Kappa was a parallel DBMS designed for knowledge information processing (KIPS). The name Kappa is an acronym for Knowledge APPlication oriented Advanced DBMS.


Kappa was developed as part of the the "Fifth Generation Computer Systems" initiative in the 1980s by Japan's Ministry of International Trade and Industry (MITI) to create computers using massively parallel computing and logic programming.

Data Model


Kappa uses a "nested relational model" that is similar to the document model in that it supported non-scalar values (e.g., arrays, nested records). It is seen as a precursor to object-relational model.

Parallel Execution

Intra-Operator (Horizontal)

Query Interface

Custom API

System Architecture