A keyword that associates an operating system user to the database user who invokes the external routine.
If you specify INVOKER, then database_name or user_name must be the logon database or user for the user.
You can assign only one INVOKER authorization name per database.
You can specify either a DEFINER or an INVOKER, but not both.
Example: Creating an INVOKER Authorization
This example creates an INVOKER authorization object with the name sales for the user name sam johnson and the user password tercesym.
CREATE AUTHORIZATION sales AS INVOKER USER 'sam johnson' PASSWORD 'tercesym';
The system uses this OS platform user context to execute all external routines that contain an EXTERNAL SECURITY INVOKER clause when invoked by the database user that created this authorization.