File store (was Re: Salutations)

[Derek Atkins]

David Merrill <dmerrill@lupercalia.net> writes:

> One problem, though. Say the user 
> jumps to a date in their ledger that is 11 months ago. How do you know
> the balance after a given transaction back then, without having to
> load the intervening transactions? In an environment with, say, 10,000
> transactions per month, you just can't require the system to go
> through them to come up with balances. The running balance just about
> *has* to be stored along with the transactions somehow.

I would basically have periodic checkpoints, maybe weekly, probably
monthly, and definitely yearly.  Then you just work forwards or
backwards from the most convenient checkpoint.  Obviously, if you
change a transaction you have to modify all checkpoints after that
point?

-derek

-- 
       Derek Atkins, SB '93 MIT EE, SM '95 MIT Media Laboratory
       Member, MIT Student Information Processing Board  (SIPB)
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