Fwd: weird behavior of ORDER BY

pgsql-bugs@postgresql.org


Hello, friends!

This statement returns nothing:

WITH x AS (VALUES (1))
SELECT * FROM x
ORDER BY unnest(NULL :: INT [])
;

--0 rows retrieved
--PostgreSQL 9.6.1, compiled by Visual C++ build 1800, 64-bit
--PostgreSQL 10.3, compiled by Visual C++ build 1800, 64-bit

I think any "ORDER BY" construct can't filter result set.