###Check max sequence is ok on both dataguard and cascades both are in sync

## normally this part is ok ,Check the protection mode and role in standby cascade database it should be maximum performance, if not change to maximum performance. Once mode is fine
SELECT OPEN_MODE,PROTECTION_MODE,DATABASE_ROLE FROM V$DATABASE; OPEN_MODE PROTECTION_MODE DATABASE_ROLE
NOTE: If protection_mode is other than maximum performance, then alter it as below.
SQL> ALTER DATABASE SET STANDBY DATABASE TO MAXIMIZE PERFORMANCE;

 ##Stop recovery on both dataguard  and cascades 
recover managed standby database cancel;
####Now Action on cascades only :
###Now activate standby 
alter database recover managed standby database finish;
alter database activate standby database;
##Check the role and mode of the database cascade, it should be primary now 
select name,open_mode,database_role from v$database;
#### open database and bounce , recovery should be stopped to avoid active dataguard flag .
Alter databas open;
Bounce your database and verify database name its open mode and its role.
select database_role from v$database;

###Change dbname with nid utility 
Step:1 Mount the database with old db name(standby)
Step:2 Run the nid utility (syntax: nid sys/password@CURRENT_DBNAME DBNAME=NEW_DBNAME)
Step:3 Once you run the nid utility the name will be changed to new db name.
Step:4 Then you have to change the db_name in the parameter file. Using alter system  command and start db in nomount to check ok .
Step:5 change the spfile to a new db name. Check spfile name correct with new dbname.
Step:6 Now open the database with reset logs option.
Step7:  register database information for listener  alter system register. 
###And check connection using sqlplus from client .