Goun Na created HIVE-19283:
------------------------------
Summary: Select count(distinct()) a couple of times stuck in last
reducer
Key: HIVE-19283
URL: https://issues.apache.org/jira/browse/HIVE-19283
Project: Hive
Issue Type: Improvement
Components: CBO, Logical Optimizer
Affects Versions: 2.1.1
Reporter: Goun Na
Assignee: Ashutosh Chauhan
Distinct count query performance is significantly improved due to HIVE-10568.
{code:java}
select count(distinct elevenst_id)
from 11st.log_table
where part_dt between '20180101' and '20180131'{code}
However, some queries that contain several distinct counts are still slow. It
starts with multiple mappers, but stuck in the last one reducer.
{code:java}
select
count(distinct elevenst_id)
, count(distinct member_id)
, count(distinct user_id)
, count(distinct action_id)
, count(distinct other_id)
from 11st.log_table
where part_dt between '20180101' and '20180131'{code}
--
This message was sent by Atlassian JIRA
(v7.6.3#76005)
