This test's output changes depending on which worker is
picked for explain (e.g., worker port in the output changes).
Given that the test is only aiming to ensure that CTEs inside
CTEs work fine in DML queries, it should be fine to get rid of
the EXPLAIN. The output is verified to be correct as well.
Previously we checked if an operator is in pg_catalog, and if it wasn't we prefixed it with namespace in worker queries. This can have a huge impact on performance of physical planner when using custom data types.
This happened regardless of current search_path config, because Citus overrides the search path in get_query_def_extended(). When we do so, the check for existence of the operator in current search path in generate_operator_name() fails for any operators outside pg_catalog. This means that nothing gets cached, and in the following calls we will again recheck the system tables for existence of the operators, which took an additional 40-50ms for some of the usecases we were seeing.
In this change we skip the pg_catalog check, and always prefix the operator with its namespace.
Onder Kalaci
Hadi Moshayedi
Marco Slot