Kevin Grittner <kgri...@gmail.com> writes: > On Fri, Sep 2, 2016 at 9:25 AM, Tom Lane <t...@sss.pgh.pa.us> wrote: >> ORDER BY is not a useful suggestion when there is nothing >> you could order by to get the old behavior.
> I'm apparently missing something, because I see a column with the > header "generate_series" in the result set. You are apparently only thinking about generate_series and not any other SRF. Other SRFs don't necessarily produce outputs that are in a nice sortable order. Even for one that does, sorting by it would destroy the existing behavior: regression=# select *, generate_series(1,3) from int8_tbl; q1 | q2 | generate_series ------------------+-------------------+----------------- 123 | 456 | 1 123 | 456 | 2 123 | 456 | 3 123 | 4567890123456789 | 1 123 | 4567890123456789 | 2 123 | 4567890123456789 | 3 4567890123456789 | 123 | 1 4567890123456789 | 123 | 2 4567890123456789 | 123 | 3 4567890123456789 | 4567890123456789 | 1 4567890123456789 | 4567890123456789 | 2 4567890123456789 | 4567890123456789 | 3 4567890123456789 | -4567890123456789 | 1 4567890123456789 | -4567890123456789 | 2 4567890123456789 | -4567890123456789 | 3 (15 rows) Now you could argue that the ordering of the table rows themselves is poorly defined, and you'd be right, but that doesn't change the fact that the generate_series output has a well-defined repeating sequence. People might be relying on that property. regards, tom lane -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers