Skip to content

[parquet] Avoid a clone while resolving the read strategy #9056

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
alamb merged 3 commits into from
Jan 5, 2026
Merged

[parquet] Avoid a clone while resolving the read strategy #9056

Changes from all commits
Commits
Show all changes
3 commits
Select commit Hold shift + click to select a range
e070bdc
Avoid a clone while resolving the read plan
alamb Dec 28, 2025
fe10c50
Implement suggestions from @hhhizzz
alamb Dec 29, 2025
ef2a9a2
Merge branch 'main' into alamb/no_clone
alamb Jan 5, 2026
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
23 changes: 13 additions & 10 deletions parquet/src/arrow/arrow_reader/read_plan.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -110,19 +110,22 @@ impl ReadPlanBuilder {
None => return RowSelectionStrategy::Selectors,
};

let trimmed = selection.clone().trim();
Copy link
Contributor Author

@alamb alamb Dec 28, 2025

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

this clone shows up in the traces for some of the clickbench queries. I think this is because there are 9000 selectors for these queries

let selectors: Vec<RowSelector> = trimmed.into();
if selectors.is_empty() {
return RowSelectionStrategy::Mask;
}

let total_rows: usize = selectors.iter().map(|s| s.row_count).sum();
let selector_count = selectors.len();
if selector_count == 0 {
// total_rows: total number of rows selected / skipped
// effective_count: number of non-empty selectors
let (total_rows, effective_count) =
selection.iter().fold((0usize, 0usize), |(rows, count), s| {
if s.row_count > 0 {
(rows + s.row_count, count + 1)
} else {
(rows, count)
}
});

if effective_count == 0 {
return RowSelectionStrategy::Mask;
}

if total_rows < selector_count.saturating_mul(threshold) {
if total_rows < effective_count.saturating_mul(threshold) {
RowSelectionStrategy::Mask
} else {
RowSelectionStrategy::Selectors
Expand Down
Loading