i am designing a Product Search Engine like yahoo,msn,aol Shopping etc. i have a product feed from the merchant in 2 format one i have in category wise product feed and other complete of there product feed.

i have following doubt :

1. Should i make Parent Category Table Like Electronic , Clothing, etc and used category wise feeds this will be complicated as everyday category changed by the merchant and we have to refine feeds manually, or should i design one whole table and insert all the datafeed provided by merchant by this all the result will be in one table. if i do so there are million of of product and took verymuch time in Full Text Index.

2. if i make separate category wise table then how search box will work.

3. is there any best way to fast the search other then indexing , and what indexing type we use to make fast search engine.

Kindly Help me out.

Thanks in Advance

Naveen Singh