Simon Riggs <si...@2ndquadrant.com> writes: > On 11 May 2015 at 22:20, Heikki Linnakangas <hlinn...@iki.fi> wrote: >> So the lesson here is that having a permanent pg_multixact is not nice, >> and we should get rid of it. Here's how to do that:
> An alternate proposal: > 1. Store only the Locking xids in the Members SLRU > 2. In the Offsets SLRU store: 1) the Updating Xid and 2) the offset to the > Locking xids in the Members SLRU. > This means the Offsets SLRU will be around twice the size it was before BUT > since we reduce the size of each Members array by one, there is a balanced > saving there, so this change is disk-space-neutral. > That way if we need to make Offsets SLRU persistent it won't bloat. > We then leave the Members SLRU as non-persistent, just as it was <9.3 I don't think you can do that, because it supposes that locking XIDs need not be remembered across a crash. Don't prepared transactions break that assumption? regards, tom lane -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers