When the CML developers choose development tools and decide how to implement the logical three-tier model, they must also choose the interface by which the application will communicate with the database. The best interface to use depends on the development language and the type of application under development. The choices fall into three categories:
The CML application implements object interfaces and embedded SQL. The RDS data objects, instantiated in the VBScript of application ASP pages, use embedded SQL to query the SQL Server database. The CML components, residing in the business-services tier, do not use any embedded SQL statements, but call stored procedures in the SQL Server database. The benefits of stored procedures in the CML application are described in Stored Procedures.