Selective indexing speeds production systems

Presents performance results for a production system environment, CLIPS++, that demonstrate the advantage of selectively building and applying simple index structures. We contrast this to the extensive body of work on matching, which, over the years, has evolved increasingly complex compositions of index structures which are then uniformly applied to all the data types and rules in a production system program. Over a set of benchmark programs, the fastest executions are always attained by carefully selecting a good mixture of indexes rather than universal use of a single index.