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Oracle Database Tips by Donald BurlesonMay 23, 2015


Question:  What is the oraclr_connection_data entry in the tnsnames.ora file?  How does it relate to the error message ORA-28575?  What does CLR stand for?


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


Answer:  One reason for the  "ORA-28575: unable to open RPC connection to external procedure agent" is not having the correct ORACLR entry in your TNSNAMES.ORA file.

See here for details on the ORA-28575 error.

By default, the Oracle Database Extensions for .NET uses CLRExtProc as the SID, and the Oracle CLR (Common Language Runtime) is installed as a part of .NET.  Oracle CLR host is installed as part of Oracle Database Extensions for .NET installation and runs in the extproc process, hence the name CLRExtProc.

You can check for ORACLR_CONNECTION_DATA in tnsnames.ora and CLRExtProc related entries in listener.ora.

To test a CLR connection, enter "tnsping ORACLR_CONNECTION_DATA" and see if it succeeds.

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