Issue No. 07 - July (1985 vol. 34)
null Yang-Chang Hong , Department of Mathematics and Computer Science, University of California
Algorithms are described and analyzed for the efficient evaluation of the primitive operators of a relational algebra on a database machine architecture. The architecture contains a RAM divided up into partitions, each partition having a separate server. Tuples from the first operand relation are stored in linked lists in the partitioned RAM via bit and pointer arrays based on hashed column values. Each tuple in the second operand relation is either deposited in the corresponding partition server queue based on the hashed value, or it is ignored. Cross-referencing involved in the operations is removed without performing a sorting operation, which significantly reduces the time complexity. A procedure is also presented for computing the optimal number of partition servers for different applications.
selectivity, Bit and pointer arrays, cross-referencing, explicit joins, hashed values, implicit joins, linked lists, partitioned RAM, relational algebraic primitives
n. Yang-Chang Hong, "Efficient Computing of Relational Algebraic Primitives in a Database Machine Architecture," in IEEE Transactions on Computers, vol. 34, no. , pp. 588-595, 1985.