[
https://issues.apache.org/jira/browse/HIVE-9644?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]
Gopal V updated HIVE-9644:
--------------------------
Summary: CASE comparison operator rotation optimization (was: Constant
folding case for CASE/WHEN)
> CASE comparison operator rotation optimization
> ----------------------------------------------
>
> Key: HIVE-9644
> URL: https://issues.apache.org/jira/browse/HIVE-9644
> Project: Hive
> Issue Type: Bug
> Components: Logical Optimizer
> Affects Versions: 1.2.0
> Reporter: Gopal V
>
> Constant folding for queries don't kick in for some automatically generated
> query patterns which look like this.
> {code}
> hive> explain select count(1) from store_sales where (case ss_sold_date when
> '1998-01-01' then 1 else null end)=1;
> {code}
> This should get rewritten by pushing the equality into the case branches.
> {code}
> select count(1) from store_sales where (case ss_sold_date when '1998-01-01'
> then 1=1 else null=1 end);
> {code}
> Ending up with a simplified filter condition, resolving itself as
> {code}
> select count(1) from store_sales where ss_sold_date= '1998-01-01' ;
> {code}
--
This message was sent by Atlassian JIRA
(v6.3.4#6332)
