Oracle Interview Questions and Answers for Beginners - 1

Question: 1

What is a user defined lock?

Oracle manages database resources through locking mechanism.

These locks are usually managed by the system and are released on commit or rollback of a transaction.

However, Oracle has provided this functionality to the users so that they can create user defined locks.

These locks are similar to system created locks in functionality but are not released automatically when transaction commits or rollbacks. Therefore, a user has to be extremely careful while using user defined locks.

Question: 2

What functionality does Oracle provide to secure sensitive information?

You can use the dbms_obfuscation_toolkit package to encrypt sensitive information.

The Data Encryption Standard (DES) or triples DES algorithm can be used to encrypt the data.

Question: 3

List some of the procedures provided by the dbms_aq package.

Some of the procedures provided by the dbms_aq package are enqueue, dequeue, register and unregister.

Question: 4

How can you grant privileges on AQ to other users?

You cannot grant privileges on AQ by using grant statement similar to other Oracle objects.

grant_system_privilege – Grants AQ system privileges

revoke_ system_privilege – Revokes AQ system privileges

grant_queue_privilege – Grants privileges on AQ

revoke_queue_privilege – Revokes privileges on AQ.

Question: 5

How can you enable flashback feature?

Oracle provides the dbms_flashback package to use flashback feature.

The package has the following procedures to facilitate this feature:

Enable_at_time

Enable_at_system_change_number

Get_system_change_number

Disable