Horton

Re: ALTER TABLE ... REPLACE WITH

Robert Haas <robertmhaas@gmail.com>

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From: Robert Haas <robertmhaas@gmail.com>
To: Josh Berkus <josh@agliodbs.com>
Cc: Tom Lane <tgl@sss.pgh.pa.us>, Simon Riggs <simon@2ndquadrant.com>, pgsql-hackers@postgresql.org
Date: 2010-12-14T19:36:31Z
Lists: pgsql-hackers 
On Tue, Dec 14, 2010 at 2:34 PM, Josh Berkus <josh@agliodbs.com> wrote:
> On 12/14/10 11:07 AM, Robert Haas wrote:
>> Because then you have to take an AccessExclusiveLock on the target
>> table, of course.
>
> Well, you have to do that for DROP TABLE as well, and I don't see any
> way around doing it for REPLACE WITH.

Sure, but in Simon's proposal you can load the data FIRST and then
take a lock just long enough to do the swap.  That's very different
from needing to hold the lock during the whole data load.

-- 
Robert Haas
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