1. A method of storing data, from a markup document containing a plurality of elements and a plurality of attributes in a relational database, said method comprising: storing an element record for every element of said plurality of elements in an element table of said relational database so that said relational database includes a plurality of element records, wherein each element record includes a unique element ID, and an element data set; and storing an attribute record for every attribute of said plurality of attributes in an attribute table of said relational database so that said relational database includes a plurality of attribute records, wherein said attribute record comprises an attribute data set for one attribute and an element ID of an element to which the one attribute is assigned wherein said element table and said attribute table include content of said markup document and further wherein a new markup document having a same content as said markup document can be constructed by retrieving said element data set in each of said plurality of element records stored in said element table of said relational database and by retrieving said attribute data set in each of said plurality of attribute records stored in said attribute table of said relational database.