a routine that is not in the compilation unit that calls it

a routine written in C or some other external language

A routine written in a language external to the database (for example, ), whose body is stored outside the database but whose name and parameters are registered in the system catalog tables.

In REXX, a program external to the user's program, language processor, or both. These routines can be written in any language (including REXX) that supports the system-dependent interfaces used by REXX to start it.

A function written in a third-generation language (3GL), such as C, and callable from within PL/SQL or SQL as if it were a PL/SQL function or procedure.

A procedure or function called from outside the program in which the routine is defined.

A routine defined in another compilation unit.