On Wed, May 29, 2013 at 9:57 AM, Andres Freund <andres@2ndquadrant.com> wrote:
>> Thought about that, but given that 9.3's visibilitymap_set already will
>> already FPI heap pages I concluded it wouldn't really be an improvement
>> since it's only one ||log_heap_page or so there. Not sure what's
>> better. Will write the patch and see how it goes.
>
> Ended up using log_newpage_buffer since reusing visibilitymap_set's
> record would break the wal format as we currently do not accept an FPI
> on the heap pages during replay when < 9.3. Forcing to upgrade the
> client first would be rather unfriendly...
>
> That has the disadvantage of logging a full heap page since it doesn't
> use the hole optimization but this happens really infrequently, so ...
Yeah, I think it's fine. The patch also looks fine, although I think
the comments could use a bit of tidying. I guess we need to
back-patch this all the way back to 8.4? It will require some
adjustments for the older branches.
--
Robert Haas
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