diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 48631cc341..219ba9abf3 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -12794,6 +12794,13 @@ postgres=# SELECT * FROM unnest2(ARRAY[[1,2],[3,4]]);
server start time
+
+ pg_trigger_depth()
+ int
+ current nesting level of PostgreSQL triggers
+ (0 if not called, directly or indirectly, from inside a trigger)
+
+
session_user
name
diff --git a/src/backend/commands/trigger.c b/src/backend/commands/trigger.c
index f5e12e5681..2838b66e40 100644
--- a/src/backend/commands/trigger.c
+++ b/src/backend/commands/trigger.c
@@ -59,6 +59,8 @@
/* GUC variables */
int SessionReplicationRole = SESSION_REPLICATION_ROLE_ORIGIN;
+/* How many levels deep into trigger execution are we? */
+static int MyTriggerDepth = 0;
#define GetModifiedColumns(relinfo, estate) \
(rt_fetch((relinfo)->ri_RangeTableIndex, (estate)->es_range_table)->modifiedCols)
@@ -1838,7 +1840,18 @@ ExecCallTriggerFunc(TriggerData *trigdata,
pgstat_init_function_usage(&fcinfo, &fcusage);
- result = FunctionCallInvoke(&fcinfo);
+ MyTriggerDepth++;
+ PG_TRY();
+ {
+ result = FunctionCallInvoke(&fcinfo);
+ }
+ PG_CATCH();
+ {
+ MyTriggerDepth--;
+ PG_RE_THROW();
+ }
+ PG_END_TRY();
+ MyTriggerDepth--;
pgstat_end_function_usage(&fcusage, true);
@@ -4632,3 +4645,9 @@ AfterTriggerSaveEvent(EState *estate, ResultRelInfo *relinfo,
&new_event, &new_shared);
}
}
+
+Datum
+pg_trigger_depth(PG_FUNCTION_ARGS)
+{
+ PG_RETURN_INT32(MyTriggerDepth);
+}
diff --git a/src/include/catalog/pg_proc.h b/src/include/catalog/pg_proc.h
index b6ac1959cc..ef5ca3047d 100644
--- a/src/include/catalog/pg_proc.h
+++ b/src/include/catalog/pg_proc.h
@@ -2698,6 +2698,9 @@ DESCR("statistics: reset collected statistics for a single table or index in the
DATA(insert OID = 3777 ( pg_stat_reset_single_function_counters PGNSP PGUID 12 1 0 0 0 f f f f f v 1 0 2278 "26" _null_ _null_ _null_ _null_ pg_stat_reset_single_function_counters _null_ _null_ _null_ ));
DESCR("statistics: reset collected statistics for a single function in the current database");
+DATA(insert OID = 3163 ( pg_trigger_depth PGNSP PGUID 12 1 0 0 0 f f f t f s 0 0 23 "" _null_ _null_ _null_ _null_ pg_trigger_depth _null_ _null_ _null_ ));
+DESCR("current trigger depth");
+
DATA(insert OID = 3778 ( pg_tablespace_location PGNSP PGUID 12 1 0 0 0 f f f t f s 1 0 25 "26" _null_ _null_ _null_ _null_ pg_tablespace_location _null_ _null_ _null_ ));
DESCR("tablespace location");
diff --git a/src/include/commands/trigger.h b/src/include/commands/trigger.h
index ba0f32464e..93033414d9 100644
--- a/src/include/commands/trigger.h
+++ b/src/include/commands/trigger.h
@@ -205,4 +205,6 @@ extern bool RI_Initial_Check(Trigger *trigger,
extern int RI_FKey_trigger_type(Oid tgfoid);
+extern Datum pg_trigger_depth(PG_FUNCTION_ARGS);
+
#endif /* TRIGGER_H */
diff --git a/src/test/regress/expected/triggers.out b/src/test/regress/expected/triggers.out
index b4d391974d..d039b6e38b 100644
--- a/src/test/regress/expected/triggers.out
+++ b/src/test/regress/expected/triggers.out
@@ -1443,3 +1443,120 @@ NOTICE: drop cascades to 2 other objects
DETAIL: drop cascades to view city_view
drop cascades to view european_city_view
DROP TABLE country_table;
+-- Test pg_trigger_depth()
+create table depth_a (id int not null primary key);
+NOTICE: CREATE TABLE / PRIMARY KEY will create implicit index "depth_a_pkey" for table "depth_a"
+create table depth_b (id int not null primary key);
+NOTICE: CREATE TABLE / PRIMARY KEY will create implicit index "depth_b_pkey" for table "depth_b"
+create table depth_c (id int not null primary key);
+NOTICE: CREATE TABLE / PRIMARY KEY will create implicit index "depth_c_pkey" for table "depth_c"
+create function depth_a_tf() returns trigger
+ language plpgsql as $$
+begin
+ raise notice '%: depth = %', tg_name, pg_trigger_depth();
+ insert into depth_b values (new.id);
+ raise notice '%: depth = %', tg_name, pg_trigger_depth();
+ return new;
+end;
+$$;
+create trigger depth_a_tr before insert on depth_a
+ for each row execute procedure depth_a_tf();
+create function depth_b_tf() returns trigger
+ language plpgsql as $$
+begin
+ raise notice '%: depth = %', tg_name, pg_trigger_depth();
+ begin
+ execute 'insert into depth_c values (' || new.id::text || ')';
+ exception
+ when sqlstate 'U9999' then
+ raise notice 'SQLSTATE = U9999: depth = %', pg_trigger_depth();
+ end;
+ raise notice '%: depth = %', tg_name, pg_trigger_depth();
+ if new.id = 1 then
+ execute 'insert into depth_c values (' || new.id::text || ')';
+ end if;
+ return new;
+end;
+$$;
+create trigger depth_b_tr before insert on depth_b
+ for each row execute procedure depth_b_tf();
+create function depth_c_tf() returns trigger
+ language plpgsql as $$
+begin
+ raise notice '%: depth = %', tg_name, pg_trigger_depth();
+ if new.id = 1 then
+ raise exception sqlstate 'U9999';
+ end if;
+ raise notice '%: depth = %', tg_name, pg_trigger_depth();
+ return new;
+end;
+$$;
+create trigger depth_c_tr before insert on depth_c
+ for each row execute procedure depth_c_tf();
+select pg_trigger_depth();
+ pg_trigger_depth
+------------------
+ 0
+(1 row)
+
+insert into depth_a values (1);
+NOTICE: depth_a_tr: depth = 1
+NOTICE: depth_b_tr: depth = 2
+CONTEXT: SQL statement "insert into depth_b values (new.id)"
+PL/pgSQL function "depth_a_tf" line 4 at SQL statement
+NOTICE: depth_c_tr: depth = 3
+CONTEXT: SQL statement "insert into depth_c values (1)"
+PL/pgSQL function "depth_b_tf" line 5 at EXECUTE statement
+SQL statement "insert into depth_b values (new.id)"
+PL/pgSQL function "depth_a_tf" line 4 at SQL statement
+NOTICE: SQLSTATE = U9999: depth = 2
+CONTEXT: SQL statement "insert into depth_b values (new.id)"
+PL/pgSQL function "depth_a_tf" line 4 at SQL statement
+NOTICE: depth_b_tr: depth = 2
+CONTEXT: SQL statement "insert into depth_b values (new.id)"
+PL/pgSQL function "depth_a_tf" line 4 at SQL statement
+NOTICE: depth_c_tr: depth = 3
+CONTEXT: SQL statement "insert into depth_c values (1)"
+PL/pgSQL function "depth_b_tf" line 12 at EXECUTE statement
+SQL statement "insert into depth_b values (new.id)"
+PL/pgSQL function "depth_a_tf" line 4 at SQL statement
+ERROR: U9999
+CONTEXT: SQL statement "insert into depth_c values (1)"
+PL/pgSQL function "depth_b_tf" line 12 at EXECUTE statement
+SQL statement "insert into depth_b values (new.id)"
+PL/pgSQL function "depth_a_tf" line 4 at SQL statement
+select pg_trigger_depth();
+ pg_trigger_depth
+------------------
+ 0
+(1 row)
+
+insert into depth_a values (2);
+NOTICE: depth_a_tr: depth = 1
+NOTICE: depth_b_tr: depth = 2
+CONTEXT: SQL statement "insert into depth_b values (new.id)"
+PL/pgSQL function "depth_a_tf" line 4 at SQL statement
+NOTICE: depth_c_tr: depth = 3
+CONTEXT: SQL statement "insert into depth_c values (2)"
+PL/pgSQL function "depth_b_tf" line 5 at EXECUTE statement
+SQL statement "insert into depth_b values (new.id)"
+PL/pgSQL function "depth_a_tf" line 4 at SQL statement
+NOTICE: depth_c_tr: depth = 3
+CONTEXT: SQL statement "insert into depth_c values (2)"
+PL/pgSQL function "depth_b_tf" line 5 at EXECUTE statement
+SQL statement "insert into depth_b values (new.id)"
+PL/pgSQL function "depth_a_tf" line 4 at SQL statement
+NOTICE: depth_b_tr: depth = 2
+CONTEXT: SQL statement "insert into depth_b values (new.id)"
+PL/pgSQL function "depth_a_tf" line 4 at SQL statement
+NOTICE: depth_a_tr: depth = 1
+select pg_trigger_depth();
+ pg_trigger_depth
+------------------
+ 0
+(1 row)
+
+drop table depth_a, depth_b, depth_c;
+drop function depth_a_tf();
+drop function depth_b_tf();
+drop function depth_c_tf();
diff --git a/src/test/regress/sql/triggers.sql b/src/test/regress/sql/triggers.sql
index e52131dbba..f88cb81940 100644
--- a/src/test/regress/sql/triggers.sql
+++ b/src/test/regress/sql/triggers.sql
@@ -961,3 +961,67 @@ SELECT * FROM city_view;
DROP TABLE city_table CASCADE;
DROP TABLE country_table;
+
+
+-- Test pg_trigger_depth()
+
+create table depth_a (id int not null primary key);
+create table depth_b (id int not null primary key);
+create table depth_c (id int not null primary key);
+
+create function depth_a_tf() returns trigger
+ language plpgsql as $$
+begin
+ raise notice '%: depth = %', tg_name, pg_trigger_depth();
+ insert into depth_b values (new.id);
+ raise notice '%: depth = %', tg_name, pg_trigger_depth();
+ return new;
+end;
+$$;
+create trigger depth_a_tr before insert on depth_a
+ for each row execute procedure depth_a_tf();
+
+create function depth_b_tf() returns trigger
+ language plpgsql as $$
+begin
+ raise notice '%: depth = %', tg_name, pg_trigger_depth();
+ begin
+ execute 'insert into depth_c values (' || new.id::text || ')';
+ exception
+ when sqlstate 'U9999' then
+ raise notice 'SQLSTATE = U9999: depth = %', pg_trigger_depth();
+ end;
+ raise notice '%: depth = %', tg_name, pg_trigger_depth();
+ if new.id = 1 then
+ execute 'insert into depth_c values (' || new.id::text || ')';
+ end if;
+ return new;
+end;
+$$;
+create trigger depth_b_tr before insert on depth_b
+ for each row execute procedure depth_b_tf();
+
+create function depth_c_tf() returns trigger
+ language plpgsql as $$
+begin
+ raise notice '%: depth = %', tg_name, pg_trigger_depth();
+ if new.id = 1 then
+ raise exception sqlstate 'U9999';
+ end if;
+ raise notice '%: depth = %', tg_name, pg_trigger_depth();
+ return new;
+end;
+$$;
+create trigger depth_c_tr before insert on depth_c
+ for each row execute procedure depth_c_tf();
+
+select pg_trigger_depth();
+insert into depth_a values (1);
+select pg_trigger_depth();
+insert into depth_a values (2);
+select pg_trigger_depth();
+
+drop table depth_a, depth_b, depth_c;
+drop function depth_a_tf();
+drop function depth_b_tf();
+drop function depth_c_tf();