On Sat, May 1, 2010 at 1:17 PM, Scott Marlowe <scott.marlowe@xxxxxxxxx> wrote: > On Sat, May 1, 2010 at 1:08 PM, Robert Haas <robertmhaas@xxxxxxxxx> wrote: >> On Sat, May 1, 2010 at 12:13 PM, Scott Marlowe <scott.marlowe@xxxxxxxxx> wrote: >>> On Fri, Apr 30, 2010 at 4:50 PM, Josh Berkus <josh@xxxxxxxxxxxx> wrote: >>>> Which is the opposite of my experience; currently we have several >>>> clients who have issues which required more-frequent analyzes on >>>> specific tables. Before 8.4, vacuuming more frequently, especially on >>>> large tables, was very costly; vacuum takes a lot of I/O and CPU. Even >>>> with 8.4 it's not something you want to increase without thinking about >>>> the tradeoff >>> >>> Actually I would think that statement would be be that before 8.3 >>> vacuum was much more expensive. The changes to vacuum for 8.4 mostly >>> had to do with moving FSM to disk, making seldom vacuumed tables >>> easier to keep track of, and making autovac work better in the >>> presence of long running transactions. The ability to tune IO load >>> etc was basically unchanged in 8.4. >> >> What about http://www.postgresql.org/docs/8.4/static/storage-vm.html ? > > That really only has an effect no tables that aren't updated very > often. Unless you've got a whole bunch of those, it's not that big of > a deal. sigh, s/ no / on / Anyway, my real point was that the big improvements that made vacuum so much better came in 8.3, with HOT updates and multi-threaded vacuum (that might have shown up in 8.2 even) 8.3 was a huge improvement and compelling upgrade from 8.1 for me. -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
