Extended Stored Procedure API
The Extended Stored Procedure application programming interface (API) is a server-
based API specific to Microsoft® SQL Server™  2000 . It can be used to produce 
extended stored procedures. An extended stored procedure is a C or C++ dynamic-
link library (DLL) that can be called from Transact-SQL using the same syntax as 
calling a Transact-SQL stored procedure. Extended stored procedures are a way to 
extend the capabilities of Transact-SQL to include any resources or services 
available to Microsoft Win32® applications.

Programming Extended Stored Procedures
Microsoft Open Data Services provides a server-based application programming 
interface (API) for extending Microsoft® SQL Server™ functionality. The API 
consists of C and C++ functions and macros used to build applications in the 
following categories: 

Extended stored procedures.

Gateway applications. 

Extended Stored Procedures
Packaged as dynamic-link libraries (DLLs), extended stored procedures provide a 
way to extend SQL Server functionality through functions developed by using 
C/C++, the Open Data Services API, and the Microsoft Win32® API. These 
functions can send result sets and output parameters back to the client from a 
variety of external data sources.

Gateway Applications
In the past, Open Data Services was used to write server applications, such as 
gateways to non-SQL Server database environments. With the emergence of 
newer and more powerful technologies, such as Windows NT Component Services 
and SQL Server distributed queries, the need for Open Data Services gateway applications has largely been replaced. 

If you have existing gateway applications, you cannot use opends60.dll and ums.dll 
that are shipped with SQL Server  2000  to run the applications. Gateway 
applications are no longer supported.

You can continue to run gateway applications using the opends60.dll and ums.dll 
that shipped with SQL Server  7 . 0 .