Working with Unusable Indexes
The database may mark an index unusable in various situations, including when an index creation or rebuild fails midway. For example, when the table data becomes more up-to-date than the indexes on that table, SQL*Loader leaves the index in an unusable state. A direct path load may leave an index in an unusable state when any of the following occur:
- SQL*Loader fails to update the index because the index runs out of space.
- The instance fails during the building of the index.
- A unique key has duplicate values.
- An index isn't in the same order as that specified by a sorted indexes clause.
In addition to these reasons, an index can also acquire a status of UNUSABLE following various maintenance operations. For example, ...
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