Richard Neill <rn214@xxxxxxxxx> writes: > SELECT > SUM (case when id > 1200000 and id < 1210000 then 1 else 0 end) AS c1, > SUM (case when id > 1210000 and id < 1220000 then 1 else 0 end) AS c2, > ... > FROM tbl_tracker; > This can be manually optimised into a far uglier (but much much faster) > query: > SELECT * FROM > (SELECT COUNT (1) AS c1 FROM tbl_tracker > WHERE id > 1200000 and id < 1210000) AS s1, > (SELECT COUNT (1) AS c2 FROM tbl_tracker > WHERE id > 1210000 and id < 1220000) AS s2, > ... We're unlikely to consider doing this, for a couple of reasons: it's unlikely to come up often enough to justify the cycles the planner would spend looking for the case *on every query*, and it requires very special knowledge about the behavior of two specific aggregate functions, which is something the planner tends to avoid using. regards, tom lane -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
