diff --git a/datafusion/physical-plan/src/joins/sort_merge_join.rs b/datafusion/physical-plan/src/joins/sort_merge_join.rs
index e56ef32045b71..d35dda0dd696b 100644
--- a/datafusion/physical-plan/src/joins/sort_merge_join.rs
+++ b/datafusion/physical-plan/src/joins/sort_merge_join.rs
@@ -1116,10 +1116,13 @@ impl SMJStream {
     // NULLs on streamed side.
     //
     // Applicable only in case of Full join.
+    //
+    // If `output_not_matched_filter` is true, this will also produce record batches
+    // for buffered rows which are joined with streamed side but don't match join filter.
     fn freeze_buffered(
         &mut self,
         batch_count: usize,
-        output_join_filter_fail_batch: bool,
+        output_not_matched_filter: bool,
     ) -> Result<()> {
         if !matches!(self.join_type, JoinType::Full) {
             return Ok(());
@@ -1139,7 +1142,7 @@ impl SMJStream {
             buffered_batch.null_joined.clear();
 
             // For buffered rows which are joined with streamed side but doesn't satisfy the join filter
-            if output_join_filter_fail_batch {
+            if output_not_matched_filter {
                 let buffered_indices = UInt64Array::from_iter_values(
                     buffered_batch.join_filter_failed_idxs.iter().copied(),
                 );
@@ -1475,10 +1478,10 @@ fn produce_buffered_null_batch(
         .map(|f| new_null_array(f.data_type(), buffered_indices.len()))
         .collect::<Vec<_>>();
 
-    streamed_columns.extend(buffered_columns);
-    let columns = streamed_columns;
-
-    Ok(Some(RecordBatch::try_new(schema.clone(), columns)?))
+    Ok(Some(RecordBatch::try_new(
+        schema.clone(),
+        streamed_columns,
+    )?))
 }
 
 /// Get `buffered_indices` rows for `buffered_data[buffered_batch_idx]`