ZODB.Use Case Model.Accounting and Quotas

Documentation

In some cases, it is necessary to track usage by "customers" and to impose "quotas".

Option 1

We could define an "account" field on a transaction to record
some sort of "customer" identity for tracking an quota purposes.

Maybe there are ways to define sub-accounts.

If a storage supports accounting, then it records accounting
information and provides for retrieval of such information.

If a storage supports quotas, then it checks to see that an account
quota would not be exceeded by commiting a transaction. Obviously,
sub-accounts complicate this somewhat.