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

On Dec 1, 1:36*pm, Mladen Gogala <gogala.mla... (AT) gmail (DOT) com> wrote:
and alter database switch role; is really cool to watch... makes
primary the standby and standby the primary all automagically.

On Dec 2, 5:36*am, Mladen Gogala <gogala.mla... (AT) gmail (DOT) com> wrote:
And with the DGBroker, it's child's play to switch roles across
sites. Flicking the DR site to active and back to inactive is a joy
to watch. Bugs not-withstanding, it's finally a good and usable
technology. The main reason I'm going 11gr2 next year.

Now, if only they fixed their transmit mechanism to use SAN dark fibre
for replication (or any other transmit mechanism - including carrier
pigeons!) instead of TCP/IP only.... It'd really be something I could
use tomorrow.

Right now, it takes 30 secs to transmit one of my 1GB redo logs to DR
via TCP/IP, while the db generates one of them every 20 secs at peak
times: hardly a feasible solution, isn't it?