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Re: Performance question 83 GB Table 150 million rows, distinct select - Mailing list pgsql-performance

From Josh Berkus
Subject Re: Performance question 83 GB Table 150 million rows, distinct select
Date
Msg-id 4EC49945.40408@agliodbs.com
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In response to Re: Performance question 83 GB Table 150 million rows, distinct select  (Tory M Blue <tmblue@gmail.com>)
Responses Re: Performance question 83 GB Table 150 million rows, distinct select  (Tory M Blue <tmblue@gmail.com>)
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Tory,

A seq scan across 83GB in 4 minutes is pretty good.   That's over
300MB/s.  Even if you assume that 1/3 of the table was already cached,
that's still over 240mb/s.  Good disk array.

Either you need an index, or you need to not do this query at user
request time.  Or a LOT more RAM.

--
Josh Berkus
PostgreSQL Experts Inc.
http://pgexperts.com

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