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Initial Configuration
Initial configuration implies that database attributes and parameters must be formed prior to building the desired database. However, that is not necessarily the easiest method to use.
When you use Oracle Expert to help configure a new database, you should allow the Oracle Server to create a default instance of the database and then build upon that implementation. By allowing a default database to be created, you enable Oracle Expert to acquire automatically much of the needed information regarding your database.
This chapter describes the following:
Advantages of Using Oracle Expert for Initial Configuration
When you use Oracle Expert for initial configuration tuning, Oracle Expert can provide more appropriate instance parameters for the database you are creating than the Oracle Server default instance parameters. Oracle Expert takes the following data into account before recommending instance parameters for the database you are creating:
- system data
Includes memory and CPU data, plus the operating system page size.
- Database class data
Includes the version of the database, specified options, and database user, tablespace, and public synonym data.
- control parameter values
Includes data about the type of workload (OLTP, DSS, or batch) that runs against the database, your tolerance for unscheduled downtime, and other control parameter values.
Oracle Expert analyzes all this data before providing instance parameter recommendations for a database you are creating. Oracle Expert makes better recommendations when provided with complete and accurate system, Database class, and control parameters data.
Configuring a New Database
Initial configuration allows you to start with a newly created Oracle database and quickly customize the database for your environment. As additional information about the environment becomes available, use Oracle Expert to further tune the database.
Performing Initial Configuration for a Database
Perform the following steps:
- Discover the database from the Oracle Enterprise Manager console.
- Select the database you want to tune from the Oracle Expert tree list.
- Create a new tuning session by choosing File=>Create.
- To change the default name of the tuning session, click on the default name and type in the new name.
- On the Scope page, select all the instance tuning categories. Do not select the application and structure tuning categories.
- In the Control Parameters section of the Scope page, choose the class of workload (for example, OLTP, DSS, batch) you expect to run against the database. Adjust the other control parameters according to the type of database you want.
- On the View/Edit page of the tuning session window, do the following:
- Click on the System folder. Choose Edit=>Add. For the Name attribute, type in the name of the system where the instance will run. Supply the most accurate values you can for the memory, CPU, and operating page size parameters. Click the OK button to save the values you added.
- Click on the new system icon. Choose Edit=>Modify. On the Rules page, supply the most accurate value you can for the "Default concurrent sessions" rule.
- Click on the Database object, choose Edit=>Modify and enter the values for the attributes that do not contain values.
- Click on the Instance object, choose Edit=>Modify and enter the name of the system object you just created for the instance's System attribute. Also, enter values for attributes that do not contain values. Click the OK button to save the values you added.
- On the Analyze page of the tuning session window, click the Perform Analysis button. Oracle Expert evaluates the system, instance, database, and control parameters to determine appropriate settings for the INIT.ORA file.
- On the Implement page of the tuning session window, click the Generate Files button to create the INIT.ORA file.
- Update your database's INIT.ORA file, using the entries contained in the INIT.ORA generated by Oracle Expert.
Improving the Initial Configuration of the Database
Once you have performed the initial configuration of your new database, improve on the initial configuration by performing the following steps:
- After the database is up and running, provide Oracle Expert with schema and workload data.
- Collect instance statistics while requests from a representative workload are accessing the database. The instance tuning recommendations Oracle Expert generates from the instance statistics gathered while the instance is in use will be better than the initial instance tuning recommendations.
Now that the instance has been tuned, Oracle Expert will be able to provide you with good results when you perform application tuning and structure tuning.
User-Provided Information
Providing accurate information about the following aspects of your database helps Oracle Expert generate a good initial configuration:
- default concurrent sessions (system rules)
- amount of CPU and memory available for database use (system attributes)
- hardware information, such as total memory (system attributes)
- control parameters
If you cannot provide an exact value for some of these items, you can specify a range of values using control parameters, and Oracle Expert will use this data to make initial configuration recommendations. In some cases, Oracle Expert can make initial configuration recommendations for part of your database even when you are unable to provide all the previously mentioned information.
Oracle Expert Recommendations
When you select tuning categories for the instance, application, and structure tuning types, Oracle Expert makes recommendations such as:
- initial SGA parameter settings for the instance
- how to optimize parallel query operations for the instance
- how to optimize sort operations for the instance
- how Oracle segments should be separated into different tablespaces
- the storage parameters for Oracle segments
- the columns for which an index should be created in tables
