53.58. pg_trigger

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

Table 53.58. pg_trigger Columns

Column Type


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 .


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.


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