From 3025af920cf3e1ec3623eacea3bc2839fec4199d Mon Sep 17 00:00:00 2001
From: zhengpeng <847850277@qq.com>
Date: Thu, 9 Jul 2026 16:11:48 +0800
Subject: [PATCH 1/2] feat: Fix inferred predicates for null-aware anti joins

---
 datafusion/optimizer/src/push_down_filter.rs  |  7 +++
 .../test_files/not_in_null_pushdown.slt       | 48 +++++++++++++++++++
 2 files changed, 55 insertions(+)
 create mode 100644 datafusion/sqllogictest/test_files/not_in_null_pushdown.slt

diff --git a/datafusion/optimizer/src/push_down_filter.rs b/datafusion/optimizer/src/push_down_filter.rs
index f30b1187b7bca..280e1c76ea1bb 100644
--- a/datafusion/optimizer/src/push_down_filter.rs
+++ b/datafusion/optimizer/src/push_down_filter.rs
@@ -589,6 +589,13 @@ fn infer_join_predicates(
 
     let join_type = join.join_type;
 
+    // Null-aware anti joins implement NOT IN semantics, where NULLs on the
+    // right side affect the result. Inferring predicates across the join can
+    // incorrectly filter those NULLs.
+    if join_type == JoinType::LeftAnti && join.null_aware {
+        return Ok(vec![]);
+    }
+
     let mut inferred_predicates = InferredPredicates::new(join_type);
 
     infer_join_predicates_from_predicates(
diff --git a/datafusion/sqllogictest/test_files/not_in_null_pushdown.slt b/datafusion/sqllogictest/test_files/not_in_null_pushdown.slt
new file mode 100644
index 0000000000000..d2ef490d6813f
--- /dev/null
+++ b/datafusion/sqllogictest/test_files/not_in_null_pushdown.slt
@@ -0,0 +1,48 @@
+# Licensed to the Apache Software Foundation (ASF) under one
+# or more contributor license agreements.  See the NOTICE file
+# distributed with this work for additional information
+# regarding copyright ownership.  The ASF licenses this file
+# to you under the Apache License, Version 2.0 (the
+# "License"); you may not use this file except in compliance
+# with the License.  You may obtain a copy of the License at
+#
+#   http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing,
+# software distributed under the License is distributed on an
+# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+# KIND, either express or implied.  See the License for the
+# specific language governing permissions and limitations
+# under the License.
+
+# Regression test for NOT IN null-aware semantics. The right-side NULL must not
+# be removed by inferred predicate pushdown through the null-aware anti join.
+
+statement ok
+CREATE TABLE pushdown_t(id INT, a INT)
+
+statement ok
+INSERT INTO pushdown_t VALUES (1, 1), (2, 2)
+
+statement ok
+CREATE TABLE pushdown_u(k INT)
+
+statement ok
+INSERT INTO pushdown_u VALUES (NULL)
+
+# Expected result is empty:
+# - id=1: a <> 1 is false
+# - id=2: a <> 1 is true, but 2 NOT IN (NULL) is UNKNOWN
+# WHERE only keeps TRUE, so neither row should be returned.
+query I
+SELECT id
+FROM pushdown_t
+WHERE a != 1
+  AND a NOT IN (SELECT k FROM pushdown_u);
+----
+
+statement ok
+DROP TABLE pushdown_t
+
+statement ok
+DROP TABLE pushdown_u

From 28900737a2cf00e19693e1b3b21858b6ed836fa7 Mon Sep 17 00:00:00 2001
From: zhengpeng <847850277@qq.com>
Date: Thu, 9 Jul 2026 16:28:13 +0800
Subject: [PATCH 2/2] feat: Fix inferred predicates for null-aware anti joins

---
 datafusion/optimizer/src/push_down_filter.rs | 18 +++++++++---------
 1 file changed, 9 insertions(+), 9 deletions(-)

diff --git a/datafusion/optimizer/src/push_down_filter.rs b/datafusion/optimizer/src/push_down_filter.rs
index 280e1c76ea1bb..619d53fb045fe 100644
--- a/datafusion/optimizer/src/push_down_filter.rs
+++ b/datafusion/optimizer/src/push_down_filter.rs
@@ -576,6 +576,15 @@ fn infer_join_predicates(
     predicates: &[Expr],
     on_filters: &[Expr],
 ) -> Result<Vec<Expr>> {
+    let join_type = join.join_type;
+
+    // Null-aware anti joins implement NOT IN semantics, where NULLs on the
+    // right side can affect the result. Inferring predicates across the join can
+    // incorrectly filter those NULLs.
+    if join_type == JoinType::LeftAnti && join.null_aware {
+        return Ok(vec![]);
+    }
+
     // Only allow both side key is column.
     let join_col_keys = join
         .on
@@ -587,15 +596,6 @@ fn infer_join_predicates(
         })
         .collect::<Vec<_>>();
 
-    let join_type = join.join_type;
-
-    // Null-aware anti joins implement NOT IN semantics, where NULLs on the
-    // right side affect the result. Inferring predicates across the join can
-    // incorrectly filter those NULLs.
-    if join_type == JoinType::LeftAnti && join.null_aware {
-        return Ok(vec![]);
-    }
-
     let mut inferred_predicates = InferredPredicates::new(join_type);
 
     infer_join_predicates_from_predicates(