The query optimizer is one of the core components of the database system. It optimizes the SQL statements that you enter, selects the optimal statement execution plans, and returns the results to the client. The optimizer is the core factor that determines whether the database performance is efficient and stable. Especially in HTAP scenarios (including complex analytical queries), the optimizer is critical to the execution efficiency of complex queries with a large amount of data involved.
This following features of the PolarDB for MySQL query optimizer are detailed in subsequent topics: