Greetings. I was trying to understand what - if any - are the guarantees with regards to ordering for combining queries (UNION/UNION ALL/...). From this message[1], it seems that UNION ALL does preserve the ordering of the operand queries, whereas UNION does not (presumably neither do INTERSECT, INTERSECT ALL, EXCEPT and EXCEPT ALL).
The documentation[2] makes no mention of this, I'd suggest adding a note clarifying this. Thanks, Shay [1] https://www.postgresql.org/message-id/26825.1064858...@sss.pgh.pa.us [2] https://www.postgresql.org/docs/current/queries-union.html
