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PG 9..5 index performance Q's 2+ messages / 2 participants [nested] [flat]
* PG 9..5 index performance Q's @ 2016-11-08 18:31 ghiureai <isabella.ghiurea@nrc-cnrc.gc.ca> 0 siblings, 1 reply; 2+ messages in thread From: ghiureai @ 2016-11-08 18:31 UTC (permalink / raw) To: pgsql-admin Hi List, running PGSQL 9.5.1 ( EL7) , we are seeing a issues with one of our SQL statement getting the wrong plan once in a while ( large temp tables being generate, exec time takes > 3 minutes compared with fastes plan < 1 min), we want to undestand why a new/ expensive plan is been used instead of efficient one, there are not data changes on the tables, any tips where to look? Second , I would like to know if when re-creating one index ( non pk ) on a large table with already existing indexes, are All tables statistics being re-generated? ( there is a way to control persistency of old stats?) Isabella -- Sent via pgsql-admin mailing list (pgsql-admin@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-admin ^ permalink raw reply [nested|flat] 2+ messages in thread
* Re: PG 9..5 index performance Q's @ 2016-11-08 18:56 Igor Neyman <ineyman@perceptron.com> parent: ghiureai <isabella.ghiurea@nrc-cnrc.gc.ca> 0 siblings, 0 replies; 2+ messages in thread From: Igor Neyman @ 2016-11-08 18:56 UTC (permalink / raw) To: ghiureai <isabella.ghiurea@nrc-cnrc.gc.ca>; pgsql-admin -----Original Message----- From: pgsql-admin-owner@postgresql.org [mailto:pgsql-admin-owner@postgresql.org] On Behalf Of ghiureai Sent: Tuesday, November 08, 2016 1:31 PM To: pgsql-admin@postgresql.org Subject: [ADMIN] PG 9..5 index performance Q's Hi List, running PGSQL 9.5.1 ( EL7) , we are seeing a issues with one of our SQL statement getting the wrong plan once in a while ( large temp tables being generate, exec time takes > 3 minutes compared with fastes plan < 1 min), we want to undestand why a new/ expensive plan is been used instead of efficient one, there are not data changes on the tables, any tips where to look? Second , I would like to know if when re-creating one index ( non pk ) on a large table with already existing indexes, are All tables statistics being re-generated? ( there is a way to control persistency of old stats?) Isabella _____________________________________________________________________________________________________________________ Without seeing execution plans (both: fast and slow) it's hard to tell. Auto_explain extension can help you catching these plans in PG log. Your temp tables - are they being analyzed? Regards, Igor Neyman -- Sent via pgsql-admin mailing list (pgsql-admin@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-admin ^ permalink raw reply [nested|flat] 2+ messages in thread
end of thread, other threads:[~2016-11-08 18:56 UTC | newest] Thread overview: 2+ messages (download: mbox mbox.gz follow: Atom feed) -- links below jump to the message on this page -- 2016-11-08 18:31 PG 9..5 index performance Q's ghiureai <isabella.ghiurea@nrc-cnrc.gc.ca> 2016-11-08 18:56 ` Igor Neyman <ineyman@perceptron.com>
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