Just a day ago, I was invited at Round Table meeting at prestigious organization. They were planning to implement High Availability solution using Database Mirroring. During the meeting, I have made few notes of what was being discussed there. I just thought it would be interested for all of you know about it.
- Database Mirroring works on physical log records.
- SQL Server 2008 compresses the Transaction Log at Principal Server before it is transferred to mirror server.
- System databases can not be mirrored.
- Database which needs to be mirrored requires it to be in FULL recovery mode.
- High Safety Mode – Synchronous operation – Log are committed on Principal and Mirror when databases are synchronized.
- High Performance Mode – Asynchronous operation – Principal commits and Mirror tries to keep up with received log records from Principal.
- Database mirroring can be configured along with log shipping, database snapshots and replication.
- Unlike replication (subscriber server) in mirroring the mirrored server can not be used during mirroring operation going on.
- Automatic Failover is only possible when high safety mode is configured with automatic failover.
Mirroring is very big subject and as I mentioned this is just a quick note of what we had discussed there. Let me know if you like me my blog which are quick note kind of.
Reference : Pinal Dave (http://blog.SQLAuthority.com)