[Issue] Slow performance with linked tables. [Cause and Resolution] 
Cause: Some queries might be slow after upsizing for the following reasons: The application depends on functions that do not exist in SQL Server or SQL Azure. This causes Jet to pull down tables locally to run a SELECT query. Queries that update or delete many rows are sent by Jet as a parameterized query for each row. Resolution: Convert the slow-running queries to pass-through queries, stored procedures, or views. Converting to pass-through queries will have the following issues: Pass-through queries cannot be modified. Modifying the query result or adding new records must be done in an alternative way, such as by having explicit Modify or Add buttons on your form that is bound to the query. Some queries require user input, but pass-through queries do not support user input. User input can be obtained by Visual Basic for Applications (VBA) code that prompts for parameters, or by a form that is used as an input control. In both cases, the VBA code submits the query with the user input to the server.