Package org.apache.jena.sparql.algebra.optimize

Class TransformExtendCombine

  • All Implemented Interfaces:
    Transform
    public class TransformExtendCombine
extends TransformCopy
    An optimizer that aims to combine multiple extend clauses together.

    Since the semantics of extend are such that the expressions are expected to be evaluated in order we can combine extends together. This can make evaluation more efficient because all the assignments are done in a single step though depending on the underlying store this may make little or no difference.

    Note that standard algebra construction will cause much of this to happen naturally but sometimes it is useful to apply this as an additional independent transform.