On Wed, 9 Mar 2016 20:43:14 +0200 R Smith <rsmith at rsweb.co.za> wrote:
> SELECT P.id FROM ( > SELECT 0 AS sect, id FROM t WHERE id >= 'pen' > UNION ALL > SELECT 1, id FROM t WHERE id < 'pen' > ) AS P > ORDER BY P.sect, P.id > ; This is the correct answer. I'm not sure what you meant by "axiom" in your earlier post. To the best of my knowledge, UNION ALL makes no promise about order (and standard SQL proscribes ORDER BY in a subquery). If the implementation finds it more efficient, for instance, to send alternating rows from each element in the union, it's free to do so. --jkl
