The value of RDMS for Prolog is often over-estimated, as Prolog
itself can manage substantial amounts of data. Nevertheless a
Prolog/RDMS interface provides advantages if data is already provided in
an RDMS, data must be shared with other applications, there are strong
persistency requirements or there is too much data to fit in memory.
The popularity of ODBC makes it possible to design a single
foreign-language module that provides RDMS access for a wide variety of
databases on a wide variety of platforms. The SWI-Prolog RDMS interface
is closely modeled after the ODBC API. This API is rather low-level, but
defaults and dynamic typing provided by Prolog give the user quite
simple access to RDMS, while the interface provides the best possible
performance given the RDMS independency constraint.
The Prolog community knows about various high-level connections
between RDMS and Prolog. We envision these layered on top of the ODBC
connection described here.
