Bruce Momjian <[EMAIL PROTECTED]> writes: > I suppose we could allow one backend to mark the page with a shared lock > for primary key purposes while others read it. Does that buy us > anything?
That doesn't work, unless you insist that the first backend can't exit its transaction until all the other ones are done. Which introduces its own possibilities for deadlock --- but even worse, how does the first backend *know* that the other ones are done? You're right back where you started: it has to be possible to tell which backends have share-locked a particular row. regards, tom lane ---------------------------(end of broadcast)--------------------------- TIP 8: explain analyze is your friend