These schemes have in common that they can:

• compute and current bill promptly on demand,
• cancel service (access) upon escrowed conditions.

Segment Interface

Duration

A simple scheme is to charge by the unit of time. This can be generalized by changing the rate dynamically. It can also be modulated as in turning off access during certain hours.
Access can be canceled by invoking a node key to a segment node.

Charge by some measure of reads to the data.

I don’t propose to count the loads to the segment, but clusters (in time) of accesses to a page (a cluster in space) can be counted. For a slowly changing data base we may count versions of a page so the reader is never charged twice for looking at the same version of a page.
A segment keeper is required to produce these measurements.

Delayed

Sometimes an owner of dynamic data segments his market by putting a higher price on prompt data at than delayed data. It is not clear that capability systems bring anything special to this tactic.

Data Snapshots

Virtual copies of a segment may be made. This may be added value (for data coherency) or degraded value for a reduced price.
KeyKos can provide such copies virtually so that the cost of provision is proportional to the number of pages changed in the underlying segment during the lifetime of the copy. Keykos provided a virtual snapshot in order to take a checkpoint. (2016) Snapshots may also be used to exploit these opportunities.

Size of Report

With confinement of the buyer’s program, we can price by report size. The factory logic is able to run the buyer’s code in a way that assures the data owner that the cumulative size of the reports from the buyer’s programs to the buyer is available to the seller. Again an escrowed termination condition may be established. This invites data compression games but the limits on this are well known. A crude entropy gauge could be installed to measure the effective report size.