drill-issues mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Aman Sinha (JIRA)" <j...@apache.org>
Subject [jira] [Commented] (DRILL-1887) SQL Standard : NULL values are not considered equal. But drill treats them as equal
Date Thu, 18 Dec 2014 19:04:15 GMT

    [ https://issues.apache.org/jira/browse/DRILL-1887?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14252054#comment-14252054
] 

Aman Sinha commented on DRILL-1887:
-----------------------------------

It looks like an issue with hash joins.  Merge join produces the right result.  Odd that the
existing test cases don't cover this.  

> SQL Standard : NULL values are not considered equal. But drill treats them as equal
> -----------------------------------------------------------------------------------
>
>                 Key: DRILL-1887
>                 URL: https://issues.apache.org/jira/browse/DRILL-1887
>             Project: Apache Drill
>          Issue Type: Bug
>            Reporter: Rahul Challapalli
>
> git.commit.id.abbrev=9dfa4a1
> Dataset1:
> {code}
> {
>  "col1":1,
>  "col2":"abc"
> }
> {
>  "col1":2,
>  "col2":null
> }
> {code}
> Dataset 2:
> {code}
> {
>  "col1":1,
>  "col2":null
> }
> {
>  "col1":2,
>  "col2":null
> }
> {
>  "col1":2,
>  "col2":"abc"
> }
> {code}
> Query :
> {code}
> select * from `a.json` a join `b.json` b on a.col2=b.col2; 
> +------------+------------+------------+------------+
> |    col1    |    col2    |   col10    |   col20    |
> +------------+------------+------------+------------+
> | 1          | abc        | 2          | abc        |
> | 2          | null       | 1          | null       |
> | 2          | null       | 2          | null       |
> +------------+------------+------------+------------+
> {code}
> Most database engines treat 2 NULL values as not being equal. This makes it hard to compare
DRILL's results against any Standard SQL engine. However I am not sure whether drill is intentionally
designed to behave this way.



--
This message was sent by Atlassian JIRA
(v6.3.4#6332)

Mime
View raw message