Convert Physical Standby into Active Data Guard

 

When Do Clients Need Active Data Guard?

1. Reporting Off the Standby:

   • When the client wants to run reports, analytics, or queries without slowing down the primary database.

2. Offload Backups:

   • When the client wants to take RMAN backups from the standby instead of the primary.

3. High Availability with Extra Use:

   • When the client wants the standby to stay fully synchronized with the primary and still do useful work.

4. Minimize Primary Load:

• When the primary database is very busy, and they want to reduce performance impact by offloading read-only tasks

Key DBA Considerations:

• Requires Active Data Guard license.

• Standby remains transactionally consistent with the primary.

• Supports flashback, RMAN backups, and queries simultaneously.

Enable Active Data Guard

Lets Open Physical Standby and test active data guard

On standby:
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SQL> alter database recover managed standby database cancel;
SQL> alter database open;
SQL> select name, open_mode, database_role from v$database;
SQL> alter database recover managed standby database disconnect;

Verify MRP is Running - Use below query to check if MRP is running in the background or not

On standby (active data guard):
===============================
SQL> select process, status, sequence# from v$managed_standby;

with apply means the background manage recovery processes is up and running in Active data

Test Active Data Guard

As our active data guard is open for read only queries and background recover is active, let us create a table on primary and see if it is reflected on standby

On primary:
===========
SQL> create table dg_test(sno number(2),sname varchar2(10));

SQL>select username from dba_users;

we can perform select queries on Data Guard Standby.
for Active Data Guard you need to buy license 

Revert back to physical standby

If you want to convert active data guard back to physical standby, follow below commands

On standby:
===========
SQL> alter database recover managed standby database cancel;
SQL> shutdown immediate;
SQL> startup mount;
SQL> select name, open_mode, database_role from v$database;
SQL> alter database recover managed standby database disconnect;
SQL> select process, status, sequence# from v$managed_standby;