Oracle Active Data Guard

From: Mladen Gogala <gogala.mladen_at_gmail.com>
Date: Thu, 1 Dec 2011 18:36:58 +0000 (UTC)
Message-ID: <pan.2011.12.01.18.36.58_at_gmail.com>



Oracle 11g has a very interesting option: active DG. Basically, one can create a physical standby db which is open for querying. It is much better thing than a logical standby database because there is no hassle with streams and unsupported types. The cost of the "active DG" is the same as the cost of an EE license on the CPU basis, which means that this is the same thing as logical standby, at least money wise. There is even a new status field:

DGMGRL> show database stby

Database - stby

  Role: PHYSICAL STANDBY
  Intended State: APPLY-ON
  Transport Lag: 0 seconds
  Apply Lag: 0 seconds
  Real Time Query: ON
  Instance(s):
    O11

Database Status:
SUCCESS The "Real Time Query: ON" means that this database is open for querying.

This is a great thing, especially when paired with fast fail-over mechanism. This makes a logical standby completely obsolete. I am getting more and more enthusiastic about Oracle 11g. I believe it's the time to convert.

-- 
http://mgogala.byethost5.com
Received on Thu Dec 01 2011 - 12:36:58 CST

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