Question: The Oracle marketing people are at-it
again, and I noticed that within Oracle 11g "active" data guard is an extra cost
option! In Oracle 10g, there was no distinction between an "active" data
guard and an inactive one, so I wonder if Data Guard costs extra in Oracle 11g?
Answer: The only way to know for sure if Data Guard is still free in
11g EE is to contract your CSR (customer support representative). Oracle
is always re-naming products, and it's not uncommon for a single feature to have
many names (e.g. Oracle VPD is the same as RLS). As to Data Guard, Oracle
is slicing-off the functionality as Data Guard matures.
Also see my notes on
instances with active data guard.
You are correct, the Oracle web site says that Data Guard (SQL Apply and Redo
Apply) comes as part of 10g Enterprise Edition (EE).
Active Data Guard - Now an extra cost option
In 11g, "active data guard" is indeed an "option". The description
suggests that "active data guard" is Data Guard with physical standby, opened
for read-only transactions:
Oracle Active Data Guard - Oracle active data guard is an option for Oracle Database 11g Enterprise
Edition?enhances Quality of Service by offloading resource-intensive
activities from a production database to one or more synchronized standby
Oracle Active Data Guard enables read-only access to a physical standby
database for queries, sorting, reporting, web-based access, etc., while
continuously applying changes received from the production database.
Oracle Active Data Guard also enables the use of fast incremental backups
when offloading backups to a standby database, and can provide additional
benefits of high availability and disaster protection against planned or
unplanned outages at the production site.
The docs also say that active data guard implies that it is essentially redo
apply services used with physical standby:
"If a license for the Oracle Active Data Guard option has been purchased,
Redo Apply Services can also run on a physical standby database instance
that is open."
Let's look at the 11g new features for Data Guard. Oracle 11g Data
Guard introduced several new features. The
Oracle 11g New
Features book notes some Data Guard Pricing changes:
"As site failures do not happen on a regular occurrence these disaster
recovery (DR) servers can be sitting idle for long periods of time without
any use or value being obtained.
Prior to 11g businesses were unable to
benefit as greatly from their DR investment. Oracle's goal for 11g was to
make DR cost effective, better utilize standby resources and allow for easy
testing of DR.
Data Guard is included with the Enterprise Edition of Oracle, but it should
be noted that a named user or processor license may need to be purchased for
the database. It's always recommended to check with an Oracle sales."
The book also confirms that "active Data Guard" is essentially Data Guard
Physical Standby with read-only access:
"Oracle Active Data Guard allows DBAs and users to run real-time queries
on a physical standby system for reporting and other purposes while still
seeing transactional consistent results. As opposed to previous versions
where applying of logs had to stop while reporting was taking place, it now
Oracle versions 9 and 10 couldn't have the physical standby in readable
state; 11g has this and is fully synced. This ability makes an organizations
DR investment much more valuable. This capability is known as Real-Time