_SETNULL_UPD:
        case F_RI_FKEY_SETDEFAULT_DEL:
        case F_RI_FKEY_SETDEFAULT_UPD:
        case F_RI_FKEY_NOACTION_DEL:
        case F_RI_FKEY_NOACTION_UPD:
            return RI_TRIGGER_PK;
 
        case F_RI_FKEY_CHECK_INS:
        case F_RI_FKEY_CHECK_UPD:
            return RI_TRIGGER_FK;
    }
 
    return RI_TRIGGER_NONE;
}

References RI_TRIGGER_FK, RI_TRIGGER_NONE, and RI_TRIGGER_PK.

Referenced by AfterTriggerSaveEvent(), ExecCrossPartitionUpdateForeignKey(), GetForeignKeyActionTriggers(), and GetForeignKeyCheckTriggers().

◆ ri_GenerateQual()

static void ri_GenerateQual	(	StringInfo	buf,
		const char *	sep,
		const char *	leftop,
		Oid	leftoptype,
		Oid	opoid,
		const char *	rightop,
		Oid	rightoptype
	)

static

Definition at line 2068 of file ri_triggers.c.

{
    appendStringInfo(buf, " %s ", sep);
    generate_operator_clause(buf, leftop, leftoptype, opoid,
                             rightop, rightoptype);
}

References appendStringInfo(), buf, and generate_operator_clause().

Referenced by ri_Check_Pk_Match(), RI_FKey_cascade_del(), RI_FKey_cascade_upd(), RI_FKey_check(), RI_Initial_Check(), RI_PartitionRemove_Check(), ri_restrict(), and ri_set().

◆ ri_GenerateQualCollation()

static void ri_GenerateQualCollation	(	StringInfo	buf,
		Oid	collation
	)

static

Definition at line 2095 of file ri_triggers.c.

{
    HeapTuple   tp;
    Form_pg_collation colltup;
    char       *collname;
    char        onename[MAX_QUOTED_NAME_LEN];
 
    /* Nothing to do if it's a noncollatable data type */
    if (!OidIsValid(collation))
        return;
 
    tp = SearchSysCache1(COLLOID, ObjectIdGetDatum(collation));
    if (!HeapTupleIsValid(tp))
        elog(ERROR, "cache lookup failed for collation %u", collation);
    colltup = (Form_pg_collation) GETSTRUCT(tp);
    collname = NameStr(colltup->collname);
 
    /*
     * We qualify the name always, for simplicity and to ensure the query is
     * not search-path-dependent.
     */
    quoteOneName(onename, get_namespace_name(colltup->collnamespace));
    appendStringInfo(buf, " COLLATE %s", onename);
    quoteOneName(onename, collname);
    appendStringInfo(buf, ".%s", onename);
 
    ReleaseSysCache(tp);
}

References appendStringInfo(), buf, elog, ERROR, get_namespace_name(), GETSTRUCT(), HeapTupleIsValid, MAX_QUOTED_NAME_LEN, NameStr, ObjectIdGetDatum(), OidIsValid, quoteOneName(), ReleaseSysCache(), and SearchSysCache1().

Referenced by RI_Initial_Check(), and RI_PartitionRemove_Check().

◆ ri_HashCompareOp()

static RI_CompareHashEntry * ri_HashCompareOp	(	Oid	eq_opr,
		Oid	typeid
	)

static

Definition at line 3117 of file ri_triggers.c.

{
    RI_CompareKey key;
    RI_CompareHashEntry *entry;
    bool        found;
 
    /*
     * On the first call initialize the hashtable
     */
    if (!ri_compare_cache)
        ri_InitHashTables();
 
    /*
     * Find or create a hash entry.  Note we're assuming RI_CompareKey
     * contains no struct padding.
     */
    key.eq_opr = eq_opr;
    key.typeid = typeid;
    entry = (RI_CompareHashEntry *) hash_search(ri_compare_cache,
                                                &key,
                                                HASH_ENTER, &found);
    if (!found)
        entry->valid = false;
 
    /*
     * If not already initialized, do so.  Since we'll keep this hash entry
     * for the life of the backend, put any subsidiary info for the function
     * cache structs into TopMemoryContext.
     */
    if (!entry->valid)
    {
        Oid         lefttype,
                    righttype,
                    castfunc;
        CoercionPathType pathtype;
 
        /* We always need to know how to call the equality operator */
        fmgr_info_cxt(get_opcode(eq_opr), &entry->eq_opr_finfo,
                      TopMemoryContext);
 
        /*
         * If we chose to use a cast from FK to PK type, we may have to apply
         * the cast function to get to the operator's input type.
         *
         * XXX eventually it would be good to support array-coercion cases
         * here and in ri_CompareWithCast().  At the moment there is no point
         * because cases involving nonidentical array types will be rejected
         * at constraint creation time.
         *
         * XXX perhaps also consider supporting CoerceViaIO?  No need at the
         * moment since that will never be generated for implicit coercions.
         */
        op_input_types(eq_opr, &lefttype, &righttype);
        Assert(lefttype == righttype);
        if (typeid == lefttype)
            castfunc = InvalidOid;  /* simplest case */
        else
        {
            pathtype = find_coercion_pathway(lefttype, typeid,
                                             COERCION_IMPLICIT,
                                             &castfunc);
            if (pathtype != COERCION_PATH_FUNC &&
                pathtype != COERCION_PATH_RELABELTYPE)
            {
                /*
                 * The declared input type of the eq_opr might be a
                 * polymorphic type such as ANYARRAY or ANYENUM, or other
                 * special cases such as RECORD; find_coercion_pathway
                 * currently doesn't subsume these special cases.
                 */
                if (!IsBinaryCoercible(typeid, lefttype))
                    elog(ERROR, "no conversion function from %s to %s",
                         format_type_be(typeid),
                         format_type_be(lefttype));
            }
        }
        if (OidIsValid(castfunc))
            fmgr_info_cxt(castfunc, &entry->cast_func_finfo,
                          TopMemoryContext);
        else
            entry->cast_func_finfo.fn_oid = InvalidOid;
        entry->valid = true;
    }
 
    return entry;
}

References Assert(), RI_CompareHashEntry::cast_func_finfo, COERCION_IMPLICIT, COERCION_PATH_FUNC, COERCION_PATH_RELABELTYPE, elog, RI_CompareHashEntry::eq_opr_finfo, ERROR, find_coercion_pathway(), fmgr_info_cxt(), FmgrInfo::fn_oid, format_type_be(), get_opcode(), HASH_ENTER, hash_search(), InvalidOid, IsBinaryCoercible(), sort-test::key, OidIsValid, op_input_types(), ri_compare_cache, ri_InitHashTables(), TopMemoryContext, and RI_CompareHashEntry::valid.

Referenced by ri_CompareWithCast().

◆ ri_HashPreparedPlan()

static void ri_HashPreparedPlan	(	RI_QueryKey *	key,
		SPIPlanPtr	plan
	)

static

Definition at line 2948 of file ri_triggers.c.

{
    RI_QueryHashEntry *entry;
    bool        found;
 
    /*
     * On the first call initialize the hashtable
     */
    if (!ri_query_cache)
        ri_InitHashTables();
 
    /*
     * Add the new plan.  We might be overwriting an entry previously found
     * invalid by ri_FetchPreparedPlan.
     */
    entry = (RI_QueryHashEntry *) hash_search(ri_query_cache,
                                              key,
                                              HASH_ENTER, &found);
    Assert(!found || entry->plan == NULL);
    entry->plan = plan;
}

References Assert(), HASH_ENTER, hash_search(), sort-test::key, RI_QueryHashEntry::plan, plan, ri_InitHashTables(), and ri_query_cache.

Referenced by ri_PlanCheck().

◆ ri_InitHashTables()

static void ri_InitHashTables ( void )

static

Definition at line 2860 of file ri_triggers.c.

{
    HASHCTL     ctl;
 
    ctl.keysize = sizeof(Oid);
    ctl.entrysize = sizeof(RI_ConstraintInfo);
    ri_constraint_cache = hash_create("RI constraint cache",
                                      RI_INIT_CONSTRAINTHASHSIZE,
                                      &ctl, HASH_ELEM | HASH_BLOBS);
 
    /* Arrange to flush cache on pg_constraint changes */
    CacheRegisterSyscacheCallback(CONSTROID,
                                  InvalidateConstraintCacheCallBack,
                                  (Datum) 0);
 
    ctl.keysize = sizeof(RI_QueryKey);
    ctl.entrysize = sizeof(RI_QueryHashEntry);
    ri_query_cache = hash_create("RI query cache",
                                 RI_INIT_QUERYHASHSIZE,
                                 &ctl, HASH_ELEM | HASH_BLOBS);
 
    ctl.keysize = sizeof(RI_CompareKey);
    ctl.entrysize = sizeof(RI_CompareHashEntry);
    ri_compare_cache = hash_create("RI compare cache",
                                   RI_INIT_QUERYHASHSIZE,
                                   &ctl, HASH_ELEM | HASH_BLOBS);
}

References CacheRegisterSyscacheCallback(), ctl, HASH_BLOBS, hash_create(), HASH_ELEM, InvalidateConstraintCacheCallBack(), ri_compare_cache, ri_constraint_cache, RI_INIT_CONSTRAINTHASHSIZE, RI_INIT_QUERYHASHSIZE, and ri_query_cache.

Referenced by ri_FetchPreparedPlan(), ri_HashCompareOp(), ri_HashPreparedPlan(), and ri_LoadConstraintInfo().

◆ RI_Initial_Check()

bool RI_Initial_Check	(	Trigger *	trigger,
		Relation	fk_rel,
		Relation	pk_rel
	)

Definition at line 1519 of file ri_triggers.c.

{
    const RI_ConstraintInfo *riinfo;
    StringInfoData querybuf;
    char        pkrelname[MAX_QUOTED_REL_NAME_LEN];
    char        fkrelname[MAX_QUOTED_REL_NAME_LEN];
    char        pkattname[MAX_QUOTED_NAME_LEN + 3];
    char        fkattname[MAX_QUOTED_NAME_LEN + 3];
    RangeTblEntry *rte;
    RTEPermissionInfo *pk_perminfo;
    RTEPermissionInfo *fk_perminfo;
    List       *rtes = NIL;
    List       *perminfos = NIL;
    const char *sep;
    const char *fk_only;
    const char *pk_only;
    int         save_nestlevel;
    char        workmembuf[32];
    int         spi_result;
    SPIPlanPtr  qplan;
 
    riinfo = ri_FetchConstraintInfo(trigger, fk_rel, false);
 
    /*
     * Check to make sure current user has enough permissions to do the test
     * query.  (If not, caller can fall back to the trigger method, which
     * works because it changes user IDs on the fly.)
     *
     * XXX are there any other show-stopper conditions to check?
     */
    pk_perminfo = makeNode(RTEPermissionInfo);
    pk_perminfo->relid = RelationGetRelid(pk_rel);
    pk_perminfo->requiredPerms = ACL_SELECT;
    perminfos = lappend(perminfos, pk_perminfo);
    rte = makeNode(RangeTblEntry);
    rte->rtekind = RTE_RELATION;
    rte->relid = RelationGetRelid(pk_rel);
    rte->relkind = pk_rel->rd_rel->relkind;
    rte->rellockmode = AccessShareLock;
    rte->perminfoindex = list_length(perminfos);
    rtes = lappend(rtes, rte);
 
    fk_perminfo = makeNode(RTEPermissionInfo);
    fk_perminfo->relid = RelationGetRelid(fk_rel);
    fk_perminfo->requiredPerms = ACL_SELECT;
    perminfos = lappend(perminfos, fk_perminfo);
    rte = makeNode(RangeTblEntry);
    rte->rtekind = RTE_RELATION;
    rte->relid = RelationGetRelid(fk_rel);
    rte->relkind = fk_rel->rd_rel->relkind;
    rte->rellockmode = AccessShareLock;
    rte->perminfoindex = list_length(perminfos);
    rtes = lappend(rtes, rte);
 
    for (int i = 0; i < riinfo->nkeys; i++)
    {
        int         attno;
 
        attno = riinfo->pk_attnums[i] - FirstLowInvalidHeapAttributeNumber;
        pk_perminfo->selectedCols = bms_add_member(pk_perminfo->selectedCols, attno);
 
        attno = riinfo->fk_attnums[i] - FirstLowInvalidHeapAttributeNumber;
        fk_perminfo->selectedCols = bms_add_member(fk_perminfo->selectedCols, attno);
    }
 
    if (!ExecCheckPermissions(rtes, perminfos, false))
        return false;
 
    /*
     * Also punt if RLS is enabled on either table unless this role has the
     * bypassrls right or is the table owner of the table(s) involved which
     * have RLS enabled.
     */
    if (!has_bypassrls_privilege(GetUserId()) &&
        ((pk_rel->rd_rel->relrowsecurity &&
          !object_ownercheck(RelationRelationId, RelationGetRelid(pk_rel),
                             GetUserId())) ||
         (fk_rel->rd_rel->relrowsecurity &&
          !object_ownercheck(RelationRelationId, RelationGetRelid(fk_rel),
                             GetUserId()))))
        return false;
 
    /*----------
     * The query string built is:
     *  SELECT fk.keycols FROM [ONLY] relname fk
     *   LEFT OUTER JOIN [ONLY] pkrelname pk
     *   ON (pk.pkkeycol1=fk.keycol1 [AND ...])
     *   WHERE pk.pkkeycol1 IS NULL AND
     * For MATCH SIMPLE:
     *   (fk.keycol1 IS NOT NULL [AND ...])
     * For MATCH FULL:
     *   (fk.keycol1 IS NOT NULL [OR ...])
     *
     * We attach COLLATE clauses to the operators when comparing columns
     * that have different collations.
     *----------
     */
    initStringInfo(&querybuf);
    appendStringInfoString(&querybuf, "SELECT ");
    sep = "";
    for (int i = 0; i < riinfo->nkeys; i++)
    {
        quoteOneName(fkattname,
                     RIAttName(fk_rel, riinfo->fk_attnums[i]));
        appendStringInfo(&querybuf, "%sfk.%s", sep, fkattname);
        sep = ", ";
    }
 
    quoteRelationName(pkrelname, pk_rel);
    quoteRelationName(fkrelname, fk_rel);
    fk_only = fk_rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE ?
        "" : "ONLY ";
    pk_only = pk_rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE ?
        "" : "ONLY ";
    appendStringInfo(&querybuf,
                     " FROM %s%s fk LEFT OUTER JOIN %s%s pk ON",
                     fk_only, fkrelname, pk_only, pkrelname);
 
    strcpy(pkattname, "pk.");
    strcpy(fkattname, "fk.");
    sep = "(";
    for (int i = 0; i < riinfo->nkeys; i++)
    {
        Oid         pk_type = RIAttType(pk_rel, riinfo->pk_attnums[i]);
        Oid         fk_type = RIAttType(fk_rel, riinfo->fk_attnums[i]);
        Oid         pk_coll = RIAttCollation(pk_rel, riinfo->pk_attnums[i]);
        Oid         fk_coll = RIAttCollation(fk_rel, riinfo->fk_attnums[i]);
 
        quoteOneName(pkattname + 3,
                     RIAttName(pk_rel, riinfo->pk_attnums[i]));
        quoteOneName(fkattname + 3,
                     RIAttName(fk_rel, riinfo->fk_attnums[i]));
        ri_GenerateQual(&querybuf, sep,
                        pkattname, pk_type,
                        riinfo->pf_eq_oprs[i],
                        fkattname, fk_type);
        if (pk_coll != fk_coll)
            ri_GenerateQualCollation(&querybuf, pk_coll);
        sep = "AND";
    }
 
    /*
     * It's sufficient to test any one pk attribute for null to detect a join
     * failure.
     */
    quoteOneName(pkattname, RIAttName(pk_rel, riinfo->pk_attnums[0]));
    appendStringInfo(&querybuf, ") WHERE pk.%s IS NULL AND (", pkattname);
 
    sep = "";
    for (int i = 0; i < riinfo->nkeys; i++)
    {
        quoteOneName(fkattname, RIAttName(fk_rel, riinfo->fk_attnums[i]));
        appendStringInfo(&querybuf,
                         "%sfk.%s IS NOT NULL",
                         sep, fkattname);
        switch (riinfo->confmatchtype)
        {
            case FKCONSTR_MATCH_SIMPLE:
                sep = " AND ";
                break;
            case FKCONSTR_MATCH_FULL:
                sep = " OR ";
                break;
        }
    }
    appendStringInfoChar(&querybuf, ')');
 
    /*
     * Temporarily increase work_mem so that the check query can be executed
     * more efficiently.  It seems okay to do this because the query is simple
     * enough to not use a multiple of work_mem, and one typically would not
     * have many large foreign-key validations happening concurrently.  So
     * this seems to meet the criteria for being considered a "maintenance"
     * operation, and accordingly we use maintenance_work_mem.  However, we
     * must also set hash_mem_multiplier to 1, since it is surely not okay to
     * let that get applied to the maintenance_work_mem value.
     *
     * We use the equivalent of a function SET option to allow the setting to
     * persist for exactly the duration of the check query.  guc.c also takes
     * care of undoing the setting on error.
     */
    save_nestlevel = NewGUCNestLevel();
 
    snprintf(workmembuf, sizeof(workmembuf), "%d", maintenance_work_mem);
    (void) set_config_option("work_mem", workmembuf,
                             PGC_USERSET, PGC_S_SESSION,
                             GUC_ACTION_SAVE, true, 0, false);
    (void) set_config_option("hash_mem_multiplier", "1",
                             PGC_USERSET, PGC_S_SESSION,
                             GUC_ACTION_SAVE, true, 0, false);
 
    SPI_connect();
 
    /*
     * Generate the plan.  We don't need to cache it, and there are no
     * arguments to the plan.
     */
    qplan = SPI_prepare(querybuf.data, 0, NULL);
 
    if (qplan == NULL)
        elog(ERROR, "SPI_prepare returned %s for %s",
             SPI_result_code_string(SPI_result), querybuf.data);
 
    /*
     * Run the plan.  For safety we force a current snapshot to be used. (In
     * transaction-snapshot mode, this arguably violates transaction isolation
     * rules, but we really haven't got much choice.) We don't need to
     * register the snapshot, because SPI_execute_snapshot will see to it. We
     * need at most one tuple returned, so pass limit = 1.
     */
    spi_result = SPI_execute_snapshot(qplan,
                                      NULL, NULL,
                                      GetLatestSnapshot(),
                                      InvalidSnapshot,
                                      true, false, 1);
 
    /* Check result */
    if (spi_result != SPI_OK_SELECT)
        elog(ERROR, "SPI_execute_snapshot returned %s", SPI_result_code_string(spi_result));
 
    /* Did we find a tuple violating the constraint? */
    if (SPI_processed > 0)
    {
        TupleTableSlot *slot;
        HeapTuple   tuple = SPI_tuptable->vals[0];
        TupleDesc   tupdesc = SPI_tuptable->tupdesc;
        RI_ConstraintInfo fake_riinfo;
 
        slot = MakeSingleTupleTableSlot(tupdesc, &TTSOpsVirtual);
 
        heap_deform_tuple(tuple, tupdesc,
                          slot->tts_values, slot->tts_isnull);
        ExecStoreVirtualTuple(slot);
 
        /*
         * The columns to look at in the result tuple are 1..N, not whatever
         * they are in the fk_rel.  Hack up riinfo so that the subroutines
         * called here will behave properly.
         *
         * In addition to this, we have to pass the correct tupdesc to
         * ri_ReportViolation, overriding its normal habit of using the pk_rel
         * or fk_rel's tupdesc.
         */
        memcpy(&fake_riinfo, riinfo, sizeof(RI_ConstraintInfo));
        for (int i = 0; i < fake_riinfo.nkeys; i++)
            fake_riinfo.fk_attnums[i] = i + 1;
 
        /*
         * If it's MATCH FULL, and there are any nulls in the FK keys,
         * complain about that rather than the lack of a match.  MATCH FULL
         * disallows partially-null FK rows.
         */
        if (fake_riinfo.confmatchtype == FKCONSTR_MATCH_FULL &&
            ri_NullCheck(tupdesc, slot, &fake_riinfo, false) != RI_KEYS_NONE_NULL)
            ereport(ERROR,
                    (errcode(ERRCODE_FOREIGN_KEY_VIOLATION),
                     errmsg("insert or update on table \"%s\" violates foreign key constraint \"%s\"",
                            RelationGetRelationName(fk_rel),
                            NameStr(fake_riinfo.conname)),
                     errdetail("MATCH FULL does not allow mixing of null and nonnull key values."),
                     errtableconstraint(fk_rel,
                                        NameStr(fake_riinfo.conname))));
 
        /*
         * We tell ri_ReportViolation we were doing the RI_PLAN_CHECK_LOOKUPPK
         * query, which isn't true, but will cause it to use
         * fake_riinfo.fk_attnums as we need.
         */
        ri_ReportViolation(&fake_riinfo,
                           pk_rel, fk_rel,
                           slot, tupdesc,
                           RI_PLAN_CHECK_LOOKUPPK, false, false);
 
        ExecDropSingleTupleTableSlot(slot);
    }
 
    if (SPI_finish() != SPI_OK_FINISH)
        elog(ERROR, "SPI_finish failed");
 
    /*
     * Restore work_mem and hash_mem_multiplier.
     */
    AtEOXact_GUC(true, save_nestlevel);
 
    return true;
}

References AccessShareLock, ACL_SELECT, appendStringInfo(), appendStringInfoChar(), appendStringInfoString(), AtEOXact_GUC(), bms_add_member(), RI_ConstraintInfo::confmatchtype, RI_ConstraintInfo::conname, StringInfoData::data, elog, ereport, errcode(), errdetail(), errmsg(), ERROR, errtableconstraint(), ExecCheckPermissions(), ExecDropSingleTupleTableSlot(), ExecStoreVirtualTuple(), FirstLowInvalidHeapAttributeNumber, RI_ConstraintInfo::fk_attnums, FKCONSTR_MATCH_FULL, FKCONSTR_MATCH_SIMPLE, GetLatestSnapshot(), GetUserId(), GUC_ACTION_SAVE, has_bypassrls_privilege(), heap_deform_tuple(), i, if(), initStringInfo(), InvalidSnapshot, lappend(), list_length(), maintenance_work_mem, makeNode, MakeSingleTupleTableSlot(), MAX_QUOTED_NAME_LEN, MAX_QUOTED_REL_NAME_LEN, NameStr, NewGUCNestLevel(), NIL, RI_ConstraintInfo::nkeys, object_ownercheck(), RI_ConstraintInfo::pf_eq_oprs, PGC_S_SESSION, PGC_USERSET, RI_ConstraintInfo::pk_attnums, quoteOneName(), quoteRelationName(), RelationData::rd_rel, RelationGetRelationName, RelationGetRelid, RTEPermissionInfo::relid, RTEPermissionInfo::requiredPerms, ri_FetchConstraintInfo(), ri_GenerateQual(), ri_GenerateQualCollation(), RI_KEYS_NONE_NULL, ri_NullCheck(), RI_PLAN_CHECK_LOOKUPPK, ri_ReportViolation(), RIAttCollation, RIAttName, RIAttType, RTE_RELATION, RangeTblEntry::rtekind, RTEPermissionInfo::selectedCols, set_config_option(), snprintf, SPI_connect(), SPI_execute_snapshot(), SPI_finish(), SPI_OK_FINISH, SPI_OK_SELECT, SPI_prepare(), SPI_processed, SPI_result, SPI_result_code_string(), SPI_tuptable, TupleTableSlot::tts_isnull, TupleTableSlot::tts_values, TTSOpsVirtual, SPITupleTable::tupdesc, and SPITupleTable::vals.

Referenced by validateForeignKeyConstraint().

◆ ri_KeysEqual()

static bool ri_KeysEqual	(	Relation	rel,
		TupleTableSlot *	oldslot,
		TupleTableSlot *	newslot,
		const RI_ConstraintInfo *	riinfo,
		bool	rel_is_pk
	)

static

Definition at line 2985 of file ri_triggers.c.

{
    const int16 *attnums;
 
    if (rel_is_pk)
        attnums = riinfo->pk_attnums;
    else
        attnums = riinfo->fk_attnums;
 
    /* XXX: could be worthwhile to fetch all necessary attrs at once */
    for (int i = 0; i < riinfo->nkeys; i++)
    {
        Datum       oldvalue;
        Datum       newvalue;
        bool        isnull;
 
        /*
         * Get one attribute's oldvalue. If it is NULL - they're not equal.
         */
        oldvalue = slot_getattr(oldslot, attnums[i], &isnull);
        if (isnull)
            return false;
 
        /*
         * Get one attribute's newvalue. If it is NULL - they're not equal.
         */
        newvalue = slot_getattr(newslot, attnums[i], &isnull);
        if (isnull)
            return false;
 
        if (rel_is_pk)
        {
            /*
             * If we are looking at the PK table, then do a bytewise
             * comparison.  We must propagate PK changes if the value is
             * changed to one that "looks" different but would compare as
             * equal using the equality operator.  This only makes a
             * difference for ON UPDATE CASCADE, but for consistency we treat
             * all changes to the PK the same.
             */
            CompactAttribute *att = TupleDescCompactAttr(oldslot->tts_tupleDescriptor, attnums[i] - 1);
 
            if (!datum_image_eq(oldvalue, newvalue, att->attbyval, att->attlen))
                return false;
        }
        else
        {
            Oid         eq_opr;
 
            /*
             * When comparing the PERIOD columns we can skip the check
             * whenever the referencing column stayed equal or shrank, so test
             * with the contained-by operator instead.
             */
            if (riinfo->hasperiod && i == riinfo->nkeys - 1)
                eq_opr = riinfo->period_contained_by_oper;
            else
                eq_opr = riinfo->ff_eq_oprs[i];
 
            /*
             * For the FK table, compare with the appropriate equality
             * operator.  Changes that compare equal will still satisfy the
             * constraint after the update.
             */
            if (!ri_CompareWithCast(eq_opr, RIAttType(rel, attnums[i]), RIAttCollation(rel, attnums[i]),
                                    newvalue, oldvalue))
                return false;
        }
    }
 
    return true;
}

References CompactAttribute::attbyval, CompactAttribute::attlen, datum_image_eq(), RI_ConstraintInfo::ff_eq_oprs, RI_ConstraintInfo::fk_attnums, RI_ConstraintInfo::hasperiod, i, RI_ConstraintInfo::nkeys, RI_ConstraintInfo::period_contained_by_oper, RI_ConstraintInfo::pk_attnums, ri_CompareWithCast(), RIAttCollation, RIAttType, slot_getattr(), TupleTableSlot::tts_tupleDescriptor, and TupleDescCompactAttr().

Referenced by RI_FKey_fk_upd_check_required(), and RI_FKey_pk_upd_check_required().

◆ ri_LoadConstraintInfo()

static const RI_ConstraintInfo * ri_LoadConstraintInfo ( Oid constraintOid )

static

Definition at line 2268 of file ri_triggers.c.

{
    RI_ConstraintInfo *riinfo;
    bool        found;
    HeapTuple   tup;
    Form_pg_constraint conForm;
 
    /*
     * On the first call initialize the hashtable
     */
    if (!ri_constraint_cache)
        ri_InitHashTables();
 
    /*
     * Find or create a hash entry.  If we find a valid one, just return it.
     */
    riinfo = (RI_ConstraintInfo *) hash_search(ri_constraint_cache,
                                               &constraintOid,
                                               HASH_ENTER, &found);
    if (!found)
        riinfo->valid = false;
    else if (riinfo->valid)
        return riinfo;
 
    /*
     * Fetch the pg_constraint row so we can fill in the entry.
     */
    tup = SearchSysCache1(CONSTROID, ObjectIdGetDatum(constraintOid));
    if (!HeapTupleIsValid(tup)) /* should not happen */
        elog(ERROR, "cache lookup failed for constraint %u", constraintOid);
    conForm = (Form_pg_constraint) GETSTRUCT(tup);
 
    if (conForm->contype != CONSTRAINT_FOREIGN) /* should not happen */
        elog(ERROR, "constraint %u is not a foreign key constraint",
             constraintOid);
 
    /* And extract data */
    Assert(riinfo->constraint_id == constraintOid);
    if (OidIsValid(conForm->conparentid))
        riinfo->constraint_root_id =
            get_ri_constraint_root(conForm->conparentid);
    else
        riinfo->constraint_root_id = constraintOid;
    riinfo->oidHashValue = GetSysCacheHashValue1(CONSTROID,
                                                 ObjectIdGetDatum(constraintOid));
    riinfo->rootHashValue = GetSysCacheHashValue1(CONSTROID,
                                                  ObjectIdGetDatum(riinfo->constraint_root_id));
    memcpy(&riinfo->conname, &conForm->conname, sizeof(NameData));
    riinfo->pk_relid = conForm->confrelid;
    riinfo->fk_relid = conForm->conrelid;
    riinfo->confupdtype = conForm->confupdtype;
    riinfo->confdeltype = conForm->confdeltype;
    riinfo->confmatchtype = conForm->confmatchtype;
    riinfo->hasperiod = conForm->conperiod;
 
    DeconstructFkConstraintRow(tup,
                               &riinfo->nkeys,
                               riinfo->fk_attnums,
                               riinfo->pk_attnums,
                               riinfo->pf_eq_oprs,
                               riinfo->pp_eq_oprs,
                               riinfo->ff_eq_oprs,
                               &riinfo->ndelsetcols,
                               riinfo->confdelsetcols);
 
    /*
     * For temporal FKs, get the operators and functions we need. We ask the
     * opclass of the PK element for these. This all gets cached (as does the
     * generated plan), so there's no performance issue.
     */
    if (riinfo->hasperiod)
    {
        Oid         opclass = get_index_column_opclass(conForm->conindid, riinfo->nkeys);
 
        FindFKPeriodOpers(opclass,
                          &riinfo->period_contained_by_oper,
                          &riinfo->agged_period_contained_by_oper,
                          &riinfo->period_intersect_oper);
    }
 
    ReleaseSysCache(tup);
 
    /*
     * For efficient processing of invalidation messages below, we keep a
     * doubly-linked count list of all currently valid entries.
     */
    dclist_push_tail(&ri_constraint_cache_valid_list, &riinfo->valid_link);
 
    riinfo->valid = true;
 
    return riinfo;
}

Referenced by ri_FetchConstraintInfo().

◆ ri_NullCheck()

static int ri_NullCheck	(	TupleDesc	tupDesc,
		TupleTableSlot *	slot,
		const RI_ConstraintInfo *	riinfo,
		bool	rel_is_pk
	)

static

Definition at line 2823 of file ri_triggers.c.

{
    const int16 *attnums;
    bool        allnull = true;
    bool        nonenull = true;
 
    if (rel_is_pk)
        attnums = riinfo->pk_attnums;
    else
        attnums = riinfo->fk_attnums;
 
    for (int i = 0; i < riinfo->nkeys; i++)
    {
        if (slot_attisnull(slot, attnums[i]))
            nonenull = false;
        else
            allnull = false;
    }
 
    if (allnull)
        return RI_KEYS_ALL_NULL;
 
    if (nonenull)
        return RI_KEYS_NONE_NULL;
 
    return RI_KEYS_SOME_NULL;
}

References RI_ConstraintInfo::fk_attnums, i, RI_ConstraintInfo::nkeys, RI_ConstraintInfo::pk_attnums, RI_KEYS_ALL_NULL, RI_KEYS_NONE_NULL, RI_KEYS_SOME_NULL, and slot_attisnull().

Referenced by ri_Check_Pk_Match(), RI_FKey_check(), RI_FKey_fk_upd_check_required(), RI_FKey_pk_upd_check_required(), and RI_Initial_Check().

◆ RI_PartitionRemove_Check()

void RI_PartitionRemove_Check	(	Trigger *	trigger,
		Relation	fk_rel,
		Relation	pk_rel
	)

Definition at line 1813 of file ri_triggers.c.

{
    const RI_ConstraintInfo *riinfo;
    StringInfoData querybuf;
    char       *constraintDef;
    char        pkrelname[MAX_QUOTED_REL_NAME_LEN];
    char        fkrelname[MAX_QUOTED_REL_NAME_LEN];
    char        pkattname[MAX_QUOTED_NAME_LEN + 3];
    char        fkattname[MAX_QUOTED_NAME_LEN + 3];
    const char *sep;
    const char *fk_only;
    int         save_nestlevel;
    char        workmembuf[32];
    int         spi_result;
    SPIPlanPtr  qplan;
    int         i;
 
    riinfo = ri_FetchConstraintInfo(trigger, fk_rel, false);
 
    /*
     * We don't check permissions before displaying the error message, on the
     * assumption that the user detaching the partition must have enough
     * privileges to examine the table contents anyhow.
     */
 
    /*----------
     * The query string built is:
     *  SELECT fk.keycols FROM [ONLY] relname fk
     *    JOIN pkrelname pk
     *    ON (pk.pkkeycol1=fk.keycol1 [AND ...])
     *    WHERE (<partition constraint>) AND
     * For MATCH SIMPLE:
     *   (fk.keycol1 IS NOT NULL [AND ...])
     * For MATCH FULL:
     *   (fk.keycol1 IS NOT NULL [OR ...])
     *
     * We attach COLLATE clauses to the operators when comparing columns
     * that have different collations.
     *----------
     */
    initStringInfo(&querybuf);
    appendStringInfoString(&querybuf, "SELECT ");
    sep = "";
    for (i = 0; i < riinfo->nkeys; i++)
    {
        quoteOneName(fkattname,
                     RIAttName(fk_rel, riinfo->fk_attnums[i]));
        appendStringInfo(&querybuf, "%sfk.%s", sep, fkattname);
        sep = ", ";
    }
 
    quoteRelationName(pkrelname, pk_rel);
    quoteRelationName(fkrelname, fk_rel);
    fk_only = fk_rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE ?
        "" : "ONLY ";
    appendStringInfo(&querybuf,
                     " FROM %s%s fk JOIN %s pk ON",
                     fk_only, fkrelname, pkrelname);
    strcpy(pkattname, "pk.");
    strcpy(fkattname, "fk.");
    sep = "(";
    for (i = 0; i < riinfo->nkeys; i++)
    {
        Oid         pk_type = RIAttType(pk_rel, riinfo->pk_attnums[i]);
        Oid         fk_type = RIAttType(fk_rel, riinfo->fk_attnums[i]);
        Oid         pk_coll = RIAttCollation(pk_rel, riinfo->pk_attnums[i]);
        Oid         fk_coll = RIAttCollation(fk_rel, riinfo->fk_attnums[i]);
 
        quoteOneName(pkattname + 3,
                     RIAttName(pk_rel, riinfo->pk_attnums[i]));
        quoteOneName(fkattname + 3,
                     RIAttName(fk_rel, riinfo->fk_attnums[i]));
        ri_GenerateQual(&querybuf, sep,
                        pkattname, pk_type,
                        riinfo->pf_eq_oprs[i],
                        fkattname, fk_type);
        if (pk_coll != fk_coll)
            ri_GenerateQualCollation(&querybuf, pk_coll);
        sep = "AND";
    }
 
    /*
     * Start the WHERE clause with the partition constraint (except if this is
     * the default partition and there's no other partition, because the
     * partition constraint is the empty string in that case.)
     */
    constraintDef = pg_get_partconstrdef_string(RelationGetRelid(pk_rel), "pk");
    if (constraintDef && constraintDef[0] != '\0')
        appendStringInfo(&querybuf, ") WHERE %s AND (",
                         constraintDef);
    else
        appendStringInfoString(&querybuf, ") WHERE (");
 
    sep = "";
    for (i = 0; i < riinfo->nkeys; i++)
    {
        quoteOneName(fkattname, RIAttName(fk_rel, riinfo->fk_attnums[i]));
        appendStringInfo(&querybuf,
                         "%sfk.%s IS NOT NULL",
                         sep, fkattname);
        switch (riinfo->confmatchtype)
        {
            case FKCONSTR_MATCH_SIMPLE:
                sep = " AND ";
                break;
            case FKCONSTR_MATCH_FULL:
                sep = " OR ";
                break;
        }
    }
    appendStringInfoChar(&querybuf, ')');
 
    /*
     * Temporarily increase work_mem so that the check query can be executed
     * more efficiently.  It seems okay to do this because the query is simple
     * enough to not use a multiple of work_mem, and one typically would not
     * have many large foreign-key validations happening concurrently.  So
     * this seems to meet the criteria for being considered a "maintenance"
     * operation, and accordingly we use maintenance_work_mem.  However, we
     * must also set hash_mem_multiplier to 1, since it is surely not okay to
     * let that get applied to the maintenance_work_mem value.
     *
     * We use the equivalent of a function SET option to allow the setting to
     * persist for exactly the duration of the check query.  guc.c also takes
     * care of undoing the setting on error.
     */
    save_nestlevel = NewGUCNestLevel();
 
    snprintf(workmembuf, sizeof(workmembuf), "%d", maintenance_work_mem);
    (void) set_config_option("work_mem", workmembuf,
                             PGC_USERSET, PGC_S_SESSION,
                             GUC_ACTION_SAVE, true, 0, false);
    (void) set_config_option("hash_mem_multiplier", "1",
                             PGC_USERSET, PGC_S_SESSION,
                             GUC_ACTION_SAVE, true, 0, false);
 
    SPI_connect();
 
    /*
     * Generate the plan.  We don't need to cache it, and there are no
     * arguments to the plan.
     */
    qplan = SPI_prepare(querybuf.data, 0, NULL);
 
    if (qplan == NULL)
        elog(ERROR, "SPI_prepare returned %s for %s",
             SPI_result_code_string(SPI_result), querybuf.data);
 
    /*
     * Run the plan.  For safety we force a current snapshot to be used. (In
     * transaction-snapshot mode, this arguably violates transaction isolation
     * rules, but we really haven't got much choice.) We don't need to
     * register the snapshot, because SPI_execute_snapshot will see to it. We
     * need at most one tuple returned, so pass limit = 1.
     */
    spi_result = SPI_execute_snapshot(qplan,
                                      NULL, NULL,
                                      GetLatestSnapshot(),
                                      InvalidSnapshot,
                                      true, false, 1);
 
    /* Check result */
    if (spi_result != SPI_OK_SELECT)
        elog(ERROR, "SPI_execute_snapshot returned %s", SPI_result_code_string(spi_result));
 
    /* Did we find a tuple that would violate the constraint? */
    if (SPI_processed > 0)
    {
        TupleTableSlot *slot;
        HeapTuple   tuple = SPI_tuptable->vals[0];
        TupleDesc   tupdesc = SPI_tuptable->tupdesc;
        RI_ConstraintInfo fake_riinfo;
 
        slot = MakeSingleTupleTableSlot(tupdesc, &TTSOpsVirtual);
 
        heap_deform_tuple(tuple, tupdesc,
                          slot->tts_values, slot->tts_isnull);
        ExecStoreVirtualTuple(slot);
 
        /*
         * The columns to look at in the result tuple are 1..N, not whatever
         * they are in the fk_rel.  Hack up riinfo so that ri_ReportViolation
         * will behave properly.
         *
         * In addition to this, we have to pass the correct tupdesc to
         * ri_ReportViolation, overriding its normal habit of using the pk_rel
         * or fk_rel's tupdesc.
         */
        memcpy(&fake_riinfo, riinfo, sizeof(RI_ConstraintInfo));
        for (i = 0; i < fake_riinfo.nkeys; i++)
            fake_riinfo.pk_attnums[i] = i + 1;
 
        ri_ReportViolation(&fake_riinfo, pk_rel, fk_rel,
                           slot, tupdesc, 0, false, true);
    }
 
    if (SPI_finish() != SPI_OK_FINISH)
        elog(ERROR, "SPI_finish failed");
 
    /*
     * Restore work_mem and hash_mem_multiplier.
     */
    AtEOXact_GUC(true, save_nestlevel);
}

References appendStringInfo(), appendStringInfoChar(), appendStringInfoString(), AtEOXact_GUC(), RI_ConstraintInfo::confmatchtype, StringInfoData::data, elog, ERROR, ExecStoreVirtualTuple(), RI_ConstraintInfo::fk_attnums, FKCONSTR_MATCH_FULL, FKCONSTR_MATCH_SIMPLE, GetLatestSnapshot(), GUC_ACTION_SAVE, heap_deform_tuple(), i, initStringInfo(), InvalidSnapshot, maintenance_work_mem, MakeSingleTupleTableSlot(), MAX_QUOTED_NAME_LEN, MAX_QUOTED_REL_NAME_LEN, NewGUCNestLevel(), RI_ConstraintInfo::nkeys, RI_ConstraintInfo::pf_eq_oprs, pg_get_partconstrdef_string(), PGC_S_SESSION, PGC_USERSET, RI_ConstraintInfo::pk_attnums, quoteOneName(), quoteRelationName(), RelationData::rd_rel, RelationGetRelid, ri_FetchConstraintInfo(), ri_GenerateQual(), ri_GenerateQualCollation(), ri_ReportViolation(), RIAttCollation, RIAttName, RIAttType, set_config_option(), snprintf, SPI_connect(), SPI_execute_snapshot(), SPI_finish(), SPI_OK_FINISH, SPI_OK_SELECT, SPI_prepare(), SPI_processed, SPI_result, SPI_result_code_string(), SPI_tuptable, TupleTableSlot::tts_isnull, TupleTableSlot::tts_values, TTSOpsVirtual, SPITupleTable::tupdesc, and SPITupleTable::vals.

Referenced by ATDetachCheckNoForeignKeyRefs().

◆ ri_PerformCheck()

static bool ri_PerformCheck	(	const RI_ConstraintInfo *	riinfo,
		RI_QueryKey *	qkey,
		SPIPlanPtr	qplan,
		Relation	fk_rel,
		Relation	pk_rel,
		TupleTableSlot *	oldslot,
		TupleTableSlot *	newslot,
		bool	is_restrict,
		bool	detectNewRows,
		int	expect_OK
	)

static

Definition at line 2484 of file ri_triggers.c.

{
    Relation    query_rel,
                source_rel;
    bool        source_is_pk;
    Snapshot    test_snapshot;
    Snapshot    crosscheck_snapshot;
    int         limit;
    int         spi_result;
    Oid         save_userid;
    int         save_sec_context;
    Datum       vals[RI_MAX_NUMKEYS * 2];
    char        nulls[RI_MAX_NUMKEYS * 2];
 
    /*
     * Use the query type code to determine whether the query is run against
     * the PK or FK table; we'll do the check as that table's owner
     */
    if (qkey->constr_queryno <= RI_PLAN_LAST_ON_PK)
        query_rel = pk_rel;
    else
        query_rel = fk_rel;
 
    /*
     * The values for the query are taken from the table on which the trigger
     * is called - it is normally the other one with respect to query_rel. An
     * exception is ri_Check_Pk_Match(), which uses the PK table for both (and
     * sets queryno to RI_PLAN_CHECK_LOOKUPPK_FROM_PK).  We might eventually
     * need some less klugy way to determine this.
     */
    if (qkey->constr_queryno == RI_PLAN_CHECK_LOOKUPPK)
    {
        source_rel = fk_rel;
        source_is_pk = false;
    }
    else
    {
        source_rel = pk_rel;
        source_is_pk = true;
    }
 
    /* Extract the parameters to be passed into the query */
    if (newslot)
    {
        ri_ExtractValues(source_rel, newslot, riinfo, source_is_pk,
                         vals, nulls);
        if (oldslot)
            ri_ExtractValues(source_rel, oldslot, riinfo, source_is_pk,
                             vals + riinfo->nkeys, nulls + riinfo->nkeys);
    }
    else
    {
        ri_ExtractValues(source_rel, oldslot, riinfo, source_is_pk,
                         vals, nulls);
    }
 
    /*
     * In READ COMMITTED mode, we just need to use an up-to-date regular
     * snapshot, and we will see all rows that could be interesting. But in
     * transaction-snapshot mode, we can't change the transaction snapshot. If
     * the caller passes detectNewRows == false then it's okay to do the query
     * with the transaction snapshot; otherwise we use a current snapshot, and
     * tell the executor to error out if it finds any rows under the current
     * snapshot that wouldn't be visible per the transaction snapshot.  Note
     * that SPI_execute_snapshot will register the snapshots, so we don't need
     * to bother here.
     */
    if (IsolationUsesXactSnapshot() && detectNewRows)
    {
        CommandCounterIncrement();  /* be sure all my own work is visible */
        test_snapshot = GetLatestSnapshot();
        crosscheck_snapshot = GetTransactionSnapshot();
    }
    else
    {
        /* the default SPI behavior is okay */
        test_snapshot = InvalidSnapshot;
        crosscheck_snapshot = InvalidSnapshot;
    }
 
    /*
     * If this is a select query (e.g., for a 'no action' or 'restrict'
     * trigger), we only need to see if there is a single row in the table,
     * matching the key.  Otherwise, limit = 0 - because we want the query to
     * affect ALL the matching rows.
     */
    limit = (expect_OK == SPI_OK_SELECT) ? 1 : 0;
 
    /* Switch to proper UID to perform check as */
    GetUserIdAndSecContext(&save_userid, &save_sec_context);
    SetUserIdAndSecContext(RelationGetForm(query_rel)->relowner,
                           save_sec_context | SECURITY_LOCAL_USERID_CHANGE |
                           SECURITY_NOFORCE_RLS);
 
    /* Finally we can run the query. */
    spi_result = SPI_execute_snapshot(qplan,
                                      vals, nulls,
                                      test_snapshot, crosscheck_snapshot,
                                      false, false, limit);
 
    /* Restore UID and security context */
    SetUserIdAndSecContext(save_userid, save_sec_context);
 
    /* Check result */
    if (spi_result < 0)
        elog(ERROR, "SPI_execute_snapshot returned %s", SPI_result_code_string(spi_result));
 
    if (expect_OK >= 0 && spi_result != expect_OK)
        ereport(ERROR,
                (errcode(ERRCODE_INTERNAL_ERROR),
                 errmsg("referential integrity query on \"%s\" from constraint \"%s\" on \"%s\" gave unexpected result",
                        RelationGetRelationName(pk_rel),
                        NameStr(riinfo->conname),
                        RelationGetRelationName(fk_rel)),
                 errhint("This is most likely due to a rule having rewritten the query.")));
 
    /* XXX wouldn't it be clearer to do this part at the caller? */
    if (qkey->constr_queryno != RI_PLAN_CHECK_LOOKUPPK_FROM_PK &&
        expect_OK == SPI_OK_SELECT &&
        (SPI_processed == 0) == (qkey->constr_queryno == RI_PLAN_CHECK_LOOKUPPK))
        ri_ReportViolation(riinfo,
                           pk_rel, fk_rel,
                           newslot ? newslot : oldslot,
                           NULL,
                           qkey->constr_queryno, is_restrict, false);
 
    return SPI_processed != 0;
}

References CommandCounterIncrement(), RI_ConstraintInfo::conname, RI_QueryKey::constr_queryno, elog, ereport, errcode(), errhint(), errmsg(), ERROR, GetLatestSnapshot(), GetTransactionSnapshot(), GetUserIdAndSecContext(), InvalidSnapshot, IsolationUsesXactSnapshot, NameStr, RI_ConstraintInfo::nkeys, RelationGetForm, RelationGetRelationName, ri_ExtractValues(), RI_MAX_NUMKEYS, RI_PLAN_CHECK_LOOKUPPK, RI_PLAN_CHECK_LOOKUPPK_FROM_PK, RI_PLAN_LAST_ON_PK, ri_ReportViolation(), SECURITY_LOCAL_USERID_CHANGE, SECURITY_NOFORCE_RLS, SetUserIdAndSecContext(), SPI_execute_snapshot(), SPI_OK_SELECT, SPI_processed, and SPI_result_code_string().

Referenced by ri_Check_Pk_Match(), RI_FKey_cascade_del(), RI_FKey_cascade_upd(), RI_FKey_check(), ri_restrict(), and ri_set().

◆ ri_PlanCheck()

static SPIPlanPtr ri_PlanCheck	(	const char *	querystr,
		int	nargs,
		Oid *	argtypes,
		RI_QueryKey *	qkey,
		Relation	fk_rel,
		Relation	pk_rel
	)

static

Definition at line 2441 of file ri_triggers.c.

{
    SPIPlanPtr  qplan;
    Relation    query_rel;
    Oid         save_userid;
    int         save_sec_context;
 
    /*
     * Use the query type code to determine whether the query is run against
     * the PK or FK table; we'll do the check as that table's owner
     */
    if (qkey->constr_queryno <= RI_PLAN_LAST_ON_PK)
        query_rel = pk_rel;
    else
        query_rel = fk_rel;
 
    /* Switch to proper UID to perform check as */
    GetUserIdAndSecContext(&save_userid, &save_sec_context);
    SetUserIdAndSecContext(RelationGetForm(query_rel)->relowner,
                           save_sec_context | SECURITY_LOCAL_USERID_CHANGE |
                           SECURITY_NOFORCE_RLS);
 
    /* Create the plan */
    qplan = SPI_prepare(querystr, nargs, argtypes);
 
    if (qplan == NULL)
        elog(ERROR, "SPI_prepare returned %s for %s", SPI_result_code_string(SPI_result), querystr);
 
    /* Restore UID and security context */
    SetUserIdAndSecContext(save_userid, save_sec_context);
 
    /* Save the plan */
    SPI_keepplan(qplan);
    ri_HashPreparedPlan(qkey, qplan);
 
    return qplan;
}

References RI_QueryKey::constr_queryno, elog, ERROR, GetUserIdAndSecContext(), RelationGetForm, ri_HashPreparedPlan(), RI_PLAN_LAST_ON_PK, SECURITY_LOCAL_USERID_CHANGE, SECURITY_NOFORCE_RLS, SetUserIdAndSecContext(), SPI_keepplan(), SPI_prepare(), SPI_result, and SPI_result_code_string().

Referenced by ri_Check_Pk_Match(), RI_FKey_cascade_del(), RI_FKey_cascade_upd(), RI_FKey_check(), ri_restrict(), and ri_set().

◆ ri_ReportViolation()

static void ri_ReportViolation	(	const RI_ConstraintInfo *	riinfo,
		Relation	pk_rel,
		Relation	fk_rel,
		TupleTableSlot *	violatorslot,
		TupleDesc	tupdesc,
		int	queryno,
		bool	is_restrict,
		bool	partgone
	)

static

Definition at line 2651 of file ri_triggers.c.

{
    StringInfoData key_names;
    StringInfoData key_values;
    bool        onfk;
    const int16 *attnums;
    Oid         rel_oid;
    AclResult   aclresult;
    bool        has_perm = true;
 
    /*
     * Determine which relation to complain about.  If tupdesc wasn't passed
     * by caller, assume the violator tuple came from there.
     */
    onfk = (queryno == RI_PLAN_CHECK_LOOKUPPK);
    if (onfk)
    {
        attnums = riinfo->fk_attnums;
        rel_oid = fk_rel->rd_id;
        if (tupdesc == NULL)
            tupdesc = fk_rel->rd_att;
    }
    else
    {
        attnums = riinfo->pk_attnums;
        rel_oid = pk_rel->rd_id;
        if (tupdesc == NULL)
            tupdesc = pk_rel->rd_att;
    }
 
    /*
     * Check permissions- if the user does not have access to view the data in
     * any of the key columns then we don't include the errdetail() below.
     *
     * Check if RLS is enabled on the relation first.  If so, we don't return
     * any specifics to avoid leaking data.
     *
     * Check table-level permissions next and, failing that, column-level
     * privileges.
     *
     * When a partition at the referenced side is being detached/dropped, we
     * needn't check, since the user must be the table owner anyway.
     */
    if (partgone)
        has_perm = true;
    else if (check_enable_rls(rel_oid, InvalidOid, true) != RLS_ENABLED)
    {
        aclresult = pg_class_aclcheck(rel_oid, GetUserId(), ACL_SELECT);
        if (aclresult != ACLCHECK_OK)
        {
            /* Try for column-level permissions */
            for (int idx = 0; idx < riinfo->nkeys; idx++)
            {
                aclresult = pg_attribute_aclcheck(rel_oid, attnums[idx],
                                                  GetUserId(),
                                                  ACL_SELECT);
 
                /* No access to the key */
                if (aclresult != ACLCHECK_OK)
                {
                    has_perm = false;
                    break;
                }
            }
        }
    }
    else
        has_perm = false;
 
    if (has_perm)
    {
        /* Get printable versions of the keys involved */
        initStringInfo(&key_names);
        initStringInfo(&key_values);
        for (int idx = 0; idx < riinfo->nkeys; idx++)
        {
            int         fnum = attnums[idx];
            Form_pg_attribute att = TupleDescAttr(tupdesc, fnum - 1);
            char       *name,
                       *val;
            Datum       datum;
            bool        isnull;
 
            name = NameStr(att->attname);
 
            datum = slot_getattr(violatorslot, fnum, &isnull);
            if (!isnull)
            {
                Oid         foutoid;
                bool        typisvarlena;
 
                getTypeOutputInfo(att->atttypid, &foutoid, &typisvarlena);
                val = OidOutputFunctionCall(foutoid, datum);
            }
            else
                val = "null";
 
            if (idx > 0)
            {
                appendStringInfoString(&key_names, ", ");
                appendStringInfoString(&key_values, ", ");
            }
            appendStringInfoString(&key_names, name);
            appendStringInfoString(&key_values, val);
        }
    }
 
    if (partgone)
        ereport(ERROR,
                (errcode(ERRCODE_FOREIGN_KEY_VIOLATION),
                 errmsg("removing partition \"%s\" violates foreign key constraint \"%s\"",
                        RelationGetRelationName(pk_rel),
                        NameStr(riinfo->conname)),
                 errdetail("Key (%s)=(%s) is still referenced from table \"%s\".",
                           key_names.data, key_values.data,
                           RelationGetRelationName(fk_rel)),
                 errtableconstraint(fk_rel, NameStr(riinfo->conname))));
    else if (onfk)
        ereport(ERROR,
                (errcode(ERRCODE_FOREIGN_KEY_VIOLATION),
                 errmsg("insert or update on table \"%s\" violates foreign key constraint \"%s\"",
                        RelationGetRelationName(fk_rel),
                        NameStr(riinfo->conname)),
                 has_perm ?
                 errdetail("Key (%s)=(%s) is not present in table \"%s\".",
                           key_names.data, key_values.data,
                           RelationGetRelationName(pk_rel)) :
                 errdetail("Key is not present in table \"%s\".",
                           RelationGetRelationName(pk_rel)),
                 errtableconstraint(fk_rel, NameStr(riinfo->conname))));
    else if (is_restrict)
        ereport(ERROR,
                (errcode(ERRCODE_RESTRICT_VIOLATION),
                 errmsg("update or delete on table \"%s\" violates RESTRICT setting of foreign key constraint \"%s\" on table \"%s\"",
                        RelationGetRelationName(pk_rel),
                        NameStr(riinfo->conname),
                        RelationGetRelationName(fk_rel)),
                 has_perm ?
                 errdetail("Key (%s)=(%s) is referenced from table \"%s\".",
                           key_names.data, key_values.data,
                           RelationGetRelationName(fk_rel)) :
                 errdetail("Key is referenced from table \"%s\".",
                           RelationGetRelationName(fk_rel)),
                 errtableconstraint(fk_rel, NameStr(riinfo->conname))));
    else
        ereport(ERROR,
                (errcode(ERRCODE_FOREIGN_KEY_VIOLATION),
                 errmsg("update or delete on table \"%s\" violates foreign key constraint \"%s\" on table \"%s\"",
                        RelationGetRelationName(pk_rel),
                        NameStr(riinfo->conname),
                        RelationGetRelationName(fk_rel)),
                 has_perm ?
                 errdetail("Key (%s)=(%s) is still referenced from table \"%s\".",
                           key_names.data, key_values.data,
                           RelationGetRelationName(fk_rel)) :
                 errdetail("Key is still referenced from table \"%s\".",
                           RelationGetRelationName(fk_rel)),
                 errtableconstraint(fk_rel, NameStr(riinfo->conname))));
}

References ACL_SELECT, ACLCHECK_OK, appendStringInfoString(), check_enable_rls(), RI_ConstraintInfo::conname, StringInfoData::data, ereport, errcode(), errdetail(), errmsg(), ERROR, errtableconstraint(), RI_ConstraintInfo::fk_attnums, getTypeOutputInfo(), GetUserId(), idx(), initStringInfo(), InvalidOid, name, NameStr, RI_ConstraintInfo::nkeys, OidOutputFunctionCall(), pg_attribute_aclcheck(), pg_class_aclcheck(), RI_ConstraintInfo::pk_attnums, RelationData::rd_att, RelationData::rd_id, RelationGetRelationName, RI_PLAN_CHECK_LOOKUPPK, RLS_ENABLED, slot_getattr(), TupleDescAttr(), and val.

Referenced by RI_Initial_Check(), RI_PartitionRemove_Check(), and ri_PerformCheck().

◆ ri_restrict()

static Datum ri_restrict	(	TriggerData *	trigdata,
		bool	is_no_action
	)

static

Definition at line 712 of file ri_triggers.c.

{
    const RI_ConstraintInfo *riinfo;
    Relation    fk_rel;
    Relation    pk_rel;
    TupleTableSlot *oldslot;
    RI_QueryKey qkey;
    SPIPlanPtr  qplan;
 
    riinfo = ri_FetchConstraintInfo(trigdata->tg_trigger,
                                    trigdata->tg_relation, true);
 
    /*
     * Get the relation descriptors of the FK and PK tables and the old tuple.
     *
     * fk_rel is opened in RowShareLock mode since that's what our eventual
     * SELECT FOR KEY SHARE will get on it.
     */
    fk_rel = table_open(riinfo->fk_relid, RowShareLock);
    pk_rel = trigdata->tg_relation;
    oldslot = trigdata->tg_trigslot;
 
    /*
     * If another PK row now exists providing the old key values, we should
     * not do anything.  However, this check should only be made in the NO
     * ACTION case; in RESTRICT cases we don't wish to allow another row to be
     * substituted.
     *
     * If the foreign key has PERIOD, we incorporate looking for replacement
     * rows in the main SQL query below, so we needn't do it here.
     */
    if (is_no_action && !riinfo->hasperiod &&
        ri_Check_Pk_Match(pk_rel, fk_rel, oldslot, riinfo))
    {
        table_close(fk_rel, RowShareLock);
        return PointerGetDatum(NULL);
    }
 
    SPI_connect();
 
    /*
     * Fetch or prepare a saved plan for the restrict lookup (it's the same
     * query for delete and update cases)
     */
    ri_BuildQueryKey(&qkey, riinfo, is_no_action ? RI_PLAN_NO_ACTION : RI_PLAN_RESTRICT);
 
    if ((qplan = ri_FetchPreparedPlan(&qkey)) == NULL)
    {
        StringInfoData querybuf;
        char        pkrelname[MAX_QUOTED_REL_NAME_LEN];
        char        fkrelname[MAX_QUOTED_REL_NAME_LEN];
        char        attname[MAX_QUOTED_NAME_LEN];
        char        periodattname[MAX_QUOTED_NAME_LEN];
        char        paramname[16];
        const char *querysep;
        Oid         queryoids[RI_MAX_NUMKEYS];
        const char *fk_only;
 
        /* ----------
         * The query string built is
         *  SELECT 1 FROM [ONLY] <fktable> x WHERE $1 = fkatt1 [AND ...]
         *         FOR KEY SHARE OF x
         * The type id's for the $ parameters are those of the
         * corresponding PK attributes.
         * ----------
         */
        initStringInfo(&querybuf);
        fk_only = fk_rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE ?
            "" : "ONLY ";
        quoteRelationName(fkrelname, fk_rel);
        appendStringInfo(&querybuf, "SELECT 1 FROM %s%s x",
                         fk_only, fkrelname);
        querysep = "WHERE";
        for (int i = 0; i < riinfo->nkeys; i++)
        {
            Oid         pk_type = RIAttType(pk_rel, riinfo->pk_attnums[i]);
            Oid         fk_type = RIAttType(fk_rel, riinfo->fk_attnums[i]);
 
            quoteOneName(attname,
                         RIAttName(fk_rel, riinfo->fk_attnums[i]));
            sprintf(paramname, "$%d", i + 1);
            ri_GenerateQual(&querybuf, querysep,
                            paramname, pk_type,
                            riinfo->pf_eq_oprs[i],
                            attname, fk_type);
            querysep = "AND";
            queryoids[i] = pk_type;
        }
 
        /*----------
         * For temporal foreign keys, a reference could still be valid if the
         * referenced range didn't change too much.  Also if a referencing
         * range extends past the current PK row, we don't want to check that
         * part: some other PK row should fulfill it.  We only want to check
         * the part matching the PK record we've changed.  Therefore to find
         * invalid records we do this:
         *
         * SELECT 1 FROM [ONLY] <fktable> x WHERE $1 = x.fkatt1 [AND ...]
         * -- begin temporal
         * AND $n && x.fkperiod
         * AND NOT coalesce((x.fkperiod * $n) <@
         *  (SELECT range_agg(r)
         *   FROM (SELECT y.pkperiod r
         *         FROM [ONLY] <pktable> y
         *         WHERE $1 = y.pkatt1 [AND ...] AND $n && y.pkperiod
         *         FOR KEY SHARE OF y) y2), false)
         * -- end temporal
         * FOR KEY SHARE OF x
         *
         * We need the coalesce in case the first subquery returns no rows.
         * We need the second subquery because FOR KEY SHARE doesn't support
         * aggregate queries.
         */
        if (riinfo->hasperiod && is_no_action)
        {
            Oid         pk_period_type = RIAttType(pk_rel, riinfo->pk_attnums[riinfo->nkeys - 1]);
            Oid         fk_period_type = RIAttType(fk_rel, riinfo->fk_attnums[riinfo->nkeys - 1]);
            StringInfoData intersectbuf;
            StringInfoData replacementsbuf;
            char       *pk_only = pk_rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE ?
                "" : "ONLY ";
 
            quoteOneName(attname, RIAttName(fk_rel, riinfo->fk_attnums[riinfo->nkeys - 1]));
            sprintf(paramname, "$%d", riinfo->nkeys);
 
            appendStringInfoString(&querybuf, " AND NOT coalesce(");
 
            /* Intersect the fk with the old pk range */
            initStringInfo(&intersectbuf);
            appendStringInfoChar(&intersectbuf, '(');
            ri_GenerateQual(&intersectbuf, "",
                            attname, fk_period_type,
                            riinfo->period_intersect_oper,
                            paramname, pk_period_type);
            appendStringInfoChar(&intersectbuf, ')');
 
            /* Find the remaining history */
            initStringInfo(&replacementsbuf);
            appendStringInfoString(&replacementsbuf, "(SELECT pg_catalog.range_agg(r) FROM ");
 
            quoteOneName(periodattname, RIAttName(pk_rel, riinfo->pk_attnums[riinfo->nkeys - 1]));
            quoteRelationName(pkrelname, pk_rel);
            appendStringInfo(&replacementsbuf, "(SELECT y.%s r FROM %s%s y",
                             periodattname, pk_only, pkrelname);
 
            /* Restrict pk rows to what matches */
            querysep = "WHERE";
            for (int i = 0; i < riinfo->nkeys; i++)
            {
                Oid         pk_type = RIAttType(pk_rel, riinfo->pk_attnums[i]);
 
                quoteOneName(attname,
                             RIAttName(pk_rel, riinfo->pk_attnums[i]));
                sprintf(paramname, "$%d", i + 1);
                ri_GenerateQual(&replacementsbuf, querysep,
                                paramname, pk_type,
                                riinfo->pp_eq_oprs[i],
                                attname, pk_type);
                querysep = "AND";
                queryoids[i] = pk_type;
            }
            appendStringInfoString(&replacementsbuf, " FOR KEY SHARE OF y) y2)");
 
            ri_GenerateQual(&querybuf, "",
                            intersectbuf.data, fk_period_type,
                            riinfo->agged_period_contained_by_oper,
                            replacementsbuf.data, ANYMULTIRANGEOID);
            /* end of coalesce: */
            appendStringInfoString(&querybuf, ", false)");
        }
 
        appendStringInfoString(&querybuf, " FOR KEY SHARE OF x");
 
        /* Prepare and save the plan */
        qplan = ri_PlanCheck(querybuf.data, riinfo->nkeys, queryoids,
                             &qkey, fk_rel, pk_rel);
    }
 
    /*
     * We have a plan now. Run it to check for existing references.
     */
    ri_PerformCheck(riinfo, &qkey, qplan,
                    fk_rel, pk_rel,
                    oldslot, NULL,
                    !is_no_action,
                    true,       /* must detect new rows */
                    SPI_OK_SELECT);
 
    if (SPI_finish() != SPI_OK_FINISH)
        elog(ERROR, "SPI_finish failed");
 
    table_close(fk_rel, RowShareLock);
 
    return PointerGetDatum(NULL);
}

Referenced by RI_FKey_noaction_del(), RI_FKey_noaction_upd(), RI_FKey_restrict_del(), RI_FKey_restrict_upd(), and ri_set().

◆ ri_set()

static Datum ri_set	(	TriggerData *	trigdata,
		bool	is_set_null,
		int	tgkind
	)

static

Definition at line 1195 of file ri_triggers.c.

{
    const RI_ConstraintInfo *riinfo;
    Relation    fk_rel;
    Relation    pk_rel;
    TupleTableSlot *oldslot;
    RI_QueryKey qkey;
    SPIPlanPtr  qplan;
    int32       queryno;
 
    riinfo = ri_FetchConstraintInfo(trigdata->tg_trigger,
                                    trigdata->tg_relation, true);
 
    /*
     * Get the relation descriptors of the FK and PK tables and the old tuple.
     *
     * fk_rel is opened in RowExclusiveLock mode since that's what our
     * eventual UPDATE will get on it.
     */
    fk_rel = table_open(riinfo->fk_relid, RowExclusiveLock);
    pk_rel = trigdata->tg_relation;
    oldslot = trigdata->tg_trigslot;
 
    SPI_connect();
 
    /*
     * Fetch or prepare a saved plan for the trigger.
     */
    switch (tgkind)
    {
        case RI_TRIGTYPE_UPDATE:
            queryno = is_set_null
                ? RI_PLAN_SETNULL_ONUPDATE
                : RI_PLAN_SETDEFAULT_ONUPDATE;
            break;
        case RI_TRIGTYPE_DELETE:
            queryno = is_set_null
                ? RI_PLAN_SETNULL_ONDELETE
                : RI_PLAN_SETDEFAULT_ONDELETE;
            break;
        default:
            elog(ERROR, "invalid tgkind passed to ri_set");
    }
 
    ri_BuildQueryKey(&qkey, riinfo, queryno);
 
    if ((qplan = ri_FetchPreparedPlan(&qkey)) == NULL)
    {
        StringInfoData querybuf;
        char        fkrelname[MAX_QUOTED_REL_NAME_LEN];
        char        attname[MAX_QUOTED_NAME_LEN];
        char        paramname[16];
        const char *querysep;
        const char *qualsep;
        Oid         queryoids[RI_MAX_NUMKEYS];
        const char *fk_only;
        int         num_cols_to_set;
        const int16 *set_cols;
 
        switch (tgkind)
        {
            case RI_TRIGTYPE_UPDATE:
                num_cols_to_set = riinfo->nkeys;
                set_cols = riinfo->fk_attnums;
                break;
            case RI_TRIGTYPE_DELETE:
 
                /*
                 * If confdelsetcols are present, then we only update the
                 * columns specified in that array, otherwise we update all
                 * the referencing columns.
                 */
                if (riinfo->ndelsetcols != 0)
                {
                    num_cols_to_set = riinfo->ndelsetcols;
                    set_cols = riinfo->confdelsetcols;
                }
                else
                {
                    num_cols_to_set = riinfo->nkeys;
                    set_cols = riinfo->fk_attnums;
                }
                break;
            default:
                elog(ERROR, "invalid tgkind passed to ri_set");
        }
 
        /* ----------
         * The query string built is
         *  UPDATE [ONLY] <fktable> SET fkatt1 = {NULL|DEFAULT} [, ...]
         *          WHERE $1 = fkatt1 [AND ...]
         * The type id's for the $ parameters are those of the
         * corresponding PK attributes.
         * ----------
         */
        initStringInfo(&querybuf);
        fk_only = fk_rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE ?
            "" : "ONLY ";
        quoteRelationName(fkrelname, fk_rel);
        appendStringInfo(&querybuf, "UPDATE %s%s SET",
                         fk_only, fkrelname);
 
        /*
         * Add assignment clauses
         */
        querysep = "";
        for (int i = 0; i < num_cols_to_set; i++)
        {
            quoteOneName(attname, RIAttName(fk_rel, set_cols[i]));
            appendStringInfo(&querybuf,
                             "%s %s = %s",
                             querysep, attname,
                             is_set_null ? "NULL" : "DEFAULT");
            querysep = ",";
        }
 
        /*
         * Add WHERE clause
         */
        qualsep = "WHERE";
        for (int i = 0; i < riinfo->nkeys; i++)
        {
            Oid         pk_type = RIAttType(pk_rel, riinfo->pk_attnums[i]);
            Oid         fk_type = RIAttType(fk_rel, riinfo->fk_attnums[i]);
 
            quoteOneName(attname,
                         RIAttName(fk_rel, riinfo->fk_attnums[i]));
 
            sprintf(paramname, "$%d", i + 1);
            ri_GenerateQual(&querybuf, qualsep,
                            paramname, pk_type,
                            riinfo->pf_eq_oprs[i],
                            attname, fk_type);
            qualsep = "AND";
            queryoids[i] = pk_type;
        }
 
        /* Prepare and save the plan */
        qplan = ri_PlanCheck(querybuf.data, riinfo->nkeys, queryoids,
                             &qkey, fk_rel, pk_rel);
    }
 
    /*
     * We have a plan now. Run it to update the existing references.
     */
    ri_PerformCheck(riinfo, &qkey, qplan,
                    fk_rel, pk_rel,
                    oldslot, NULL,
                    false,
                    true,       /* must detect new rows */
                    SPI_OK_UPDATE);
 
    if (SPI_finish() != SPI_OK_FINISH)
        elog(ERROR, "SPI_finish failed");
 
    table_close(fk_rel, RowExclusiveLock);
 
    if (is_set_null)
        return PointerGetDatum(NULL);
    else
    {
        /*
         * If we just deleted or updated the PK row whose key was equal to the
         * FK columns' default values, and a referencing row exists in the FK
         * table, we would have updated that row to the same values it already
         * had --- and RI_FKey_fk_upd_check_required would hence believe no
         * check is necessary.  So we need to do another lookup now and in
         * case a reference still exists, abort the operation.  That is
         * already implemented in the NO ACTION trigger, so just run it. (This
         * recheck is only needed in the SET DEFAULT case, since CASCADE would
         * remove such rows in case of a DELETE operation or would change the
         * FK key values in case of an UPDATE, while SET NULL is certain to
         * result in rows that satisfy the FK constraint.)
         */
        return ri_restrict(trigdata, true);
    }
}

References appendStringInfo(), attname, RI_ConstraintInfo::confdelsetcols, StringInfoData::data, elog, ERROR, RI_ConstraintInfo::fk_attnums, RI_ConstraintInfo::fk_relid, i, initStringInfo(), MAX_QUOTED_NAME_LEN, MAX_QUOTED_REL_NAME_LEN, RI_ConstraintInfo::ndelsetcols, RI_ConstraintInfo::nkeys, RI_ConstraintInfo::pf_eq_oprs, RI_ConstraintInfo::pk_attnums, PointerGetDatum(), quoteOneName(), quoteRelationName(), RelationData::rd_rel, ri_BuildQueryKey(), ri_FetchConstraintInfo(), ri_FetchPreparedPlan(), ri_GenerateQual(), RI_MAX_NUMKEYS, ri_PerformCheck(), RI_PLAN_SETDEFAULT_ONDELETE, RI_PLAN_SETDEFAULT_ONUPDATE, RI_PLAN_SETNULL_ONDELETE, RI_PLAN_SETNULL_ONUPDATE, ri_PlanCheck(), ri_restrict(), RI_TRIGTYPE_DELETE, RI_TRIGTYPE_UPDATE, RIAttName, RIAttType, RowExclusiveLock, SPI_connect(), SPI_finish(), SPI_OK_FINISH, SPI_OK_UPDATE, sprintf, table_close(), table_open(), TriggerData::tg_relation, TriggerData::tg_trigger, and TriggerData::tg_trigslot.

Referenced by RI_FKey_setdefault_del(), RI_FKey_setdefault_upd(), RI_FKey_setnull_del(), and RI_FKey_setnull_upd().

Variable Documentation

◆ ri_compare_cache

HTAB* ri_compare_cache = NULL

static

Definition at line 185 of file ri_triggers.c.

Referenced by ri_HashCompareOp(), and ri_InitHashTables().

◆ ri_constraint_cache

HTAB* ri_constraint_cache = NULL

static

Definition at line 183 of file ri_triggers.c.

Referenced by InvalidateConstraintCacheCallBack(), ri_InitHashTables(), and ri_LoadConstraintInfo().

◆ ri_constraint_cache_valid_list

dclist_head ri_constraint_cache_valid_list

static

Definition at line 186 of file ri_triggers.c.

Referenced by InvalidateConstraintCacheCallBack(), and ri_LoadConstraintInfo().

◆ ri_query_cache

HTAB* ri_query_cache = NULL

static

Definition at line 184 of file ri_triggers.c.

Referenced by ri_FetchPreparedPlan(), ri_HashPreparedPlan(), and ri_InitHashTables().

Data Structures

Macros

Typedefs

Functions

Variables

Macro Definition Documentation

◆ MAX_QUOTED_NAME_LEN

◆ MAX_QUOTED_REL_NAME_LEN

◆ RI_INIT_CONSTRAINTHASHSIZE

◆ RI_INIT_QUERYHASHSIZE

◆ RI_KEYS_ALL_NULL

◆ RI_KEYS_NONE_NULL

◆ RI_KEYS_SOME_NULL

◆ RI_MAX_NUMKEYS

◆ RI_PLAN_CASCADE_ONDELETE

◆ RI_PLAN_CASCADE_ONUPDATE

◆ RI_PLAN_CHECK_LOOKUPPK

◆ RI_PLAN_CHECK_LOOKUPPK_FROM_PK

◆ RI_PLAN_LAST_ON_PK

◆ RI_PLAN_NO_ACTION

◆ RI_PLAN_RESTRICT

◆ RI_PLAN_SETDEFAULT_ONDELETE

◆ RI_PLAN_SETDEFAULT_ONUPDATE

◆ RI_PLAN_SETNULL_ONDELETE

◆ RI_PLAN_SETNULL_ONUPDATE

◆ RI_TRIGTYPE_DELETE

◆ RI_TRIGTYPE_INSERT

◆ RI_TRIGTYPE_UPDATE

◆ RIAttCollation

◆ RIAttName

◆ RIAttType

Typedef Documentation

◆ RI_CompareHashEntry

◆ RI_CompareKey

◆ RI_ConstraintInfo

◆ RI_QueryHashEntry

◆ RI_QueryKey

Function Documentation

◆ get_ri_constraint_root()

◆ InvalidateConstraintCacheCallBack()

◆ quoteOneName()

◆ quoteRelationName()

◆ ri_BuildQueryKey()

◆ ri_Check_Pk_Match()

◆ ri_CheckTrigger()

◆ ri_CompareWithCast()

◆ ri_ExtractValues()

◆ ri_FetchConstraintInfo()

◆ ri_FetchPreparedPlan()

◆ RI_FKey_cascade_del()

◆ RI_FKey_cascade_upd()

◆ RI_FKey_check()

◆ RI_FKey_check_ins()

◆ RI_FKey_check_upd()

◆ RI_FKey_fk_upd_check_required()

◆ RI_FKey_noaction_del()

◆ RI_FKey_noaction_upd()

◆ RI_FKey_pk_upd_check_required()

◆ RI_FKey_restrict_del()

◆ RI_FKey_restrict_upd()

◆ RI_FKey_setdefault_del()

◆ RI_FKey_setdefault_upd()

◆ RI_FKey_setnull_del()

◆ RI_FKey_setnull_upd()

◆ RI_FKey_trigger_type()

◆ ri_GenerateQual()

◆ ri_GenerateQualCollation()

◆ ri_HashCompareOp()

◆ ri_HashPreparedPlan()

◆ ri_InitHashTables()

◆ RI_Initial_Check()

◆ ri_KeysEqual()

◆ ri_LoadConstraintInfo()

◆ ri_NullCheck()

◆ RI_PartitionRemove_Check()

◆ ri_PerformCheck()

◆ ri_PlanCheck()

◆ ri_ReportViolation()

◆ ri_restrict()

◆ ri_set()