diff --git a/src/mito2/src/request.rs b/src/mito2/src/request.rs
index e225d1e47ea7..0cd59aa1d98c 100644
--- a/src/mito2/src/request.rs
+++ b/src/mito2/src/request.rs
@@ -1047,6 +1047,57 @@ mod tests {
         check_invalid_request(&err, r#"unknown columns: ["k1"]"#);
     }
 
+    #[test]
+    fn test_fill_impure_columns_err() {
+        let rows = Rows {
+            schema: vec![new_column_schema(
+                "k0",
+                ColumnDataType::Int64,
+                SemanticType::Tag,
+            )],
+            rows: vec![Row {
+                values: vec![i64_value(1)],
+            }],
+        };
+        let metadata = {
+            let mut builder = RegionMetadataBuilder::new(RegionId::new(1, 1));
+            builder
+                .push_column_metadata(ColumnMetadata {
+                    column_schema: datatypes::schema::ColumnSchema::new(
+                        "ts",
+                        ConcreteDataType::timestamp_millisecond_datatype(),
+                        false,
+                    )
+                    .with_default_constraint(Some(ColumnDefaultConstraint::Function(
+                        "now()".to_string(),
+                    )))
+                    .unwrap(),
+                    semantic_type: SemanticType::Timestamp,
+                    column_id: 1,
+                })
+                .push_column_metadata(ColumnMetadata {
+                    column_schema: datatypes::schema::ColumnSchema::new(
+                        "k0",
+                        ConcreteDataType::int64_datatype(),
+                        true,
+                    ),
+                    semantic_type: SemanticType::Tag,
+                    column_id: 2,
+                })
+                .primary_key(vec![2]);
+            builder.build().unwrap()
+        };
+
+        let mut request = WriteRequest::new(RegionId::new(1, 1), OpType::Put, rows).unwrap();
+        let err = request.check_schema(&metadata).unwrap_err();
+        assert!(err.is_fill_default());
+        assert!(request
+            .fill_missing_columns(&metadata)
+            .unwrap_err()
+            .to_string()
+            .contains("Unexpected impure default value with region_id"));
+    }
+
     #[test]
     fn test_fill_missing_columns() {
         let rows = Rows {
diff --git a/src/operator/src/insert.rs b/src/operator/src/insert.rs
index ad118dbd441b..33eb7e040823 100644
--- a/src/operator/src/insert.rs
+++ b/src/operator/src/insert.rs
@@ -218,10 +218,7 @@ impl Inserter {
         .convert(requests)
         .await?;
 
-        // Fill impure default values in the request
-        let inserts = fill_reqs_with_impure_default(&table_infos, inserts)?;
-
-        self.do_request(inserts, &ctx).await
+        self.do_request(inserts, &table_infos, &ctx).await
     }
 
     /// Handles row inserts request with metric engine.
@@ -266,9 +263,7 @@ impl Inserter {
         .convert(requests)
         .await?;
 
-        // Fill impure default values in the request
-        let inserts = fill_reqs_with_impure_default(&table_infos, inserts)?;
-        self.do_request(inserts, &ctx).await
+        self.do_request(inserts, &table_infos, &ctx).await
     }
 
     pub async fn handle_table_insert(
@@ -291,9 +286,8 @@ impl Inserter {
 
         let table_infos =
             HashMap::from_iter([(table_info.table_id(), table_info.clone())].into_iter());
-        // Fill impure default values in the request
-        let inserts = fill_reqs_with_impure_default(&table_infos, inserts)?;
-        self.do_request(inserts, &ctx).await
+
+        self.do_request(inserts, &table_infos, &ctx).await
     }
 
     pub async fn handle_statement_insert(
@@ -308,10 +302,8 @@ impl Inserter {
 
         let table_infos =
             HashMap::from_iter([(table_info.table_id(), table_info.clone())].into_iter());
-        // Fill impure default values in the request
-        let inserts = fill_reqs_with_impure_default(&table_infos, inserts)?;
 
-        self.do_request(inserts, ctx).await
+        self.do_request(inserts, &table_infos, ctx).await
     }
 }
 
@@ -319,8 +311,12 @@ impl Inserter {
     async fn do_request(
         &self,
         requests: InstantAndNormalInsertRequests,
+        table_infos: &HashMap<TableId, Arc<TableInfo>>,
         ctx: &QueryContextRef,
     ) -> Result<Output> {
+        // Fill impure default values in the request
+        let requests = fill_reqs_with_impure_default(table_infos, requests)?;
+
         let write_cost = write_meter!(
             ctx.current_catalog(),
             ctx.current_schema(),
diff --git a/src/operator/src/req_convert/insert/fill_impure_default.rs b/src/operator/src/req_convert/insert/fill_impure_default.rs
index c3ed4700b081..d473d55dfb7f 100644
--- a/src/operator/src/req_convert/insert/fill_impure_default.rs
+++ b/src/operator/src/req_convert/insert/fill_impure_default.rs
@@ -44,7 +44,7 @@ pub struct ImpureDefaultFiller {
 impl ImpureDefaultFiller {
     pub fn new(table_info: TableInfoRef) -> Result<Self> {
         let impure_column_list = find_all_impure_columns(&table_info);
-        let pks = table_info.meta.primary_key_indices.clone();
+        let pks = &table_info.meta.primary_key_indices;
         let pk_names = pks
             .iter()
             .map(|&i| table_info.meta.schema.column_name_by_index(i).to_string())
@@ -93,6 +93,10 @@ impl ImpureDefaultFiller {
             })
             .collect();
 
+        if self.impure_columns.len() == impure_columns_in_reqs.len() {
+            return;
+        }
+
         let (schema_append, row_append): (Vec<_>, Vec<_>) = self
             .impure_columns
             .iter()
@@ -107,7 +111,7 @@ impl ImpureDefaultFiller {
 
         rows.schema.extend(schema_append);
         for row in rows.rows.iter_mut() {
-            row.values.extend(row_append.clone());
+            row.values.extend_from_slice(row_append.as_slice());
         }
     }
 }