**Maybe he did that for a good reason, such as performances or ROI ?**.

> The best thing to do, is asking him questions. With a certain amount of "why" you will certainly make him understand he is probably wrong by itself (if he really is).

I one case myself that is not related to performances but return on investment. I have a table containing objects that have a specific value for each hour of the week (168h in a week). We had the choice to create a ObjectHour table that would contain the value, but also a key to the Object and the day number of hour number. But we also had the opportunity to put the 168 values right in the row. Probably like what your coleague did.

The developers estimated both solutions. The simple solution (168 columns) was a lot cheaper to do than its well designed counterpart. For the exact same result for the customer.

**We decided to go for the simple/cheapest solution to focus our efforts of more important stuffs such as security.** 

We will have many opportunities to improve that in the future. Time to market was the priority for us at the time.