hive subquery optimization using cluster by

Asked Sep 19 '18 at 18:52

Active Sep 19 '18 at 18:52

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I am joining two tables that are not bucketed. In the subquery, the data is clustered by join key. Does this help improving performance of the query compared joined without cluster by

select
a.user_key,b.user_key
from 
(select user_key from 
table1 
cluster by user_key) a 
left join 
(select user_key from 
table2 
cluster by user_key) b on a.user_key=b.user_key

asked Sep 19 '18 at 18:52

Naveenan

[reference](https://stackoverflow.com/questions/13715044/hive-cluster-by-vs-order-by-vs-sort-by) – samkart Sep 19 '18 at 19:39
This reference doesn't answer about the performance difference of using cluster by in a sub query – Naveenan Sep 20 '18 at 17:49

hive subquery optimization using cluster by

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