Data Structure Question

I'm in the middle of creating a web invoicing system for my company and want to try a new approach to an old problem.

The each invoice our billing coordinators enter into our current system dumps data into two table.

The first table contains the date entered, invoice Number, Amounts paid...and like data. The second table contains line items with a fk on the incoive number. Very Simple, but the data grows fast in the second table rather rapidly.

The records, after created, printed, and mailed are rarely ever touched again.

So my question is this:

When I'm programming the interface that dumps the data into Oracle I'm thinking about creating just one table using the following structure:

invoice Number, Amounts paid... and a CLOB field that contains the line item data. (Varchar2 is not large enough.) The data that I will be dumping into this field will be stored in an XML format for easy retrieval at a later date if necessary.

Has anyone done this before, and what is the disk cost of the clob datatype? Am I going down a bad path?
We create some 70 invoices a week.

Any feedback? Received on Thu Jan 20 2005 - 14:11:13 CST