On 06.02.2012 11:25, Simon Riggs wrote:
> On Mon, Feb 6, 2012 at 10:02 AM, Heikki Linnakangas
> <heikki.linnakangas@enterprisedb.com> wrote:
>> Good idea. However, the followup idea to that discussion was to not only
>> avoid the I/O needed to mark tuples as frozen, but to avoid xid wraparound
>> altogether, by allowing clog to grow indefinitely. You do want to freeze at
>> some point of course, to truncate the clog, but it would be nice to not have
>> a hard limit. The way to do that is to store an xid "epoch" in the page
>> header, so that Xids are effectively 64-bits wide, even though the xid
>> fields on the tuple header are only 32-bits wide. That does require a new
>> field in the page header.
>
> We wouldn't need to do that would we?
Huh? Do you mean that we wouldn't need to implement that feature?
-- Heikki Linnakangas EnterpriseDB http://www.enterprisedb.com