Finding Duplicate Indexes in Large SQL Server Databases
One important component of tuning a large, heavily used database, is to ensure that the tables are indexed optimally: enough indexing, but not too much indexing for the application you are running. There are rules of thumb about index tuning, but the entire issue is so complex that there's no "silver bullet" solution that will work for every case. However, in tuning indexes we can generally say that it's not a good idea to maintain duplicate indexes on the same data. SQL Server does not provide checks to prevent duplicate indexes from being created, as long as the names are different
Image 2: 
Image 3: 
Image 4: 