A methodology for coupling fragments of XPath with structural indexes for XML documents

We introduce a new methodology for coupling language-induced partitions and index-induced partitions on XML documents that is aimed for the benefit of efficient evaluation of XPath queries. In particular, we identify XPath fragments which are ideally coupled with the newly introduced image-partition which has its definition grounded in the well-known image structural index and its associated partition. We then utilize these couplings to investigate fundamental questions about the use of structural indexes in XPath query evaluation.