[jira] [Commented] (CALCITE-3890) Infer IS NOT NULL predicate from join

["Julian Hyde (Jira)" <ji...@apache.org>]

    [ https://issues.apache.org/jira/browse/CALCITE-3890?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17072391#comment-17072391 ] 

Julian Hyde commented on CALCITE-3890:
--------------------------------------

I agree. And we can also push down filters: ‘id is not null’ to both inputs, in this case. 

Hopefully we can use existing logic, e.g. {{class Strong}}, for this deduction. 

> Infer IS NOT NULL predicate from join
> -------------------------------------
>
>                 Key: CALCITE-3890
>                 URL: https://issues.apache.org/jira/browse/CALCITE-3890
>             Project: Calcite
>          Issue Type: Improvement
>          Components: core
>            Reporter: Chunwei Lei
>            Priority: Major
>
> We can infer IS NOT NULL predicate from join which implies some columns may not be null. For instance, 
>  
> {code:java}
> select * from a join b on a.id = b.id;
> {code}
> we can infer a.id is not null and b.id is not null.



--
This message was sent by Atlassian Jira
(v8.3.4#803005)