presto内存配置

说明

• query.max-memory: The maximum amount of distributed memory that a query may use.
• query.max-memory-per-node: The maximum amount of user memory that a query may use on any one machine.
• query.max-total-memory-per-node: The maximum amount of user and system memory that a query may use on any one machine, where system memory is the memory used during execution by readers, writers, and network buffers, etc.

注意：

• query.max-memory:表示单个查询在分布在所有相关节点上能用的内存之和的最大值。
• query.max-memory-per-node：单个查询在单个节点上用户内存能用的最大值，从定义上就能看出：query.max-memory-per-node 必须小于query.max-total-memory-per-node
• 同样： query.max-memory 也必须小于query.max-total-memory
• 另外：query.max-total-memory-per-node 与memory.heap-headroom-per-node 之和必须小于 jvm max memory .也就是jvm.config 中配置的-Xmx

总结

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