Fix Pg13 compatibility for old migrations during upgrade

Older versions of Pg don't accept a complex expression
in EXECUTE ... INTO. Instead, the expression must be
a single variable name.

Author: ehuelsmann

sql/changes/1.13/old-migration-schemas-cleanup.sql

@@ -4,6 +4,7 @@ create or replace function pg_temp.schedule_schema_deletion(in_schema text)
 declare
   t_transdate date;
   t_cleanup_date date;
+  t_query text;
 begin
   perform *
      from information_schema.schemata
@@ -13,7 +14,8 @@ begin
     return;
   end if;
 
-  execute 'select max(transdate) from ' || quote_ident(in_schema) || '.acc_trans' into t_transdate;
+  t_query := 'select max(transdate) from ' || quote_ident(in_schema) || '.acc_trans';
+  execute t_query into t_transdate;
   t_cleanup_date := greatest(
     coalesce((t_transdate + '7 years'::interval), CURRENT_DATE),
     (CURRENT_DATE + '2 years'::interval)

sql/changes/1.13/old-migration-schemas-cleanup.sql@1

@@ -0,0 +1,40 @@
+
+create or replace function pg_temp.schedule_schema_deletion(in_schema text)
+  returns void as $$
+declare
+  t_transdate date;
+  t_cleanup_date date;
+begin
+  perform *
+     from information_schema.schemata
+    where schema_name = in_schema;
+
+  if not found then
+    return;
+  end if;
+
+  execute 'select max(transdate) from ' || quote_ident(in_schema) || '.acc_trans' into t_transdate;
+  t_cleanup_date := greatest(
+    coalesce((t_transdate + '7 years'::interval), CURRENT_DATE),
+    (CURRENT_DATE + '2 years'::interval)
+  );
+  insert into defaults (setting_key, "value")
+  values ('post-upgrade-run:cleanup-migration-schema/' || in_schema,
+          json_build_object('action', 'cleanup-migration-schema',
+                            'description', 'Cleanup of migration schema "' || in_schema || '"',
+                            'run-after', t_cleanup_date::text,
+                            'args', json_build_object('schema', in_schema)::text));
+
+  return;
+end;
+$$ language plpgsql;
+
+DO $$
+BEGIN
+  perform pg_temp.schedule_schema_deletion('lsmb12');
+  perform pg_temp.schedule_schema_deletion('lsmb13');
+  perform pg_temp.schedule_schema_deletion('sl28');
+  perform pg_temp.schedule_schema_deletion('sl30');
+  perform pg_temp.schedule_schema_deletion('sl32');
+END;
+$$ LANGUAGE plpgsql;