Tom Lane wrote: > I think an absolute minimum requirement for a sane design is that no two > workers ever try to vacuum the same table concurrently, and I don't see > where that behavior will emerge from your proposal; whereas it's fairly > easy to make it happen if non-first workers pay attention to what other > workers are doing.
FWIW, I've always considered this to be a very important and obvious issue, and I think I've neglected mentioning it (maybe I did too few times). But I think this is pretty easy to do, just have each worker advertise the current table it's working on in shared memory, and add a recheck loop on the table-pick algorithm (with appropriate grabs of the autovacuum lwlock), to make sure no one starts to vacuum the same table you're going to process, at the same time. -- Alvaro Herrera http://www.CommandPrompt.com/ PostgreSQL Replication, Consulting, Custom Development, 24x7 support ---------------------------(end of broadcast)--------------------------- TIP 3: Have you checked our extensive FAQ? http://www.postgresql.org/docs/faq
