[
https://issues.apache.org/jira/browse/FLINK-25593?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17764949#comment-17764949
]
Yunhong Zheng commented on FLINK-25593:
---------------------------------------
Hi, [~luoyuxia] .Is this still in progress? If not, could you assign to me!
Thanks!
> A redundant scan could be skipped if it is an input of join and the other
> input is empty after partition prune
> --------------------------------------------------------------------------------------------------------------
>
> Key: FLINK-25593
> URL: https://issues.apache.org/jira/browse/FLINK-25593
> Project: Flink
> Issue Type: Sub-task
> Components: Table SQL / Planner
> Reporter: Jing Zhang
> Assignee: luoyuxia
> Priority: Major
>
> A redundant scan could be skipped if it is an input of join and the other
> input is empty after partition prune.
> For example:
> ltable has two partitions: pt=0 ad pt=1, rtable has one partition pt1=0.
> The schema of ltable is (lkey string, value int).
> The schema of rtable is (rkey string, value int).
> {code:sql}
> SELECT * FROM ltable, rtable WHERE pt=2 and pt1=0 and `lkey`=rkey
> {code}
> The plan is as following.
> {code:java}
> Calc(select=[lkey, value, CAST(2 AS INTEGER) AS pt, rkey, value1, CAST(0 AS
> INTEGER) AS pt1])
> +- HashJoin(joinType=[InnerJoin], where=[=(lkey, rkey)], select=[lkey, value,
> rkey, value1], build=[right])
> :- Exchange(distribution=[hash[lkey]])
> : +- TableSourceScan(table=[[hive, source_db, ltable, partitions=[],
> project=[lkey, value]]], fields=[lkey, value])
> +- Exchange(distribution=[hash[rkey]])
> +- TableSourceScan(table=[[hive, source_db, rtable,
> partitions=[{pt1=0}], project=[rkey, value1]]], fields=[rkey, value1])
> {code}
> There is no need to scan right side because the left input of join has 0
> partitions after partition prune.
--
This message was sent by Atlassian Jira
(v8.20.10#820010)
