fix: don't unifies projection if expr is non-trival #8454
Merged
Conversation
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
github-actions
bot
added
core
alamb
approved these changes
Dec 7, 2023
There was a problem hiding this comment.
Thank you for the contribution @haohuaijin . This change makes sense to me
cc @mustafasrepo and @Dandandan
| let mut column_ref_map: HashMap<Column, usize> = HashMap::new(); | ||
|
|
||
| // Collect the column references usage in the outer projection. | ||
| projection.expr().iter().for_each(|(expr, _)| { |
There was a problem hiding this comment.
I may be mistaken and it may not matter, but I think this will prevent pushing down exprs that refer to the same column more than once
Projection exprs=[b as c, b as d]
Projection exprs = [a as b]
Into
Projection exprs=[a as c, a as d]
There was a problem hiding this comment.
We don't prevent Column and Literal push_down. We prevent other express push_down, used to prevent multiple evaluation of the same expression.
if column_ref_map.iter().any(|(column, count)| {
*count > 1 && !is_expr_trivial(&child.expr()[column.index()].0.clone())
}) {
return Ok(None);
}
mustafasrepo
approved these changes
Dec 8, 2023
Weijun-H
reviewed
Dec 8, 2023
Co-authored-by: Alex Huang <huangweijun1001@gmail.com>
|
Thank you @haohuaijin,. @Weijun-H and @mustafasrepo |
appletreeisyellow
pushed a commit
to appletreeisyellow/datafusion
that referenced
this pull request
Dec 15, 2023
* fix: don't unifies projection if expr is non-trival * Update datafusion/core/src/physical_optimizer/projection_pushdown.rs Co-authored-by: Alex Huang <huangweijun1001@gmail.com> --------- Co-authored-by: Alex Huang <huangweijun1001@gmail.com>
5 tasks
# for free
to join this conversation on GitHub.
Already have an account?
# to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
Which issue does this PR close?
Closes #8453
Rationale for this change
What changes are included in this PR?
don't unifies projection if the expression in non-trival. see discussion in #8296
Are these changes tested?
Are there any user-facing changes?
add physical plan check in
.slttest