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From: Tom Lane <tgl@sss.pgh.pa.us>
To: Robert Haas <robertmhaas@gmail.com>
Cc: Jeff Janes <jeff.janes@gmail.com>
Cc: pgsql-hackers <pgsql-hackers@postgresql.org>
Cc: Daniel Farina <daniel@heroku.com>
Cc: Craig Ringer <ringerc@ringerc.id.au>
Cc: Harold A. Giménez <harold.gimenez@gmail.com>
Subject: Re: [PERFORM] DELETE vs TRUNCATE explanation
Date: Mon, 16 Jul 2012 12:57:39 -0400
Message-ID: <13011.1342457859@sss.pgh.pa.us> (raw)
In-Reply-To: <CA+TgmoYRXMWQ_DGmmqu3Zp8oW3Lt-9Lc1q3EHaV_ZmjWqaPkuA@mail.gmail.com>
References: <4FFCCAC4.4030503@ringerc.id.au>
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Robert Haas <robertmhaas@gmail.com> writes:
> In my view, the elephant in the room here is that it's dramatically
> inefficient for every backend to send an fsync request on every block
> write.

Yeah.  This was better before the decision was taken to separate
bgwriter from checkpointer; before that, only local communication was
involved for the bulk of write operations (or at least so we hope).
I remain less than convinced that that split was really a great idea.

			regards, tom lane



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