NTT

NTT is a strongly typed, algebraic query language for PCTE. The PCTE standard defines navigational access to objects via an API (application program interface), but no set-oriented query language. NTT is the first set-oriented query language for PCTE which fulfils the widely accepted quality criteria for query languages, notably closure under the underlying data model and object preservation. Closure and object preservation are particularly important since a PCTE object base is mainly accessed by applications via an object-oriented API, and since the both properties are indispensable conditions for a view definition language.
One of NTT's key properties is that it is especially suitable for highly distributed databases that are only partly accessible. Under these conditions NTT uses sophisticated techniques to process a vague result as precise as possible.

For a brief description of the language see the NTT tutorial.
There are both an interactive frontend and a C API as well as a Java Interface for the embedded use in a host program freely available.

NTT was designed by Oliver Haase and implemented by Hendrik Lehmann
at the Research Group for Practical Computer Science of the department 12
(Electrical Engineering and Computer Science) at the University of Siegen, Germany.

Please contact the NTT administrator for any problems, questions or suggestions concerning NTT or its web pages.