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From "Rui Li (JIRA)" <j...@apache.org>
Subject [jira] [Updated] (HIVE-5831) filter input files for bucketed tables
Date Fri, 15 Nov 2013 07:33:20 GMT

     [ https://issues.apache.org/jira/browse/HIVE-5831?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]

Rui Li updated HIVE-5831:
-------------------------

    Description: 
When the users query a bucketed table and use the bucketed column in the predicate, only the
buckets that satisfy the predicate need to be scanned, thus improving the performance.
Given a table test:
CREATE TABLE test (x INT, y STRING) CLUSTERED BY ( x ) INTO 10 BUCKETS;
The following query only has to scan bucket 5:
SELECT * FROM test WHERE x=5;

  was:
When the users query a bucketed table and use the bucketed column in the predicate, only the
buckets that satisfy the predicate need to be scanned, thus improving the performance.
Given a table test:
CREATE TABLE test (x INT, y STRING) CLUSTERED BY (x) INTO 10 BUCKETS;
The following query only has to scan bucket 5:
SELECT * FROM test WHERE x=5;


> filter input files for bucketed tables
> --------------------------------------
>
>                 Key: HIVE-5831
>                 URL: https://issues.apache.org/jira/browse/HIVE-5831
>             Project: Hive
>          Issue Type: Improvement
>          Components: Query Processor
>            Reporter: Rui Li
>
> When the users query a bucketed table and use the bucketed column in the predicate, only
the buckets that satisfy the predicate need to be scanned, thus improving the performance.
> Given a table test:
> CREATE TABLE test (x INT, y STRING) CLUSTERED BY ( x ) INTO 10 BUCKETS;
> The following query only has to scan bucket 5:
> SELECT * FROM test WHERE x=5;



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