File store (was Re: Salutations)

[Al Snell]

On Mon, 11 Dec 2000, David Merrill wrote:

> So that means you would retrieve the current balance, and then work
> *backwards* from there to calculate running balances in the ledger?
> That sounds like it would work with small data sets.
> 
> 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.

(grumble) I didn't make myself clear: the point of my proposal about
transferring all the account balances to an equity account and back again
at period closing was that, to find the current balance, you'd only need
to go back to the most recent period boundary - since the initial
transaction will transfer the balance in from the equity account.

Yet because the transactions in and out of the account in the same instant
of period ending balance each other out, you can still do queries on the
entire table, across periods.

ABS

-- 
                               Alaric B. Snell
 http://www.alaric-snell.com/  http://RFC.net/  http://www.warhead.org.uk/
   Any sufficiently advanced technology can be emulated in software