Dbvisit Replicate (logical replication) as a DR option

[Mike Donovan]

Dbvisit Replicate can be used to provide DR cover by creating an active-active/Oracle to Oracle replication partnership. However, it is important to be aware that there are consequences of this approach:

Negatives:

• More overhead in terms of processing power/memory needed. Applying archives is a lot more efficient than applying SQL
• More manual intervention required in terms of conflict resolution between the source and target destinations
• Not a binary copy, so if a password is changed in the source database it is not updated in the target, then when it comes to failover the system will not work because of an old passsword etc

But on the positive side of the ledger:

• No dataloss when it comes to failover time.
• No rebuilds required after failover
• Can switch back and forward between source and target as much as you like
• Can actually use the target/DR database as a read/write reporting server at any time - it is an open Oracle instance in its own right

So, in terms of recovering after an outage/disaster event, Dbvisit Replicate will be able to synchronise the replication partnership again provided that:

1. You have all the archivelogs
2. The speed of mining/applying is faster than new transactions coming in. Otherwise it will never catchup