Test calls to CDB_Invalidate_Varnish

Also drops the DELETE trigger on CDB_TableMetadata as the call to
CDB_Invalidate_Varnish would then get an OID, which is pretty useless.
Closes #8

expected/test_ddl_triggers.out

@@ -25,6 +25,7 @@ NOTICE:  trigger "update_the_geom_webmercator_trigger" for table "c.t3" does not
 NOTICE:  trigger "update_updated_at_trigger" for table "c.t3" does not exist, skipping
 NOTICE:  trigger "test_quota" for table "c.t3" does not exist, skipping
 NOTICE:  trigger "test_quota_per_row" for table "c.t3" does not exist, skipping
+NOTICE:  cdb_invalidate_varnish(c.t3) called
 select
  cartodb_id, created_at=updated_at as "c=u",
  NOW() - updated_at < '1 secs' as "u<1s",
@@ -64,6 +65,7 @@ NOTICE:  event trigger "cdb_on_relation_drop" does not exist, skipping
 NOTICE:  event trigger "cdb_on_alter_column" does not exist, skipping
 NOTICE:  event trigger "cdb_on_drop_column" does not exist, skipping
 NOTICE:  event trigger "cdb_on_add_column" does not exist, skipping
+NOTICE:  cdb_invalidate_varnish(c.t3) called
 select
  cartodb_id, created_at=updated_at as "c=u",
  NOW() - updated_at < '1 secs' as "u<1s",
@@ -100,6 +102,7 @@ NOTICE:  event trigger "cdb_on_relation_drop" does not exist, skipping
 NOTICE:  event trigger "cdb_on_alter_column" does not exist, skipping
 NOTICE:  event trigger "cdb_on_drop_column" does not exist, skipping
 NOTICE:  event trigger "cdb_on_add_column" does not exist, skipping
+NOTICE:  cdb_invalidate_varnish(c.t3) called
 select
  cartodb_id, created_at=updated_at as "c=u",
  NOW() - updated_at < '1 secs' as "u<1s",
@@ -139,6 +142,7 @@ NOTICE:  event trigger "cdb_on_relation_drop" does not exist, skipping
 NOTICE:  event trigger "cdb_on_alter_column" does not exist, skipping
 NOTICE:  event trigger "cdb_on_drop_column" does not exist, skipping
 NOTICE:  event trigger "cdb_on_add_column" does not exist, skipping
+NOTICE:  cdb_invalidate_varnish(c.t3) called
 select
  cartodb_id, created_at=updated_at as "c=u",
  NOW() - updated_at < '1 secs' as "u<1s",
@@ -169,6 +173,7 @@ select pg_sleep(.1);
 (1 row)
 
 alter table c.t3 add column id2 int;
+NOTICE:  cdb_invalidate_varnish(c.t3) called
 select
  cartodb_id, created_at=updated_at as "c=u",
  NOW() - updated_at < '1 secs' as "u<1s",

expected/test_setup.out

@@ -1,3 +1,9 @@
 CREATE EXTENSION postgis;
 CREATE EXTENSION schema_triggers;
 CREATE EXTENSION cartodb;
+CREATE FUNCTION public.cdb_invalidate_varnish(table_name text)
+RETURNS void AS $$
+BEGIN
+  RAISE NOTICE 'cdb_invalidate_varnish(%) called', table_name;
+END;
+$$ LANGUAGE 'plpgsql';

scripts-available/CDB_TableMetadata.sql

@@ -94,7 +94,9 @@ $$
 LANGUAGE plpgsql VOLATILE SECURITY DEFINER;
 
 DROP TRIGGER IF EXISTS table_modified ON CDB_TableMetadata;
-CREATE TRIGGER table_modified AFTER INSERT OR UPDATE OR DELETE
+-- NOTE: on DELETE we would be unable to convert the table
+--       oid (regclass) to its name
+CREATE TRIGGER table_modified AFTER INSERT OR UPDATE
 ON CDB_TableMetadata FOR EACH ROW EXECUTE PROCEDURE
  _CDB_TableMetadata_Updated();
 

sql/test_setup.sql

@@ -1,3 +1,9 @@
 CREATE EXTENSION postgis;
 CREATE EXTENSION schema_triggers;
 CREATE EXTENSION cartodb;
+CREATE FUNCTION public.cdb_invalidate_varnish(table_name text)
+RETURNS void AS $$
+BEGIN
+  RAISE NOTICE 'cdb_invalidate_varnish(%) called', table_name;
+END;
+$$ LANGUAGE 'plpgsql';