多查询共享技术研究综述

Traditional database systems are built around a model of query-at-a-time, and concurrent queries in the context are executed independently. Due to the limitations of this model, traditional databases cannot optimize multiple queries at a time. Multi-query sharing technology is designed to share the common part between queries to improve the overall response time and throughput of the system. This study divides the multi-query execution mode into two categories and introduces their respective prototype systems: the multi-query prototype system based on the global query plan and on demand simultaneous pipelining. Also, the advantages of the two systems and the applicable scenarios are discussed. In the following content, the multi-query sharing technology is divided into multiple query sharing technologies in the query compilation phase and query execution phase according to the various stages of the query. There are two major types of multi-query sharing technologies. Taking these two directions as clues, the research results in various directions such as the multi-query plan representation method, multi-query expression combination, multi-query sharing algorithm, and multi-query optimization are reviewed here. On this basis, the applications of shared query technology in relational database and non-relational database are also introduced. Finally, it analyzes the opportunities and challenges faced by shared query technology.