diff --git a/source/common/src/trow.c b/source/common/src/trow.c
index d1516403c1..22bdd960ea 100644
--- a/source/common/src/trow.c
+++ b/source/common/src/trow.c
@@ -1063,7 +1063,7 @@ bool tdSTpRowGetVal(STSRow *pRow, col_id_t colId, col_type_t colType, int32_t fl
 
 int32_t tdGetColDataOfRow(SCellVal *pVal, SDataCol *pCol, int32_t row, int8_t bitmapMode) {
   if (isAllRowsNone(pCol)) {
-    pVal->valType = TD_VTYPE_NULL;
+    pVal->valType = TD_VTYPE_NONE;
 #ifdef TD_SUPPORT_READ2
     pVal->val = (void *)getNullValue(pCol->type);
 #else
diff --git a/source/dnode/vnode/src/tsdb/tsdbReadImpl.c b/source/dnode/vnode/src/tsdb/tsdbReadImpl.c
index bebdfb3b63..c1a1e7570e 100644
--- a/source/dnode/vnode/src/tsdb/tsdbReadImpl.c
+++ b/source/dnode/vnode/src/tsdb/tsdbReadImpl.c
@@ -330,12 +330,12 @@ int tsdbLoadBlockDataCols(SReadH *pReadh, SBlock *pBlock, SBlockInfo *pBlkInfo,
     ASSERT(pReadh->pDCols[0]->bitmapMode != 0);
   }
 
-
   if (mergeBitmap && !tdDataColsIsBitmapI(pReadh->pDCols[0])) {
     for (int i = 0; i < numOfColsIds; ++i) {
       SDataCol *pDataCol = pReadh->pDCols[0]->cols + i;
-      if (pDataCol->bitmap) {
+      if (pDataCol->len > 0 && pDataCol->bitmap) {
         ASSERT(pDataCol->colId != PRIMARYKEY_TIMESTAMP_COL_ID);
+        ASSERT(pDataCol->pBitmap);
         tdMergeBitmap(pDataCol->pBitmap, pReadh->pDCols[0]->numOfRows, pDataCol->pBitmap);
         tdDataColsSetBitmapI(pReadh->pDCols[0]);
       }