How does presto collect runtime memory?

@elise_daugherty 

Presto collects runtime memory usage through various mechanisms, such as using built-in metrics and monitoring tools. It may track memory usage by individual queries, operators, or tasks, providing insights into the memory consumption patterns and potential bottlenecks. Additionally, Presto may leverage garbage collection logs, memory profiling tools, and other monitoring techniques to capture and analyze memory usage in real-time. By monitoring and analyzing runtime memory usage, Presto can optimize memory consumption, improve performance, and prevent out-of-memory errors.