1. An method to access an object representation of a data set, comprising: requesting a markup representation of the data set at a relational data store, the data set having a first portion stored at a first table structure of the relational data store and a second portion stored at a second table structure of the relational data store; receiving from the relational data store the markup representation of the data set; and generating the object representation of the data set based on the markup representation of the data set, the object representation of the data set including a first element having a value of the first portion and a second element having a value of the second portion.