Re: Design/Recovery Questions on Two-Phase Commit (2PC) Protocol

From: Lee <leereilly_at_gmail.com>
Date: 26 Aug 2005 10:16:18 -0700
Message-ID: <1125076578.390623.319930@z14g2000cwz.googlegroups.com>

Thanks for your replies. I'm see the following on the Oracle replication FAQ:

• BEGIN --- Oracle Server supports two different forms of replication: basic and advanced replication.

Basic replication is implemented using standard CREATE SNAPSHOT or CREATE MATERIALIZED VIEW statements. It can only replicate data (not procedures, indexes, etc), replication is always one-way, and snapshot copies are read only.

Advanced replication supports various configurations of updateble-snapshot, multi-master and update anywhere replication. It is more difficult to configure but allows data and other database objects like indexes and procedures to be replicated.
--- END ---
BASIC replication is apparently "always one-way", where as ADVANCED replication supports "update anywhere replication". In my previous example, with 3 databases, would advanced replication mean that changes to any database would be applied to the remaining two? Here's a crude ASCII drawing, that really is pretty useless, but is included as I spent 5 minutes on it...

            [DB1] update triggers DB2 & DB3 update
            /   \
           /     \
          /       \
         /         \
        /           \
       /             \

    [DB2]-----------[DB3] update triggers DB2 & DB3 update     update triggers DB1 & DB3 update Received on Fri Aug 26 2005 - 12:16:18 CDT