> the Don't Repeat Yourself principle I think this is meant mostly to apply to code. For data, redundancy is a very common strategy for assuring accuracy and d

> the Don't Repeat Yourself principle I think this is meant mostly to apply to code. For data, redundancy is a very common strategy for assuring accuracy and durability. > If you say the same thing in two different places, one of them is always going to be wrong. Yes! This is the exact point. The mismatch flags that there is an error that needs to be investigated and added to the ledger as a correcting transaction.