[
https://issues.apache.org/jira/browse/HIVE-21152?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]
Zoltan Haindrich updated HIVE-21152:
------------------------------------
Attachment: HIVE-21152.02.patch
> Rewrite if expression to case and recognize simple case as an if
> ----------------------------------------------------------------
>
> Key: HIVE-21152
> URL: https://issues.apache.org/jira/browse/HIVE-21152
> Project: Hive
> Issue Type: Improvement
> Components: CBO
> Reporter: Zoltan Haindrich
> Assignee: Zoltan Haindrich
> Priority: Major
> Attachments: HIVE-21152.01.patch, HIVE-21152.02.patch
>
>
> * {{IF}} is not part of the sql standard; however given its special form its
> simpler - and currently in Hive it also has vectorized support
> * people writing standard sql may write: {{CASE WHEN member=1 THEN attr+1
> else attr+2 END}} which is essentially an if.
> The idea is to rewrite IFs to CASEs for the cbo; and recognize simple
> "CASE"-s as IFs to get vectorization on them if possible
--
This message was sent by Atlassian JIRA
(v7.6.3#76005)
