Problem in understanding odp mysql tables

hi
I downloaded rdf dump of dmoz.I downloaded two files "content.rdf.u8" and "structure.rdf.u8" and then i stored the data of these files to mysql databse.4 tables were created named structure,datatypes,content_links and content_description.now i want to use the Shopping Category but i am not understanding the purpose of these 4 tables and do not know how to use these 4 tables.plz some body tell me how can i use these tables.
thanks
Usman

iam facing problem in parsing rdf dump into mysql tables.please tell me how
you stored data into tables.

Thanks in advance
sudhakar