Beginning Oracle Database 11g Administration From Novice to Professional

CHAPTER 16 INSTANCE TUNING 379
6. Connect to the database as the user. Query the table and
find the session ID of the blocked session. Because you know that it is waiting for
an event to complete, you can use the command
.
7. Query the view and obtain the serial number of the blocked process. Use
the command .
8. Begin tracing the blocked session by using the
session; issue the command
. Refer to Oracle Database 11g PL/SQL Packages and Types
Reference for a description of the procedure.
9. Generate a Statspack snapshot by using the procedure. Using a
special version of the procedure, capture performance information for the blocked
session in addition to systemwide information; issue the command
.
10. Now resume the first session and issue the command. This will release
the blocked session, and Oracle will display the error
.
11. Identify the trace file for the second session by using the command
. Review the trace file and locate the lines similar to the following line:
12. Confirm that the object number listed in the trace file corresponds to the
table. Use the command
.
13. Perform the experiment once more and confirm that additional wait messages
appear in the trace file.
14. Navigate to the folder where the trace file is located and invoke the utility
from the command line. You have to specify the name of the trace file and choose
a name for the output file. Review the output file created by .
15. Generate another Statspack snapshot by using the procedure with
the same parameter used in step 9. Use the command
.
16. Connect to the database as the or user and generate a Statspack
report from the snapshots obtained in step 9 and step 15. Run the
script by using the command .