Message-ID: <4E54104B.107@ca.afilias.info>
Date: Tue, 23 Aug 2011 16:40:43 -0400
From: Steve Singer <ssinger@ca.afilias.info>
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To: Tom Lane <tgl@sss.pgh.pa.us>
CC: Robert Haas <robertmhaas@gmail.com>,
	PostgreSQL-development Hackers <pgsql-hackers@postgresql.org>
Subject: Re: skip WAL on COPY patch
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On 11-08-23 04:17 PM, Tom Lane wrote:
> Robert Haas<robertmhaas@gmail.com>  writes:
>> What I think would be really interesting is a way to make this work
>> when the table *isn't* empty.  In other words, have a COPY option that
>> (1) takes an exclusive lock on the table, (2) writes the data being
>> inserted into new pages beyond the old EOF, and (3) arranges for crash
>> recovery or transaction abort to truncate the table back to its
>> previous length.  Then you could do fast bulk loads even into a table
>> that's already populated, so long as you don't mind that the table
>> will be excusive-locked and freespace within existing heap pages won't
>> be reused.
>
> What are you going to do with the table's indexes?
>
> 			regards, tom lane
>

What about not updating the indexes during the copy operation then to an 
automatic rebuild of the indexes after the copy (but during the same 
transaction).  If your only adding a few rows to a large table this 
wouldn't be what you want, but if your only adding a few rows then a 
small amount of WAL isn't a big concern either.