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Date: Fri, 15 Dec 2006 13:24:52 +0100
From: Martijn van Oosterhout <kleptog@svana.org>
To: Gregory Stark <stark@enterprisedb.com>
Cc: Simon Riggs <simon@2ndquadrant.com>, Tom Lane <tgl@sss.pgh.pa.us>,
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Subject: Re: [HACKERS] EXPLAIN ANALYZE on 8.2
Message-ID: <20061215122452.GI958@svana.org>
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On Fri, Dec 15, 2006 at 12:15:59PM +0000, Gregory Stark wrote:
> There are various attempts at providing better timing infrastructure at l=
ow
> overhead but I'm not sure what's out there currently. I expect to do this=
 what
> we'll have to do is invent a pg_* abstraction that has various implementa=
tions
> on different architectures. On Solaris it can use DTrace internally, on L=
inux
> it might have something else (or more likely several different options
> depending on the age and config options of the kernel).=20

I think we need to move to a sampling approach. setitimer is good,
except it doesn't tell you if signals have been lost. Given they are
most likely to be lost during high disk I/O, they're actually
significant. I'm trying to think of a way around that. Then you don't
need a cheap gettimeofday at all...

Have a nice day,
--=20
Martijn van Oosterhout   <kleptog@svana.org>   http://svana.org/kleptog/
> From each according to his ability. To each according to his ability to l=
itigate.

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