so we migrated Oracle 12.2 to 19c and the Asp.Net app that connects to oracle service is now failing with the following error: Oracle 12560: TNS Protocol Adapter Error
before anything, I'd like to confirm that the .net dll System.Data.OracleClient would work against Oracle 19c or are we looking at migrating forcefully to ODP.Net??
It mainly depends on the client version, not the database version.
The System.Data.OracleClient namespace does not work anymore with Oracle client 18c or newer. If your application (i.e. the client) runs on your 19cdatabase server, then it will not work anymore.
NB, the System.Data.OracleClient driver is deprecated for more than 10 years.
System.Data.OracleClient requires Oracle client software version 8.1.7 or greater. So if you use ODP.NET v.12.X, this bunch of OracleClient and ODP.NET will work with Oracle 19c. See also Connecting to Oracle19C Server using Oracle11g client
