Adds INList and Between expr to skip outer join

datafusion/optimizer/src/eliminate_outer_join.rs

@@ -23,7 +23,7 @@ use datafusion_expr::{Expr, Filter, Operator};
 
 use crate::optimizer::ApplyOrder;
 use datafusion_common::tree_node::Transformed;
-use datafusion_expr::expr::{BinaryExpr, Cast, TryCast};
+use datafusion_expr::expr::{BinaryExpr, Cast, InList, TryCast};
 use std::sync::Arc;
 
 ///
@@ -298,6 +298,23 @@ fn extract_non_nullable_columns(
             right_schema,
             false,
         ),
+        // IN list and BETWEEN are null-rejecting on the input expression:
+        // if the input column is NULL, the result is NULL (filtered out),
+        // regardless of whether the list/range contains NULLs.
+        Expr::InList(InList { expr, .. }) => extract_non_nullable_columns(
+            expr,
+            non_nullable_cols,
+            left_schema,
+            right_schema,
+            false,
+        ),
+        Expr::Between(between) => extract_non_nullable_columns(
+            &between.expr,
+            non_nullable_cols,
+            left_schema,
+            right_schema,
+            false,
+        ),
         _ => {}
     }
 }
@@ -309,6 +326,7 @@ mod tests {
     use crate::assert_optimized_plan_eq_snapshot;
     use crate::test::*;
     use arrow::datatypes::DataType;
+    use datafusion_common::ScalarValue;
     use datafusion_expr::{
         Operator::{And, Or},
         binary_expr, cast, col, lit,
@@ -436,6 +454,221 @@ mod tests {
         ")
     }
 
+    #[test]
+    fn eliminate_left_with_in_list() -> Result<()> {
+        let t1 = test_table_scan_with_name("t1")?;
+        let t2 = test_table_scan_with_name("t2")?;
+
+        // t2.b IN (1, 2, 3) rejects nulls — if t2.b is NULL the IN returns
+        // NULL which is filtered out. So Left Join should become Inner Join.
+        let plan = LogicalPlanBuilder::from(t1)
+            .join(
+                t2,
+                JoinType::Left,
+                (vec![Column::from_name("a")], vec![Column::from_name("a")]),
+                None,
+            )?
+            .filter(col("t2.b").in_list(vec![lit(1u32), lit(2u32), lit(3u32)], false))?
+            .build()?;
+
+        assert_optimized_plan_equal!(plan, @r"
+        Filter: t2.b IN ([UInt32(1), UInt32(2), UInt32(3)])
+          Inner Join: t1.a = t2.a
+            TableScan: t1
+            TableScan: t2
+        ")
+    }
+
+    #[test]
+    fn eliminate_left_with_in_list_containing_null() -> Result<()> {
+        let t1 = test_table_scan_with_name("t1")?;
+        let t2 = test_table_scan_with_name("t2")?;
+
+        // IN list with NULL still rejects null input columns:
+        // if t2.b is NULL, NULL IN (1, NULL) evaluates to NULL, which is filtered out
+        let plan = LogicalPlanBuilder::from(t1)
+            .join(
+                t2,
+                JoinType::Left,
+                (vec![Column::from_name("a")], vec![Column::from_name("a")]),
+                None,
+            )?
+            .filter(
+                col("t2.b")
+                    .in_list(vec![lit(1u32), lit(ScalarValue::UInt32(None))], false),
+            )?
+            .build()?;
+
+        assert_optimized_plan_equal!(plan, @r"
+        Filter: t2.b IN ([UInt32(1), UInt32(NULL)])
+          Inner Join: t1.a = t2.a
+            TableScan: t1
+            TableScan: t2
+        ")
+    }
+
+    #[test]
+    fn eliminate_left_with_not_in_list() -> Result<()> {
+        let t1 = test_table_scan_with_name("t1")?;
+        let t2 = test_table_scan_with_name("t2")?;
+
+        // NOT IN also rejects nulls: if t2.b is NULL, NOT (NULL IN (...))
+        // evaluates to NULL, which is filtered out
+        let plan = LogicalPlanBuilder::from(t1)
+            .join(
+                t2,
+                JoinType::Left,
+                (vec![Column::from_name("a")], vec![Column::from_name("a")]),
+                None,
+            )?
+            .filter(col("t2.b").in_list(vec![lit(1u32), lit(2u32)], true))?
+            .build()?;
+
+        assert_optimized_plan_equal!(plan, @r"
+        Filter: t2.b NOT IN ([UInt32(1), UInt32(2)])
+          Inner Join: t1.a = t2.a
+            TableScan: t1
+            TableScan: t2
+        ")
+    }
+
+    #[test]
+    fn eliminate_left_with_between() -> Result<()> {
+        let t1 = test_table_scan_with_name("t1")?;
+        let t2 = test_table_scan_with_name("t2")?;
+
+        // BETWEEN rejects nulls: if t2.b is NULL, NULL BETWEEN 1 AND 10
+        // evaluates to NULL, which is filtered out
+        let plan = LogicalPlanBuilder::from(t1)
+            .join(
+                t2,
+                JoinType::Left,
+                (vec![Column::from_name("a")], vec![Column::from_name("a")]),
+                None,
+            )?
+            .filter(col("t2.b").between(lit(1u32), lit(10u32)))?
+            .build()?;
+
+        assert_optimized_plan_equal!(plan, @r"
+        Filter: t2.b BETWEEN UInt32(1) AND UInt32(10)
+          Inner Join: t1.a = t2.a
+            TableScan: t1
+            TableScan: t2
+        ")
+    }
+
+    #[test]
+    fn eliminate_right_with_between() -> Result<()> {
+        let t1 = test_table_scan_with_name("t1")?;
+        let t2 = test_table_scan_with_name("t2")?;
+
+        // Right join: filter on left (nullable) side with BETWEEN should convert to Inner
+        let plan = LogicalPlanBuilder::from(t1)
+            .join(
+                t2,
+                JoinType::Right,
+                (vec![Column::from_name("a")], vec![Column::from_name("a")]),
+                None,
+            )?
+            .filter(col("t1.b").between(lit(1u32), lit(10u32)))?
+            .build()?;
+
+        assert_optimized_plan_equal!(plan, @r"
+        Filter: t1.b BETWEEN UInt32(1) AND UInt32(10)
+          Inner Join: t1.a = t2.a
+            TableScan: t1
+            TableScan: t2
+        ")
+    }
+
+    #[test]
+    fn eliminate_full_with_between() -> Result<()> {
+        let t1 = test_table_scan_with_name("t1")?;
+        let t2 = test_table_scan_with_name("t2")?;
+
+        // Full join with BETWEEN on both sides should become Inner
+        let plan = LogicalPlanBuilder::from(t1)
+            .join(
+                t2,
+                JoinType::Full,
+                (vec![Column::from_name("a")], vec![Column::from_name("a")]),
+                None,
+            )?
+            .filter(binary_expr(
+                col("t1.b").between(lit(1u32), lit(10u32)),
+                And,
+                col("t2.b").between(lit(5u32), lit(20u32)),
+            ))?
+            .build()?;
+
+        assert_optimized_plan_equal!(plan, @r"
+        Filter: t1.b BETWEEN UInt32(1) AND UInt32(10) AND t2.b BETWEEN UInt32(5) AND UInt32(20)
+          Inner Join: t1.a = t2.a
+            TableScan: t1
+            TableScan: t2
+        ")
+    }
+
+    #[test]
+    fn eliminate_full_with_in_list() -> Result<()> {
+        let t1 = test_table_scan_with_name("t1")?;
+        let t2 = test_table_scan_with_name("t2")?;
+
+        // Full join with IN filters on both sides should become Inner
+        let plan = LogicalPlanBuilder::from(t1)
+            .join(
+                t2,
+                JoinType::Full,
+                (vec![Column::from_name("a")], vec![Column::from_name("a")]),
+                None,
+            )?
+            .filter(binary_expr(
+                col("t1.b").in_list(vec![lit(1u32), lit(2u32)], false),
+                And,
+                col("t2.b").in_list(vec![lit(3u32), lit(4u32)], false),
+            ))?
+            .build()?;
+
+        assert_optimized_plan_equal!(plan, @r"
+        Filter: t1.b IN ([UInt32(1), UInt32(2)]) AND t2.b IN ([UInt32(3), UInt32(4)])
+          Inner Join: t1.a = t2.a
+            TableScan: t1
+            TableScan: t2
+        ")
+    }
+
+    #[test]
+    fn no_eliminate_left_with_in_list_or_is_null() -> Result<()> {
+        let t1 = test_table_scan_with_name("t1")?;
+        let t2 = test_table_scan_with_name("t2")?;
+
+        // WHERE (t2.b IN (1, 2)) OR (t2.b IS NULL)
+        // The OR with IS NULL makes the predicate null-tolerant:
+        // when t2.b is NULL, IS NULL returns true, so the whole OR is true.
+        // The outer join must be preserved.
+        let plan = LogicalPlanBuilder::from(t1)
+            .join(
+                t2,
+                JoinType::Left,
+                (vec![Column::from_name("a")], vec![Column::from_name("a")]),
+                None,
+            )?
+            .filter(binary_expr(
+                col("t2.b").in_list(vec![lit(1u32), lit(2u32)], false),
+                Or,
+                col("t2.b").is_null(),
+            ))?
+            .build()?;
+
+        // Should NOT be converted to Inner — OR with IS NULL preserves null rows
+        assert_optimized_plan_equal!(plan, @r"
+        Filter: t2.b IN ([UInt32(1), UInt32(2)]) OR t2.b IS NULL
+          Left Join: t1.a = t2.a
+            TableScan: t1
+            TableScan: t2
+        ")
+    }
+
     #[test]
     fn eliminate_full_with_type_cast() -> Result<()> {
         let t1 = test_table_scan_with_name("t1")?;