On Tue, Dec 30, 2008 at 2:02 AM, Reg Me Please <regmeplease@xxxxxxxxx> wrote: > Only one question remains in my mind: > > why the planner is not using the partial index? > > The partial index is covering 2 predicates out of the 3 used in the where > condition. Actually there is a boolean flag (to exclude "disabled" rows), > a timestamp (for row age) and an int8 (a FK to another table). > The first two are in the partial index in order to exclude "disabled" and > older rows. The int8 is the "random" key I mentioned earlier. > > So the WHERE condition reads like: > > flag AND tstz >= '2008-01-01'::timestamptz and thekey=42 > > I can see in the EXPLAIN that there is no mention to the partial index. > Please keep in mind that the table has 8+M rows, few of which are flagged, > about 70% don't match the age limit and few dozens match the key. > In my opinion the partial index should help a lot. Can you show us the DDL for the index creation and the select query as well? -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
