On Thu, Sep 11, 2008 at 8:56 AM, Bill Moran <wmoran@xxxxxxxxxxxxxxxxxxxxxxx> wrote: > In response to Alvaro Herrera <alvherre@xxxxxxxxxxxxxxxxx>: > >> Bill Moran wrote: >> > In response to "Gauthier, Dave" <dave.gauthier@xxxxxxxxx>: >> > >> > > I might be able to answer my own question... >> > > >> > > vacuum FULL (analyze is optional) >> > >> > CLUSTER _may_ be a better choice, but carefully read the docs regarding >> > it's drawbacks first. You may want to do some benchmarks to see if it's >> > really needed before you commit to it as a scheduled operation. >> >> What drawbacks? > > There's the whole "there will be two copies of the table on-disk" thing > that could be an issue if it's a large table. I've also found cluster to be pretty slow, even on 8.3. On a server that hits 30-40Megs a second write speed for random access during pgbench, it's writing out at 1 to 2 megabytes a second when it runs, and takes the better part of a day on our biggest table. vacuumdb -fz + reindexdb ran in about 6 hours which means we could fit it into our maintenance window. vacuum moves a lot more data per second than cluster.
