eG Monitoring
 

Measures reported by MsSqlUnusedIdxTest

One of the balancing acts of SQL Server is the use of indexes. Too few indexes can cause scans to occur which hurts performance and too many indexes causes overhead for index maintenance during data updates and also a bloated database. Administrators hence need to continuously track which indexes are used and how they are used. Unused indexes in particular can have a negative impact on performance. This is because when the underlying table data is modified, the index may need to be updated also. This takes additional time and can even increase the probability of blocking. To avoid this, administrators need to rapidly isolate the unused indexes and drop them.

The Unused Indexes test facilitates this. Using this test, administrators can quickly determine the number of unused indexes in each database, and also understand how badly that index impacts database performance.

The measures made by this test are as follows:

Measurement Description Measurement Unit Interpretation
Unused_index_count Indicates the total number of unused indexes currently found in this database. Number Use the detailed diagnosis of this measure to know which indexes in a database are unused. The detailed diagnosis also reveals how often each such index has been updated, so that you can assess the unnecessary overheads that the database may have incurred in the process.