Previous works in change detection on XML focused on detecting changes to text file using ordered and unordered tree model. These approaches are not suitable for detecting changes to large XML document as it requires a lot of memory to keep the two versions of XML documents in the memory. In this paper, we take a more conservative yet novel approach of using traditional relational database engines for detecting content changes of ordered large XML data. First, we store XML documents in RDBMS. Then, we detect the changes by using a set of SQL queries. Experimental results show that our approach has better scalability, better performance, and comparable result quality compared to the state-of-the-art approaches.