Explanation/Reference:
Box 1: sys.db_db_missing_index_group_stats
Box 2: group_handle
Example: The following query determines which missing indexes comprise a particular missing index group, and displays their column details. For the sake of this example, the missing index group handle is
24.
SELECT migs.group_handle, mid.*
FROM sys.dm_db_missing_index_group_stats AS migs
INNER JOIN sys.dm_db_missing_index_groups AS mig
ON (migs.group_handle = mig.index_group_handle)
INNER JOIN sys.dm_db_missing_index_details AS mid
ON (mig.index_handle = mid.index_handle)
WHERE migs.group_handle = 24;
Box 3: sys.db_db_missing_index_group_stats
The sys.db_db_missing_index_group_stats table include the required columns for the subquery:
avg_total_user_cost and avg_user_impact.
Example: Find the 10 missing indexes with the highest anticipated improvement for user queries The following query determines which 10 missing indexes would produce the highest anticipated cumulative improvement, in descending order, for user queries.
SELECT TOP 10 *
FROM sys.dm_db_missing_index_group_stats
ORDER BY avg_total_user_cost * avg_user_impact * (user_seeks + user_scans)DESC;