13Copyright © 2005, Oracle. All rights reserved.

Performance Management

13-2 Copyright © 2005, Oracle. All rights reserved.

Objectives

After completing this lesson, you should be able to do the following:

• Use Enterprise Manager to monitor performance

• Tune SQL by using the SQL Tuning Advisor

• Tune SQL by using the SQL Access Advisor

• Use Automatic Shared Memory Management (ASSM)

• Use the Memory Advisor to size memory buffers

• View performance-related dynamic views

• Troubleshoot invalid and unusable objects

13-3 Copyright © 2005, Oracle. All rights reserved.

Performance Monitoring

Memory allocation

issues

Memory allocation

issues

Input/outputdevice

contention

Input/outputdevice

contention

Application code

problems

Application code

problems

Resourcecontention

Resourcecontention

Network bottlenecks

Network bottlenecks

?DBA

> Perf MonTuning AdvAccess AdvMemoryStatsInvalid Obj

13-4 Copyright © 2005, Oracle. All rights reserved.

Performance Monitoring

13-5 Copyright © 2005, Oracle. All rights reserved.

Performance Monitoring

13-6 Copyright © 2005, Oracle. All rights reserved.

Performance Monitoring

13-7 Copyright © 2005, Oracle. All rights reserved.

Performance Monitoring: Top Sessions

13-8 Copyright © 2005, Oracle. All rights reserved.

Performance Monitoring: Top Services

13-9 Copyright © 2005, Oracle. All rights reserved.

SQL Tuning Advisor: Overview

Add missing index

Run access advisor

Restructure SQL

Tune SQL plan

(SQL profile)

Automatic Tuning Optimizer

SQL analysisoptimization mode

Access analysis optimization mode

Plan tuning optimization mode

Statistics checkoptimization mode Detect stale or missing

statistics

Comprehensive SQL tuning

SQL Tuning Advisor

Perf Mon> Tuning Adv

Access AdvMemoryStatsInvalid Obj

13-10 Copyright © 2005, Oracle. All rights reserved.

SQL Tuning Advisor Options and Recommendations

13-11 Copyright © 2005, Oracle. All rights reserved.

Using the SQL Tuning Advisor

• Use the SQL Tuning Advisor to analyze SQL statements and obtain performance recommendations.

• Sources for SQL Tuning Advisor to analyze– Top SQL: Analyzes the top SQL statements

currently active– SQL Tuning Sets: Analyzes a set of SQL statements

you provide– Snapshots: Analyzes a snapshot– Baselines: Analyzes a baseline

13-12 Copyright © 2005, Oracle. All rights reserved.

Using the SQL Tuning Advisor: Example

13-13 Copyright © 2005, Oracle. All rights reserved.

SQL Tuning Advisor: SQL Statistics

select count(*) from x where object_id < 340

select count(*) from x where object_id < 220

Each statement causes a hard parse.

13-14 Copyright © 2005, Oracle. All rights reserved.

SQL Tuning Advisor:Identifying Duplicate SQL

Bind variable candidates

13-15 Copyright © 2005, Oracle. All rights reserved.

Using the SQL Access AdvisorPerf MonTuning Adv

> Access AdvMemoryStatsInvalid Obj

13-17 Copyright © 2005, Oracle. All rights reserved.

Managing MemoryComponents

• Automatic Shared Memory Management:– Is recommended to simplify management– Enables you to specify the total SGA memory

through one initialization parameter– Enables the Oracle server to manage the amount of

memory allocated to the shared pool, Java pool, buffer cache, streams pool, and the large pool

• Manually setting shared memory management:– Sizes the components through multiple individual

initialization parameters– Uses the Memory Advisor to make

recommendations

Perf MonTuning AdvAccess Adv

> MemoryStatsInvalid Obj

13-18 Copyright © 2005, Oracle. All rights reserved.

Enabling Automatic SharedMemory Management (ASMM)

Click Enable to enable Automatic Shared

Memory Management.

13-20 Copyright © 2005, Oracle. All rights reserved.

Manually Setting SharedMemory Management

13-21 Copyright © 2005, Oracle. All rights reserved.

Using the Memory Advisor

13-22 Copyright © 2005, Oracle. All rights reserved.

V$SYSTEM_EVENT• event• total_waits• total_timeouts• time_waited• average_wait• time_waited_micro

Dynamic Performance Statistics

V$SYSSTAT• statistic# • name• class• value• stat_id

V$SESSION_EVENT• sid• event• total_waits• total_timeouts• time_waited• average_wait• max_wait• time_waited_micro• event_id

V$SESSTAT• sid• statistic#• value

V$SERVICE_EVENT• service_name• service_name_hash• event• event_id• total_waits• total_timeouts• time_waited• average_wait• time_waited_micro

V$SERVICE_STATS• service_name_hash• service_name• stat_id• stat_name• value

Systemwide Session specific Service specific

Cumulative stats

Wait events

…Access AdvMemory

> StatsInvalid Obj

13-24 Copyright © 2005, Oracle. All rights reserved.

Instance/DatabaseV$DATABASEV$INSTANCEV$PARAMETERV$SPPARAMETERV$SYSTEM_PARAMETERV$PROCESSV$BGPROCESSV$PX_PROCESS_SYSSTAT

V$SYSTEM_EVENT

Troubleshooting and Tuning Views

DiskV$DATAFILEV$FILESTATV$LOGV$LOG_HISTORYV$DBFILEV$TEMPFILEV$TEMPSEG_USAGEV$SEGMENT_STATISTICS

ContentionV$LOCKV$UNDOSTATV$WAITSTATV$LATCH

MemoryV$BUFFER_POOL_STATISTICSV$LIBRARYCACHEV$SGAINFOV$PGASTAT

13-25 Copyright © 2005, Oracle. All rights reserved.

Invalid and Unusable Objects

Effect on Performance:

• PL/SQL code objects are recompiled.

• Indexes are rebuilt.

Perf MonTuning AdvAccess AdvMemoryStats

> Invalid Obj

13-27 Copyright © 2005, Oracle. All rights reserved.

Summary

In this lesson, you should have learned how to:

• Use Enterprise Manager to monitor performance

• Tune SQL using the SQL Tuning Advisor

• Tune SQL using the SQL Access Advisor

• Use Automatic Shared Memory Management

• Use the Memory Advisor to size memory buffers

• View performance-related dynamic views

• Troubleshoot invalid and unusable objects

13-28 Copyright © 2005, Oracle. All rights reserved.

Practice Overview:Monitoring and Improving Performance

This practice covers the following topics:

• Detecting and repairing unusable indexes

• Using the SQL Tuning Advisor

• Using the Performance page in Enterprise Manager