Assume that you use AlwaysOn Availability Group (AG) in Microsoft SQL Server. When you execute a query that retrieves data by using non-clustered index seek together with a clustered columnstore index on a secondary replica, the query may take much longer to complete than when it is executed on the primary replica.
Or, assume that you have a non-clustered index on a clustered columnstore index, and Snapshot Isolation level is used. When you execute a query that retrieves data by using non-clustered index seek together with clustered columnstore index key lookup, query execution may also be slow.
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.