"Pavan Deolasee" <pavan.deolasee@gmail.com> writes:
> Would it help to set the status of the XMIN/XMAX of tuples early enough such
> that the heap page is still in the buffer cache, but late enough such that
> the XMIN/XMAX transactions are finished ? How about doing it when the
> bgwriter is about to write the page to disk ?
No. The bgwriter would then become subject to deadlocks because it
would be needing to read in clog pages before it could flush out
dirty pages. In any case, if the table is in active use then some
passing backend has probably updated the bits already ...
regards, tom lane