Drop a slow query index

You can drop an index for a slow query when the index isn’t used by the database or doesn’t improve query performance. You can drop the index immediately or schedule the drop for a later time.

Avant de commencer

Role required: admin

Pourquoi et quand exécuter cette tâche

During the index evaluation period, the Index Suggestion Engine (ISE) might generate a recommendation to drop the index. A recommendation to drop an index is generated in the following cases:

• The database doesn't use the index
• The index doesn't improve query execution time

Remarque :

If you want to retain an index even though the ISE generates a recommendation to drop it, you can use the Accept option in the Index Suggestion record to continue using the index. Before using this option, contact Customer Service and Support for guidance.

Procédure

1. Navigate to All > System Diagnostics > Index Suggestions > Index Suggestions > In Progress.
2. In the Index Suggestions table, select the table associated with the index suggestion you want to drop in the Table Name column.
3. In the Index Suggestion record, select Schedule Drop.
4. In the Schedule Index Drop window, select the time when you want the index dropped and select Drop.
   Remarque :

   If the index you want dropped involves large tables, such as the Incident or CMDB table, dropping the index may take up to one hour or longer.

   • Drop now —The Schedule Index Drop progress indicator window shows the progress of the index drop. When the index drop completes, select Close. If the drop is successful, the Index Suggestion record shows the index state as Dropped.
   • Drop later —When you schedule the drop, the index state changes to Drop Scheduled. When the system drops the index at the scheduled time, the index state changes to Dropped.
5. Verify that the index was dropped by reviewing the index state in the Index Suggestion record or in the Index Suggestion table (System Diagnostics > Index Suggestions > Index Suggestions > Done).