hive-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Teddy Choi (JIRA)" <j...@apache.org>
Subject [jira] [Created] (HIVE-15741) Faster unsafe byte array comparisons
Date Fri, 27 Jan 2017 01:15:24 GMT
Teddy Choi created HIVE-15741:
---------------------------------

             Summary: Faster unsafe byte array comparisons
                 Key: HIVE-15741
                 URL: https://issues.apache.org/jira/browse/HIVE-15741
             Project: Hive
          Issue Type: Improvement
            Reporter: Teddy Choi
            Assignee: Teddy Choi
            Priority: Minor


Byte array comparison is heavily used in joins and string conditions. Pure Java implementation
is simple but not performant. An implementation with Unsafe#getLong is much faster. It's already
implemented in org.apache.hadoop.io.WritableComparator#compare. The WritableComparator class
handles exceptional cases, including a different endian and no access to Unsafe, and it was
used for many years in production.

This patch will replace pure Java byte array comparisons with safe and faster unsafe ones
to get more performance.



--
This message was sent by Atlassian JIRA
(v6.3.4#6332)

Mime
View raw message