Jan Lehnardt wrote:
If you query `_view/viewname`, you get the total sum of all `doc.amount`
instances.
If you are using [2008, 11, 22, 21, 01, 00] for the date you can do:
- query `_view/viewname?group_level=1` to get all amounts per year
- query `_view/viewname?group_level=2` to get all amounts per months
- etc...
This would only give you the net difference for the given time period,
not the absolute balance in the account. To get the balance for date d
you need "sum(doc.amount) where doc.date < d".
A possible compromise would be to use group_level to find the balance
per component and then add those together on the client. Example:
balance(2008-11-22) =
sum(-inf to 2007-) +
sum(2008-01- to 2008-10-) +
sum(2008-11-01 to 2008-11-22)
Or is this what you meant?
A less arbitrary grouping method could also be used like converting the
date to a second count and grouping by individual bits.
This doesn't quite meet my criteria but would at least make better use
of view indexes, assuming they work like I imagine they do. If a view
like the above existed and I updated an old transaction, there would
only be one rereduce for each group level, right?
