Mailing-List: contact dev-help@crunch.apache.org; run by ezmlm
Precedence: bulk
Reply-To: dev@crunch.apache.org
Date: Mon, 10 Jun 2013 17:18:20 +0000 (UTC)
From: "Gabriel Reid (JIRA)" <jira@apache.org>
To: crunch-dev@incubator.apache.org
Message-ID: <JIRA.12651960.1370815174344.94299.1370884700523@arcas>
In-Reply-To: <JIRA.12651960.1370815174344@arcas>
References: <JIRA.12651960.1370815174344@arcas>
Subject: [jira] [Commented] (CRUNCH-215) Add BloomFilterJoinStrategy
MIME-Version: 1.0
Content-Type: text/plain; charset=utf-8
Content-Transfer-Encoding: 7bit


    [ https://issues.apache.org/jira/browse/CRUNCH-215?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13679644#comment-13679644 ] 

Gabriel Reid commented on CRUNCH-215:
-------------------------------------

Ok, got it, thanks for the explanation. In any case, the code for the toBytes method is written now, so it should be a simple thing to move it to the PType implementation classes. It would probably also be worth having optimized versions for primitive values, instead of writing them to an Avro/Writable first to get the bytes representation. But yeah, that's for another JIRA.
                
> Add BloomFilterJoinStrategy
> ---------------------------
>
>                 Key: CRUNCH-215
>                 URL: https://issues.apache.org/jira/browse/CRUNCH-215
>             Project: Crunch
>          Issue Type: New Feature
>            Reporter: Gabriel Reid
>            Assignee: Gabriel Reid
>         Attachments: CRUNCH-215.patch
>
>
> Bloom filters can be very effective for pre-filtering one side of a join when one side of the join has a small subset of the keys of the other side (i.e. there are many keys on one side that will not be joined).
> The Bloom filter can be built up based on the keys of one side of the join (the side with fewer keys), and then can be applied as a filter to the other side of the join before it is sent through the shuffle and reduce phases.

--
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