Re: [PERFORM] Very slow inner join query Unacceptable latency.

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Тема: Re: [PERFORM] Very slow inner join query Unacceptable latency.
Дата: ,
Msg-id: 20130529074419.5a830134ae84016b0174832fdc1a3173.028401a187.wbe@email11.secureserver.net
(см: обсуждение, исходный текст)
Список: pgsql-general

<span style="font-family:Verdana; color:#000000; font-size:10pt;"><div>We re-tested these settings a few times after
ourinitial test and realized that the execution time I posted was shewed, because the execution plan was cached after
theinitial run. Subsequent executions ran in a little over a second.</div><div>There ended up being no
significant savingby setting these parameters. Un-cached the query ran in about 55
seconds. </div><div> </div><blockquoteid="replyBlockquote" style="BORDER-LEFT: blue 2px solid; PADDING-LEFT: 8px;
FONT-FAMILY:verdana; COLOR: black; MARGIN-LEFT: 8px; FONT-SIZE: 10pt" webmail="1"><div id="wmQuoteWrapper">--------
OriginalMessage --------<br />Subject: Re: [GENERAL] [PERFORM] Very slow inner join query Unacceptable<br />latency.<br
/>From:Scott Marlowe <<a href="mailto:"></a>><br />Date: Fri, May
24,2013 3:03 pm<br />To: <a href="mailto:"></a><br />Cc: Jaime Casanova
<<ahref="mailto:"></a>>, psql performance list<br /><<a
href="mailto:"></a>>,Postgres General<br /><<a
href="mailto:"></a>><br/><br />On Fri, May 24, 2013 at 3:44
PM,<<a href="mailto:"></a>> wrote:<br /><br />> Total runtime:
1606.728ms 1.6 seconds <- very good response time<br />> improvement<br />><br />> (7 rows)<br />><br
/>>Questions:<br />><br />> Any concerns with setting these conf variables you recommended; work_mem,<br
/>>random_page_cost dbserver wide (in postgresql,conf)?<br />><br />> Thanks so much!!!<br /><br />Yes 500MB
ispretty high especially if you have a lot of connections.<br />Try it with it back down to 16MB and see how it does.
Workmem is per<br />sort so a setting as high as 500MB can exhaust memory on the machine<br />under heavy load.<br
/><br/>--<br />To understand recursion, one must first understand recursion.<br /></div></blockquote></span> 

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