Declarative Algorithms in Datalog with Extrema: Their Formal Semantics Simplified

Recent advances are making possible the use of aggregates in recursive queries thus enabling the declarative expression classic algorithms and their efficient and scalable implementation. These advances rely the notion of Pre-Mappability (PreM) of constraints that, along with the seminaive-fixpoint operational semantics, guarantees formal non-monotonic semantics for recursive programs with min and max constraints. In this extended abstract, we introduce basic templates to simplify and automate task of proving PreM

A Declarative Language for Advanced Analytics and its Scalable Implementation

Advanced analytics are used to discover hidden patterns and trends in massive datasets. Great strides have been made by researchers to provide computational models, systems and accompanying languages for analytics. However, there is still a dire need for highly expressive declarative languages that enable the compilation, optimization and evaluation of advanced analytics over massive datasets. Specifically, a language for analytics needs (i) to support the expression of analytics over multiple data models (ii) to provide high-level declarative constructs enabling system optimizations, and (iii) be conducive for iterative or recursive evaluation.In this dissertation, we propose an expressive Datalog language for advanced analytics, and compilation and optimization techniques for its efficient evaluation on systems designed for iterative execution. Specifically, this dissertation makes two main contributions:(i) We develop and demonstrate a next generation Datalog System - the Deductive Application Language System (DeALS). To extend the range of analytics supported in DeALS, we add support for aggregation in recursion into our logic-based language. We propose the design and implementation of several monotonic aggregates that can be used in recursive Datalog rules and evaluated efficiently using our novel optimization techniques. We demonstrate the effectiveness of these aggregates and conduct an experimental comparison with other Datalog systems and determine that DeALS combines superior generality with superior performance.(ii) We design and implement BigDatalog, a Datalog system on Apache Spark, for large-scale advanced analytics. We implement BigDatalog for efficient distributed evaluation and to utilize communication-reduction techniques during evaluation. We propose compilation and optimization techniques, as well as job scheduling techniques, to support efficiently the evaluation of DeAL programs on Spark. We conduct an experimental comparison with other state-of-the-art large-scale Datalog systems and demonstrate the efficacy of our techniques and effectiveness of our Spark extensions in supporting Datalog-based analytics

Graph Queries in a Next-Generation Datalog System

Recent theoretical advances have enabled the use of special monotonic aggregates in recursion. These special aggregates make possible the concise expression and efficient implementation of a rich new set of advanced applications. Among these applications, graph queries are particularly important because of their pervasiveness in data intensive application areas. In this demonstration, we present our Deductive Application Language (DeAL) System, the first of a new generation of Deductive Database Systems that support applications that could not be expressed using regular stratification, or could be expressed using XY-stratification (also supported in DeAL) but suffer from inefficient execution. Using example queries, we will (i) show how complex graph queries can be concisely expressed using DeAL and (ii) illustrate the formal semantics and efficient implementation of these powerful new monotonic constructs. 1