Re: tracking commit timestamps

On Mon, Nov 10, 2014 at 8:40 AM, Alvaro Herrera
<alvherre@2ndquadrant.com> wrote:
> Ah, right.  So AFAIK we don't need to keep anything older than
> RecentXmin or something like that -- which is not too old.  If I recall
> correctly Josh Berkus was saying in a thread about pg_multixact that it
> used about 128kB or so in <= 9.2 for his customers; that one was also
> limited to RecentXmin AFAIR.  I think a similar volume of commit_ts data
> would be pretty acceptable.  Moreso considering that it's turned off by
> default.

I'm not sure whether keeping it just back to RecentXmin will be enough
for everybody's needs.  But we certainly don't need to keep the last
2^32 records as someone-or-other was suggesting.

-- 
Robert Haas
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