Lehrgebiet Informationssysteme

FB Informatik

LG IS

AG DBIS

(C) AG DBIS

Preserving Consistency in Nested Transactions

H. Schöning

University of Kaiserslautern
P.O. Box 3049, 67653 Kaiserslautern, Germany
e-mail: haerder@informatik.uni-kl.de

Full paper (postscript version compressed by gzip)

Abstract:

The support of advanced applications such as CAD/CAM by so- called non-standard database systems (NDBS) has emerged as an important direction in database system research. Since in these areas complex integrity constraints play an important role, NDBS have to provide a flexible mechanism in order to deal with them. For this purpose, the nested transaction concept developed for advanced applications is combined with a concept of levels of consistency. Each level of a nested transaction hierarchy is associated with a specific type of consistency, which is guaranteed at this level.

The implementation is based on the existence of a recording routing (called when consistency violations are found) and a checking routine (called at the end of a (sub-) transaction) for each type of consistency. The approach allows for tailoring the actions of both routines to the specific needs imposed by a particular type of consistency. The overall flexibility and the extensibility of the approach are illustrated by its implementation in the PRIMA project.

Published in Proc. 23rd Annual Hawaii Int. Conf. on System Sciences, Hawaii, 1990, Vol. II, pp. 472-480.