Constraints
Before configuring KOVAE, you are advised to understand the impact of KOVAE on the system and its constraints on applications.
Impact on the System
- For the database, after KOVAE is installed, some SQL statements that meet the conditions are offloaded to KOVAE for execution. The execution time of these SQL statements can be shortened.
- For the OS, after KOVAE is installed:
- CPU usage will increase. The extent depends on the combined impact of kovae_threadpool_size, kovae_parallel_threads, the available number of CPUs, and the number of SQL statements being executed on KOVAE.
- Memory usage will increase. The maximum memory usage when executing a single SQL statement ≈ (Total number of parallel operators related to the SQL statement + Number of operators x Data queue size) x 1,024 rows x Size of data in a single row.
The default maximum number of lines that can be batch processed is 1,024.
- The occupied drive space may increase. If the amount of data stored by the Join, Sort, Materialize, and Agg operators exceeds the specified value, data is flushed to drives and cached in the drive space. In addition, based on the configured log level, KOVAE outputs logs to the MySQL error log file or outputs logs in the background.
Application Constraints
- Currently, KOVAE adapts only to MySQL 8.0.25. Other MySQL versions are not verified.
- KOVAE performs parallel executions. If the result set is not sorted in the SQL statements, the result set may be sorted differently from that of the native MySQL result set.
- Only some SQL statements can be offloaded to KOVAE for execution. For details, see SQL Statement Specifications Supported by KOVAE. In addition, you can add hints or set cost thresholds to control the offloading conditions for SQL statements.
Parent topic: Feature Description