Optimize oldest query select (without HAVING)

Author: Roman Nikolaev

mamonsu/plugins/pgsql/oldest.py

@@ -19,15 +19,15 @@ class Oldest(Plugin):
     OldestQuerySql = """
 SELECT 
   CASE WHEN extract(epoch from max(now() - xact_start)) IS NOT null 
+        AND extract(epoch from max(now() - xact_start))>0
     THEN extract(epoch from max(now() - xact_start)) 
     ELSE 0 
   END 
 FROM pg_catalog.pg_stat_activity 
 WHERE 
   pid NOT IN(select pid from pg_stat_replication) AND 
   pid <> pg_backend_pid() AND 
-  query NOT ilike '%%VACUUM%%' 
-HAVING extract(epoch from max(now() - xact_start))>0;
+  query NOT ilike '%%VACUUM%%';
 """
 
     OldestQuerySql_bootstrap = """

mamonsu/tools/bootstrap/sql.py

@@ -69,15 +69,15 @@
 RETURNS DOUBLE PRECISION AS $$
     SELECT 
         CASE WHEN extract(epoch from max(now() - xact_start)) IS NOT null 
+              AND extract(epoch from max(now() - xact_start))>0
             THEN extract(epoch from max(now() - xact_start)) 
             ELSE 0 
         END 
     FROM pg_catalog.pg_stat_activity 
     WHERE 
         pid NOT IN(select pid from pg_stat_replication) AND 
         pid <> pg_backend_pid() AND 
-        query NOT ilike '%%VACUUM%%' 
-    HAVING extract(epoch from max(now() - xact_start))>0
+        query NOT ilike '%%VACUUM%%'
 $$ LANGUAGE SQL SECURITY DEFINER;
 
 CREATE OR REPLACE FUNCTION public.mamonsu_count_{3}_files()