
Chapter
13:
A
Superjoin
Algorithm
for
Deductive
Databases
541
(7)
XPreds = [[Χ, Y, Χ], [Y, X, Z] ] % note repeated
variable
NBits = [[3, 1, 4], [2, 3, 5]]
Sfb = [XI, X2, X3, Yl, Y2, Zl, Z2, Z3, Z4, Z5]
Cost = 3
References
1.
Aho, Α. V. and Ullman, J. D. [1979] Optimal Partial-Match Retrieval When
Fields Are Independently Specified, ACM Transactions on Database Systems
4(2):168-179.
2.
Balbin, I. and Ramamohanarao, K. [1986] A Differential Approach to Query Op-
timisation in Recursive Deductive Databases, Technical Report 86/7, Department
of Computer Science, University of Melbourne.
3.
Bancilhon, F., Maier, D., Sagiv, Y., and Ullman, J. D. [1985 ...