Fix function and view for autovacuum activity

Changelog: changed

db/migrate/20220422200633_fix_view_for_per_table_autovacuum_status.rb

+# frozen_string_literal: true
+
+class FixViewForPerTableAutovacuumStatus < Gitlab::Database::Migration[2.0]
+  def up
+    execute <<~SQL
+      DROP VIEW IF EXISTS postgres_autovacuum_activity;
+      DROP FUNCTION IF EXISTS postgres_pg_stat_activity_autovacuum;
+
+      CREATE OR REPLACE FUNCTION postgres_pg_stat_activity_autovacuum() RETURNS TABLE(query text, query_start timestamptz) AS
+      $$
+        SELECT query, query_start
+        FROM pg_stat_activity
+        WHERE datname = current_database()
+          AND state = 'active'
+          AND backend_type = 'autovacuum worker'
+      $$
+      LANGUAGE sql
+      VOLATILE
+      SECURITY DEFINER
+      SET search_path = 'pg_catalog', 'pg_temp';
+
+      CREATE VIEW postgres_autovacuum_activity AS
+        WITH processes as
+          (
+            SELECT query, query_start, (regexp_matches(query, '^autovacuum: VACUUM (\w+)\.(\w+)')) as matches
+            FROM postgres_pg_stat_activity_autovacuum()
+            WHERE query ~* '^autovacuum: VACUUM \w+\.\w+'
+          )
+        SELECT matches[1] || '.' || matches[2] as table_identifier,
+              matches[1] as schema,
+              matches[2] as table,
+              query_start as vacuum_start
+        FROM processes;
+
+      COMMENT ON VIEW postgres_autovacuum_activity IS 'Contains information about PostgreSQL backends currently performing autovacuum operations on the tables indicated here.';
+    SQL
+  end
+
+  def down
+    execute(<<~SQL)
+      DROP VIEW IF EXISTS postgres_autovacuum_activity;
+      DROP FUNCTION IF EXISTS postgres_pg_stat_activity_autovacuum;
+
+      CREATE OR REPLACE FUNCTION postgres_pg_stat_activity_autovacuum() RETURNS SETOF pg_catalog.pg_stat_activity AS
+      $$
+        SELECT *
+        FROM pg_stat_activity
+        WHERE datname = current_database()
+          AND state = 'active'
+          AND backend_type = 'autovacuum worker'
+      $$
+      LANGUAGE sql
+      VOLATILE
+      SECURITY DEFINER
+      SET search_path = 'pg_catalog', 'pg_temp';
+
+      CREATE VIEW postgres_autovacuum_activity AS
+        WITH processes as
+          (
+            SELECT query, query_start, (regexp_matches(query, '^autovacuum: VACUUM (\w+)\.(\w+)')) as matches
+            FROM postgres_pg_stat_activity_autovacuum()
+            WHERE query ~* '^autovacuum: VACUUM \w+\.\w+'
+          )
+        SELECT matches[1] || '.' || matches[2] as table_identifier,
+              matches[1] as schema,
+              matches[2] as table,
+              query_start as vacuum_start
+        FROM processes;
+
+      COMMENT ON VIEW postgres_autovacuum_activity IS 'Contains information about PostgreSQL backends currently performing autovacuum operations on the tables indicated here.';
+    SQL
+  end
+end

db/schema_migrations/20220422200633

+666eff0892b795c7f1a84dfcdb6fad6266f952bb91b69c81e803d16ecdc0d11d
\ No newline at end of file

db/structure.sql

@@ -106,11 +106,11 @@ BEGIN
 END;
 $$;
-CREATE FUNCTION postgres_pg_stat_activity_autovacuum() RETURNS SETOF pg_stat_activity
+CREATE FUNCTION postgres_pg_stat_activity_autovacuum() RETURNS TABLE(query text, query_start timestamp with time zone)
     LANGUAGE sql SECURITY DEFINER
     SET search_path TO 'pg_catalog', 'pg_temp'
     AS $$
-  SELECT *
+  SELECT query, query_start
   FROM pg_stat_activity
   WHERE datname = current_database()
     AND state = 'active'
@@ -18744,7 +18744,7 @@ CREATE VIEW postgres_autovacuum_activity AS
          SELECT postgres_pg_stat_activity_autovacuum.query,
             postgres_pg_stat_activity_autovacuum.query_start,
             regexp_matches(postgres_pg_stat_activity_autovacuum.query, '^autovacuum: VACUUM (w+).(w+)'::text) AS matches
-           FROM postgres_pg_stat_activity_autovacuum() postgres_pg_stat_activity_autovacuum(datid, datname, pid, usesysid, usename, application_name, client_addr, client_hostname, client_port, backend_start, xact_start, query_start, state_change, wait_event_type, wait_event, state, backend_xid, backend_xmin, query, backend_type)
+           FROM postgres_pg_stat_activity_autovacuum() postgres_pg_stat_activity_autovacuum(query, query_start)
           WHERE (postgres_pg_stat_activity_autovacuum.query ~* '^autovacuum: VACUUM w+.w+'::text)
         )
  SELECT ((processes.matches[1] || '.'::text) || processes.matches[2]) AS table_identifier,