14 Copyright © 2004, Oracle. All rights reserved. Performance Monitoring

14-2 Copyright © 2004, Oracle. All rights reserved. Objectives After completing this lesson you should be able to do the following: Troubleshoot invalid and unusable objects Gather optimizer statistics View performance metrics React to performance issues

14-3 Copyright © 2004, Oracle. All rights reserved. Performance Monitoring Memory allocation issues Memory allocation issues Input/output device contention Input/output device contention Application code problems Application code problems Resource contention Resource contention Network bottlenecks Network bottlenecks ? DBA

14-4 Copyright © 2004, Oracle. All rights reserved. Monitoring Methodologies Reactive Proactive –Server-generated alerts –Automated Database Diagnostic Monitor (ADDM)

14-5 Copyright © 2004, Oracle. All rights reserved. Database and Instance Metrics Several hundred different performance statistics are available through: Data dictionary Dynamic performance views Optimizer statistics DBA

14-6 Copyright © 2004, Oracle. All rights reserved. Database and Instance Metrics Notes Only Page

14-7 Copyright © 2004, Oracle. All rights reserved. Data Dictionary Metrics Object status: PL/SQL code objects Indexes

14-8 Copyright © 2004, Oracle. All rights reserved. Invalid and Unusable Objects PL/SQL code objects are recompiled. Indexes are rebuilt.

14-9 Copyright © 2004, Oracle. All rights reserved. Invalid and Unusable Objects Full Notes Page

14-10 Copyright © 2004, Oracle. All rights reserved. Optimizer Statistics Optimizer statistics are: Not real-time Persistent across instance restarts SQL> SELECT COUNT(*) FROM hr.employees; COUNT(*) SQL> SELECT num_rows FROM dba_tables 2 WHERE owner='HR' AND table_name = 'EMPLOYEES'; NUM_ROWS

14-11 Copyright © 2004, Oracle. All rights reserved. Optimizer Statistics Full Notes Page

14-12 Copyright © 2004, Oracle. All rights reserved. Manually Gather Optimizer Statistics If database was not created with the DBCA If tables are extremely volatile

14-13 Copyright © 2004, Oracle. All rights reserved. Automate Optimizer Statistics Collection Use the Oracle Scheduler to automate customized statistics collection.

14-14 Copyright © 2004, Oracle. All rights reserved. Schedule Optimizer Statistics Collection Statistics should be gathered as needed to ensure the optimizer can make appropriate decisions.

14-15 Copyright © 2004, Oracle. All rights reserved. Dynamic Performance Views Dynamic Performance views are: Real-time Non-persistent across instance restarts SQL> SELECT name, value FROM v$sysstat 2 WHERE name='sorts (memory)' ORDER BY name; NAME VALUE sorts (memory) SQL> / NAME VALUE sorts (memory)

14-16 Copyright © 2004, Oracle. All rights reserved. Viewing Metric Information Use the All Metrics link in the Related Links region. Drill-down for in-depth analysis.

14-17 Copyright © 2004, Oracle. All rights reserved. Reacting to Performance Issues Use Enterprise Manager to: Find key performance issues Drill down to the root cause

14-18 Copyright © 2004, Oracle. All rights reserved. Reacting to Performance Issues Drill down into performance measurements to identify bottlenecks Key bottleneck: log buffer space

14-19 Copyright © 2004, Oracle. All rights reserved. Summary In this lesson you should have learned how to: Troubleshoot invalid and unusable objects Gather optimizer statistics View performance metrics React to performance issues

14-20 Copyright © 2004, Oracle. All rights reserved. Practice 14: Monitoring Performance This practice covers the following: Viewing performance metrics Repairing unusable indexes Manually collecting optimizer statistics Automating statistics collection

14-21 Copyright © 2004, Oracle. All rights reserved. Practice Lesson 14 Full Notes Page

14-22 Copyright © 2004, Oracle. All rights reserved. Practice Lesson 14 Full Notes Page