Re: no XLOG during COPY?

From: Andrew Dunstan <andrew(at)dunslane(dot)net>
To: Simon Riggs <simon(at)2ndQuadrant(dot)com>
Cc: Heikki Linnakangas <heikki(dot)linnakangas(at)enterprisedb(dot)com>, PostgreSQL-development <pgsql-hackers(at)postgresql(dot)org>
Subject: Re: no XLOG during COPY?
Date: 2008-09-15 12:09:45
Message-ID: 48CE5089.2020800@dunslane.net
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Simon Riggs wrote:
> On Thu, 2008-09-11 at 15:25 -0400, Andrew Dunstan wrote:
>
>
>> Great, thanks (and also to Guillaume).
>>
>> It looks to me like the simple way around this issue would be to provide
>> an option to have pg_restore emit:
>> begin; truncate foo; copy foo ... commit;
>>
>> The truncate will be trivial as there won't be any data or indexes at
>> that stage anyway.
>>
>
> Not sure which stage you're talking about. If this is a parallel restore
> and you are running a create in one session and a load in another, then
> ISTM you have no way of knowing that for certain.
>
>

Er, who doesn't know what for certain, exactly? pg_restore will
certainly know that it has created the table in another session and can
thus safely truncate the table in the same transaction as the data load.

cheers

andrew

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