Im trying to design a Logical Schema for a DB Design, I expect the DB to grow to a very large size, so I need to find the best possible design.

1. An Advertisement is charged a Fee always.
2. An Event is Charged a Fee if the listing is made by a Profitable Organization.

3. A Profitable Organizations Listing is charged a Fee.
4. All Fees are Charged to Accounts.

I Have used three associative entities, Listing_Fee, Event_Fee, and Ad_Fee, is this an OK design solution, are the joins a concern. I used this setup as opposed to a single table for all three, because each row, will always omit two other columns, (int* 2) * Number of Records, This cold be a Huge Number, and large amount of redundant space.

Any Comments Appreciated.

three associative tables is okay, yes, assuming you have three many-to-many relationships

i have a hard time believing a fee is an independent entity in its own right, though

that's like having an ecommerce site which has products for sale, and setting up a Price table, so that each row is a separate price, and then setting up an association table to products...

Its not exactly its own entity, it sits as ad_fee between an advertisement and the Account. So [PKFK] AD_ID and [PKFK] Account_ID. I Was thinking I could Assign the Price too the Associative Entities, so There will be an individual record of each charge (As there will be one for each time period). Or Should I use an Invoice or Something else?

i have no idea, sorry

i don't have your understanding of the business requirements

There will be a fee charged for each of the entities, based on a time period, month or year. To charge them How would you do it, would you use a Invoice for each individual fee.

i have no idea, sorry

i don't have your understanding of the business requirements

Nate, if you could explain your application more thoroughly we might be able to help you.