performance tuning with em 10g

7/28/2019 Performance Tuning with EM 10g

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DBA FORUM

Performance Tuning with EM 10gOfir Manor

Technology Specialist

Oracle Corporation


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Topics

Enterprise Manager 10g

Automatic gathering of workload history (AWR)

Automatic diagnosis of performance (ADDM) Manual diagnosis of performance with EM

Further diagnosis and resolution with various

advisors

Whats New in 10g Release 2?

Questions


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Enterprise Manager 10g

New, cool web interface

No client installation works from a browser

Installed with the database Easy to use

Supports the 10g new features

Centralized version (Grid Control) VS

Standalone version (DB Control)


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Grid Control VS Database Control

Grid Control Centralized solution, manages all your servers.

Runs on a dedicated machine with centralized repository.

Install one management agent per server, to manage all

software (10g/9i db, listener, app server components) The agent should be installed before creating the database.

Drill into a specific database to manage it.

Database Control Standalone process/service to manage a single 10g instance

(no agent installation). Default URL: http:/server_name:5500/em

Local repository SYSMAN schema

Use EMCTL to manage (start/stop), if necessary.


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Grid Control VS Database Control


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Automatic Workload Repository (AWR)

Built-in feature of the database (not part of EM)

The Data Warehouse of the Database repository

of the workload history of the database.

Capture of workload information snapshots: Major extension of StatsPack

Collects a wider range of data using new 10g views

Automatic periodic snapshots (every hour by default)

Efficient, fast capture Self-manages space requirements

Workload History is saved for 7 days by default


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Automatic Workload Repository (AWR)

Typical workloads should be saved as a baseline for

future comparison Preserved Snapshots Sets

Retention period should be set to hold at least one

complete business cycle (week / month). STATISTICS_LEVEL should remain TYPICAL

Database Performance Tuning Guide 10g Release 1

Chapter 5: Automatic Performance Statistics

EM: Administration -> Automatic Workload Repository Demo


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Automatic Database Diagnostic Monitor(ADDM)

A full self-diagnostic engine built inside the database.

Runs automatically after every snapshot analyzes theworkload since the previous snapshot.

Identifies problem areas + non-problem areas. Provides performance findings and recommendation.

Aims to minimize DB time - the cumulative time spent bythe database server in processing user requests.

DB time includes wait time and CPU time of all non-idle user

sessions

The impact of the findings and recommendations are allmeasured in time (seconds) and as a percent of DB time


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Automatic Database Diagnostic Monitor(ADDM)

ADDM findings are ordered by impact (percent of DBtime or total time)

Each finding might have one or more recommendations,ordered by benefit, with an action and a rationale.

Apply recommendation button, when appropriate, orlinks to a specific advisor

Example: running SQL Tuning Advisor for a specific SQL.


Chapter 6: Automatic Performance Diagnostics EM: Home -> Diagnostic Summary -> Performance

EM: Performance -> Advisor Central

Demo


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Manual diagnosis of performance withEM the Performance tab

See what is happening now.

Uses the same data resources as AWR and ADDM.

See wait events group by class of the active sessions

and drill into the problematic class: investigate topsessions and SQLs that relate to the wait class.

Alternatively, directly investigate: Top Consumers by session, client, service etc.

Top SQL in a time window

Locks and blocking sessions

Also, can investigate the history (from the AWR)

Demo


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Advisor Central

Home of various advisors

ADDM What are the performance issues andhow to fix them.

SQL Tuning Advisor Analyze a single SQL orSQL workload, give tuning recommendations:Statistics missing? SQL Profiles?


Chapter 13: Automatic SQL Tuning SQL Access Advisor analyze a workload,

recommend to add (/drop) indexes and MVs.


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Advisor Central

Segment Advisor find candidates for onlineshrink.

Memory Advisors - PGA size (+ shared pool

and buffer cache if automatic shared memorymanagement is turned off for some reason).

MTTR Advisor see how different MTTRtarget will affect the overall IO rate.

Undo Advisor see how different undoretention time will affect undo storage space.


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Enterprise Manager General Tips

Regional Settings Set Locale to English.

Install the SVG plugin for your browser http://www.adobe.com/svg/viewer/install/main.html

Dont work on multiple tabs of EM in the same

browser (some EM operations are stateful)

Windows: Grant OS user Log on as a batch

job with the OS Local Security Policy tool.
http://www.adobe.com/svg/viewer/install/main.htmlhttp://www.adobe.com/svg/viewer/install/main.html


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Whats New in 10g Release 2?

New, Easier to Use Performance Screens

Enhanced Performance Self-Diagnostics More powerful ADDM

Current Activity Performance Analysis AWR Diff-Diff Reporting

Segment Advisor runs automatically duringmaintenance windows

SGA-attach mechanism for performance data Enables analysis of slow or hung systems


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Q U E S T I O N SANSWERS

[email protected]

performance tuning with em 10g

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