diff --git a/source/common/src/tdataformat.c b/source/common/src/tdataformat.c
index 1d52a77472..7657c198e5 100644
--- a/source/common/src/tdataformat.c
+++ b/source/common/src/tdataformat.c
@@ -2218,13 +2218,13 @@ static void tColDataMergeImpl(SColData *pColData, int32_t iStart, int32_t iEnd /
   switch (pColData->flag) {
     case HAS_NONE:
     case HAS_NULL: {
-      pColData->nVal = pColData->nVal - (iEnd - iStart - 1);
+      pColData->nVal -= (iEnd - iStart - 1);
     } break;
     case (HAS_NULL | HAS_NONE): {
-      if (GET_BIT1(pColData->pBitMap, iStart) == BIT_FLG_NONE) {
+      if (GET_BIT1(pColData->pBitMap, iStart) == 0) {
         for (int32_t i = iStart + 1; i < iEnd; ++i) {
-          if (GET_BIT1(pColData->pBitMap, i) == BIT_FLG_NULL) {
-            SET_BIT1(pColData->pBitMap, iStart, BIT_FLG_NULL);
+          if (GET_BIT1(pColData->pBitMap, i) == 1) {
+            SET_BIT1(pColData->pBitMap, iStart, 1);
             break;
           }
         }
@@ -2233,7 +2233,7 @@ static void tColDataMergeImpl(SColData *pColData, int32_t iStart, int32_t iEnd /
         SET_BIT1(pColData->pBitMap, j, GET_BIT1(pColData->pBitMap, i));
       }
 
-      pColData->nVal = pColData->nVal - (iEnd - iStart - 1);
+      pColData->nVal -= (iEnd - iStart - 1);
 
       uint8_t flag = 0;
       for (int32_t i = 0; i < pColData->nVal; ++i) {
@@ -2254,7 +2254,7 @@ static void tColDataMergeImpl(SColData *pColData, int32_t iStart, int32_t iEnd /
       if (IS_VAR_DATA_TYPE(pColData->type)) {
         int32_t nDiff = pColData->aOffset[iEnd - 1] - pColData->aOffset[iStart];
 
-        memmove(&pColData->pData[pColData->aOffset[iStart]], &pColData->pData[pColData->aOffset[iEnd - 1]],
+        memmove(pColData->pData + pColData->aOffset[iStart], pColData->pData + pColData->aOffset[iEnd - 1],
                 pColData->nData - pColData->aOffset[iEnd - 1]);
         pColData->nData -= nDiff;
 
@@ -2262,13 +2262,13 @@ static void tColDataMergeImpl(SColData *pColData, int32_t iStart, int32_t iEnd /
           pColData->aOffset[j] = pColData->aOffset[i] - nDiff;
         }
       } else {
-        memmove(&pColData->pData[TYPE_BYTES[pColData->type] * iStart],
-                &pColData->pData[TYPE_BYTES[pColData->type] * (iEnd - 1)],
+        memmove(pColData->pData + TYPE_BYTES[pColData->type] * iStart,
+                pColData->pData + TYPE_BYTES[pColData->type] * (iEnd - 1),
                 TYPE_BYTES[pColData->type] * (pColData->nVal - iEnd + 1));
         pColData->nData -= (TYPE_BYTES[pColData->type] * (iEnd - iStart - 1));
       }
 
-      pColData->nVal = pColData->nVal - (iEnd - iStart - 1);
+      pColData->nVal -= (iEnd - iStart - 1);
     } break;
     case (HAS_VALUE | HAS_NONE): {
       uint8_t bv;
@@ -2337,13 +2337,13 @@ static void tColDataMergeImpl(SColData *pColData, int32_t iStart, int32_t iEnd /
           SET_BIT1(pColData->pBitMap, j, GET_BIT1(pColData->pBitMap, i));
         }
       }
-      pColData->nVal = pColData->nVal - (iEnd - iStart - 1);
+      pColData->nVal -= (iEnd - iStart - 1);
     } break;
     case (HAS_VALUE | HAS_NULL): {
       if (IS_VAR_DATA_TYPE(pColData->type)) {
         int32_t nDiff = pColData->aOffset[iEnd - 1] - pColData->aOffset[iStart];
 
-        memmove(&pColData->pData[pColData->aOffset[iStart]], &pColData->pData[pColData->aOffset[iEnd - 1]],
+        memmove(pColData->pData + pColData->aOffset[iStart], pColData->pData + pColData->aOffset[iEnd - 1],
                 pColData->nData - pColData->aOffset[iEnd - 1]);
         pColData->nData -= nDiff;
 
@@ -2351,8 +2351,8 @@ static void tColDataMergeImpl(SColData *pColData, int32_t iStart, int32_t iEnd /
           pColData->aOffset[j] = pColData->aOffset[i] - nDiff;
         }
       } else {
-        memmove(&pColData->pData[TYPE_BYTES[pColData->type] * iStart],
-                &pColData->pData[TYPE_BYTES[pColData->type] * (iEnd - 1)],
+        memmove(pColData->pData + TYPE_BYTES[pColData->type] * iStart,
+                pColData->pData + TYPE_BYTES[pColData->type] * (iEnd - 1),
                 TYPE_BYTES[pColData->type] * (pColData->nVal - iEnd + 1));
         pColData->nData -= (TYPE_BYTES[pColData->type] * (iEnd - iStart - 1));
       }
@@ -2361,12 +2361,11 @@ static void tColDataMergeImpl(SColData *pColData, int32_t iStart, int32_t iEnd /
         SET_BIT1(pColData->pBitMap, j, GET_BIT1(pColData->pBitMap, i));
       }
 
-      pColData->nVal = pColData->nVal - (iEnd - iStart - 1);
+      pColData->nVal -= (iEnd - iStart - 1);
 
       uint8_t flag = 0;
       for (int32_t i = 0; i < pColData->nVal; ++i) {
-        uint8_t bv = GET_BIT1(pColData->pBitMap, i);
-        if (bv) {
+        if (GET_BIT1(pColData->pBitMap, i)) {
           flag |= HAS_VALUE;
         } else {
           flag |= HAS_NULL;
@@ -2379,7 +2378,7 @@ static void tColDataMergeImpl(SColData *pColData, int32_t iStart, int32_t iEnd /
     case (HAS_VALUE | HAS_NULL | HAS_NONE): {
       // TODO
       ASSERT(0);
-      pColData->nVal = pColData->nVal - (iEnd - iStart - 1);
+      pColData->nVal -= (iEnd - iStart - 1);
     } break;
     default:
       ASSERT(0);
@@ -2389,7 +2388,7 @@ static void tColDataMergeImpl(SColData *pColData, int32_t iStart, int32_t iEnd /
 static void tColDataMerge(SColData *aColData, int32_t nColData) {
   int32_t iStart = 0;
   for (;;) {
-    if (iStart >= aColData[0].nVal) break;
+    if (iStart >= aColData[0].nVal - 1) break;
 
     int32_t iEnd = iStart + 1;
     while (iEnd < aColData[0].nVal) {