Mutual credit accounting is very easy because you just store all the transactions in one table with
- a payer
- a payee
- a quantity
, and then add up all the transactions per user to get the balances. However once a mutual credit system gets larger, it becomes expensive to add up all these transactions. So a caching strategy is needed.
The easiest and most obvious caching is on the member balances. But there are two other main needs: