I was ordered to design a database where I have some knowledge about but am not that good. Which I did ad it has 13 tables and +- 16 referential links. These tables were designed so that they could hold for the beginning 40000 records. I estimate the total size of the data not being bigger theb 100MB for the beginning. Now the person who designs the frontend in PHP says No.1 the database can not handle a query efficiently(fast) due to its complexity and that he has to restructure the whole database so it fits into only 4 tables. This will increase the size quite a lot. Now I am wondering : I heard don't know if it is true that YAHOO is usign MySQL. So I am wondering does YAHOO not have quite a large amount of record and data , and I guess they must also not have a very simplified database structure or do they ??? The question revolves around the though that I though a database is most efficient when it follows those 3 norms thingy(like I said not an expert database designer). Could anybody give me some extra info please.