From: Tom Lane <tgl@sss.pgh.pa.us>
To: Greg Smith <greg@2ndQuadrant.com>
Cc: pgsql-docs <pgsql-docs@postgresql.org>
Subject: Re: Clarify TIMING OFF behavior
Date: Sun, 19 May 2013 22:06:20 -0400
Message-ID: <13411.1369015580@sss.pgh.pa.us> (raw)
In-Reply-To: <51985D31.1030705@2ndQuadrant.com>
References: <51985D31.1030705@2ndQuadrant.com>
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Greg Smith <greg@2ndQuadrant.com> writes:
> While chatting in #pedant today, I noticed that it's not clear that
> EXPLAIN (ANALYZE ON, TIMING OFF) will still collect the total runtime of
> the statement. Attached patch clarifies that. It also comments why the
> related code runs INSTR_TIME_SET_CURRENT in all cases. That's actually
> how I noticed that--a read through explain.c now could rightly wonder
> "why is it still collecting that bit of time info when TIMING is off?"
Applied with a little bit of further wordsmithing.
> There's an argument possible here that a third TIMING option besides
> ON/OFF should really exist, one that really doesn't do any timing at
> all. I don't think enough use cases for that exist to justify coding
> it.
Agreed. If you can't tolerate two gettimeofday calls per EXPLAIN,
you don't need a new EXPLAIN option ... you need new hardware.
regards, tom lane
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To: pgsql-docs@postgresql.org
Cc: tgl@sss.pgh.pa.us, greg@2ndQuadrant.com
Subject: Re: Clarify TIMING OFF behavior
In-Reply-To: <13411.1369015580@sss.pgh.pa.us>
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