On Wed, Mar 30, 2011 at 10:40 AM, Greg Stark <gsst...@mit.edu> wrote: > But one way or another the hint bits have to get set sometime. The > sooner that happens the less clog i/o has to happen in the meantime.
I talked about this with Merlin a bit yesterday. I think that his thought is that most transactions will access a small enough number of distinct CLOG pages, and the cache accesses might be fast enough, that we really wouldn't need to get the hint bits set, or at least that vacuum/freeze time would be soon enough. I'm not sure if that's actually true, though - I think the overhead of the cache might be higher than he's imagining. However, there's a sure-fire way to find out... code it up and see how it plays. -- Robert Haas EnterpriseDB: http://www.enterprisedb.com The Enterprise PostgreSQL Company -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
