This analysis explores the kernel-level differences in DISTINCT query optimization among several Chinese database systems. By examining actual execution plans and performance metrics, the author reveals how different architectures approach deduplication and sorting. The findings show that some databases have more sophisticated optimization logic, leading to significant performance gains. For database architects and engineers, understanding these nuances is crucial for making informed decisions about database selection and query tuning. The post also discusses the implications for real-world applications where DISTINCT operations are common.
A technical comparison of how domestic Chinese databases optimize DISTINCT queries at the kernel level.