Ovid is right.

However, if you are absolutely convinced you want contact with the client (employer) in the future you will ignore him and your app will explode! The question is "when?".

If you're going to do what you're going to do, it's extra work, but be clever about it. Reduce your chances of explosion by:

1) including a "i got it! checkmark" in the detail data. When you summarize, "Chekov!" the data you included. (do you have commit/rollback? you better!)

2) Then ... run a hourly, daily, weekly, monthly or annual check on the total vs. the "checked off" detail. Chose the time period that makes sense in your case. Too often is as bad as too infrequently.

3) Run a test of your SQL sum vs. the select of the "summary". The summary is instantaneous, right? How about the sum? Under 5 secs? Listen to Ovid!

4) Watch out for your "sumarization" kicking the rest of your app in the pants. Triggers (that's what this is) cost cycles.

Good Luck! Normalization is "the law". Break it only when the reward:risk ratio is high enough. The penalty is code no one else can undestand.

Gary