kosiew commented on code in PR #17518:
URL: https://github.com/apache/datafusion/pull/17518#discussion_r2358521191
##########
datafusion/common/src/join_type.rs:
##########
@@ -74,6 +74,12 @@ pub enum JoinType {
RightMark,
}
+const LEFT_PRESERVING: &[JoinType] =
+ &[JoinType::Left, JoinType::Full, JoinType::LeftMark];
Review Comment:
Semi and Anti joins purposely aren’t listed in LEFT_PRESERVING: they only
return the subset of left rows that either match (Semi) or don’t match (Anti),
so they don’t preserve all left input rows. The right-side analogue has the
same behaviour, which is why only the outer/mark variants appear in those
preservation tables.
--
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.
To unsubscribe, e-mail: [email protected]
For queries about this service, please contact Infrastructure at:
[email protected]
---------------------------------------------------------------------
To unsubscribe, e-mail: [email protected]
For additional commands, e-mail: [email protected]
