On Thu, Apr 07, 2005 at 02:34:03PM +0800, Qingqing Zhou wrote: > > "Alvaro Herrera" <[EMAIL PROTECTED]> writes > > Because we can't reuse MultiXactIds at system crash (else we risk taking > > an Id which is already stored in some tuple), we need to XLog it. Not > > at the locking operation, because we don't want to log that one (too > > expensive.) We can log the current value of MultiXactId counter once in > > a while; say, one each (say) 1000 acquisitions. Following a crash, the > > value is restored to the last one logged + 1000. (I think this can be a > > problem if we log one acquisition, then write some tuples, and then > > crash, without flushing the acquisition logged. Maybe a solution is to > > force a flush after logging an acquisition.) > > Does Oid have a similar problem?
Good question. Yes, and in fact the solution is similar; see XLogPutNextOid(). I think we could do the same for MultiXactId. -- Alvaro Herrera (<[EMAIL PROTECTED]>) "La soledad es compañía" ---------------------------(end of broadcast)--------------------------- TIP 4: Don't 'kill -9' the postmaster
