> There is, I believe, a problem there; there is a scenario where data > can get "dropped out from under" those old connections. > > This has been added to the TODO... > > http://www.postgresql.org/docs/faqs.TODO.html > > * Make CLUSTER preserve recently-dead tuples per MVCC requirements
OK, I can see this being a problem in the general case. However, for my queue table the current behavior is a life-saver. Would it be possible to still provide a variant of rebuild which is documented to not be MVCC compliant ? Something like: I don't care the old transactions which did not touch yet this table to see the old data for this table, I want to rebuild it. I actually don't care about clustering in this case, only about rebuilding the table once I can get an exclusive lock on it. I guess this would be possible with the "switch to a copy" method except the new table is a different entity (as mentioned in another post) and it will not preserve the dependencies of the original table. I guess what I'm asking for is a kind of "REBUILD TABLE" which is not MVCC by definition but it would be useful in the mentioned queue table case. Cheers, Csaba. ---------------------------(end of broadcast)--------------------------- TIP 2: Don't 'kill -9' the postmaster