markw(at)osdl(dot)org writes:
> I take it PQexec() should wait until the COMMIT finishes?
Yeah, it does. Where is the next iteration of the transaction coming
from?
Another thought occurred to me --- you said you have many parallel
instances of this transaction, but they affect different rows because
they have different keys. Is it possible there's a logic bug that
occasionally allows parallel transactions to be fired with the same key?
regards, tom lane