Andres Freund wrote: > On 2015-09-07 10:34:10 -0300, Alvaro Herrera wrote: > > I wonder if it would make sense to explore an idea that has been floated > > for years now -- to have pg_clog pages be allocated as part of shared > > buffers rather than have their own separate pool. That way, no separate > > hardcoded allocation limit is needed. It's probably pretty tricky to > > implement, though :-( > > I still think that'd be a good plan, especially as it'd also let us use > a lot of related infrastructure. I doubt we could just use the standard > cache replacement mechanism though - it's not particularly efficient > either... I also have my doubts that a hash table lookup at every clog > lookup is going to be ok performancewise.
Yeah. I guess we'd have to mark buffers as unusable for regular pages ("somehow"), and have a separate lookup mechanism. As I said, it is likely to be tricky. -- Álvaro Herrera http://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Remote DBA, 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