From: Adriaan van Os <postgres@microbizz.nl>
To: pgsql-performance@postgresql.org
Subject: Re: insert vs select into performance
Date: Wed, 18 Jul 2007 21:28:40 +0200
Message-ID: <469E69E8.3080204@microbizz.nl> (raw)
In-Reply-To: <20070718113141.GH12481@mathom.us>
References: <469D1AD3.9030004@ifi.uio.no>
<0D6011B2-D09F-45E8-A5D7-5F84ADD1DC2B@seespotcode.net>
<5666.1184704280@sss.pgh.pa.us>
<469D2D59.9030106@ifi.uio.no>
<20070718113141.GH12481@mathom.us>
Michael Stone wrote:
> On Tue, Jul 17, 2007 at 10:58:01PM +0200, Thomas Finneid wrote:
>> I am not sure I understand you correctly here, are you saying that
>> SELECT INTO in 8.1 disables WAL logging and uses just a single fsync
>> at the end? in that case it means that I could disable WAL as well and
>> achieve the same performance, does it not?
>
> Yes. The difference is that the select into optimization just means that
> if the system crashes the data you're inserting is invalid (and is
> properly cleaned up), and disabling the WAL means that if the system
> crashes everything is invalid (and can't be cleaned up).
So, how does one (temporarily) disable WAL logging ? Or, for example, disable WAL logging for a
temporary table ?
Regards,
Adriaan van Os
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To: pgsql-performance@postgresql.org
Cc: postgres@microbizz.nl
Subject: Re: insert vs select into performance
In-Reply-To: <469E69E8.3080204@microbizz.nl>
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