The Polyhedra foreign database interface, or DBI for short, is a special Polyhedra server that does not store in RAM (as does the Polyhedra IMDB products) or in a file (which is what Polyhedra FlashLite does). Instead, the information is held in a 'foreign' database, which the DBI accesses via the ODBC driver provided for use with the foreign DBMS.
The disadvantages of this approach are obvious. They include performance, as Polyhedra has to rely on 3rd-party software to store, retrieve and update the data on its behalf. It also imposes a limit on the data types that can be supported, as they have to be supported both by Polyhedra and the foreign DBMS. However, there are various advantages, of which the main one is that it allows a Polyhedra-based application to access and update data that (for whatever reason) has to be held outside Polyhedra, and thus become part of a larger system. here are just two out of many instances where the Polyhedra DBI can be of service:
The DBI is only available on x86 platforms running Windows or Linux, and has no support for the historian or trigger code - but it emulates active queries on behalf of the client applications.