Maintaining indexes on your table is an important part of keeping your database healthy and its performance adequate. There are two maintenance operations for any index: rebuilding and reorganizing. Both operations were designed to get rid of index fragmentation, but differ in how this is done.

 RebuildReorganizeWhat it doesDrops the existing index and recreates it from scratch.Physically reorganizes the leaf nodes of the index.When to useIndex fragmentation >= 40%Index fragmentation >= 10% and < 40%Impact on systemHigh.

Database will be offline during process, unless you have Enterprise Edition and have enabled the ONLINE option. Online rebuild requires more resources than o  ...