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fix: pgrst_ddl_watch triggering PostgREST notifications unnecessarily #2464

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fix: pgrst_ddl_watch triggering PostgREST notifications unnecessarily #2464

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63 changes: 63 additions & 0 deletions migrations/db/migrations/20260923021047_update_pgrst_watch_triggers.sql
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Original file line number Diff line number Diff line change
@@ -0,0 +1,63 @@
-- migrate:up

CREATE OR REPLACE FUNCTION extensions.pgrst_ddl_watch() RETURNS event_trigger
LANGUAGE plpgsql
AS $$
DECLARE
cmd record;
BEGIN
FOR cmd IN SELECT * FROM pg_event_trigger_ddl_commands()
LOOP
IF cmd.command_tag IN (
'CREATE SCHEMA', 'ALTER SCHEMA'
, 'CREATE TABLE', 'CREATE TABLE AS', 'SELECT INTO', 'ALTER TABLE'
, 'CREATE FOREIGN TABLE', 'ALTER FOREIGN TABLE'
, 'CREATE VIEW', 'ALTER VIEW'
, 'CREATE MATERIALIZED VIEW', 'ALTER MATERIALIZED VIEW'
, 'CREATE FUNCTION', 'ALTER FUNCTION'
, 'CREATE TYPE', 'ALTER TYPE'
, 'CREATE RULE'
, 'COMMENT'
)
-- don't notify in case of CREATE TEMP table or other objects created on pg_temp
-- also exclude any objects inside Supabase schemas
AND COALESCE(cmd.schema_name, '') NOT IN ('pg_temp', 'auth', 'realtime', '_realtime', 'storage')

@laurenceisla laurenceisla Sep 26, 2026

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Maybe we should add more schemas here... but for now, realtime was the one that was triggering notifications frequently.

-- Exclude any trigger created on temp tables (object_identity = 'trigger on pg_temp.table')
OR (cmd.command_tag = 'CREATE TRIGGER' AND cmd.object_identity NOT LIKE '% pg\_temp.%')

@laurenceisla laurenceisla Sep 26, 2026 •
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Initially I used:

    OR (
      -- we validate if the trigger is created on a temporary table (relpersistence = 't')
      cmd.command_tag = 'CREATE TRIGGER'
      AND NOT EXISTS (
        SELECT 1
        FROM pg_class c JOIN pg_trigger t ON c.oid = t.tgrelid
        WHERE t.oid = cmd.objid AND c.relpersistence = 't'
      )
    )

But this doesn't work for pg_event_trigger_dropped_objects (the trigger is already dropped). The current implementation does a similar job, so I kept it the same for both event triggers.

THEN
NOTIFY pgrst, 'reload schema';
END IF;
END LOOP;
END; $$;


CREATE OR REPLACE FUNCTION extensions.pgrst_drop_watch() RETURNS event_trigger
LANGUAGE plpgsql
AS $$
DECLARE
obj record;
BEGIN
FOR obj IN SELECT * FROM pg_event_trigger_dropped_objects()
LOOP
IF obj.object_type IN (
'schema'
, 'table'
, 'foreign table'
, 'view'
, 'materialized view'
, 'function'
, 'type'
, 'rule'
)
AND obj.is_temporary IS false -- no pg_temp objects
-- also exclude any objects inside Supabase schemas
AND COALESCE(obj.schema_name, '') NOT IN ('auth', 'realtime', '_realtime', 'storage')
-- Exclude any trigger created on temp tables (object_identity = 'trigger on pg_temp.table')
OR ( obj.object_type = 'trigger' AND obj.object_identity NOT LIKE '% pg\_temp.%')
THEN
NOTIFY pgrst, 'reload schema';
END IF;
END LOOP;
END; $$;

-- migrate:down
11 changes: 8 additions & 3 deletions migrations/schema-15.sql
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -339,13 +339,15 @@ BEGIN
, 'CREATE VIEW', 'ALTER VIEW'
, 'CREATE MATERIALIZED VIEW', 'ALTER MATERIALIZED VIEW'
, 'CREATE FUNCTION', 'ALTER FUNCTION'
, 'CREATE TRIGGER'
, 'CREATE TYPE', 'ALTER TYPE'
, 'CREATE RULE'
, 'COMMENT'
)
-- don't notify in case of CREATE TEMP table or other objects created on pg_temp
AND cmd.schema_name is distinct from 'pg_temp'
-- also exclude any objects inside Supabase schemas
AND COALESCE(cmd.schema_name, '') NOT IN ('pg_temp', 'auth', 'realtime', '_realtime', 'storage')
-- Exclude any trigger created on temp tables (object_identity = 'trigger on pg_temp.table')
OR (cmd.command_tag = 'CREATE TRIGGER' AND cmd.object_identity NOT LIKE '% pg\_temp.%')
THEN
NOTIFY pgrst, 'reload schema';
END IF;
Expand All @@ -372,11 +374,14 @@ BEGIN
, 'view'
, 'materialized view'
, 'function'
, 'trigger'
, 'type'
, 'rule'
)
AND obj.is_temporary IS false -- no pg_temp objects
-- also exclude any objects inside Supabase schemas
AND COALESCE(obj.schema_name, '') NOT IN ('auth', 'realtime', '_realtime', 'storage')
-- Exclude any trigger created on temp tables (object_identity = 'trigger on pg_temp.table')
OR ( obj.object_type = 'trigger' AND obj.object_identity NOT LIKE '% pg\_temp.%')
THEN
NOTIFY pgrst, 'reload schema';
END IF;
Expand Down
11 changes: 8 additions & 3 deletions migrations/schema-17.sql
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -340,13 +340,15 @@ BEGIN
, 'CREATE VIEW', 'ALTER VIEW'
, 'CREATE MATERIALIZED VIEW', 'ALTER MATERIALIZED VIEW'
, 'CREATE FUNCTION', 'ALTER FUNCTION'
, 'CREATE TRIGGER'
, 'CREATE TYPE', 'ALTER TYPE'
, 'CREATE RULE'
, 'COMMENT'
)
-- don't notify in case of CREATE TEMP table or other objects created on pg_temp
AND cmd.schema_name is distinct from 'pg_temp'
-- also exclude any objects inside Supabase schemas
AND COALESCE(cmd.schema_name, '') NOT IN ('pg_temp', 'auth', 'realtime', '_realtime', 'storage')
-- Exclude any trigger created on temp tables (object_identity = 'trigger on pg_temp.table')
OR (cmd.command_tag = 'CREATE TRIGGER' AND cmd.object_identity NOT LIKE '% pg\_temp.%')
THEN
NOTIFY pgrst, 'reload schema';
END IF;
Expand All @@ -373,11 +375,14 @@ BEGIN
, 'view'
, 'materialized view'
, 'function'
, 'trigger'
, 'type'
, 'rule'
)
AND obj.is_temporary IS false -- no pg_temp objects
-- also exclude any objects inside Supabase schemas
AND COALESCE(obj.schema_name, '') NOT IN ('auth', 'realtime', '_realtime', 'storage')
-- Exclude any trigger created on temp tables (object_identity = 'trigger on pg_temp.table')
OR ( obj.object_type = 'trigger' AND obj.object_identity NOT LIKE '% pg\_temp.%')
THEN
NOTIFY pgrst, 'reload schema';
END IF;
Expand Down
11 changes: 8 additions & 3 deletions migrations/schema-orioledb-17.sql
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -354,13 +354,15 @@ BEGIN
, 'CREATE VIEW', 'ALTER VIEW'
, 'CREATE MATERIALIZED VIEW', 'ALTER MATERIALIZED VIEW'
, 'CREATE FUNCTION', 'ALTER FUNCTION'
, 'CREATE TRIGGER'
, 'CREATE TYPE', 'ALTER TYPE'
, 'CREATE RULE'
, 'COMMENT'
)
-- don't notify in case of CREATE TEMP table or other objects created on pg_temp
AND cmd.schema_name is distinct from 'pg_temp'
-- also exclude any objects inside Supabase schemas
AND COALESCE(cmd.schema_name, '') NOT IN ('pg_temp', 'auth', 'realtime', '_realtime', 'storage')
-- Exclude any trigger created on temp tables (object_identity = 'trigger on pg_temp.table')
OR (cmd.command_tag = 'CREATE TRIGGER' AND cmd.object_identity NOT LIKE '% pg\_temp.%')
THEN
NOTIFY pgrst, 'reload schema';
END IF;
Expand All @@ -387,11 +389,14 @@ BEGIN
, 'view'
, 'materialized view'
, 'function'
, 'trigger'
, 'type'
, 'rule'
)
AND obj.is_temporary IS false -- no pg_temp objects
-- also exclude any objects inside Supabase schemas
AND COALESCE(obj.schema_name, '') NOT IN ('auth', 'realtime', '_realtime', 'storage')
-- Exclude any trigger created on temp tables (object_identity = 'trigger on pg_temp.table')
OR ( obj.object_type = 'trigger' AND obj.object_identity NOT LIKE '% pg\_temp.%')
THEN
NOTIFY pgrst, 'reload schema';
END IF;
Expand Down
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