Subject: Re: skip WAL on COPY patch
From: Jeff Davis <pgsql@j-davis.com>
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: Steve Singer <ssinger@ca.afilias.info>,
	PostgreSQL-development Hackers <pgsql-hackers@postgresql.org>
In-Reply-To: <1739.1314126320@sss.pgh.pa.us>
References: <4E53E7D5.6030808@ca.afilias.info> <1739.1314126320@sss.pgh.pa.us>
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Date: Tue, 23 Aug 2011 14:20:12 -0700
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On Tue, 2011-08-23 at 15:05 -0400, Tom Lane wrote:
> Steve Singer <ssinger@ca.afilias.info> writes:
> > The attached patch adds an option to the COPY command to skip writing 
> > WAL when the following conditions are all met:
> 
> > 1) The table is empty (zero size on disk)
> > 2) The copy command can obtain an access exclusive lock on the table 
> > with out blocking.
> > 3) The WAL isn't needed for replication
> 
> Exposing this as a user-visible option seems a seriously bad idea.

In that particular way, I agree. But it might be useful if there were a
more general declarative option like "BULKLOAD". We might then use that
information for a number of optimizations that make sense for large
loads.

Regards,
	Jeff Davis