Book Image

Oracle Database 11gR2 Performance Tuning Cookbook

By : Ciro Fiorillo
Book Image

Oracle Database 11gR2 Performance Tuning Cookbook

By: Ciro Fiorillo

Overview of this book

Oracle's Database offers great performance, scalability, and many features for DBAs and developers. Due to a wide choice of technologies, successful applications are good candidates to run into performance issues and when a problem arises it's very difficult to identify the cause and the right solution to the problem. The Oracle Database 11g R2 Performance Tuning Cookbook helps DBAs and developers to understand every aspect of Oracle Database that can affect performance. You will be guided through implementing the correct solution in a proactive way before problems arise, and how to diagnose issues on your Oracle database-based solutions. This fast-paced book offers solutions starting from application design and development, through the implementation of well-performing applications, to the details of deployment and delivering best-performance databases. With this book you will quickly learn to apply the right methodology to tune the performance of an Oracle Database, and to optimize application design and SQL and PL/SQL code. By following the real-world examples you will see how to store your data in correct structures and access and manipulate them at a lightning speed. You will learn to speed up sort operations, hack the optimizer and the data loading process, and diagnose and tune memory, I/O, and contention issues. The purpose of this cookbook is to provide concise recipes, which will help you to build and maintain a very high-speed Oracle Database environment.
Table of Contents (21 chapters)
Oracle Database 11gR2 Performance Tuning Cookbook
Credits
About the Author
Acknowledgement
About the Reviewers
www.PacktPub.com
Preface
Index

V$SESSION


This view displays information on each current session.

Fields

The most relevant view fields are as follows:

  • SID: The session identifier

  • SADDR: The session address

  • SERIAL#: The session serial number

  • PROCESS: The operating system client process ID

  • PADDR: The address of the process that owns this session

  • AUDSID: The auditing session ID

  • EVENT: The resource or event for which the session is waiting

  • P1, P2, P3: Wait event parameters

  • WAIT_TIME: This is set to:

    • -2 if TIMED_STATISTICS is set to false

    • -1 if the last wait duration was less than a hundredth of a second

    • 0 if the session is currently waiting

    • A value greater than zero, which is the duration of the last wait in hundredths of a second

  • LAST_CALL_ET: The elapsed time in seconds since the session has become active/inactive

  • SQL_ID: The identifier of the currently executed SQL statement

  • PREV_SQL_ID: The identifier of the last SQL statement executed

  • ROW_WAIT_BLOCK#: The identifier for the block containing the row specified in ROW_WAIT_ROW#

  • ROW_WAIT_ROW#: The current row being locked

  • ROW_WAIT_FILE#: The file identifier for the datafile containing the row specified in ROW_WAIT_ROW#

  • ROW_WAIT_OBJ#: The object ID for the table containing the row specified in ROW_WAIT_ROW#

See also

  • The V$SESSION_EVENT and V$SESSTAT sections in this appendix