Re: Deriving Recovery Snapshots - Mailing list pgsql-hackers

From Simon Riggs
Subject Re: Deriving Recovery Snapshots
Date
Msg-id 1224738332.27145.582.camel@ebony.2ndQuadrant
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In response to Re: Deriving Recovery Snapshots  (Simon Riggs <simon@2ndQuadrant.com>)
Responses Re: Deriving Recovery Snapshots
List pgsql-hackers
On Wed, 2008-10-22 at 21:47 +0100, Simon Riggs wrote:

> But once you reach 64 transactions, you'll need to write an extra WAL
> record for every subtransaction, which currently I've managed to avoid.

Yes, I've managed to avoid it, but it will simplify the patch if you
think its not worth bothering with. This won't really effect anybody
I've met running straight Postgres, but it may effect EDB. It's not a
problem for me, but I was second guessing objections.

If I do that then I can just pass the slotId in full on every WAL
record, which simplifies a couple of other things also.

So, does everybody accept that we will write a WAL record for every
subtransaction assigned, once we hit the size limit of the subxid cache?
i.e. currently 65th subxid  and beyond.

-- Simon Riggs           www.2ndQuadrant.comPostgreSQL Training, Services and Support



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