Exemplary embodiments involve a processor receiving a function call formatted to interact with a relational database. The function call references an object in the relational database by referencing at least one table of the relational database and at least one column of the at least one table. The processor transforms the function call into a transformed function call formatted for interacting with a hierarchical data structure. The hierarchical data structure comprises a plurality of nodes, wherein each node has a single parent node. The processor applies the transformed function call to one or more nodes of the hierarchical data structure.