SQL Server Tuning----index missing

SELECT

Mig.index_group_handle, Mid.index_handle,

CONVERT (Decimal (28,1),

Migs.avg_total_user_cost * Migs.avg_user_impact * (Migs.user_seeks + Migs.user_scans)

) as Improvement_measure,

' CREATE index idx_ ' + object_name (object_id,database_id) + ' _missing_ ' +

Replace (replace (replace (ISNULL (Mid.equality_columns, ') + ' _ ' +

ISNULL (Mid.inequality_columns, '), ', ', ' _ '), ', '), ' [', ' '), '] ', ') +

' On [' + object_name (object_id,database_id) + '] (' + ISNULL (mid.equality_columns, ')

+ Case when Mid.equality_columns was not null and mid.inequality_columns was not null then ', ' ELSE ' END

+ ISNULL (mid.inequality_columns, ")

+ ') ' + isnull (' Include (' + included_columns + ') ', ') + ' with (Online=on) ' as Create_index_statement,

migs.*, mid.database_id, mid.[object_id]

From Sys.dm_db_missing_index_groups mig

INNER JOIN sys.dm_db_missing_index_group_stats MiGs on migs.group_handle = Mig.index_group_handle

INNER JOIN sys.dm_db_missing_index_details mid on mig.index_handle = Mid.index_handle

WHERE CONVERT (Decimal (28,1), Migs.avg_total_user_cost * migs.avg_user_impact * (Migs.user_seeks + Migs.user_scans)) ; 10

ORDER by Migs.avg_total_user_cost * Migs.avg_user_impact * (Migs.user_seeks + Migs.user_scans) DESC

SQL Server Tuning----index missing