From: Gregory Stark <stark@enterprisedb.com>
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: pgsql-hackers@postgreSQL.org
Subject: Re: WIP patch for latestCompletedXid method of computing snapshot xmax
Date: Sat, 08 Sep 2007 22:39:45 +0100
Message-ID: <87r6l8x2e6.fsf@oxford.xeocode.com> (raw)
In-Reply-To: <28198.1189282917@sss.pgh.pa.us>
References: <3018.1189214811@sss.pgh.pa.us>
<28198.1189282917@sss.pgh.pa.us>
"Tom Lane" <tgl@sss.pgh.pa.us> writes:
> My desktop machine has a single consumer-grade IDE drive, and even with
> fsync off and synchronous_commit off, it can barely make 190 tps sustained
> pgbench throughput --- it's just disk write bound all the time. On a run
> with 8 clients, 10000 transactions per client, DB scale factor 25, I get
> this distribution of transaction times from CVS HEAD:
Wouldn't you expect to see more of an effect on cpu-bound environments? Is
there any i/o going on while these locks are being held? I suppose there's a
WAL commit record that has to be synced?
Have you tried with a smaller scale factor?
--
Gregory Stark
EnterpriseDB http://www.enterprisedb.com
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To: pgsql-hackers@postgresql.org
Cc: stark@enterprisedb.com, tgl@sss.pgh.pa.us
Subject: Re: WIP patch for latestCompletedXid method of computing snapshot xmax
In-Reply-To: <87r6l8x2e6.fsf@oxford.xeocode.com>
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