Drag Drop in same table to reorder rows, Update Attribute value to make it persistent

This post is based on Frank's article on reordering table rows using drag drop functionality of ADF Faces, post uses iterator indexing to change order of rows and it works pretty good

Recently i came across a question on OTN forum asking about making this ordering persistent on base of some attribute value so for that we have to maintain a serial no attribute for each row and when user performs Drag n Drop , serial no. will be swapped and updated ordering of rows will be shown to user and it is persistent as updated attribute's value is saved in database