Hive 配置单元如何执行查询？

配置单元接受类似SQL的查询。在幕后，如何执行查询？它与RDBMS执行SQL查询的方式相同吗

配置单元查询处理与标准RDBMS有着显著的相似性和差异性

一些关键的相似之处：

Support for a SQL  grammar. Though not full ANSI SQL 92 it is a fair subset.
Query Parser
Query Optimizer
Execution planner

一些关键区别：

Support for HDFS loading and features
Hive specific functions such as explode, regexp_*, split
Accepting/ processing Hadoop / Cluster configuration/tuning parameters
Managing Input/Output Formats such as for HDFS, S3, Avro, etc
Creation of DAG of Map/Reduce stages/jobs
Coordination with JobTracker for Management of Map/Reduce jobs including job lifecyle: submission /monitoring /

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配置单元查询解析器/规划器的输出是Map/Reduce计划，而不是传统关系数据库中的SQL执行计划。我想知道配置单元如何执行查询？