You are viewing a plain text version of this content. The canonical link for it is here.
Posted to issues@spark.apache.org by "Apache Spark (JIRA)" <ji...@apache.org> on 2017/03/27 03:29:41 UTC
[jira] [Assigned] (SPARK-20104) Don't estimate IsNull or IsNotNull
predicates for non-leaf node
[ https://issues.apache.org/jira/browse/SPARK-20104?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
Apache Spark reassigned SPARK-20104:
------------------------------------
Assignee: Apache Spark
> Don't estimate IsNull or IsNotNull predicates for non-leaf node
> ---------------------------------------------------------------
>
> Key: SPARK-20104
> URL: https://issues.apache.org/jira/browse/SPARK-20104
> Project: Spark
> Issue Type: Bug
> Components: SQL
> Affects Versions: 2.2.0
> Reporter: Zhenhua Wang
> Assignee: Apache Spark
>
> In current stage, we don't have advanced statistics such as sketches or histograms. As a result, some operator can't estimate `nullCount` accurately. E.g. left outer join estimation does not accurately update `nullCount` currently. So for IsNull and IsNotNull predicates, we only estimate them when the child is a leaf node, whose `nullCount` is accurate.
--
This message was sent by Atlassian JIRA
(v6.3.15#6346)
---------------------------------------------------------------------
To unsubscribe, e-mail: issues-unsubscribe@spark.apache.org
For additional commands, e-mail: issues-help@spark.apache.org