A new query processing strategy for relational database systems
is proposed which combines the System R strategy and the Wong-
Youssefi algorithm. It improves efficiency of query evaluation,
in particular for nested queries and complex queries (possibly
by orders of magnitude). Furthermore, it is possible (in the
future) to generalize this method to deductive database systems,
active database systems, object oriented database systems and other
extensible database systems.
This paper is to appear in Proc. of 5th Australasian Database
Conference, Christchurch, New Zealand, Jan. 94. It is available
though anonymous ftp:
under directory pub/cs/papers. The file is a postscript file named
(some figures are missing; but they can be easily constructed).
This paper may intrest implementors of relational database systems.
I very much would like to see this method implemented, tested, and
compared with traditional query evaluation strategies. Because
of resource limit, in particular, lack of funding, it is not
possible to implement this method here. Comments or collaborations
J L Han
Dept. of Math and Computing
University of Southern Queensland, Australia