Hive加入查询的性能 [英] Hive join query for performance

问题描述

我想在表格A和B上加入A.id = B.id，如下所示：

 选择A.从A.b 
 
 
 
 
 
 
 $ / code> 

在这里，我的TABLEB由两个值GOP和LOP分隔。

我还尝试在以下方法上执行相同的查询：

  insert overwrite table final 
 select A.id，B .name from（select * from TABLEa）A 
 LEFT JOIN（select * from TABLEb where A.id = B.id;分隔IN（'GOP'）B; 
 insert INTOtable final 
选择A.id，B.name from（select * from TABLEa）A 
 LEFT JOIN（select * from TABLEb where IN（'LOP'）B on A.id = B.id; 
  

任何人都可以知道哪种方法应该更好？ b
$ b

请帮忙

解决方案

  select 
 A.id，
 B.name 
 from 
 TABLEa as A 
在分区IN（'GOP'，'LOP'）和A.id = B上，LEFT JOIN TABLEb为B .id 
  

I want to left join Table A with B on A.id=B.id like below:

select A.id,B.name from (select * from TABLEa)A 
LEFT JOIN (select * from TABLEb where partition IN ('GOP','LOP')B on A.id=B.id

here my TABLEb is partitioned by two values GOP and LOP.

I also tried to do same query on following approach:

insert overwrite table final 
select A.id,B.name from (select * from TABLEa)A 
LEFT JOIN (select * from TABLEb where partition IN ('GOP')B on A.id=B.id;
insert INTOtable final 
select A.id,B.name from (select * from TABLEa)A 
LEFT JOIN (select * from TABLEb where partition IN ('LOP')B on A.id=B.id;

Can any body tell which approach should be better? and reason or what makes second different than first one.

please help

解决方案

select
    A.id,
    B.name
from
    TABLEa as A 
    LEFT JOIN TABLEb as B on partition IN ('GOP','LOP') and A.id=B.id

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