Alban Hertroys-3 wrote: > > On 28 Oct 2009, at 9:57, fox7 wrote: > > You forgot to show us the most important part. > --- > Do you absolutely need to order the output of your views? You could > just order the results of your queries on your views instead. The way > you do it now the database needs to order results always, even if the > order doesn't actually matter to you. I suspect this is part of why > your query is slow. > > Besides that, the order of your V2TO view is going to be determined by > the UNION clause anyway, as it needs to sort the results of the union > to make them unique. The order by in the first subquery of that view > can safely be removed I think. > > What do you mean for analyze results? I create views by means of jdbc... For example I have created V2TO as: CREATE VIEW v2TO AS ( SELECT DISTINCT TO.term1, TO.term2 FROM TO UNION SELECT TB.term2 AS term1, TB.term1 AS term2 FROM TB; ) The following format is like it appear selecting the view in Postgre... > CREATE OR REPLACE VIEW v2TO AS ( SELECT DISTINCT TO.term1, TO.term2 > FROM TO > ORDER BY TO.term1, TO.term2) > UNION > SELECT TB.term2 AS term1, TB.term1 AS term2 > FROM TB; The problem is the execution time of the query with view...the first is ok! -- View this message in context: http://www.nabble.com/Slow-running-query-with-views...how-to-increase-efficiency--with-index--tp26086104p26093967.html Sent from the PostgreSQL - general mailing list archive at Nabble.com. -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
