diff --git a/src/storage/column_store/ob_cg_tile_scanner.cpp b/src/storage/column_store/ob_cg_tile_scanner.cpp
index 1bfb03f054..5c850d238d 100644
--- a/src/storage/column_store/ob_cg_tile_scanner.cpp
+++ b/src/storage/column_store/ob_cg_tile_scanner.cpp
@@ -256,7 +256,7 @@ int ObCGTileScanner::get_next_rows(uint64_t &count, const uint64_t capacity)
       if (OB_ISNULL(cg_scanner = cg_scanners_.at(i))) {
         ret = OB_ERR_UNEXPECTED;
         LOG_WARN("Unexpected null cg scanner", K(ret), K(i));
-      } else if (OB_CG_ROW_SCANNER == cg_scanner->get_type()) {
+      } else if (is_valid_cg_row_scanner(cg_scanner->get_type())) {
         ret = get_next_aligned_rows(static_cast<ObCGRowScanner*>(cg_scanner), count);
       } else {
         ret = cg_scanner->get_next_rows(count, capacity);
diff --git a/src/storage/column_store/ob_co_sstable_row_scanner.cpp b/src/storage/column_store/ob_co_sstable_row_scanner.cpp
index 91fe945eaf..e8e0470d32 100644
--- a/src/storage/column_store/ob_co_sstable_row_scanner.cpp
+++ b/src/storage/column_store/ob_co_sstable_row_scanner.cpp
@@ -1138,7 +1138,7 @@ int ObCOSSTableRowScanner::push_group_by_processor(ObICGIterator *cg_iterator)
   if (OB_ISNULL(cg_iterator)) {
     ret = OB_INVALID_ARGUMENT;
     LOG_WARN("Invalid argument", K(ret));
-  } else if (cg_iterator->get_type() != ObICGIterator::OB_CG_GROUP_BY_SCANNER) {
+  } else if (OB_UNLIKELY(!ObICGIterator::is_valid_group_by_cg_scanner(cg_iterator->get_type()))) {
     ret = OB_ERR_UNEXPECTED;
     LOG_WARN("Unexpected cg scanner", K(ret), K(cg_iterator->get_type()));
   } else {
diff --git a/src/storage/column_store/ob_i_cg_iterator.h b/src/storage/column_store/ob_i_cg_iterator.h
index 093468ab54..7c39aeff81 100644
--- a/src/storage/column_store/ob_i_cg_iterator.h
+++ b/src/storage/column_store/ob_i_cg_iterator.h
@@ -36,6 +36,7 @@ public:
     OB_CG_SINGLE_ROW_SCANNER,
     OB_CG_AGGREGATED_SCANNER,
     OB_CG_GROUP_BY_SCANNER,
+    OB_CG_GROUP_BY_DEFAULT_SCANNER,
     OB_CG_VIRTUAL_SCANNER,
     OB_CG_DEFAULT_SCANNER,
     OB_CG_TILE_SCANNER,
@@ -50,6 +51,14 @@ public:
   {
     return project_single_row ? (OB_CG_SINGLE_ROW_SCANNER || OB_CG_DEFAULT_SCANNER) : (OB_CG_ROW_SCANNER <= cg_iter_type && cg_iter_type < OB_CG_TILE_SCANNER);
   }
+  static bool is_valid_cg_row_scanner(const int cg_iter_type)
+  {
+    return OB_CG_ROW_SCANNER == cg_iter_type || OB_CG_GROUP_BY_SCANNER == cg_iter_type;
+  }
+  static bool is_valid_group_by_cg_scanner(const int cg_iter_type)
+  {
+    return OB_CG_GROUP_BY_SCANNER == cg_iter_type || OB_CG_GROUP_BY_DEFAULT_SCANNER == cg_iter_type;
+  }
   ObICGIterator() : cg_idx_(OB_CS_INVALID_CG_IDX) {};
   virtual ~ObICGIterator() {};
   virtual void reset() = 0;
diff --git a/src/storage/column_store/ob_virtual_cg_scanner.h b/src/storage/column_store/ob_virtual_cg_scanner.h
index 36a852d677..21ec2a75fe 100644
--- a/src/storage/column_store/ob_virtual_cg_scanner.h
+++ b/src/storage/column_store/ob_virtual_cg_scanner.h
@@ -136,7 +136,7 @@ public:
       ObSSTableWrapper &wrapper) override;
   virtual int init_group_by_info() override;
   virtual ObCGIterType get_type() override
-  { return OB_CG_GROUP_BY_SCANNER; }
+  { return OB_CG_GROUP_BY_DEFAULT_SCANNER; }
   virtual int decide_group_size(int64_t &group_size) override;
   virtual int decide_can_group_by(
       const int32_t group_by_col,