On Sat, 20 Aug 2005, Tom Lane wrote: > Gavin Sherry <[EMAIL PROTECTED]> writes: > > I've written some quick scripts. One just vacuums constantly (999 vacuums > > to 1 vacuum full) while three other scripts three randomly insert > > into, update and delete from 3 tables. There's a mix of small and large > > transactions. The tables have a single int column. It is set up to run 3 > > million transactions across the 3 scripts. > > Note that since the issues have mainly to do with update chains, it'd be > good to stress cases where a row is updated multiple times before being > deleted. And use at least one long-running transaction, so that VACUUM > can't just throw away the update chain.
Right. I modified the test so have multiple updates of a given row mixed with concurrent long running read transactions. Vacuum was running repeatedly in a concurrent session. I did not encounter any problems. However, the results are inconclusive since I ran the same test against HEAD from 10 days ago and didn't manage to trigger the problem Teodor's script did. I'll take a better look tomorrow. Gavin ---------------------------(end of broadcast)--------------------------- TIP 3: Have you checked our extensive FAQ? http://www.postgresql.org/docs/faq