Oracle BPM Interview Questions (Part-2)

Q : What is the difference between obsolete RMAN backups and expired RMAN backups 
 

A  : The term obsolete does not mean the same as expired. In short obsolete means "not needed " whereas expired means "not found."  

A status of "expired" means that the backup piece or backup set is not found in the backup destination. A status of "obsolete" means the backup piece is still available, but it is no longer needed. The backup piece is no longer needed since RMAN has been configured to no longer need this piece after so many days have elapsed, or so many backups have been performed.

Q : Is it possible to take Catalog Database Backup using RMAN? If Yes, How?

A : A recovery catalog is a schema stored in a database that tracks backups and stores of target databases. So better to take a export backup How do you identify the expired, active, obsolete backups? Which RMAN command you use?

Obsolete backups:

RMAN> report obsolete;

expired backup:

RMAN> list expired backup;

Active database: RMAN> list backup;

Q : Outline the steps involved in CANCEL based recovery from the full database from hot backup?

A : RMAN doesn't support cancel-based recovery like SQL*plus does.  

Q : Outline the steps involved in SCN based recovery from the full database from hot backup?

A : startup mount;

restore database UNTIL SCN 233545;

recover database UNTIL SCN 233545;

alter database open resetlogs;

Q : How do you verify the integrity of the image copy in RMAN environment? 

A : Use below commands :

rman> catalog datafilecopy 'f:testsystem.dbf';

rman> backup validate check logical datafile 'f:testsystem.dbf';

SQL> SELECT * FROM v$database_block_corruption; 

Q : Is it possible to specific tables when using RMAN DUPLICATE feature? If yes, how? 

A : No, table based recovery not possible in RMAN duplicate command.

Q : Outline the steps involved in TIME based recovery from the full database from hot backup? 

A : startup mount;

restore database UNTIL TIME "TO_DATE('28/12/2012 18:00:00', 'DD/MM/YYYY HH24:MI:SS')";

recover database UNTIL TIME "TO_DATE('28/12/2012 18:00:00', 'DD/MM/YYYY HH24:MI:SS')";a

Q : Outline the steps for changing the DBID in a cloned environment?  

A : shutdown Immediate

startup mount

Then, run the the DBNEWID utility from command line.

nid target =/

SQL> alter database open resetlogs;  

Q : Explain the steps to perform the point in time recovery with a backup which is taken before the resetlogs of the db?   

1. We need to list the database incarnations by using list incarnation command.

2. shutdown the database

3. startup mount the database

4. Issue reset database to incarnation to reset the incarnation.

5. Restore the database using restore command (e.g restore until scn 23243)

6.recover database

 7. Open the database using resetlogs command 

RMAN> list incarnation of database;

RMAN>reset database to incarnation 5;

run

{

set until scn 234345;

restore database;

rec..

Q : How do you install the RMAN recovery catalog? or List the steps required to enable the RMAN ?

A : Steps to be followed:  

1) Create connection string at catalog database. 

2) At catalog database create one new user or use existing user and give that user a recovery_catalog_owner privilege. 

3)  Login into RMAN with connection string 

a) export ORACLE_SID 

b) rman target catalog @connection string 

4) rman&g .