9.10 执行计划(Explain)
1.基本语法 EXPLAIN [EXTENDED | DEPENDENCY | AUTHORIZATION] query 2.案例实操 (1)查看下面这条语句的执行计划
hive (default)> explain select * from emp;
hive (default)> explain select deptno, avg(sal) avg_sal from emp group by deptno;
(2)查看详细执行计划
hive (default)> explain extended select * from emp;
hive (default)> explain extended select deptno, avg(sal) avg_sal from emp group by deptno;