hive-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Namit Jain (JIRA)" <j...@apache.org>
Subject [jira] [Created] (HIVE-3633) sort-merge join does not work with sub-queries
Date Mon, 29 Oct 2012 06:17:12 GMT
Namit Jain created HIVE-3633:
--------------------------------

             Summary: sort-merge join does not work with sub-queries
                 Key: HIVE-3633
                 URL: https://issues.apache.org/jira/browse/HIVE-3633
             Project: Hive
          Issue Type: Improvement
          Components: Query Processor
            Reporter: Namit Jain


Consider the following query:

create table smb_bucket_1(key int, value string) CLUSTERED BY (key) SORTED BY (key) INTO 6
BUCKETS STORED AS TEXTFILE;
create table smb_bucket_2(key int, value string) CLUSTERED BY (key) SORTED BY (key) INTO 6
BUCKETS STORED AS TEXTFILE;

-- load the above tables

set hive.optimize.bucketmapjoin = true;
set hive.optimize.bucketmapjoin.sortedmerge = true;
set hive.input.format = org.apache.hadoop.hive.ql.io.BucketizedHiveInputFormat;



explain
select count(*) from
(
select /*+mapjoin(a)*/ a.key as key1, b.key as key2, a.value as value1, b.value as value2
from smb_bucket_1 a join smb_bucket_2 b on a.key = b.key)
subq;


The above query does not use sort-merge join. This would be very useful as we automatically
convert the queries to use sorting and bucketing properties for join.

--
This message is automatically generated by JIRA.
If you think it was sent incorrectly, please contact your JIRA administrators
For more information on JIRA, see: http://www.atlassian.com/software/jira

Mime
View raw message