From: Tom Lane <tgl@sss.pgh.pa.us>
To: Benjamin Arai <barai@cs.ucr.edu>
Cc: pgsql-performance@postgresql.org
Subject: Re: Ensuring data integrity with fsync=off
Date: Sat, 14 Jan 2006 13:41:43 -0500
Message-ID: <20897.1137264103@sss.pgh.pa.us> (raw)
In-Reply-To: <000601c61936$38548770$fa48fd0a@uni>
References: <000601c61936$38548770$fa48fd0a@uni>
"Benjamin Arai" <barai@cs.ucr.edu> writes:
> Right now I run "sync" afte the updates have finished to ensure that the
> data is synced to disk but I am concerned about the segment data and
> anything else I am missing that PostgreSQL explicitly handles. Is there
> something I can do in addition to sync to tell PostgreSQL exlplicitly that
> it is time to ensure everything is stored in its final destionation and etc?
You need to give PG a CHECKPOINT command to flush stuff out of its
internal buffers. After that finishes, a manual "sync" commnd will
push everything down to disk.
You realize, of course, that a system failure while the updates are
running might leave your database corrupt? As long as you are prepared
to restore from scratch, this might be a good tradeoff ... but don't
let yourself get caught without an up-to-date backup ...
regards, tom lane
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To: pgsql-performance@postgresql.org
Cc: tgl@sss.pgh.pa.us, barai@cs.ucr.edu
Subject: Re: Ensuring data integrity with fsync=off
In-Reply-To: <20897.1137264103@sss.pgh.pa.us>
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