Abstract

Assume that a set U of memory locations is distributed among n memory modules, using some number a of hash functions h1 ; : : : ; ha , randomly and independently drawn from a high performance universal class of hash functions. Thus each memory location has a copies. Consider the task of accessing b out of the a copies for each of given keys x1 ; : : : ; xn 2 U , b ! a. The paper presents and analyses a simple process executing the above task on distributed memory machines (DMMs) with n processors. Efficient implementations are presented, implying ffl a simulation of an n-processor PRAM on an n-processor optical crossbar DMM with delay O(log log n), ffl a simulation as above on an arbitrary-DMM with delay O( log log n log log log n ), ffl an implementation of a static dictionary on an arbitrary-DMM with parallel access time O(log n + log log n log a ), if a hash functions are used. In particular, an access time of O(log n) can be reached if (log n) 1= log n hash funct...

Citations