Use the Analyze tool to view and collect statistics, validate structure and list chained rows for database structures such as tables, clusters and indexes.
Ways to open the Analyze Tool
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From DB Navigator |
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From the Explain Plan Tool |
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Select the collection method.
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Collection Method |
Description |
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Compute Statistics |
The entire object is scanned to gather data. The larger the object, the longer it takes to complete the analysis. Select this option only if the object is small. |
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Estimate Statistics |
Sample by rows or percentage of the object. The accuracy of the statistics depends on the representatives of the sampling. This option suits large objects. |
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Delete Statistics |
Delete the statistics gathered for the object. |
Use to verify the integrity of the selected object.
Select Cascade to additionally verify dependent objects. For example, if you validate the structure of a cluster and select Cascade, SQL Navigator checks all tables and indexes in the cluster.
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Note: Oracle returns an error message if it encounters corruption in the structure of an object. To fix errors: Drop and recreate the object from the commands on the Object Menu. |
Use to identify migrated or chained rows in a table or cluster. Having a high percentage of chained rows can impair application performance. UPDATE statements that cause migration and chaining perform poorly. Queries that select migrated or chained rows must perform more I/O than those that do not. For these reasons, it is important to detect and correct them. See Oracle documentation on the possible ways of fixing chained-rows problems.
