Re: Deadlock on Parallel Update

From: Guido Stepken <stepken_at_little-idiot.de>
Date: Sun, 17 Aug 2003 13:02:23 +0200
Message-ID: <3F3F60BF.90008@little-idiot.de>

Hi, Bosco !

Oracle has MVRC, Multi Versioning Read Concurrency. That means, that many processes can read, one can write, there will be no collisions. But there are Collisions on write-write on the same table.

MVCC, Multi Versioning Concurrency Control, ist much more advanced. No collisions at all, because every transaction gets a snapshot of all data and only works on its own snapshot. When transaction has finished, in case of a collision, the last transaction wins. PostgreSQL has such feature. Sure, you can have locks too....

I think, it is a problem with the implementation of MVRC in oracle.

regards, Guido Stepken Received on Sun Aug 17 2003 - 06:02:23 CDT