DAP4: Proposal for an abstract Constraint specification
Jimg 14:31, 22 May 2012 (PDT) Notes from an open discussion between OPeNDAP and Unidata developers.
Constraints must support subsetting and sampling on the basic data types. These operations are keyed to the types without any domain-specific features.
The constraint language will use server-side functions to support domain-specific subsetting operations. This will enable multiple sets of these kinds of operations.
This project will define a set of subsetting functions that encapsulate the operations provided by the Common Data Model (CDM).
The functions (or named sets of functions) applicable will be named in the 'get capabilities' response for each data set, so that clients at least have a shot at knowing what will work. Given that these get capabilities responses can be rendered in HTML, people with a browser can see this information too.