feat(migrations): enhance pgmq.meta table structure validation

migrations/db/migrations/20241215003910_backfill_pgmq_metadata.sql

@@ -4,25 +4,25 @@ begin
     -- Check if the pgmq.meta table exists
     if exists (
         select 1
-        from pg_catalog.pg_class c
-        join pg_catalog.pg_namespace n on c.relnamespace = n.oid
-        where n.nspname = 'pgmq' and c.relname = 'meta'
+        from pg_catalog.pg_class cls
+        join pg_catalog.pg_namespace ns on cls.relnamespace = ns.oid
+        where ns.nspname = 'pgmq' and cls.relname = 'meta'
     ) then
         -- Insert data into pgmq.meta for all tables matching the naming pattern 'pgmq.q_<queue_name>'
         insert into pgmq.meta (queue_name, is_partitioned, is_unlogged, created_at)
         select
-            substring(c.relname from 3) as queue_name,
+            substring(cls.relname from 3) as queue_name,
             false as is_partitioned,
-            case when c.relpersistence = 'u' then true else false end as is_unlogged,
+            case when cls.relpersistence = 'u' then true else false end as is_unlogged,
             now() as created_at
         from
-			pg_catalog.pg_class c
-        	join pg_catalog.pg_namespace n
-				on c.relnamespace = n.oid
+            pg_catalog.pg_class cls
+            join pg_catalog.pg_namespace ns
+                on cls.relnamespace = ns.oid
         where
-			n.nspname = 'pgmq'
-			and c.relname like 'q_%'
-	 		and c.relkind in ('r', 'p', 'u');
+            ns.nspname = 'pgmq'
+            and cls.relname like 'q_%'
+            and cls.relkind in ('r', 'p', 'u');
     end if;
 end $$;