Alvaro Herrera <alvherre(at)commandprompt(dot)com> writes:
> Hmm ... this is something that had not occured to me earlier. There is
> a connection pool here (JDBCConnectionPool I'm told; hadn't heard about
> that one) and there are about 100 backends permanently, not all of which
> are always busy. Perhaps what's going on here is that some of them are
> idle for long enough that the sinval queue gets full.
Hm, that's definitely possible, and 8.1 did not have very good code for
coping with sinval overrun. But it's not clear to me why that would
affect the rel extension code path in particular.
regards, tom lane