Re: GiST index performance

From: Heikki Linnakangas <heikki(dot)linnakangas(at)enterprisedb(dot)com>
To: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
Cc: Matthew Wakeling <matthew(at)flymine(dot)org>, Robert Haas <robertmhaas(at)gmail(dot)com>, pgsql-performance(at)postgresql(dot)org
Subject: Re: GiST index performance
Date: 2009-06-17 12:46:03
Message-ID: 4A38E58B.3010403@enterprisedb.com
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Tom Lane wrote:
> Matthew Wakeling <matthew(at)flymine(dot)org> writes:
>> I'm guessing my next step is to install a version of libc with debugging
>> symbols?
>
> Yeah, if you want to find out what's happening in libc, that's what you
> need.

Getting callgraph information from oprofile would also help. Although it
won't directly tell what function in libc is being called, you would see
where the calls are coming from, which is usually enough to guess what
the libc function is.

You can also get the oprofile data, including callgraph, into
kcachegrind, which is *very* helpful. Here's a script I use:
http://roberts.vorpus.org/~njs/op2calltree.py

--
Heikki Linnakangas
EnterpriseDB http://www.enterprisedb.com

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