Skip to content

feat: Use NDV for equality filter selectivity calculation #20789

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

Open
jonathanc-n wants to merge 3 commits into
base: main
Choose a base branch
from
+14 −3
Open

feat: Use NDV for equality filter selectivity calculation #20789

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
3 commits
Select commit Hold shift + click to select a range
9d92657
feat: Use NDV for equality filter selectivity calculation
jonathanc-n Mar 7, 2026
8faf016
fmt clippy
jonathanc-n Mar 7, 2026
0c571c7
update
jonathanc-n Mar 7, 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
2 changes: 1 addition & 1 deletion datafusion/core/tests/custom_sources_cases/statistics.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -272,7 +272,7 @@ async fn sql_filter() -> Result<()> {

let physical_plan = df.create_physical_plan().await.unwrap();
let stats = physical_plan.partition_statistics(None)?;
assert_eq!(stats.num_rows, Precision::Inexact(1));
assert_eq!(stats.num_rows, Precision::Inexact(7));

Ok(())
}
Expand Down
15 changes: 13 additions & 2 deletions datafusion/physical-expr/src/analysis.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -167,6 +167,7 @@ pub fn analyze(
schema: &Schema,
) -> Result<AnalysisContext> {
let initial_boundaries = &context.boundaries;

if initial_boundaries
.iter()
.all(|bound| bound.interval.is_none())
Expand Down Expand Up @@ -277,8 +278,18 @@ fn calculate_selectivity(
let mut acc: f64 = 1.0;
for (initial, target) in initial_boundaries.iter().zip(target_boundaries) {
match (initial.interval.as_ref(), target.interval.as_ref()) {
(Some(initial), Some(target)) => {
acc *= cardinality_ratio(initial, target);
(Some(initial_interval), Some(target_interval)) => {
// If it is equality predicate, calculate selectivity as `1 / distinct_count`
if let Precision::Exact(distinct_count)
| Precision::Inexact(distinct_count) = target.distinct_count
&& distinct_count > 0
&& !target_interval.lower().is_null()
&& target_interval.lower() == target_interval.upper()
{
acc *= 1.0 / distinct_count as f64;
continue;
}
acc *= cardinality_ratio(initial_interval, target_interval);
}
(None, Some(_)) => {
return internal_err!(
Expand Down
Loading