On Monday 06 August 2007 1:22 pm, you wrote: > "Ed L." <pgsql@xxxxxxxxxxxxx> writes: > > We're seeing some unexpected behavior in one particular > > 64-bit Pgsql 8.1.2 running on HP-UX 11.23 and Itanium 2, > > built with --enable-thread-safety. We think we are seeing > > concurrent select-for-updates of the same rows by multiple > > concurrent backends, contrary to our understanding of > > select-for-update semantics. > > You really ought to be using something newer than 8.1.2. Perhaps. But we have yet to find a way to make major version upgrades of 100+ GB, 100+ tps databases sufficiently inexpensive and painless in terms of SAN space, performance costs, and customer downtime on heavily loaded systems. So we put them off until there is a clear, directly compelling reason to upgrade. > You do have a transaction block established around this whole > process? Row locks only last as long as the current > transaction ... Of course. This is grasping at straws, but I was wondering if perhaps anyone saw anything in this behavior that might suggest a threadsafe-related anomaly? TIA. Ed ---------------------------(end of broadcast)--------------------------- TIP 3: Have you checked our extensive FAQ? http://www.postgresql.org/docs/faq