2.2.3 Troubleshooting EXTPROC

Calling an OML4R embedded R function may result in an error if a database configuration problem exists.

If an attempt to call an OML4R embedded R function results in the following error, then the external procedure did not succeed:

ORA-28575: unable to open RPC connection to external procedure agent.

This error is often a database configuration problem. It may be caused by any of the following:

• The OML4R user has not been granted RQADMIN role.

• The Oracle listener configuration is incorrect, which may occur if the default external procedure configuration (which is recommended) is not being used.

• Networking layer restrictions or issues exist.

• Restrictions on external procedure calls are in force.