Scheduling is crucial in computer system design. The right policy can significantly reduce mean response time without needing faster machines, effectively improving performance for free. Scheduling also optimizes other metrics, such as user fairness and differentiated service levels, ensuring some job classes have lower mean delays than others [1].

MySQL 8.0 uses the Contention-Aware Transaction Scheduling (CATS) algorithm to prioritize transactions waiting for locks. When multiple transactions compete for the same lock, CATS determines the priority based on scheduling weight, calculated by the number of transactions a given transaction blocks. The transaction blocking the most others gets higher priority; if weights are equal, the longest waiting transaction goes first.