On Tue, 23 Mar 2004, Tom Lane wrote: > "Marc G. Fournier" <[EMAIL PROTECTED]> writes: > > 'k, just had someone tell me that they believed that a pg_dump will lock a > > table while the dump is happening ... my first thought/response was that > > this would defeat the point of MVCC, no? And would make for a terrible > > backup procedure on a very large database, since you'd just have made your > > database useless for the duration ... > > > Can someone confirm/deny that the lock happens? > > pg_dump takes a reader's lock (AccessShareLock). This does not prevent > reads or writes of the table. It does prevent dropping the table, > making schema alterations to it (such as column add/drop), or anything > else that wants an exclusive lock. I think that VACUUM FULL is the only > thing particularly likely to cause a conflict in a running database.
Perfect, that makes sense ... thanks :) ---- Marc G. Fournier Hub.Org Networking Services (http://www.hub.org) Email: [EMAIL PROTECTED] Yahoo!: yscrappy ICQ: 7615664 ---------------------------(end of broadcast)--------------------------- TIP 4: Don't 'kill -9' the postmaster
