Extended Stored Procedures

If you use the as external name syntax, create procedure registers an extended stored procedure (ESP). Extended stored procedures execute procedural language functions rather than Transact-SQL commands.

(Windows) An ESP function should not call a C runtime signal routine. This can cause XP Server to fail, because Open Serverâ„¢ does not support signal handling on Windows NT.

To support multithreading, ESP functions should use the Open Server srv_yield function, which suspends and reschedules the XP Server thread to allow another thread of the same or higher priority to execute.

The DLL search mechanism is platform-dependent. On Windows NT, the sequence of a DLL file name search:
  1. The directory from which the application is loaded

  2. The current directory

  3. The system directory (SYSTEM32)

  4. Directories listed in the PATH environment variable

If the DLL is not in the first three directories, set the PATH to include the directory in which it is located.

On UNIX platforms, the search method varies with the particular platform. If it fails to find the DLL or shared library, it searches $SYBASE/lib.

Absolute path names are not supported.