Vacuum causing crashes

Hi,

We're running a Postgres 8.0.1 database and have a maintenance process
that runs vacuum on selected tables every 10 minutes. Each table takes
around 2-3 seconds to vacuum. Since we've started this process we've
seen a lot of postmaster crashes (it says it received signal 9). It
appears these crashes occur when we try to stop a vacuum by interrupting
the vacuumdb process, but sometimes they occur without us having to do this.

Any ideas? We didn't experience so many database crashes before we
started vacuuming regularly.

Regards
--
David Mitchell
Software Engineer
Telogis