On 10 June 2013 19:58, Heikki Linnakangas <hlinnakan...@vmware.com> wrote: > On 01.06.2013 23:21, Robert Haas wrote: >> >> On Sat, Jun 1, 2013 at 2:48 PM, Heikki Linnakangas >> <hlinnakan...@vmware.com> wrote: >>>> >>>> We define a new page-level bit, something like PD_RECENTLY_FROZEN. >>>> When this bit is set, it means there are no unfrozen tuples on the >>>> page with XIDs that predate the current half-epoch. Whenever we know >>>> this to be true, we set the bit. If the page LSN crosses more than >>>> one half-epoch boundary at a time, we freeze the page and set the bit. >>>> If the page LSN crosses exactly one half-epoch boundary, then (1) if >>>> the bit is set, we clear it and (2) if the bit is not set, we freeze >>>> the page and set the bit. >>> >>> >>> Yep, I think that would work. Want to write the patch, or should I? ;-) >> >> >> Have at it. > > > Here's a first draft. A lot of stuff missing and broken, but "make check" > passes :-).
Well done, looks like good progress. -- Simon Riggs http://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Training & Services -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
