Re: EXPLAIN ANALYZE total runtime != walltime - Mailing list pgsql-general

From Stephan Szabo
Subject Re: EXPLAIN ANALYZE total runtime != walltime
Date
Msg-id 20040825190945.H6086@megazone.bigpanda.com
Whole thread Raw
In response to EXPLAIN ANALYZE total runtime != walltime  (Jon Lapham <lapham@jandr.org>)
Responses Re: EXPLAIN ANALYZE total runtime != walltime  (Jon Lapham <lapham@jandr.org>)
List pgsql-general
On Wed, 25 Aug 2004, Jon Lapham wrote:

> I have been using the EXPLAIN ANALYZE command to debug some performance
> bottlenecks in my database.  In doing so, I have found an oddity (to me
> anyway).  The "19ms" total runtime reported below actually takes 25
> seconds on my computer (no other CPU intensive processes running).  Is
> this normal for EXPLAIN ANALYZE to report a total runtime so vastly
> different from wall clock time?
>
> During the "explain ANALYZE delete from msgid;" the CPU is pegged at
> 100% for the postmaster process, and the HD light only flashes
> intermittently, so I do not think it is HD I/O.
>
> I tossed in a "EXPLAIN ANALYZE VERBOSE" at the end of this email, in
> case that helps anyone.

I think EXPLAIN ANALYZE time doesn't include after trigger time (for
example for foreign keys).  Do any tables reference this one?

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