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ORA-12538: TNS: no such protocol adapter

Oracle Database Tips by Donald Burleson

From the Oracle documentation we see this on the ORA-12538 error:

ORA-12538: TNS:no such protocol adapter
Cause: The protocol adapter requested (by way of the '(PROTOCOL=..)'; keyword-value pair in a TNS address) is unknown. If the supplied address is typographically correct then the protocol adapter is not installed.
Action: Install the protocol adapter or correct typographically error, as appropriate. Note: if the supplied address was derived from resolving the service name, check the address in the appropriate file (TNSNAMES.ORA, LISTENER.ORA or SQLNET.ORA).


If TNS_ADMIN is set then you should be able to use a network alias, not the full "(DESCRIPTION..."  connect string. The TNS_ADMIN parm tells Oracle clients where to find the tnsnames.ora file.

Setting the ORACLE_HOME environment variable incorrectly on a Windows based system will create this problem.



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