Andrew Biagioni <andrew(dot)biagioni(at)e-greek(dot)net> writes:
> My best estimate as to when they appear is when I abort a transaction in
> PGAdminII by killing the corresponding process on the server ("kill -9 XXXX"),
Yikes. You're not serious are you?
That would certainly cause the backend to fail to clean up its temp
tables... not to mention that the postmaster will treat this as a
system crash and force all the other backends to punt too. Not the way
I'd pick to cancel a misbehaving query.
Try something less invasive next time, like kill -INT.
regards, tom lane