refactor(query): add comments
@@ -567,6 +567,8 @@ impl PhysicalPlanBuilder {
let metadata = self.metadata.read();
let ty = metadata.column(item.index).data_type();
let name = metadata.column(item.index).name();
+
+ // sort item is already a column
let scalar = PhysicalScalar::IndexedVariable {
index: item.index,
data_type: ty.clone(),
