Local-vs-Global Consistency of Annotated Relations

In database theory, two or more relations are considered consistent if they can be realized as projections of a single global universal relation. Similarly, in probability theory, two or more probability distributions over overlapping sets of random variables are called compatible if they arise as marginals of a single global joint distribution. In quantum theory, two or more observables of a quantum system are jointly measurable if they can be expressed as linear projections of a single global observable.