Find missing indexes on SQL Server

MissingIndexes.sql

-- http://www.i-programmer.info/programming/database/3208-improve-sql-performance-find-your-missing-indexes.html

SET TRANSACTION ISOLATION LEVEL 
                        READ UNCOMMITTED
SELECT TOP 20
 ROUND(s.avg_total_user_cost *
       s.avg_user_impact
        * (s.user_seeks + s.user_scans),0)
                 AS [Total Cost]
 ,d.[statement] AS [Table Name]
 ,equality_columns
 ,inequality_columns
 ,included_columns
FROM sys.dm_db_missing_index_groups g
INNER JOIN sys.dm_db_missing_index_group_stats s
  ON s.group_handle = g.index_group_handle
INNER JOIN sys.dm_db_missing_index_details d
  ON d.index_handle = g.index_handle
ORDER BY [Total Cost] DESC