[rwmj]

Maybe I'm not understanding it, but don't you keep a record of the current balance all the time? And only need to go through the transactions in order to verify the ledger invariants, which I guess would only happen fairly rarely?

[jgalt212]

I guess, but often, or often enough, you don't just need the balance now, but also then.

[accrual]

Makes sense. It seems like one would need a wrapper like "getBalance(accountName, dateTime)" which would abstract iterating over the ledger to find the balance at a certain time.

But I could see this being a performance hotspot - looping over rows and tallying a running sum across many accounts seems like a waste of cycles.

What's the alternative to the "what was the balance at date/time" in non-ledger based systems?

[em-bee]

shouldn't the balance be calculated and and compared with the actual balance after every transaction? i have an account where money went missing. the only way to find out when that happened was to have a record of the actual balance after every transaction.

[_boffin_]

Problem is solved with 4 timestamps.