52.58. pg_trigger #

   The catalog pg_trigger stores triggers on tables and views. See CREATE
   TRIGGER for more information.

   Table 52.58. pg_trigger Columns

   Column Type

   Description

   oid oid

   Row identifier

   tgrelid oid (references pg_class.oid)

   The table this trigger is on

   tgparentid oid (references pg_trigger.oid)

   Parent trigger that this trigger is cloned from (this happens when
   partitions are created or attached to a partitioned table); zero if not
   a clone

   tgname name

   Trigger name (must be unique among triggers of same table)

   tgfoid oid (references pg_proc.oid)

   The function to be called

   tgtype int2

   Bit mask identifying trigger firing conditions

   tgenabled char

   Controls in which session_replication_role modes the trigger fires. O =
   trigger fires in “origin” and “local” modes, D = trigger is disabled, R
   = trigger fires in “replica” mode, A = trigger fires always.

   tgisinternal bool

   True if trigger is internally generated (usually, to enforce the
   constraint identified by tgconstraint)

   tgconstrrelid oid (references pg_class.oid)

   The table referenced by a referential integrity constraint (zero if
   trigger is not for a referential integrity constraint)

   tgconstrindid oid (references pg_class.oid)

   The index supporting a unique, primary key, referential integrity, or
   exclusion constraint (zero if trigger is not for one of these types of
   constraint)

   tgconstraint oid (references pg_constraint.oid)

   The pg_constraint entry associated with the trigger (zero if trigger is
   not for a constraint)

   tgdeferrable bool

   True if constraint trigger is deferrable

   tginitdeferred bool

   True if constraint trigger is initially deferred

   tgnargs int2

   Number of argument strings passed to trigger function

   tgattr int2vector (references pg_attribute.attnum)

   Column numbers, if trigger is column-specific; otherwise an empty array

   tgargs bytea

   Argument strings to pass to trigger, each NULL-terminated

   tgqual pg_node_tree

   Expression tree (in nodeToString() representation) for the trigger's
   WHEN condition, or null if none

   tgoldtable name

   REFERENCING clause name for OLD TABLE, or null if none

   tgnewtable name

   REFERENCING clause name for NEW TABLE, or null if none

   Currently, column-specific triggering is supported only for UPDATE
   events, and so tgattr is relevant only for that event type. tgtype
   might contain bits for other event types as well, but those are
   presumed to be table-wide regardless of what is in tgattr.

Note

   When tgconstraint is nonzero, tgconstrrelid, tgconstrindid,
   tgdeferrable, and tginitdeferred are largely redundant with the
   referenced pg_constraint entry. However, it is possible for a
   non-deferrable trigger to be associated with a deferrable constraint:
   foreign key constraints can have some deferrable and some
   non-deferrable triggers.

Note

   pg_class.relhastriggers must be true if a relation has any triggers in
   this catalog.