HeatWave Release Notes
MySQL HeatWave uses a workload-aware, priority-based, automated scheduling mechanism to schedule concurrently issued queries for execution. The scheduling mechanism prioritizes short-running queries but considers wait time in the queue so that costlier queries are eventually scheduled for execution. This scheduling approach reduces query execution wait times overall.
Concurrency referred in this section is specifically for the concurrent query requests to one single MySQL server
When a MySQL HeatWave Cluster is idle, an arriving query is immediately scheduled for execution. It is not queued. A query is queued only if the MySQL HeatWave Cluster is running a preceding query.
A light-weight cost estimate is performed for each query at query compilation time.
Queries cancelled via Ctrl-C are removed from
the scheduling queue.
To view the MySQL HeatWave query history including query start time, end time, and wait time in the scheduling queue, see Section 5.10, “MySQL HeatWave Monitoring”.
MySQL 9.0.0 introduces a novel scheduler that a MySQL HeatWave Cluster uses to run multiple concurrent queries before placing further queries on the queue. The scheduler can interleave queries inside each MySQL HeatWave node within a MySQL HeatWave Cluster to achieve the following scheduling improvements:
Maximise query processing throughput.
Make the query wait time proportional to the query execution time.
If a query does raise an out of memory error, the scheduler runs the query a second time in isolation.
The scheduler can run up to 12 concurrent queries within a MySQL HeatWave Cluster. The actual number of concurrent queries depends upon the predicted memory requirements, and available memory.
The scheduler runs MySQL HeatWave AutoML, MySQL HeatWave GenAI, MySQL HeatWave Lakehouse and data load queries one at a time.
The scheduler can run multiple analytical queries if there is no more than one data load query running.
The scheduler can run multiple data load queries if there is no more than one analytical query running.
Learn more about Auto Query Plan Improvement.
Learn more about Dynamic Query Offload.