On Tue, Dec 27, 2011 at 10:43 PM, Merlin Moncure <mmonc...@gmail.com> wrote: > I bet if you kept a judicious number of > clog pages in each local process with some smart invalidation you > could cover enough cases that scribbling the bits down would become > unnecessary.
I don't understand how any cache can completely remove the need for hint bits. Without hint bits the xids in the tuples will be "in-doubt" forever. No matter how large your cache you'll always come across tuples that are arbitrarily old and are from an unbounded size set of xids. We could replace the xids with a frozen xid sooner but that just amounts to nearly the same thing as the hint bits only with page locking and wal records. -- greg -- Sent via pgsql-hackers mailing list (email@example.com) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers