The Index Fragmentation alarm is raised when the largest index partition on the SQL Server is more than 5% fragmented. It is a good idea to defragment large index partitions that are more than 5% fragmented.

When the alarm is raised:

  1. Open SQL Server | Databases drilldown | Fragmented Indexes.
  2. Select the index to defragment and click Fragmented Indexes | Generate defragmentation script.
  3. Use SQL Server Management Studio to schedule a job to run this script during a quiet period.