Re: Very inefficient query plan with disjunction in WHERE clause - Mailing list pgsql-performance

From Matthew Wakeling
Subject Re: Very inefficient query plan with disjunction in WHERE clause
Date
Msg-id alpine.DEB.1.10.0906021347080.4147@aragorn.flymine.org
Whole thread Raw
In response to Very inefficient query plan with disjunction in WHERE clause  (Koen Martens <pgsql@metro.cx>)
List pgsql-performance
On Mon, 1 Jun 2009, Koen Martens wrote:
> Anyway, any hints on getting this beast perform (without rewriting the query, that's not possible in this case due to
> the query being generated by an ORM) are welcome. I'm starting to think it is impossible, and that postgresql just
> doesn't work for this particular query+dataset.

Yeah, being bound by the ORM can be annoying. What version of Postgres is
this? Recent versions can sometimes do a bitmap index scan to satisfy an
OR constraint.

Matthew

--
 I work for an investment bank. I have dealt with code written by stock
 exchanges. I have seen how the computer systems that store your money are
 run. If I ever make a fortune, I will store it in gold bullion under my
 bed.                                              -- Matthew Crosby

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