diff --git a/src/query/src/optimizer/windowed_sort.rs b/src/query/src/optimizer/windowed_sort.rs
index 0d3c08bb08..c755d23e16 100644
--- a/src/query/src/optimizer/windowed_sort.rs
+++ b/src/query/src/optimizer/windowed_sort.rs
@@ -165,7 +165,7 @@ fn fetch_partition_range(input: Arc<dyn ExecutionPlan>) -> DataFusionResult<Opti
 
         if let Some(region_scan_exec) = plan.as_any().downcast_ref::<RegionScanExec>() {
             partition_ranges = Some(region_scan_exec.get_uncollapsed_partition_ranges());
-            time_index = region_scan_exec.time_index();
+            time_index = Some(region_scan_exec.time_index());
             tag_columns = Some(region_scan_exec.tag_columns());
 
             // set distinguish_partition_ranges to true, this is an incorrect workaround
diff --git a/src/table/src/table/scan.rs b/src/table/src/table/scan.rs
index cc94a054de..0eac7c0c35 100644
--- a/src/table/src/table/scan.rs
+++ b/src/table/src/table/scan.rs
@@ -146,13 +146,15 @@ impl RegionScanExec {
         let _ = scanner.prepare(partition_ranges, distinguish_partition_range);
     }
 
-    pub fn time_index(&self) -> Option<String> {
+    pub fn time_index(&self) -> String {
         self.scanner
             .lock()
             .unwrap()
-            .schema()
-            .timestamp_column()
-            .map(|x| x.name.clone())
+            .metadata()
+            .time_index_column()
+            .column_schema
+            .name
+            .clone()
     }
 
     pub fn tag_columns(&self) -> Vec<String> {