Hi -- David Teigland wrote: > I believe Ingres is the only cluster database that's open source. When I > looked a few months ago there was some work needed to hook it into our > cluster/lock managers, but that didn't look too bad as they were already > able to switch between different clustering/locking infrastrutures. That's very interesting -- I should have looked more closely at Ingres R3! :-) Naturally, their site is mostly down now that I want to look at it. Seems like they adopted OpenDLM last year. I can't quite tell, but if the Ingres Grid Option is their "single DB clustering" option, it seems to not support things like row-level locks and "update mode locks". (The Distributed Option appears to be a DTP solution for heterogeneous DBs, and the Replicator Option one for replicating between Ingres DBs, both based on two-phase commits. It looks like you turn of two-phase commits when using the Replicator and Grid Options together.) Errors are mine due to overly quick scanning of documents. I wrote: > It's perhaps worth noting that PostgreSQL and Oracle face special > complexities regarding data consistency and locking because they > provide MVCC (Multi-Version Concurrency Control) ... One small pointless correction to my own tangent is that Oracle actually calls their version MVRC and it works a little differently than PostgreSQL's, but the rough idea is the same. Chris. -- GPG Key ID: 366A375B GPG Key Fingerprint: 485E 5041 17E1 E2BB C263 E4DE C8E3 FA36 366A 375B -- Linux-cluster@xxxxxxxxxx http://www.redhat.com/mailman/listinfo/linux-cluster
