Register a C UDR
The CREATE FUNCTION statement registers user-defined functions in the database. The CREATE PROCEDURE statement registers user-defined procedures in the database. These functions store information about the UDR in the sysprocedures system catalog table.
Registration for a C UDR requires the following special clauses
of the CREATE FUNCTION and CREATE PROCEDURE statements to help the
database server identify the routine:
- The required EXTERNAL NAME clause specifies the path to the shared-object file that contains the compiled C code for the UDR.
- The required LANGUAGE clause specifies the language in which the body of the UDR is written.
- The optional WITH clause specifies the routine modifiers for the UDR.
For example, the following figure shows a CREATE FUNCTION statement
that registers a user-defined function named abs_eq() whose
corresponding C function is in a shared-object file named abs.so.