From: David Roussel <pgsql-performance@diroussel.xsmail.com>
To: Mischa Sandberg <mischa.sandberg@telus.net>
To: pgsql-perform <pgsql-performance@postgresql.org>
Subject: Re: COPY vs INSERT
Date: Wed, 04 May 2005 23:41:30 +0100
Message-ID: <1115246490.1709.233393619@webmail.messagingengine.com> (raw)
In-Reply-To: <1115146397.4277c89dc37b4@webmail.telus.net>
References: <OF93C70832.2AC188CE-ON85256FF6.0056B587-85256FF6.005774C2@us.ibm.com>
<21154.1115136741@sss.pgh.pa.us>
<1115146397.4277c89dc37b4@webmail.telus.net>
> COPY invokes all the same logic as INSERT on the server side
> (rowexclusive locking, transaction log, updating indexes, rules).
> The difference is that all the rows are inserted as a single
> transaction. This reduces the number of fsync's on the xlog,
> which may be a limiting factor for you. You'll want to crank
> WAL_BUFFERS and CHECKPOINT_SEGMENTS to match, though.
> One of my streams has 6K records; I run with WB=1000, CS=128.
So what's the difference between a COPY and a batch of INSERT
statements. Also, surely, fsyncs only occur at the end of a
transaction, no need to fsync before a commit has been issued, right?
David
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To: pgsql-performance@postgresql.org
Cc: pgsql-performance@diroussel.xsmail.com, mischa.sandberg@telus.net
Subject: Re: COPY vs INSERT
In-Reply-To: <1115246490.1709.233393619@webmail.messagingengine.com>
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