Re: What do Oracle, DB2, etc. actually *do*?

William Yu wrote:
> Here's my question about "multi-master" replication whether it's Oracle
> or not. How in the world does it work over high latency, low bandwidth
> connections w/o getting pummelled in performance?

Well, it may well be the case that it doesn't work :) Not all kinds of
replication are appropriate for all situations, and I agree that
synchronous, multi-master replication isn't likely to be useful in the
situation you describe.

One solution to multi-master replication on slow networks (or networks
with nodes that are only intermittently connected) is to be very
asynchronous: transaction commit only affects the local node, and
conflict resolution is done when replicating changes later. This is more
useful for filesystem replication: it is easier to do after-the-fact
conflict resolution, although it is still very complex. ISTM it should
be possible with DBMS replication, at least in theory.

-Neil