hive 底层模块实现-group by

准备数据 SELECT uid, SUM(COUNT) FROM logs GROUP BY uid; hive> SELECT * FROM logs; a 苹果 5 a 橙子 3 a 苹果 2 b 烧鸡 1 hive> SELECT uid, SUM(COUNT) FROM logs GROUP BY uid; a 10 b 1 计算过程 默认设置了h

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