Benchmarking queries over trees: learning the hard truth the hard way

Search queries have evolved beyond keyword queries. Many complex queries such as verbose queries, natural language question queries and document-based queries are widely used in a variety of applications. Processing these complex queries usually ...

We study the complexity and expressive power of conjunctive queries over unranked labeled trees represented using a variety of structure relations such as “child”, “descendant”, and “following” as well as unary relations for node labels. We establish a ...

We study the complexity and expressive power of conjunctive queries over unranked labeled trees, where the tree structure are represented using "axis relations" such as "child", "descendant", and "following" (we consider a superset of the XPath axes) as ...