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Re: Random plan selection in DBT-3 - Mailing list pgsql-hackers

From Tom Lane
Subject Re: Random plan selection in DBT-3
Date
Msg-id 2069.1199674489@sss.pgh.pa.us
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In response to Random plan selection in DBT-3  (ITAGAKI Takahiro <itagaki.takahiro@oss.ntt.co.jp>)
Responses Re: Random plan selection in DBT-3  (ITAGAKI Takahiro <itagaki.takahiro@oss.ntt.co.jp>)
List pgsql-hackers
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ITAGAKI Takahiro <itagaki.takahiro@oss.ntt.co.jp> writes:
> I tested 8.3beta4 with DBT-3 (TPC-H) and found unstable selection of plans.
> Planner randomly selected two types of plans (A, B) when I repeated EXPLAIN.

Are you sure the statistics weren't changing underneath you (due to
auto-vacuum or auto-analyze)?
        regards, tom lane

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