sys.dm_db_missing_index_columns

index_handle

An integer that uniquely identifies a missing index. It can be obtained from the following dynamic management objects:

sys.dm_db_missing_index_details

sys.dm_db_missing_index_groups

Information returned by sys.dm_db_missing_index_columns is updated when a query is optimized by the query optimizer, and is not persisted. Missing index information is kept only until SQL Server is restarted. Database administrators should periodically make backup copies of the missing index information if they want to keep it after server recycling.

For information about enabling and disabling missing index information collection, see About the Missing Indexes Feature.

The output from the sys.dm_db_missing_index_columns dynamic management function can be used by any tool that can read the missing index information that corresponds to an index_handle, process the information, and convert it into CREATE INDEX DDL statements that implement the missing index. For more information about creating DDL statements, see Using Missing Index Information to Write CREATE INDEX Statements.

For more information about limitations of this feature, see Limitations for Using the Missing Indexes Feature.

Transaction Consistency

Users must be granted the VIEW SERVER STATE permission or any permission that implies the VIEW SERVER STATE permission to query this dynamic management function.

The following example runs a query against the Address table and then runs a query using the sys.dm_db_missing_index_columns dynamic management view to return the table columns that are missing an index.

USE AdventureWorks;
GO
SELECT City, StateProvinceID, PostalCode
FROM Person.Address
WHERE StateProvinceID = 9;
GO
SELECT mig.*, statement AS table_name,
    column_id, column_name, column_usage
FROM sys.dm_db_missing_index_details AS mid
CROSS APPLY sys.dm_db_missing_index_columns (mid.index_handle)
INNER JOIN sys.dm_db_missing_index_groups AS mig ON mig.index_handle = mid.index_handle
ORDER BY mig.index_group_handle, mig.index_handle, column_id;
GO

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