On Fri, Oct 2, 2015 at 11:23 AM, Alvaro Herrera
<alvherre@2ndquadrant.com> wrote:
>> + /* all-frozen information is also cleared at the same time */
>> PageClearAllVisible(page);
>> + PageClearAllFrozen(page);
>
> I wonder if it makes sense to have a macro to clear both in unison,
> which seems a very common pattern.
I think PageClearAllVisible should clear both, and there should be no
other macro. There is no event that causes a page to cease being
all-visible that does not also cause it to cease being all-frozen.
You might think that deleting or locking a tuple would fall into that
category - but nope, XMAX needs to be cleared or the tuple pruned, or
there will be problems after wraparound.
--
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company
