A detailed technical article from a Chinese developer blog explores the inner workings of the KingbaseES query optimizer, a relational database management system developed by Renmin Jincang. The optimizer operates in two major phases: logical optimization using equivalence transformations based on relational algebra, and physical optimization combined with runtime condition scheduling. The logical phase rewrites the SQL query tree without changing the result, applying early filtering and join reordering. The physical phase then selects optimal execution plans based on cost estimates and runtime conditions. This deep dive is particularly valuable for database engineers and DBAs working with KingbaseES or seeking to understand optimizer internals in general. The article demonstrates how declarative SQL is translated into efficient execution strategies, a topic of evergreen relevance for performance tuning.
This article explains the internal workings of the KingbaseES query optimizer, detailing logical optimization through equivalence transformations and physical optimization with runtime condition scheduling.