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| Oracle Enterprise Manager Oracle Expert User's Guide | Library |
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The topics in this chapter include:
The Analyze page displays the following information:
If you want Oracle Expert to provide all of the index analysis recommendations it generates during the analysis, you can change the value of the "Index summary style" rule to 1 prior to the analysis. If you do, Oracle Expert will provide all of its index analysis recommendations (not just its final index analysis recommendations) on the Review Recommendations page and in the Analysis report after the analysis is done.
For example, Oracle Expert may recommend an index be created on a particular column because of several SQL statements that access the column. However, if later in the analysis Oracle Expert determines that the relative importance of the SQL statements is not high enough to justify the new index, Oracle Expert will generate another recommendation to delete the index. As another example, Oracle Expert may recommend a new index on a column based on SQL statements that access the column. However, if Oracle Expert determines later in the analysis that the "Workload Class" control parameter is set to OLTP or BATCH (both of which are update-intensive, which means the originally recommended index would slow down performance), Oracle Expert may recommend that the index be deleted.
Note that the setting of the "Index summary style" rule determines how the index analysis recommendations are provided on the Review Recommendations page and Analysis report, but not any intermediate index recommendations which may be considered, and later ruled out, during the course of the analysis. An example would be if Oracle Expert decided that table A required an index on column B but later determined that this index was not important enough to implement.
The "Index summary style" rule can be set for database, schema, or index objects on the View/Edit page of the tuning session window. Select the object, choose Edit=>Modify, select the Rules tab, then the Index Analysis tab, and provide the desired value for the rule. For more information about changing rule values, see Rules Page on page 6-4.
For complete information about the Oracle Expert recommendations and justifications for them, choose Report=>Analysis to generate an Analysis report.
Analyzing Data Efficiently
Before performing an analysis, Oracle Expert looks at the tuning categories you have selected for the tuning session. Then, during the analysis, Oracle Expert analyzes only the collected data that it requires to generate recommendations for the selected categories. This means, for example, if you select the SGA tuning category for a tuning session, Oracle Expert excludes collected Schema or Workload class data from the analysis because Oracle Expert does not use schema or workload data when making SGA tuning recommendations. Tunable Rule
The Tunable rule is another name for the "Enable or disable tuning for the current object and its children" rule, which is a Common rule available for some of the objects that you collect during a tuning session. An object's Tunable rule value (either Enabled or Disabled) determines whether or not the object is included in an Oracle Expert analysis. If the Tunable rule is not available for an object or you do not explicitly set a value for its Tunable rule, Oracle Expert uses the value of the rule from the next higher level of the View/Edit page hierarchy where the rule is instantiated (or the default value of the rule, if none of the higher objects in the hierarchy have instantiated the rule). If you explicitly set the Tunable rule value for an object, Oracle Expert uses that value for the Tunable rule. The default value of the Tunable rule for all objects is Enabled.
As another example, suppose you select the SQL Tuning category for a tuning session because you want Oracle Expert to tune the SQL statements for two applications. To perform SQL tuning, Oracle Expert requires that Workload class data be collected for these applications. If you have previously collected workload data for other applications besides the two you are interested in tuning, the other applications can be excluded from the analysis. You can exclude an application from an analysis by setting the value of the application's Tunable rule to Disabled.
Deleting an Object
Another way to exclude an object from an analysis is to delete the object. Select the object on the View/Edit page and choose Edit=>Delete. Restrictions During an Analysis
While an analysis is in progress, you cannot:
If an analysis stops due to an unexpected error, the dialog box options and their meanings are:
During an analysis Oracle Expert performs additional validation and can discover other invalid objects. For example, Oracle Expert may find schema objects that refer to other schema objects that have not been collected. Oracle Expert considers a schema object to be invalid if it refers to another schema object for which data has not been collected.
Invalidating an Analysis
A valid analysis is one that completes without errors. If a valid analysis exists and you attempt to perform a collection or modify or delete tuning session data, Oracle Expert warns you that the operation will invalidate the analysis. You will be given a choice as to whether or not to continue with the operation. If you continue, the analysis will be marked as invalid, which means:
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