This topic shows the results of online transaction processing (OLTP) performance tests on ApsaraDB PolarDB for MySQL 5.6.
The PolarDB MySQL 8.0 optimizer supports the followingmodes:
- Cost-Based Optimization (CBO): chooses the mostefficient way to optimize queries by creating a cost-based model base onstatistical information or samples collected in real time.
- Rule-Based Optimization (RBO): optimizes queries based on the preset rules.
The PolarDB for MySQL 8.0 optimizer uses CBO as the primary mode, and also supports RBO under some circumstances. You can run the ANALYZE command to collect the required statistical information, or allow the optimizer to automatically collect the information. The required information includes the table size, number of records, density vector, density histogram,Number of Distinct Value (NDV), and null ratio.