Abstract: In this thesis we present Voltaire, an ontological programming language designed specifically to manipulate large volumes of heterogeneous data. It is a set-oriented, imperative database programming language, yet functional in nature. The set expressions in the language are conducive to data intensive programming while maintaining a certain amount of efficiency by espousing the imperative paradigm. The language and its semantics are defined in a modular but additive fashion, which facilitates some measure of bootstrapping. We further argue that such an implementation model is desirable, since it provides a single execution model for evaluating queries, satisfying constraints and computing functions. The system provides automatic integrity enforcement in a lazy evaluation mode. Functions are effectively computed as the result of integrity enforcement. This is because we consider constraints as a sequence of commands to be evaluated or satisfied in the specified order. There are no arbitrary restrictions on the persistence of values--even functions can have a persistent extent. Further, the query language incorporates functions by providing access to the persistent extent of the function or by allowing an actual function call. The compiler can exploit traditional algebraic techniques for query optimization. The data definition (or data type) facility is similar to what might be found in most semantic data models and is conducive to sharing heterogeneous records. We have defined a type algebra that incorporates type, extent and behavior by providing an extensional semantics for the behavior. We also attempt to define a denotational semantics for the Voltaire language and environment. We believe Voltaire is an ideal language for data intensive programming, and contains the best features of a typed programming language and a database system. Dissertation Discovery Company and University of Florida are dedicated to making scholarly works more discoverable and accessible throughout the world. This dissertation, "Voltaire : a Database Programming Environment With a Single Execution" by Sunit Gala, was obtained from University of Florida and is being sold with permission from the author. A digital copy of this work may also be found in the university's institutional repository, IR@UF. The content of this dissertation has not been altered in any way. We have altered the formatting in order to facilitate the ease of printing and reading of the dissertation.