Symptoms
Assume that you use Microsoft SQL Server 2014. You may encounter the following issue that is related in SQL Server 2014 Release Notes:
Missing index details omit missing indexes if a hash index exists but is not suitable for the query
Issue: If you have a HASH index on columns of a memory-optimized table referenced in a query, but the index cannot be used for the query, SQL Server 2014 will not always report a missing index in SHOWPLAN_XML and in the DMV sys.dm_db_missing_index_details.
If a query contains equality predicates that involve a subset of the index key columns or if it contains inequality predicates that involve the index key columns, the HASH index cannot be used as is, and a different index would be required to execute the query efficiently.
Resolution
The issue was first fixed in the following cumulative update of SQL Server.
Cumulative Update 1 for SQL Server 2014 /en-us/help/2931693
About cumulative updates for SQL Server
Each new cumulative update for SQL Server contains all the hotfixes and all the security fixes that were included with the previous cumulative update. Check out the latest cumulative updates for SQL Server:
Status
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.