Validate indexes
If an index is corrupted, the database server cannot use it in queries.
You can validate indexes on each of the tables in the database by using the oncheck -cI command.
In addition, the Scheduler task bad_index_alert looks for indexes that have been marked as corrupted by the server. This task runs nightly. An entry is made into the sysadmin:ph_alert table for each corrupted index found by the task.
If an index is corrupted, drop and recreate it.