The performance of analytical query processing in data management systems depends primarily on the capabilities of the system's query optimizer. Increased data volumes and heightened interest in processing complex analytical queries have prompted Pivotal to build a new query optimizer.

Strong consistency is an important correctness property for replicated databases. It ensures that each transaction accesses the latest committed database state as provided in centralized databases. Achieving strong consistency in replicated databases is a major performance challenge and is typically not provided, exposing inconsistent data to client applications. We propose two scalable techniques that exploit lazy update propagation and workload information to guarantee strong consistency by delaying transaction start. We implement a prototype replicated database system and incorporate the proposed techniques for providing strong consistency. Extensive experiments using both a micro-benchmark and the TPC-W benchmark demonstrate that our proposals are viable and achieve considerable scalability while maintaining strong consistency.

We present the application of customized code generation to database query evaluation. The idea is to use a collection of highly efficient code templates and dynamically instantiate them to create query- and hardware-specific source code. The source code is compiled and dynamically linked to the database server for processing. Code generation diminishes the bloat of higher-level programming abstractions necessary for implementing generic, interpreted, SQL query engines. At the same time, the generated code is customized for the hardware it will run on. We term this approach holistic query evaluation. We present the design and development of a prototype system called HIQUE, the Holistic Integrated Query Engine, which incorporates our proposals. We undertake a detailed experimental study of the system's performance. The results show that HIQUE satisfies its design objectives, while its efficiency surpasses that of both well-established and currently-emerging query processing techniques.