The SQL passthrough feature enables applications to access data both in the frontend and backend data servers with a single connection. For example, SQL passthrough can be enabled in such a way that those SQL statements that cannot be executed in the solidDB^® frontend server are passed over to the backend. The SQL passthrough mode can be set per session or per transaction. By default, SQL passthrough is not enabled.

The connection between the frontend and backend is made with a backend compatible ODBC driver which is loaded dynamically in the solidDB^® server. The solidDB^® server uses this driver to execute the passthrough statements directly in the backend data server.