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Posted to issues@tajo.apache.org by "ASF GitHub Bot (JIRA)" <ji...@apache.org> on 2014/10/14 03:33:33 UTC
[jira] [Commented] (TAJO-1112) Implement histogram interface and a
candidate histogram
[ https://issues.apache.org/jira/browse/TAJO-1112?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14170348#comment-14170348 ]
ASF GitHub Bot commented on TAJO-1112:
--------------------------------------
GitHub user mvhlong opened a pull request:
https://github.com/apache/tajo/pull/200
TAJO-1112: Implement histogram interface and a candidate histogram
Hi everyone,
This patch contains:
+ a histogram interface with utility functions, including selectivity estimation
+ 2 candidate histograms: equi-width and equi-depth
+ some unit tests for integrity and accuracy of the histograms
In the accuracy tests, given a 100k data set and a 10k random sample (10% of the data set), the estimation accuracy is about 80% - 95%, for both random data of uniform and Gaussian distributions. Histogram construction time (just consider the first construction time, without cache effect) is about 15 ms.
Please review and advice me if anything should be improved. Sincerely!
You can merge this pull request into a Git repository by running:
$ git pull https://github.com/mvhlong/tajo TAJO-1112-new
Alternatively you can review and apply these changes as the patch at:
https://github.com/apache/tajo/pull/200.patch
To close this pull request, make a commit to your master/trunk branch
with (at least) the following in the commit message:
This closes #200
----
commit 91b2cb7ab9d60020990250cd390e277f3f1d074a
Author: mvhlong <mv...@gmail.com>
Date: 2014-10-14T00:57:02Z
internal histogram support
commit f40ec9d9d330da67aba30face5bae07366bfb444
Author: mvhlong <mv...@gmail.com>
Date: 2014-10-14T01:08:01Z
fix minor bug
----
> Implement histogram interface and a candidate histogram
> -------------------------------------------------------
>
> Key: TAJO-1112
> URL: https://issues.apache.org/jira/browse/TAJO-1112
> Project: Tajo
> Issue Type: Sub-task
> Reporter: Long Mvh
> Assignee: Long Mvh
>
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