Pre-compute the interesting orderings

datafusion/physical-expr/src/equivalence/ordering.rs

@@ -102,7 +102,6 @@ impl OrderingEquivalenceClass {
 
     /// Extend this ordering equivalence class with the `other` class.
     #[deprecated(since = "45.0.0", note = "Use add_new_orderings instead")]
-
     pub fn extend(&mut self, other: Self) {
         self.orderings.extend(other.orderings);
         // Make sure that there are no redundant orderings:

datafusion/physical-expr/src/equivalence/properties.rs

@@ -128,6 +128,8 @@ pub struct EquivalenceProperties {
     eq_group: EquivalenceGroup,
     /// Equivalent sort expressions
     oeq_class: OrderingEquivalenceClass,
+    /// Normalized sort expressions (where eq_group and constants are applied to oeq_class)
+    normalized_oeq_class: OrderingEquivalenceClass,
     /// Expressions whose values are constant
     ///
     /// TODO: We do not need to track constants separately, they can be tracked
@@ -143,6 +145,7 @@ impl EquivalenceProperties {
         Self {
             eq_group: EquivalenceGroup::empty(),
             oeq_class: OrderingEquivalenceClass::empty(),
+            normalized_oeq_class: OrderingEquivalenceClass::empty(),
             constants: vec![],
             schema,
         }
@@ -153,6 +156,7 @@ impl EquivalenceProperties {
         Self {
             eq_group: EquivalenceGroup::empty(),
             oeq_class: OrderingEquivalenceClass::new(orderings.to_vec()),
+            normalized_oeq_class: OrderingEquivalenceClass::empty(),
             constants: vec![],
             schema,
         }
@@ -168,6 +172,11 @@ impl EquivalenceProperties {
         &self.oeq_class
     }
 
+    /// Returns a reference to the normalized ordering equivalence class within.
+    pub fn normalized_oeq_class(&self) -> &OrderingEquivalenceClass {
+        &self.normalized_oeq_class
+    }
+
     /// Return the inner OrderingEquivalenceClass, consuming self
     pub fn into_oeq_class(self) -> OrderingEquivalenceClass {
         self.oeq_class
@@ -194,18 +203,23 @@ impl EquivalenceProperties {
         (!output_ordering.is_empty()).then_some(output_ordering)
     }
 
-    /// Returns the normalized version of the ordering equivalence class within.
+    /// Recalculates the normalized version of the ordering equivalence class within.
+    ///
     /// Normalization removes constants and duplicates as well as standardizing
     /// expressions according to the equivalence group within.
-    pub fn normalized_oeq_class(&self) -> OrderingEquivalenceClass {
-        OrderingEquivalenceClass::new(
-            self.oeq_class
-                .iter()
-                .map(|ordering| self.normalize_sort_exprs(ordering))
-                .collect(),
+    fn renormalize_oeq_class(&mut self) {
+        //let normalized_oeq_class = mem::take(&mut self.normalized_oeq_class);
+        let normalized_oeq_class = self.oeq_class.clone();
+        self.normalized_oeq_class = OrderingEquivalenceClass::new(
+            self.normalize_orderings(normalized_oeq_class.into_inner()),
         )
     }
 
+    fn with_renormalize_oeq_class(mut self) -> Self {
+        self.renormalize_oeq_class();
+        self
+    }
+
     /// Extends this `EquivalenceProperties` with the `other` object.
     pub fn extend(mut self, other: Self) -> Self {
         self.eq_group.extend(other.eq_group);
@@ -218,6 +232,7 @@ impl EquivalenceProperties {
     ///
     /// Call this method when existing orderings are invalidated.
     pub fn clear_orderings(&mut self) -> OrderingEquivalenceClass {
+        self.normalized_oeq_class.clear(); // clear previous normalized orderings
         mem::take(&mut self.oeq_class) // reset to default
     }
 
@@ -226,7 +241,8 @@ impl EquivalenceProperties {
     pub fn clear_per_partition_constants(&mut self) {
         self.constants.retain(|item| {
             matches!(item.across_partitions(), AcrossPartitions::Uniform(_))
-        })
+        });
+        self.renormalize_oeq_class();
     }
 
     /// Extends this `EquivalenceProperties` by adding the orderings inside the
@@ -240,8 +256,15 @@ impl EquivalenceProperties {
         &mut self,
         orderings: impl IntoIterator<Item = LexOrdering>,
     ) {
+        let (orderings, normalized_orderings): (Vec<_>, Vec<_>) = orderings
+            .into_iter()
+            .map(|sort_expr| (sort_expr.clone(), self.normalize_sort_exprs(sort_expr)))
+            .unzip();
+
         // single location oeq_class is updated
         self.oeq_class.add_new_orderings(orderings);
+        self.normalized_oeq_class
+            .add_new_orderings(normalized_orderings);
     }
 
     /// Adds a single ordering to the existing ordering equivalence class.
@@ -253,6 +276,7 @@ impl EquivalenceProperties {
     /// equivalence group within.
     pub fn add_equivalence_group(&mut self, other_eq_group: EquivalenceGroup) {
         self.eq_group.extend(other_eq_group);
+        self.renormalize_oeq_class()
     }
 
     /// Adds a new equality condition into the existing equivalence group.
@@ -282,6 +306,7 @@ impl EquivalenceProperties {
 
         // Add equal expressions to the state
         self.eq_group.add_equal_conditions(left, right);
+        self.renormalize_oeq_class();
 
         // Discover any new orderings
         self.discover_new_orderings(left)?;
@@ -325,9 +350,10 @@ impl EquivalenceProperties {
 
         // Add all new normalized constants
         self.constants.extend(normalized_constants);
+        self.renormalize_oeq_class();
 
         // Discover any new orderings based on the constants
-        for ordering in self.normalized_oeq_class().iter() {
+        for ordering in self.normalized_oeq_class().clone().iter() {
             if let Err(e) = self.discover_new_orderings(&ordering[0].expr) {
                 log::debug!("error discovering new orderings: {e}");
             }
@@ -476,15 +502,23 @@ impl EquivalenceProperties {
     /// function would return `vec![a ASC, c ASC]`. Internally, it would first
     /// normalize to `vec![a ASC, c ASC, a ASC]` and end up with the final result
     /// after deduplication.
-    fn normalize_sort_exprs(&self, sort_exprs: &LexOrdering) -> LexOrdering {
+    fn normalize_sort_exprs(&self, sort_exprs: LexOrdering) -> LexOrdering {
         // Convert sort expressions to sort requirements:
-        let sort_reqs = LexRequirement::from(sort_exprs.clone());
+        let sort_reqs = LexRequirement::from(sort_exprs);
         // Normalize the requirements:
         let normalized_sort_reqs = self.normalize_sort_requirements(&sort_reqs);
         // Convert sort requirements back to sort expressions:
         LexOrdering::from(normalized_sort_reqs)
     }
 
+    /// Applies normalization to all the orderings
+    fn normalize_orderings(&self, sort_exprs: Vec<LexOrdering>) -> Vec<LexOrdering> {
+        sort_exprs
+            .into_iter()
+            .map(|sort_expr| self.normalize_sort_exprs(sort_expr))
+            .collect()
+    }
+
     /// Normalizes the given sort requirements (i.e. `sort_reqs`) using the
     /// equivalence group and the ordering equivalence class within. It works by:
     /// - Removing expressions that have a constant value from the given requirement.
@@ -986,10 +1020,12 @@ impl EquivalenceProperties {
         let projected_orderings = self.projected_orderings(projection_mapping);
         Self {
             eq_group: projected_eq_group,
-            oeq_class: OrderingEquivalenceClass::new(projected_orderings),
+            oeq_class: OrderingEquivalenceClass::new(projected_orderings.clone()),
+            normalized_oeq_class: OrderingEquivalenceClass::new(projected_orderings),
             constants: projected_constants,
             schema: output_schema,
         }
+        .with_renormalize_oeq_class()
     }
 
     /// Returns the longest (potentially partial) permutation satisfying the
@@ -2016,8 +2052,16 @@ fn calculate_union_binary(
     // Next, calculate valid orderings for the union by searching for prefixes
     // in both sides.
     let mut orderings = UnionEquivalentOrderingBuilder::new();
-    orderings.add_satisfied_orderings(lhs.normalized_oeq_class(), lhs.constants(), &rhs);
-    orderings.add_satisfied_orderings(rhs.normalized_oeq_class(), rhs.constants(), &lhs);
+    orderings.add_satisfied_orderings(
+        lhs.normalized_oeq_class().clone(),
+        lhs.constants(),
+        &rhs,
+    );
+    orderings.add_satisfied_orderings(
+        rhs.normalized_oeq_class().clone(),
+        rhs.constants(),
+        &lhs,
+    );
     let orderings = orderings.build();
 
     let mut eq_properties =