1. Introduction In large-scale Internet applications, as the amount of data continues to grow, the single-database, single-table architecture cannot meet the needs of high concurrency and large data storage. Sub-database and sub-table is a common database architecture optimization solution, which can improve database throughput, reduce the amount of data in a single table, and improve query efficiency. However, sub-database and sub-table also bring many complex problems, such as primary key generation, paging query, distributed transaction, cross-table query, high availability, etc. This article will explain in detail the core concepts, key technologies and implementation methods of sub-database and sub-table…