Hands-On 13 (Detecting a session lock problem using OEM)

As a DBA, you are responsible for detecting a session lock problem. The following is a summary of your task:

1. Using the “Lock Monitor” tool

2. Selecting a target database

3. Identifying the Lock Session

4. Obtaining locked users

5. Obtaining a user’s lock mode

6. Resolving lock contentions

Hands-On 13 (Detecting a session lock problem using OEM)

Description:

In this exercise you will learn how to identify the session lock
problems from the "Lock Monitor" tool using the Oracle Enterprise 
Management tool (OEM).

==Start.
Expand the databases.

==
Select the DBS4RMAN database.

==
Go to the "Diagnostics Pack" tools and click on the "Lock Monitor" icon.

==
In the "Lock Manager" window, notice that the "ISELF" user is in the
exclusive mode and that it’s holding the SYSTEM user.
Although the SYSTEM user requested an exclusive lock, it was
not given to it.

Let's go to the ISELF session that was holding the SYSTEM user.
Then you commit the transaction.
==
Go back to the "Lock Manager" window, the lock disappears after the window is refreshed.

==

Now, the SYSTEM user has an exclusive lock with no holding request
locks. Now, you have a happy customer.

==

For more information about the subject, you are encouraged
to read from a wide selection of available books.

Good Luck!