Hardware device to assist adaptive reordering of sequential decisions.

摘要

A system for the adaptive reordering of sequential decisions in the search of a data base is provided with a device (Fig.3) that simplifies and speeds up a heuristic search method by implementing in hardware the computation required for the adaptive reordering. The system includes an arithmetic unit (Fig.3) for computing for each decision the ratio p/c where p is the probability of a successful outcome (12) of the decision and c is the cost of computation to make that decision. The arithmetic unit includes a device (51-54) for estimating the logarithms of the probability p and the cost c for each decision. Logarithms of ratios p/c are calculated for each decision by subtracting (55,56) the log c from the log p, and then the logarithms of the ratios for the decisions are compared (57) to produce a priority value for each decision. The decisions are reordered based on the priority value (24) assigned to each decision to obtain the optimal ordering of the decisions.