spark-issues mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Apache Spark (JIRA)" <j...@apache.org>
Subject [jira] [Assigned] (SPARK-20586) Add deterministic and distinctLike to ScalaUDF
Date Wed, 03 May 2017 22:36:04 GMT

     [ https://issues.apache.org/jira/browse/SPARK-20586?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]

Apache Spark reassigned SPARK-20586:
------------------------------------

    Assignee: Apache Spark  (was: Xiao Li)

> Add deterministic and distinctLike to ScalaUDF
> ----------------------------------------------
>
>                 Key: SPARK-20586
>                 URL: https://issues.apache.org/jira/browse/SPARK-20586
>             Project: Spark
>          Issue Type: Bug
>          Components: SQL
>    Affects Versions: 2.2.0
>            Reporter: Xiao Li
>            Assignee: Apache Spark
>
> https://hive.apache.org/javadocs/r2.0.1/api/org/apache/hadoop/hive/ql/udf/UDFType.html
> Like Hive UDFType, we should allow users to add the extra flags for ScalaUDF too. {{stateful}}/{{impliesOrder}}
are not applicable to ScalaUDF. Thus, we only add the following two flags. 
> - deterministic: Certain optimizations should not be applied if UDF is not deterministic.
Deterministic UDF returns same result each time it is invoked with a particular input. This
determinism just needs to hold within the context of a query.
> - distinctLike: A UDF is considered distinctLike if the UDF can be evaluated on just
the distinct values of a column. Examples include min and max UDFs. This information is used
by metadata-only optimizer.



--
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


Mime
View raw message