Techniques are provided for automatically rewriting a relational-to-hierarchical mapping into one or more modified mappings. In this way, clients that prefer or require different portions of the mapping-defined data are supported. For example, in one aspect of the invention, a technique for modifying a relational-to-hierarchical mapping in accordance with at least one user query includes the following steps/operations. At least one query associated with a query language that supports a hierarchical data structure is obtained. Further, at least one relational-to-hierarchical mapping for use in translating data associated with a relational data structure into data associated with the hierarchical data structure is obtained. Then, the at least one relational-to-hierarchical mapping is modified based on the at least one query such that data specifically relevant to the at least one query may be generated in accordance with the modified relational-to-hierarchical mapping.