The documentation portal is undergoing maintenance. During this period, you can't create any new user credentials. If you do, you'll need to recreate the user credential after the maintenance period ends.
For native connectivity, install the version of Oracle client appropriate for the Oracle database server version. To ensure compatibility between Informatica and databases, use the appropriate database client libraries.
You must install compatible versions of the Oracle client and Oracle database server. You must also install the same version of the Oracle client on all machines that require it. To verify compatibility, contact Oracle.