next up previous contents
Next: Shortest Path Up: Aggregation Previous: BagReduce and BagPO

Recursive Aggregation

Aggregation interacts in an interesting way with tabling. We've already seen that we can use them both: in the scenic-path example, we needed tabling to compute the paths using left recursion. We also saw an interesting recursive application of aggregation in the salary-raising example. We continue to explore the interaction of tabling, aggregation and recursion in this section by developing a program to compute the shortest paths between nodes in a (positive) weighted graph.



 

David S. Warren
1999-07-31