Adaptive selection of access path and join method

An adaptive approach which utilizes the information embedded in indexes to identify the tuples satisfying a given predicate or having a match in a join operation is proposed. An access path (index or table scan) and a join method (index join, nested loop, sort-merge) are chosen to construct the results adaptively. This leads to the optimal evaluation of queries. With an efficient implementation, the adaptive decision process becomes a part of a query evaluation procedure, so that the overhead of the approach is minimized