Matthew O'Connor wrote: > Glen Parker wrote: > > Matthew O'Connor wrote: > >> No, how dirty a table isn't subjective, what is subjective is the > >> question "Does it need to be vacuumed?". A that is 1% dirty (to use > >> your term) probably doesn't *need* to be vacuumed, but you might > >> choose to vacuum it anyway at least you might at night when the system > >> isn't in use. > > > > This leads me further from wanting to see a simple time contraint added. > > I'd like to see something more dynamic. > > > > Perhaps define a "dirtiness" rating, and then allow a minimum > > "dirtiness" to be configured. When autovacuum wakes up, it could build > > a list of sufficiently dirty tables sorted in "dirtiness" order, and > > could call an optional user defined function for each one, passing it > > useful bits of information including each table's "dirtiness". The > > function could then decide whether to vacuum or not based on whatever > > constraints the admin dreamed up. > > > > It would then be a simple matter to expose a function that, given a > > table's OID, could report its "dirtiness" level. > > The idea that has been discussed in the past is the concept of > maintenance windows, that is for any given period of time, you can set > different vacuum thresholds. So at night you might make the thresholds > very low so that nearly everything gets vacuumed but during the day you > might only vacuum when something really needs it. This accomplishes > what you are asking for in a more general way that can accommodate a > wide variety of usage patterns. I wonder if the simple solution is to just have a cron script modify postgresql.conf and pg_ctl reload. That seems very flexible, or have two postgresql.conf files and move them into place via cron. -- Bruce Momjian bruce@xxxxxxxxxx EnterpriseDB http://www.enterprisedb.com + If your life is a hard drive, Christ can be your backup. +
