On Sunday, May 20, 2012, Martijn van Oosterhout wrote: > On Sun, May 20, 2012 at 12:26:26AM -0700, Ian Harding wrote: > > I have a situation where an increase in volume of inserts into the > > main transaction table causes a huge slowdown. The table has lots of > > indexes and foreign keys and a trigger. > > > > Clearly, something is causing a resource contention issue, but here's > > my main question: > > > > I have log_lock_waits = on and deadlock_timeout = 250ms. Is there > > any way I could have delays of tens of seconds caused by a write > > conflict in a table accessed by a trigger that would not result in the > > wait being logged? > > The most common cause for slowdowns during inserts is if you're not > wrapping them into large transactions. The deadlock timeout only > tracks deadlocks, it won't trigger on normal lock waits. There can be > issues with respect to foreign keys, but I didn't think they are > triggered on inserts.
I must have misunderstood log_lock_waits. I thought it logged all lock waits longer than deadlock_timeout. > > If you are wrapping into transactions, then it may be that your disk > subsystem has slow fsyncs. > > Hope this helps, > -- > Martijn van Oosterhout <klep...@svana.org <javascript:;>> > http://svana.org/kleptog/ > > He who writes carelessly confesses thereby at the very outset that he > does > > not attach much importance to his own thoughts. > -- Arthur Schopenhauer >
