Control of a Large Massively Parallel Database Machine using SQL Catalogue Extensions and a DSDL in preference to an Operating System

Mike Unwalla, Jon Kerridge

This paper originally appeared in Advanced Database Systems: proceedings of BNCOD 10, P. M. D. Gray, R. J. Lucas (editors), 138-155, Springer-Verlag, (Lecture Notes in Computer Science 618), 1992.


The IDIOMS parallel database machine supports large applications where integrated OLTP and MIS is required. It can be considered a relational engine, and SQL is used as the MIS query language. We make some comparisons between IDIOMS and other database machines. We justify why IDIOMS does not use an operating system, and why a Data Storage Description Language (DSDL) is used to control data placement. Our implementation extends the SQL2 information schema tables. These extensions, which are described in detail, can be used by a Data Dictionary process to control resource allocation and data access. General principles behind further extensions which can be used to improve data partitioning are discussed. By means of examples, we show how our extensions support multi-column partitioning, and how, with such a partitioning strategy, MIS query access time can be reduced.