Generating code for holistic query evaluation

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.