Add / removing indices causing missing rows

[John Ewing]

I had a problem recently with Mysql 4.1.22 merge tables where a collegue did an
altereration to an indice of one of the underlying tables. The net result
was that the two tables in the union statment had the same indices but in a different order.
The first we noticed a problem was when some queries started returning odd results. Browsing the merge tables showed that certain rows which
existed in the underlying tables weren't showing up in the merge table.

Droping and recreating the indices so that all three tables had the same indice order fixed this.

My question is this.

Shouldn't the correct behavior in this situation be to throw an error when you try to access the merge table instead of silently returning erroneous results?

Thanks

J.