Create a Snapshot Standby Database

Here I have a standby database named stdby which is a PHYSICAL STANDBY. I will convert it to a SNAPSHOT STANDBY:

1.  export ORACLE_SID=stdby
2. sqlplus / as sysdba
3. alter database recover managed standby database cancel;
4. alter database convert to snapshot standby

To revert back to physical standby

1. export ORACLE_SID=stdby
2. sqlplus / as sysdba
3. shutdown immediate
4. startup mount
5. alter database convert to physical standby;
6. shutdown immediate
7. startup mount
8. alter database recover managed standby database disconnect;