https://groups.google.com/d/msg/web2py/UtBmAdvY7E0/QQ5rBVM4lEIJ
tables are given in that post. But, as I point out last, problem may be in conversion of file into blob and getting it back. BTW, if you can suggest a solution discussed in above link that will be great; although this problem is amusing, I'm in need for a solution.
