1. A method comprising: receiving, by a processor, a function call formatted to operate on a relational database; transforming, by the processor, the function call into a transformed function call formatted for interacting with a hierarchical data structure, wherein the hierarchical data structure comprises a plurality of nodes, wherein transforming the function call comprises: determining that the function call lacks at least one feature required for interacting with the hierarchical data structure, and modifying the function call to include the at least one feature; and applying, by the processor, the transformed function call to at least one node of the hierarchical data structure.