One interesting feature of Oracle Dataguard introduced with 11g :
Snapshot Standby database where we can basically convert the physical standby database into a read-write real time clone of the production database and we can then temporarily use this environment for carrying out any kind of development testing, QA type work or to test the impact of a proposed production change on an application.
The command that performs this activity is :
SQL> ALTER DATABASE CONVERT TO SNAPSHOT STANDBY;
The database role gets changed :
SQL> select open_mode,database_role from v$database; OPEN_MODE DATABASE_ROLE ---------- ---------------- READ WRITE SNAPSHOT STANDBY
To move it back to physical standby :
SQL> ALTER DATABASE CONVERT TO PHYSICAL STANDBY;