[
https://issues.apache.org/jira/browse/TAJO-838?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14255026#comment-14255026
]
ASF GitHub Bot commented on TAJO-838:
-------------------------------------
Github user jihoonson commented on the pull request:
https://github.com/apache/tajo/pull/231#issuecomment-67758735
@hyunsik, thanks for your review.
For your convenience, I would like to share my test environment.
First of all, you need to delete the catalog database because the schema of
the index table is changed.
Please back up your catalog before deletion.
When you create an index successfully, please don't forget to configure the
session variable. You must set INDEX_ENABLED as true to enable the index scan
feature.
If you have any questions, please feel free to ask me.
Thanks!
> Improve query planner to utilize index
> --------------------------------------
>
> Key: TAJO-838
> URL: https://issues.apache.org/jira/browse/TAJO-838
> Project: Tajo
> Issue Type: Sub-task
> Components: planner/optimizer
> Reporter: Jihoon Son
> Assignee: Jihoon Son
> Priority: Minor
>
> Index can improve the query performance when the selectivity of query is high.
> Thus, query planner should decide whether index is used or not for a given
> query.
> The selectivity can be guessed using statistics.
--
This message was sent by Atlassian JIRA
(v6.3.4#6332)
