GeoMedia's Oracle data server uses OCI for database connections and this library is present in Oracle's instaclient. This means GeoMedia applications can support instaclient as long as you use the easy connect method for the host string. Easy connect is in the format:
If the listener port is the default of 1521 then you can shorten this to:
While GeoMedia works here, Database Utilities will not. Database Utilities is a VB based app that utilizes ADO, OLE, and a little ODBC, it does not use OCI. If you try to run Database Utilities with instaclient, you will get the ORA-01019 error. This is due to program requirements on missing Oracle libraries.
The easiest solution is to install the standard Oracle runtime client but if you have to use instaclient, there is a workaround.
The bottom line is that if you copy all the components required from a standard client to the runtime client, Database Utilities will run with instaclient.