Billing Database, where to store information

[Matt Juszczak <matt@atopia.net>]

We are creating a new billing database at our ISP.  It is going to be 
completely web based.  Would it be better to store the billing info (such 
as customer info, etc.) in the billing database backend (like mysql), and 
then just have ldap code that, everytime there is a change made, updates 
the ldap database with the information it needs?  Or should we store data 
in two different plaes, such as first name, last name, phone #, address, 
etc. is stored in ldap, while current amount due, services offered, etc. 
is stored in the mysql database backend.

I kind of like the first idea, that way the billing database updates ldap, 
instead of relying on it.  Plus, then I wouldn't have to split the primary 
source of information into two different locations.  Just want to know 
what others think...thanks!

-Matt