add physical lambda function comments

gstvg · gstvg · commit 0188d4044a9f · 2026-03-17T23:38:33.000-03:00
diff --git a/datafusion/physical-expr/src/lambda_function.rs b/datafusion/physical-expr/src/lambda_function.rs
@@ -304,6 +304,9 @@ impl PhysicalExpr for LambdaFunctionExpr {
                                 {
                                     (Arc::clone(field), Arc::clone(column))
                                 } else {
+                                    // To avoid costly copies of uncaptured columns, we swap them with a NullArray
+                                    // while keeping the number of columns on the batch the same
+                                    // so captured columns indices are kept stable across the whole tree.
                                     (
                                         Arc::new(Field::new(
                                             field.name(),

Original file line number	Diff line number	Diff line change
`@@ -304,6 +304,9 @@ impl PhysicalExpr for LambdaFunctionExpr {`
`304`	`304`	`{`
`305`	`305`	`(Arc::clone(field), Arc::clone(column))`
`306`	`306`	`} else {`
	`307`	`+ // To avoid costly copies of uncaptured columns, we swap them with a NullArray`
	`308`	`+ // while keeping the number of columns on the batch the same`
	`309`	`+ // so captured columns indices are kept stable across the whole tree.`
`307`	`310`	`(`
`308`	`311`	`Arc::new(Field::new(`
`309`	`312`	`field.name(),`