Unable to Configure Oracle Data Source in Websphere
Confluence can not currently use Websphere datasources to access an Oracle database.
This is because in order to effectively store pages in the database, Confluence needs access to the raw Oracle connection object, rather than the wrapper that Websphere places around it. This is a known problem. For more information, please visit the CONF-3580.
The workaround is to avoid using a Websphere datasource. Use Confluence's internal connection pool instead — choose the "Direct JDBC Connection" option during setup).