[jira] [Commented] (CALCITE-5193) Push filter whose conditions include join keys and are composed by OR into inputs of full join

["Benchao Li (Jira)" <ji...@apache.org>]

    [ https://issues.apache.org/jira/browse/CALCITE-5193?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17554908#comment-17554908 ] 

Benchao Li commented on CALCITE-5193:
-------------------------------------

I'm a little confused. IMO,
{code:sql}
select * from a full join b on a.id=b.id where a.id=1 or b.id=2
{code}
should be transformed to
{code:sql}
select * from 
(select * from a where id=1 or id=2) a 
full join 
(select * from b where id=1 or id=2) b
on a.id=b.id;
{code}
instead of
{code:sql}
select * from 
(select * from a where id=1) a 
full join 
(select * from b where id=2) b
on a.id=b.id;
{code}
?

> Push filter whose conditions include join keys and are composed by OR into inputs of full join
> ----------------------------------------------------------------------------------------------
>
>                 Key: CALCITE-5193
>                 URL: https://issues.apache.org/jira/browse/CALCITE-5193
>             Project: Calcite
>          Issue Type: Improvement
>            Reporter: Chunwei Lei
>            Priority: Major
>
> For example,
> {code:java}
> select * from a full join b on a.id=b.id where a.id=1 or b.id=2
> {code}
> can be transformed to 
> {code:java}
> select * from 
> (select * from a where id=1) a 
> full join 
> (select * from b where id=2) b
> on a.id=b.id;
> {code}
> If {{a}} and {{b}} are both partitioned tables and id is the partition key, we can do partition pruning with this transformation, which is a big improvement.
> This improvement is inspired by the query 
> {code:java}
> select * from a full join b on a.id=b.id and a.pt=b.pt where COALESCE(a.pt, b.pt)='20220601';
> {code}
> which costs a lot due to it scans all partitions in table {{a}} and {{b}}.



--
This message was sent by Atlassian Jira
(v8.20.7#820007)