Joel Stevenson <joelstevenson@mac.com> writes:
> I've been running the setup on 8.1b3 and 8.1RC1 without this
> particular Assertion failure, but had not been using the NOWAIT flag
> until today. During a period of perhaps 20 processes operating on
> the queue it looks like postgres failed this assertion 17 times, the
> first coming very shortly after the processes began and the rest
> following in quick succession.
BTW, I imagine that the apparent correlation to NOWAIT is occurring
because your client-side code was not checking to see if the NOWAIT
query had failed before trying to launch another query in the same
transaction.
regards, tom lane