From: Richard Huxton <dev@archonet.com>
To: Din Adrian <adrian.din@easynet.ro>
Cc: Postgresql Performance <pgsql-performance@postgresql.org>
Subject: Re: Tunning postgresql on linux (fedora core 3)
Date: Thu, 03 Feb 2005 13:56:50 +0000
Message-ID: <42022DA2.3040000@archonet.com> (raw)
In-Reply-To: <opslmno9cpawcxfg@adi>
References: <opsll8h2shawcxfg@adi>
<420202D0.7070602@archonet.com>
<opslmno9cpawcxfg@adi>
Please CC the mailing list as well as replying to me, so that others can
help too.
Din Adrian wrote:
> yes I have read this as well ...
>
> One question about this option:
> fsync = true / false
> a) I have Raid and UPS - it is safe to turn this off ... (' But be
> very aware that any unexpected database shutdown will force you to
> restore the database from your last backup.' - from my last backup if
> the server goes down ??? why ? just at 'any unexpected database
> shutdown' ? ....!!!!!!!!!!!)
Because fsync=true flushes transaction details to disk (the Write Ahead
Log). That way if (say) the power-supply in your server fails you can
check the WAL and compare it to the main database files to make sure
everything is in a known state.
> b) in docs say that after 7.2 seting this to false does'n turn off the
> wall ...!? wich option does?
The docs don't say that, as far as I can see. It doesn't make sense to
turn off the WAL.
--
Richard Huxton
Archonet Ltd
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To: pgsql-sql@postgresql.org
Cc: dev@archonet.com, adrian.din@easynet.ro, pgsql-performance@postgresql.org
Subject: Re: Tunning postgresql on linux (fedora core 3)
In-Reply-To: <42022DA2.3040000@archonet.com>
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