trigger.h

Go to the documentation of this file.

/*-------------------------------------------------------------------------
 *
 * trigger.h
 *    Declarations for trigger handling.
 *
 * Portions Copyright (c) 1996-2025, PostgreSQL Global Development Group
 * Portions Copyright (c) 1994, Regents of the University of California
 *
 * src/include/commands/trigger.h
 *
 *-------------------------------------------------------------------------
 */
#ifndef TRIGGER_H
#define TRIGGER_H
 
#include "access/tableam.h"
#include "catalog/objectaddress.h"
#include "nodes/execnodes.h"
#include "nodes/parsenodes.h"
 
/*
 * TriggerData is the node type that is passed as fmgr "context" info
 * when a function is called by the trigger manager.
 */
 
#define CALLED_AS_TRIGGER(fcinfo) \
    ((fcinfo)->context != NULL && IsA((fcinfo)->context, TriggerData))
 
typedef uint32 TriggerEvent;
 
typedef struct TriggerData
{
    NodeTag     type;
    TriggerEvent tg_event;
    Relation    tg_relation;
    HeapTuple   tg_trigtuple;
    HeapTuple   tg_newtuple;
    Trigger    *tg_trigger;
    TupleTableSlot *tg_trigslot;
    TupleTableSlot *tg_newslot;
    Tuplestorestate *tg_oldtable;
    Tuplestorestate *tg_newtable;
    const Bitmapset *tg_updatedcols;
} TriggerData;
 
/*
 * The state for capturing old and new tuples into transition tables for a
 * single ModifyTable node (or other operation source, e.g. copyfrom.c).
 *
 * This is per-caller to avoid conflicts in setting
 * tcs_original_insert_tuple.  Note, however, that the pointed-to
 * private data may be shared across multiple callers.
 */
struct AfterTriggersTableData;  /* private in trigger.c */
 
typedef struct TransitionCaptureState
{
    /*
     * Is there at least one trigger specifying each transition relation on
     * the relation explicitly named in the DML statement or COPY command?
     * Note: in current usage, these flags could be part of the private state,
     * but it seems possibly useful to let callers see them.
     */
    bool        tcs_delete_old_table;
    bool        tcs_update_old_table;
    bool        tcs_update_new_table;
    bool        tcs_insert_new_table;
 
    /*
     * For INSERT and COPY, it would be wasteful to convert tuples from child
     * format to parent format after they have already been converted in the
     * opposite direction during routing.  In that case we bypass conversion
     * and allow the inserting code (copyfrom.c and nodeModifyTable.c) to
     * provide a slot containing the original tuple directly.
     */
    TupleTableSlot *tcs_original_insert_tuple;
 
    /*
     * Private data including the tuplestore(s) into which to insert tuples.
     */
    struct AfterTriggersTableData *tcs_private;
} TransitionCaptureState;
 
/*
 * TriggerEvent bit flags
 *
 * Note that we assume different event types (INSERT/DELETE/UPDATE/TRUNCATE)
 * can't be OR'd together in a single TriggerEvent.  This is unlike the
 * situation for pg_trigger rows, so pg_trigger.tgtype uses a different
 * representation!
 */
#define TRIGGER_EVENT_INSERT            0x00000000
#define TRIGGER_EVENT_DELETE            0x00000001
#define TRIGGER_EVENT_UPDATE            0x00000002
#define TRIGGER_EVENT_TRUNCATE          0x00000003
#define TRIGGER_EVENT_OPMASK            0x00000003
 
#define TRIGGER_EVENT_ROW               0x00000004
 
#define TRIGGER_EVENT_BEFORE            0x00000008
#define TRIGGER_EVENT_AFTER             0x00000000
#define TRIGGER_EVENT_INSTEAD           0x00000010
#define TRIGGER_EVENT_TIMINGMASK        0x00000018
 
/* More TriggerEvent flags, used only within trigger.c */
 
#define AFTER_TRIGGER_DEFERRABLE        0x00000020
#define AFTER_TRIGGER_INITDEFERRED      0x00000040
 
#define TRIGGER_FIRED_BY_INSERT(event) \
    (((event) & TRIGGER_EVENT_OPMASK) == TRIGGER_EVENT_INSERT)
 
#define TRIGGER_FIRED_BY_DELETE(event) \
    (((event) & TRIGGER_EVENT_OPMASK) == TRIGGER_EVENT_DELETE)
 
#define TRIGGER_FIRED_BY_UPDATE(event) \
    (((event) & TRIGGER_EVENT_OPMASK) == TRIGGER_EVENT_UPDATE)
 
#define TRIGGER_FIRED_BY_TRUNCATE(event) \
    (((event) & TRIGGER_EVENT_OPMASK) == TRIGGER_EVENT_TRUNCATE)
 
#define TRIGGER_FIRED_FOR_ROW(event) \
    ((event) & TRIGGER_EVENT_ROW)
 
#define TRIGGER_FIRED_FOR_STATEMENT(event) \
    (!TRIGGER_FIRED_FOR_ROW(event))
 
#define TRIGGER_FIRED_BEFORE(event) \
    (((event) & TRIGGER_EVENT_TIMINGMASK) == TRIGGER_EVENT_BEFORE)
 
#define TRIGGER_FIRED_AFTER(event) \
    (((event) & TRIGGER_EVENT_TIMINGMASK) == TRIGGER_EVENT_AFTER)
 
#define TRIGGER_FIRED_INSTEAD(event) \
    (((event) & TRIGGER_EVENT_TIMINGMASK) == TRIGGER_EVENT_INSTEAD)
 
/*
 * Definitions for replication role based firing.
 */
#define SESSION_REPLICATION_ROLE_ORIGIN     0
#define SESSION_REPLICATION_ROLE_REPLICA    1
#define SESSION_REPLICATION_ROLE_LOCAL      2
extern PGDLLIMPORT int SessionReplicationRole;
 
/*
 * States at which a trigger can be fired. These are the
 * possible values for pg_trigger.tgenabled.
 */
#define TRIGGER_FIRES_ON_ORIGIN             'O'
#define TRIGGER_FIRES_ALWAYS                'A'
#define TRIGGER_FIRES_ON_REPLICA            'R'
#define TRIGGER_DISABLED                    'D'
 
extern ObjectAddress CreateTrigger(CreateTrigStmt *stmt, const char *queryString,
                                   Oid relOid, Oid refRelOid, Oid constraintOid, Oid indexOid,
                                   Oid funcoid, Oid parentTriggerOid, Node *whenClause,
                                   bool isInternal, bool in_partition);
extern ObjectAddress CreateTriggerFiringOn(CreateTrigStmt *stmt, const char *queryString,
                                           Oid relOid, Oid refRelOid, Oid constraintOid,
                                           Oid indexOid, Oid funcoid, Oid parentTriggerOid,
                                           Node *whenClause, bool isInternal, bool in_partition,
                                           char trigger_fires_when);
 
extern void TriggerSetParentTrigger(Relation trigRel,
                                    Oid childTrigId,
                                    Oid parentTrigId,
                                    Oid childTableId);
extern void RemoveTriggerById(Oid trigOid);
extern Oid  get_trigger_oid(Oid relid, const char *trigname, bool missing_ok);
 
extern ObjectAddress renametrig(RenameStmt *stmt);
 
extern void EnableDisableTrigger(Relation rel, const char *tgname, Oid tgparent,
                                 char fires_when, bool skip_system, bool recurse,
                                 LOCKMODE lockmode);
 
extern void RelationBuildTriggers(Relation relation);
 
extern TriggerDesc *CopyTriggerDesc(TriggerDesc *trigdesc);
 
extern const char *FindTriggerIncompatibleWithInheritance(TriggerDesc *trigdesc);
 
extern TransitionCaptureState *MakeTransitionCaptureState(TriggerDesc *trigdesc,
                                                          Oid relid, CmdType cmdType);
 
extern void FreeTriggerDesc(TriggerDesc *trigdesc);
 
extern void ExecBSInsertTriggers(EState *estate,
                                 ResultRelInfo *relinfo);
extern void ExecASInsertTriggers(EState *estate,
                                 ResultRelInfo *relinfo,
                                 TransitionCaptureState *transition_capture);
extern bool ExecBRInsertTriggers(EState *estate,
                                 ResultRelInfo *relinfo,
                                 TupleTableSlot *slot);
extern void ExecARInsertTriggers(EState *estate,
                                 ResultRelInfo *relinfo,
                                 TupleTableSlot *slot,
                                 List *recheckIndexes,
                                 TransitionCaptureState *transition_capture);
extern bool ExecIRInsertTriggers(EState *estate,
                                 ResultRelInfo *relinfo,
                                 TupleTableSlot *slot);
extern void ExecBSDeleteTriggers(EState *estate,
                                 ResultRelInfo *relinfo);
extern void ExecASDeleteTriggers(EState *estate,
                                 ResultRelInfo *relinfo,
                                 TransitionCaptureState *transition_capture);
extern bool ExecBRDeleteTriggers(EState *estate,
                                 EPQState *epqstate,
                                 ResultRelInfo *relinfo,
                                 ItemPointer tupleid,
                                 HeapTuple fdw_trigtuple,
                                 TupleTableSlot **epqslot,
                                 TM_Result *tmresult,
                                 TM_FailureData *tmfd);
extern void ExecARDeleteTriggers(EState *estate,
                                 ResultRelInfo *relinfo,
                                 ItemPointer tupleid,
                                 HeapTuple fdw_trigtuple,
                                 TransitionCaptureState *transition_capture,
                                 bool is_crosspart_update);
extern bool ExecIRDeleteTriggers(EState *estate,
                                 ResultRelInfo *relinfo,
                                 HeapTuple trigtuple);
extern void ExecBSUpdateTriggers(EState *estate,
                                 ResultRelInfo *relinfo);
extern void ExecASUpdateTriggers(EState *estate,
                                 ResultRelInfo *relinfo,
                                 TransitionCaptureState *transition_capture);
extern bool ExecBRUpdateTriggers(EState *estate,
                                 EPQState *epqstate,
                                 ResultRelInfo *relinfo,
                                 ItemPointer tupleid,
                                 HeapTuple fdw_trigtuple,
                                 TupleTableSlot *newslot,
                                 TM_Result *tmresult,
                                 TM_FailureData *tmfd);
extern void ExecARUpdateTriggers(EState *estate,
                                 ResultRelInfo *relinfo,
                                 ResultRelInfo *src_partinfo,
                                 ResultRelInfo *dst_partinfo,
                                 ItemPointer tupleid,
                                 HeapTuple fdw_trigtuple,
                                 TupleTableSlot *newslot,
                                 List *recheckIndexes,
                                 TransitionCaptureState *transition_capture,
                                 bool is_crosspart_update);
extern bool ExecIRUpdateTriggers(EState *estate,
                                 ResultRelInfo *relinfo,
                                 HeapTuple trigtuple,
                                 TupleTableSlot *newslot);
extern void ExecBSTruncateTriggers(EState *estate,
                                   ResultRelInfo *relinfo);
extern void ExecASTruncateTriggers(EState *estate,
                                   ResultRelInfo *relinfo);
 
extern void AfterTriggerBeginXact(void);
extern void AfterTriggerBeginQuery(void);
extern void AfterTriggerEndQuery(EState *estate);
extern void AfterTriggerAbortQuery(void);
extern void AfterTriggerFireDeferred(void);
extern void AfterTriggerEndXact(bool isCommit);
extern void AfterTriggerBeginSubXact(void);
extern void AfterTriggerEndSubXact(bool isCommit);
extern void AfterTriggerSetState(ConstraintsSetStmt *stmt);
extern bool AfterTriggerPendingOnRel(Oid relid);
 
 
/*
 * in utils/adt/ri_triggers.c
 */
extern bool RI_FKey_pk_upd_check_required(Trigger *trigger, Relation pk_rel,
                                          TupleTableSlot *oldslot, TupleTableSlot *newslot);
extern bool RI_FKey_fk_upd_check_required(Trigger *trigger, Relation fk_rel,
                                          TupleTableSlot *oldslot, TupleTableSlot *newslot);
extern bool RI_Initial_Check(Trigger *trigger,
                             Relation fk_rel, Relation pk_rel);
extern void RI_PartitionRemove_Check(Trigger *trigger, Relation fk_rel,
                                     Relation pk_rel);
 
/* result values for RI_FKey_trigger_type: */
#define RI_TRIGGER_PK   1       /* is a trigger on the PK relation */
#define RI_TRIGGER_FK   2       /* is a trigger on the FK relation */
#define RI_TRIGGER_NONE 0       /* is not an RI trigger function */
 
extern int  RI_FKey_trigger_type(Oid tgfoid);
 
#endif                          /* TRIGGER_H */