hive-issues mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Teddy Choi (JIRA)" <>
Subject [jira] [Updated] (HIVE-15741) Faster unsafe byte array comparisons
Date Sat, 28 Jan 2017 11:37:25 GMT


Teddy Choi updated HIVE-15741:
    Attachment: HIVE-15741.3.patch

Fixed bugs.
- Added commons-logging dependency in storage-api
- Changed lengths of StringExpr.equal calls in AbstractFilterStringColLikeStringScalar

> Faster unsafe byte array comparisons
> ------------------------------------
>                 Key: HIVE-15741
>                 URL:
>             Project: Hive
>          Issue Type: Improvement
>            Reporter: Teddy Choi
>            Assignee: Teddy Choi
>            Priority: Minor
>         Attachments: HIVE-15741.1.patch, HIVE-15741.2.patch, HIVE-15741.3.patch
> 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 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

View raw message