  In this demo, we present PackageBuilder, a system that extends database
systems to support package queries. A package is a collection of tuples that
individually satisfy base constraints and collectively satisfy global
constraints. The need for package support arises in a variety of scenarios: For
example, in the creation of meal plans, users are not only interested in the
nutritional content of individual meals (base constraints), but also care to
specify daily consumption limits and control the balance of the entire plan
(global constraints). We introduce PaQL, a declarative SQL-based package query
language, and the interface abstractions which allow users to interactively
specify package queries and easily navigate through their results. To
efficiently evaluate queries, the system employs pruning and heuristics, as
well as state-of-the-art constraint optimization solvers. We demonstrate
PackageBuilder by allowing attendees to interact with the system's interface,
to define PaQL queries and to observe how query evaluation is performed.
