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"Interesting - I
use a Mac to help me design the next Cray." - Seymoure Cray
(1925-1996) |
Read
first then play the video:
OEM013(VIDEO)-Detecting
a session lock problem
Detecting a session lock
problem using OEM
Introduction
As a DBA, you are
responsible for detecting a session lock problem. The following is a
summary of your task:
Covers:
Using the “Lock Monitor”
tool
Selecting a target database
Identifying the Lock
Session
Obtaining locked users
Obtaining a user’s lock
mode
Resolving lock contentions
Hands-on
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).
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.
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