flink-issues mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From ChengXiangLi <...@git.apache.org>
Subject [GitHub] flink pull request: [FLINK-2549] add topK operator to DataSet.
Date Tue, 22 Sep 2015 09:04:44 GMT
GitHub user ChengXiangLi opened a pull request:


    [FLINK-2549] add topK operator to DataSet.

    The topK operator is implemented with `mapPartition()` followed by `reduceGroup()`, each
map tasks select top k elements, and transfer to singleton reduce task(no `group()` before
`reduceGroup()`), and then select top k elements in reduce task. 
    The main part of this implementation:
    1. An out-of-core self managed memory based PriorityQueue implementation.
    2.  Use runtime resources to build PriorityQueue for UDF. topK is not real 'native' operator
actually, it contains UDF which use self managed memory based PriorityQueue to select top
k elements.

You can merge this pull request into a Git repository by running:

    $ git pull https://github.com/ChengXiangLi/flink priorityqueue

Alternatively you can review and apply these changes as the patch at:


To close this pull request, make a commit to your master/trunk branch
with (at least) the following in the commit message:

    This closes #1161
commit 7165d5ba78376cec1b3c752afb949e6273d45869
Author: chengxiang li <chengxiang.li@intel.com>
Date:   2015-09-16T02:10:05Z

    [FLINK-2549] add topK operator to DataSet.


If your project is set up for it, you can reply to this email and have your
reply appear on GitHub as well. If your project does not have this feature
enabled and wishes so, or if the feature is enabled but not working, please
contact infrastructure at infrastructure@apache.org or file a JIRA ticket
with INFRA.

View raw message