Sebastian Ritter wrote: > A lot of the reports our technical officers submit to us include a listing > of all actioned issues for a given day along with the last modified followup > of each said issue. With the number of rows in our database increasing at a > high rate, these queries are starting to run too slowly.
> We have identified that the slowness in our queries is trying to return the > lastest followup for each actioned issue that day. Without further ado here > are two variations I have tried within the system (neither of which are > making the cut): > > V1 (correlated subquery - Very bad performance) > > (SELECT > fu.* > FROM > manage_followup fu, > manage_issue i > WHERE > i.id = fu.n_issue > AND > fu.id = (SELECT > id > FROM > manage_followup > WHERE > n_issue = i.id > ORDER BY > dt_modified DESC > LIMIT 1)) AS latestfu, > Do you have an index on (id,dt_modified) for manage_followup? Can you provide an EXPLAIN ANALYSE for this? -- Richard Huxton Archonet Ltd -- Sent via pgsql-sql mailing list (pgsql-sql@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-sql
