Re: Explain analyze time overhead

On Tue, Dec 10, 2013 at 01:53:54PM -0800, salah jubeh wrote:
> Thanks for the link, I find it very useful, unfortunatly I am using 9.1.11
> version.
>
> After digging a little bit, I find out that the gettimeofday is indeed a little
> bit slower on this particular machine than other machines, but it is not that
> significanat difference. The query I am running is not optimized, and for some
> reason the material operator is the one which causes most of the overhead. The
> whole issue is due to cross colums statistics and highly correlated predicates,
> the number of estimated records are much less than the actual number. Still, I
> did not understand completly, why the material operator consume about 9 minutes
> when I run explain analyze. i.e how many times we call gettimeofday for the
> material operator -I need to calculate this-? Finally, for testing purposes, I
> have disabled material and the query execution time dropped from 1 minute to
> 12 second.

The executable is not tied to any particular Postgres version, so you
could get the 9.3 binary and just use that.

--
Bruce Momjian <bruce(at)momjian(dot)us> http://momjian.us
EnterpriseDB http://enterprisedb.com

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