Extended Stored Procedures

An extended stored procedure is simply a procedure that is implemented in a dynamic link library (DLL) — a library that is called by an application at runtime. Extended stored procedures can be used in much the same way as database stored procedures, except that extended stored procedures normally perform tasks related to the interaction of SQL Server with its operating environment. Tasks that are either too complicated or just not possible using Transact-SQL can often be performed with extended stored procedures.

Extended stored procedures are written using the Open Data Services (ODS) API. ODS is written and supported by Microsoft and is available on the Workstation version of SQL Server and as a separate product (and in the Back-Office Development Kit). The ODS development package includes both a static-link library (Opends60.lib) and C header files that let you create fully functional database services. ODS applications are dynamically linked with Opends60.dll.