On Fri, Sep 2, 2016 at 3:31 AM, Robert Haas <robertmh...@gmail.com> wrote: > On Tue, Aug 23, 2016 at 3:10 AM, Andres Freund <and...@anarazel.de> wrote:
>> =# SELECT * FROM few, ROWS FROM(generate_series(1,3)); >> ┌────┬─────────────────┐ >> │ id │ generate_series │ >> ├────┼─────────────────┤ >> │ 1 │ 1 │ >> │ 2 │ 1 │ >> │ 1 │ 2 │ >> │ 2 │ 2 │ >> │ 1 │ 3 │ >> │ 2 │ 3 │ >> └────┴─────────────────┘ >> (6 rows) >> surely isn't what was intended. So the join order needs to be enforced. > > In general, we've been skeptical about giving any guarantees about > result ordering. +1 I think it is a very bad idea to move away from the statement that a query generates a set of rows, and that no order is guaranteed unless the top level has an ORDER BY clause. How hard is it to add ORDER BY 1, 2 to the above query? Let the optimizer notice when a node returns data in the needed order and skip the sort if possible. -- Kevin Grittner EDB: http://www.enterprisedb.com The Enterprise PostgreSQL Company -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
