Alvaro Herrera <[EMAIL PROTECTED]> writes: > I was thinking at what time was the most appropiate to insert or remove > an Xid from the cache. We can do without any excl-locking because 1) we > already assume the storing of an Xid to be atomic, and 2) no one can be > interested in querying for an Xid before the originating transaction has > had the chance to write a tuple with that Xid anyway.
Actually ... that fails if GetSnapshotData is going to copy subtrans XIDs. So this area needs more thought. > On the third hand, are we going to sh-acquire the ProcArray lock while a > GetSnapshotData copies all subxact Xids of all running transactions? > ProcArrayLock will become more of a contention point than it already is. Yeah, but sharelock is better than exclusive lock ... regards, tom lane ---------------------------(end of broadcast)--------------------------- TIP 2: Don't 'kill -9' the postmaster