Oracle Enterprise Manager Database Tuning with the Oracle Tuning Pack
Release 9.0.1

Part Number A86647-01


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Oracle Expert Methodology

Oracle Expert performs tuning by following a designed methodology.

The topics in this chapter include:

Steps in Oracle Expert Methodology

The Oracle Expert methodology includes the following steps (see Figure 10-1).

Figure 10-1 Implementation of Oracle Expert Methodology

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  1. setting the scope of the tuning session
  2. collecting the data
  3. viewing and editing the collected data
  4. analyzing the data and generating recommendations
  5. reviewing the Oracle Expert recommendations
  6. generating scripts for implementing the recommendations

Setting the Scope of the Tuning Session

When you set the scope of a new tuning session, you are telling Oracle Expert exactly what you want to tune. You can create a focused tuning session by initially selecting one or two categories. You can also create a comprehensive tuning session by selecting all of the scopes, but this may take a considerable amount of time.

Your choices can be one or more of the following:

Collecting Data

Oracle Expert collects the following classes of data as appropriate for the specified tuning scopes:

Managing SQL History Data

Oracle Expert allows you to maintain a SQL History for your service (database). The SQL History can store SQL cache, Oracle Trace, or .XDL file data. The SQL History is shared among other Oracle Tuning Pack applications and tuning sessions. With the SQL History, the user can build up the complete set of SQL statements that are executed within the database environment and share the statements with multiple tuning sessions. By sharing the SQL history, you do not have to recollect statements for each tuning session. You can merge to the SQL history (building a complete set of SQL statements executing in the database environment) or you can replace an existing SQL History with a new one. Each service, however, can only have one SQL History at a time.

Viewing and Editing Collected Data

Once you have collected the various pieces of tuning data, you can view and edit that data. The data is organized as follows:

You have the option of editing both the attributes and the rules for this data. Attribute information is the actual data collected by the product. This data can be can be edited for "what if" tuning. You should change any dependent attributes for the evaluation to provide the best recommendations. The rules can also be changed. Rule adjustments allow you to influence Oracle Expert's evaluation process.

Generating Recommendations

Once you have collected and edited the data as needed, you can have Oracle Expert perform the analysis to generate tuning recommendations.

During the analysis, Oracle Expert evaluates the collected data in conjunction with all its rules and provides optimal performance tuning recommendations.

Reviewing Recommendations

Once Oracle Expert has analyzed the data, you can review the recommendations and decide which to accept.

For example, assume that Oracle Expert recommends that you increase the shared_pool_size parameter from 300,000 bytes to 500,000 bytes. If you choose not to use this recommendation, you can decline the recommendation and analyze the data again. Oracle Expert keeps track of the recommendations you have accepted and takes into account interdependencies among the collected data before generating new recommendations.

Implementing Recommendations

When you are ready to implement the Oracle Expert recommendations, you can use Oracle Expert to create parameter files and implementation scripts. These files and scripts allow you to implement the Oracle Expert recommendations at your convenience. These files and scripts minimize the risk of introducing any new problems during implementation, and they reduce the level of expertise required to implement the recommendations.

Inputs and Outputs

Oracle Expert takes collected input, processes this input through various rules and algorithms, and creates recommendations, tuning scripts, and reports.

Figure 10-2 Oracle Expert Inputs and Outputs

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Tuning Inputs

Oracle Expert uses the following input data to generate effective tuning recommendations:

Generated Output

With inputs such as database, instance, schema, environment, workload, and rules, Oracle Expert generates the output needed for solving database performance problems. Oracle Expert generates the following:

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