Re: about explain analyze - Mailing list pgsql-hackers

From Marc G. Fournier
Subject Re: about explain analyze
Date
Msg-id 20031128125719.Q41642@ganymede.hub.org
Whole thread Raw
In response to Re: about explain analyze  (Tom Lane <tgl@sss.pgh.pa.us>)
Responses Re: about explain analyze  (Tom Lane <tgl@sss.pgh.pa.us>)
List pgsql-hackers
On Fri, 28 Nov 2003, Tom Lane wrote:

> Teodor Sigaev <teodor@sigaev.ru> writes:
> > Explain analyze takes 3 times more time for execution. Why?
>
> Measurement overhead.  It would seem your platform has a particularly
> slow version of gettimeofday() though ... I've never noticed such a
> large discrepancy myself.

Actually, I'm noticing similar "problems" with v7.4 ... "EXPLAIN ANALYZE"
seems to be showing some *very* high ms for execution time, but if you run
the actual query, it doesn't seem to take even 1/10th the time reported
...

This is on a FreeBSD 4.x box ...

----
Marc G. Fournier           Hub.Org Networking Services (http://www.hub.org)
Email: scrappy@hub.org           Yahoo!: yscrappy              ICQ: 7615664


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