diff --git a/include/common/tdataformat.h b/include/common/tdataformat.h
index 7ec75e718813b98822773cedbeec24e614b7fe33..9679e909225cf97c39eaff2787eac95135d711bb 100644
--- a/include/common/tdataformat.h
+++ b/include/common/tdataformat.h
@@ -109,7 +109,7 @@ void    tRowGet(SRow *pRow, STSchema *pTSchema, int32_t iCol, SColVal *pColVal);
 void    tRowDestroy(SRow *pRow);
 void    tRowSort(SArray *aRowP);
 int32_t tRowMerge(SArray *aRowP, STSchema *pTSchema, int8_t flag);
-int32_t tRowAppendToColData(SRow *pRow, STSchema *pTSchema, SColData *aColData, int32_t nColData);
+int32_t tRowUpsertColData(SRow *pRow, STSchema *pTSchema, SColData *aColData, int32_t nColData, int32_t flag);
 
 // SRowIter ================================
 int32_t  tRowIterOpen(SRow *pRow, STSchema *pTSchema, SRowIter **ppIter);
@@ -137,7 +137,7 @@ void    tColDataInit(SColData *pColData, int16_t cid, int8_t type, int8_t smaOn)
 void    tColDataClear(SColData *pColData);
 void    tColDataDeepClear(SColData *pColData);
 int32_t tColDataAppendValue(SColData *pColData, SColVal *pColVal);
-int32_t tColDataUpdateValue(SColData *pColData, SColVal *pColVal, int32_t flag);
+int32_t tColDataUpdateValue(SColData *pColData, SColVal *pColVal, bool forward);
 void    tColDataGetValue(SColData *pColData, int32_t iVal, SColVal *pColVal);
 uint8_t tColDataGetBitValue(const SColData *pColData, int32_t iVal);
 int32_t tColDataCopy(SColData *pColDataFrom, SColData *pColData, xMallocFn xMalloc, void *arg);
diff --git a/source/common/src/tdataformat.c b/source/common/src/tdataformat.c
index 72755dae3cc811a26ef7b2aaeb6a95cfa211aa29..4752eb4261d6a0c4220cef64a81573b073738ee8 100644
--- a/source/common/src/tdataformat.c
+++ b/source/common/src/tdataformat.c
@@ -862,7 +862,7 @@ static int32_t tRowAppendNoneToColData(SColData *aColData, int32_t nColData) {
 _exit:
   return code;
 }
-static int32_t tRowAppendNullToColData(SColData *aColData, int32_t nColData, STSchema *pSchema) {
+static int32_t tRowNullUpsertColData(SColData *aColData, int32_t nColData, STSchema *pSchema) {
   int32_t code = 0;
 
   int32_t   iColData = 0;
@@ -895,7 +895,7 @@ static int32_t tRowAppendNullToColData(SColData *aColData, int32_t nColData, STS
 _exit:
   return code;
 }
-static int32_t tRowAppendTupleToColData(SRow *pRow, STSchema *pTSchema, SColData *aColData, int32_t nColData) {
+static int32_t tRowTupleUpsertColData(SRow *pRow, STSchema *pTSchema, SColData *aColData, int32_t nColData) {
   int32_t code = 0;
 
   int32_t   iColData = 0;
@@ -1001,7 +1001,7 @@ static int32_t tRowAppendTupleToColData(SRow *pRow, STSchema *pTSchema, SColData
 _exit:
   return code;
 }
-static int32_t tRowAppendKVToColData(SRow *pRow, STSchema *pTSchema, SColData *aColData, int32_t nColData) {
+static int32_t tRowKVUpsertColData(SRow *pRow, STSchema *pTSchema, SColData *aColData, int32_t nColData) {
   int32_t code = 0;
 
   SKVIdx   *pKVIdx = (SKVIdx *)pRow->data;
@@ -1087,30 +1087,27 @@ static int32_t tRowAppendKVToColData(SRow *pRow, STSchema *pTSchema, SColData *a
 _exit:
   return code;
 }
-int32_t tRowAppendToColData(SRow *pRow, STSchema *pTSchema, SColData *aColData, int32_t nColData) {
+/* flag > 0: forward update
+ * flag == 0: append
+ * flag < 0: backward update
+ */
+int32_t tRowUpsertColData(SRow *pRow, STSchema *pTSchema, SColData *aColData, int32_t nColData, int32_t flag) {
   ASSERT(pRow->sver == pTSchema->version);
   ASSERT(nColData > 0);
 
-  int32_t code = 0;
-
   if (pRow->flag == HAS_NONE) {
-    code = tRowAppendNoneToColData(aColData, nColData);
-    goto _exit;
+    if (flag) {
+      return TSDB_CODE_SUCCESS;
+    } else {
+      return tRowAppendNoneToColData(aColData, nColData);
+    }
   } else if (pRow->flag == HAS_NULL) {
-    code = tRowAppendNullToColData(aColData, nColData, pTSchema);
-    goto _exit;
+    return tRowNullUpsertColData(aColData, nColData, pTSchema);
+  } else if (pRow->flag >> 4) {  // KV row
+    return tRowKVUpsertColData(pRow, pTSchema, aColData, nColData);
+  } else {  // TUPLE row
+    return tRowTupleUpsertColData(pRow, pTSchema, aColData, nColData);
   }
-
-  if (pRow->flag >> 4) {  // KV row
-    code = tRowAppendKVToColData(pRow, pTSchema, aColData, nColData);
-    if (code) goto _exit;
-  } else {
-    code = tRowAppendTupleToColData(pRow, pTSchema, aColData, nColData);
-    if (code) goto _exit;
-  }
-
-_exit:
-  return code;
 }
 
 // STag ========================================
@@ -1910,91 +1907,91 @@ int32_t tColDataAppendValue(SColData *pColData, SColVal *pColVal) {
       pColVal->value.nData);
 }
 
-static int32_t tColDataUpdateValue10(SColData *pColData, uint8_t *pData, uint32_t nData, int32_t flag) {
+static int32_t tColDataUpdateValue10(SColData *pColData, uint8_t *pData, uint32_t nData, bool forward) {
   ASSERT(0);
   return 0;
 }
-static int32_t tColDataUpdateValue11(SColData *pColData, uint8_t *pData, uint32_t nData, int32_t flag) {
+static int32_t tColDataUpdateValue11(SColData *pColData, uint8_t *pData, uint32_t nData, bool forward) {
   ASSERT(0);
   return 0;
 }
-static int32_t tColDataUpdateValue12(SColData *pColData, uint8_t *pData, uint32_t nData, int32_t flag) {
+static int32_t tColDataUpdateValue12(SColData *pColData, uint8_t *pData, uint32_t nData, bool forward) {
   ASSERT(0);
   return 0;
 }
-static int32_t tColDataUpdateValue20(SColData *pColData, uint8_t *pData, uint32_t nData, int32_t flag) {
+static int32_t tColDataUpdateValue20(SColData *pColData, uint8_t *pData, uint32_t nData, bool forward) {
   ASSERT(0);
   return 0;
 }
-static int32_t tColDataUpdateValue21(SColData *pColData, uint8_t *pData, uint32_t nData, int32_t flag) {
+static int32_t tColDataUpdateValue21(SColData *pColData, uint8_t *pData, uint32_t nData, bool forward) {
   ASSERT(0);
   return 0;
 }
-static int32_t tColDataUpdateValue22(SColData *pColData, uint8_t *pData, uint32_t nData, int32_t flag) {
+static int32_t tColDataUpdateValue22(SColData *pColData, uint8_t *pData, uint32_t nData, bool forward) {
   ASSERT(0);
   return 0;
 }
-static int32_t tColDataUpdateValue30(SColData *pColData, uint8_t *pData, uint32_t nData, int32_t flag) {
+static int32_t tColDataUpdateValue30(SColData *pColData, uint8_t *pData, uint32_t nData, bool forward) {
   ASSERT(0);
   return 0;
 }
-static int32_t tColDataUpdateValue31(SColData *pColData, uint8_t *pData, uint32_t nData, int32_t flag) {
+static int32_t tColDataUpdateValue31(SColData *pColData, uint8_t *pData, uint32_t nData, bool forward) {
   ASSERT(0);
   return 0;
 }
-static int32_t tColDataUpdateValue32(SColData *pColData, uint8_t *pData, uint32_t nData, int32_t flag) {
+static int32_t tColDataUpdateValue32(SColData *pColData, uint8_t *pData, uint32_t nData, bool forward) {
   ASSERT(0);
   return 0;
 }
-static int32_t tColDataUpdateValue40(SColData *pColData, uint8_t *pData, uint32_t nData, int32_t flag) {
+static int32_t tColDataUpdateValue40(SColData *pColData, uint8_t *pData, uint32_t nData, bool forward) {
   ASSERT(0);
   return 0;
 }
-static int32_t tColDataUpdateValue41(SColData *pColData, uint8_t *pData, uint32_t nData, int32_t flag) {
+static int32_t tColDataUpdateValue41(SColData *pColData, uint8_t *pData, uint32_t nData, bool forward) {
   ASSERT(0);
   return 0;
 }
-static int32_t tColDataUpdateValue42(SColData *pColData, uint8_t *pData, uint32_t nData, int32_t flag) {
+static int32_t tColDataUpdateValue42(SColData *pColData, uint8_t *pData, uint32_t nData, bool forward) {
   ASSERT(0);
   return 0;
 }
-static int32_t tColDataUpdateValue50(SColData *pColData, uint8_t *pData, uint32_t nData, int32_t flag) {
+static int32_t tColDataUpdateValue50(SColData *pColData, uint8_t *pData, uint32_t nData, bool forward) {
   ASSERT(0);
   return 0;
 }
-static int32_t tColDataUpdateValue51(SColData *pColData, uint8_t *pData, uint32_t nData, int32_t flag) {
+static int32_t tColDataUpdateValue51(SColData *pColData, uint8_t *pData, uint32_t nData, bool forward) {
   ASSERT(0);
   return 0;
 }
-static int32_t tColDataUpdateValue52(SColData *pColData, uint8_t *pData, uint32_t nData, int32_t flag) {
+static int32_t tColDataUpdateValue52(SColData *pColData, uint8_t *pData, uint32_t nData, bool forward) {
   ASSERT(0);
   return 0;
 }
-static int32_t tColDataUpdateValue60(SColData *pColData, uint8_t *pData, uint32_t nData, int32_t flag) {
+static int32_t tColDataUpdateValue60(SColData *pColData, uint8_t *pData, uint32_t nData, bool forward) {
   ASSERT(0);
   return 0;
 }
-static int32_t tColDataUpdateValue61(SColData *pColData, uint8_t *pData, uint32_t nData, int32_t flag) {
+static int32_t tColDataUpdateValue61(SColData *pColData, uint8_t *pData, uint32_t nData, bool forward) {
   ASSERT(0);
   return 0;
 }
-static int32_t tColDataUpdateValue62(SColData *pColData, uint8_t *pData, uint32_t nData, int32_t flag) {
+static int32_t tColDataUpdateValue62(SColData *pColData, uint8_t *pData, uint32_t nData, bool forward) {
   ASSERT(0);
   return 0;
 }
-static int32_t tColDataUpdateValue70(SColData *pColData, uint8_t *pData, uint32_t nData, int32_t flag) {
+static int32_t tColDataUpdateValue70(SColData *pColData, uint8_t *pData, uint32_t nData, bool forward) {
   ASSERT(0);
   return 0;
 }
-static int32_t tColDataUpdateValue71(SColData *pColData, uint8_t *pData, uint32_t nData, int32_t flag) {
+static int32_t tColDataUpdateValue71(SColData *pColData, uint8_t *pData, uint32_t nData, bool forward) {
   ASSERT(0);
   return 0;
 }
-static int32_t tColDataUpdateValue72(SColData *pColData, uint8_t *pData, uint32_t nData, int32_t flag) {
+static int32_t tColDataUpdateValue72(SColData *pColData, uint8_t *pData, uint32_t nData, bool forward) {
   ASSERT(0);
   return 0;
 }
-static int32_t (*tColDataUpdateValueImpl[8][3])(SColData *pColData, uint8_t *pData, uint32_t nData, int32_t flag) = {
+static int32_t (*tColDataUpdateValueImpl[8][3])(SColData *pColData, uint8_t *pData, uint32_t nData, bool forward) = {
     {NULL, NULL, NULL},                                                     // 0
     {tColDataUpdateValue10, tColDataUpdateValue11, tColDataUpdateValue12},  // HAS_NONE
     {tColDataUpdateValue20, tColDataUpdateValue21, tColDataUpdateValue22},  // HAS_NULL
@@ -2004,11 +2001,11 @@ static int32_t (*tColDataUpdateValueImpl[8][3])(SColData *pColData, uint8_t *pDa
     {tColDataUpdateValue60, tColDataUpdateValue61, tColDataUpdateValue62},  // HAS_VALUE|HAS_NULL
     {tColDataUpdateValue70, tColDataUpdateValue71, tColDataUpdateValue72},  // HAS_VALUE|HAS_NULL|HAS_NONE
 };
-int32_t tColDataUpdateValue(SColData *pColData, SColVal *pColVal, int32_t flag) {
+int32_t tColDataUpdateValue(SColData *pColData, SColVal *pColVal, bool forward) {
   ASSERT(pColData->cid == pColVal->cid && pColData->type == pColVal->type);
   return tColDataUpdateValueImpl[pColData->flag][pColVal->flag](
       pColData, IS_VAR_DATA_TYPE(pColData->type) ? pColVal->value.pData : (uint8_t *)&pColVal->value.val,
-      pColVal->value.nData, flag);
+      pColVal->value.nData, forward);
 }
 
 static FORCE_INLINE void tColDataGetValue1(SColData *pColData, int32_t iVal, SColVal *pColVal) {  // HAS_NONE
diff --git a/source/dnode/vnode/src/inc/tsdb.h b/source/dnode/vnode/src/inc/tsdb.h
index de764045b22a0aa1e2326ca4b8e895cd8bf5b3a8..34dfe43b3e91e4f864090adad06ada61c3df722c 100644
--- a/source/dnode/vnode/src/inc/tsdb.h
+++ b/source/dnode/vnode/src/inc/tsdb.h
@@ -163,7 +163,7 @@ void    tBlockDataDestroy(SBlockData *pBlockData);
 int32_t tBlockDataInit(SBlockData *pBlockData, TABLEID *pId, STSchema *pTSchema, int16_t *aCid, int32_t nCid);
 void    tBlockDataReset(SBlockData *pBlockData);
 int32_t tBlockDataAppendRow(SBlockData *pBlockData, TSDBROW *pRow, STSchema *pTSchema, int64_t uid);
-int32_t tBlockDataAppendRowEx(SBlockData *pBlockData, TSDBROW *pRow, STSchema *pTSchema, int64_t uid);
+int32_t tBlockDataUpsertRow(SBlockData *pBlockData, TSDBROW *pRow, STSchema *pTSchema, int64_t uid);
 void    tBlockDataClear(SBlockData *pBlockData);
 void    tBlockDataGetColData(SBlockData *pBlockData, int16_t cid, SColData **ppColData);
 int32_t tCmprBlockData(SBlockData *pBlockData, int8_t cmprAlg, uint8_t **ppOut, int32_t *szOut, uint8_t *aBuf[],
diff --git a/source/dnode/vnode/src/tsdb/tsdbCompact.c b/source/dnode/vnode/src/tsdb/tsdbCompact.c
index 85d0b8223cdf7057c36a013b1edca5765bf07f61..16a255a1e0ca2243668a0b1cea0660703174dbcb 100644
--- a/source/dnode/vnode/src/tsdb/tsdbCompact.c
+++ b/source/dnode/vnode/src/tsdb/tsdbCompact.c
@@ -855,7 +855,7 @@ static int32_t tsdbCompactFileSet(STsdbCompactor *pCompactor) {
   }
 
   while (pRowInfo) {
-    // write block data according to table id if necessary
+    // write block data according to table id if necessary (TODO)
     if ((pCompactor->tableId.suid != pRowInfo->suid) ||
         (pCompactor->tableId.uid != pRowInfo->uid &&
          (pRowInfo->suid == 0 || (pCompactor->bData.uid && pCompactor->bData.nRow >= pCompactor->minRows)))) {
@@ -869,18 +869,17 @@ static int32_t tsdbCompactFileSet(STsdbCompactor *pCompactor) {
       TSDB_CHECK_CODE(code, lino, _exit);
     }
 
-    // check if append/merge the row causes nRow exceed maxRows
+    // check if append/merge the row causes nRow exceed maxRows (TODO)
     if (0 /* add the row causes row exceed maxRows */) {
       code = tsdbCompactWriteBlockData(pCompactor);
       TSDB_CHECK_CODE(code, lino, _exit);
     }
 
     // append/merge the row
-    // code = tBlockDataAppendRowEx(&pCompactor->bData, &pRowInfo->row, pTSchema, pRowInfo->uid);
-    // TSDB_CHECK_CODE(code, lino, _exit);
-
     pCompactor->tableId.suid = pRowInfo->suid;
     pCompactor->tableId.uid = pRowInfo->uid;
+    code = tBlockDataUpsertRow(&pCompactor->bData, &pRowInfo->row, pTSchema, pRowInfo->uid);
+    TSDB_CHECK_CODE(code, lino, _exit);
 
     // iter to the next row
     code = tsdbCompactNextRow(pCompactor);
diff --git a/source/dnode/vnode/src/tsdb/tsdbUtil.c b/source/dnode/vnode/src/tsdb/tsdbUtil.c
index b47d49dfb7966f9b3173ebbd87d5410e4deab272..5c0424de34ce7e35f2ac189741662b321ceb1d8a 100644
--- a/source/dnode/vnode/src/tsdb/tsdbUtil.c
+++ b/source/dnode/vnode/src/tsdb/tsdbUtil.c
@@ -1030,7 +1030,12 @@ void tBlockDataClear(SBlockData *pBlockData) {
   }
 }
 
-static int32_t tBlockDataAppendBlockRow(SBlockData *pBlockData, SBlockData *pBlockDataFrom, int32_t iRow) {
+/* flag > 0: forward update
+ * flag == 0: insert
+ * flag < 0: backward update
+ */
+static int32_t tBlockDataUpsertBlockRow(SBlockData *pBlockData, SBlockData *pBlockDataFrom, int32_t iRow,
+                                        int32_t flag) {
   int32_t code = 0;
 
   SColVal   cv = {0};
@@ -1045,12 +1050,21 @@ static int32_t tBlockDataAppendBlockRow(SBlockData *pBlockData, SBlockData *pBlo
     }
 
     if (pColDataFrom == NULL || pColDataFrom->cid > pColDataTo->cid) {
-      code = tColDataAppendValue(pColDataTo, &COL_VAL_NONE(pColDataTo->cid, pColDataTo->type));
+      cv = COL_VAL_NONE(pColDataTo->cid, pColDataTo->type);
+      if (flag) {
+        code = tColDataUpdateValue(pColDataTo, &cv, flag > 0);
+      } else {
+        code = tColDataAppendValue(pColDataTo, &cv);
+      }
       if (code) goto _exit;
     } else {
       tColDataGetValue(pColDataFrom, iRow, &cv);
 
-      code = tColDataAppendValue(pColDataTo, &cv);
+      if (flag) {
+        code = tColDataUpdateValue(pColDataTo, &cv, flag > 0);
+      } else {
+        code = tColDataAppendValue(pColDataTo, &cv);
+      }
       if (code) goto _exit;
 
       pColDataFrom = (++iColDataFrom < pBlockDataFrom->nColData) ? &pBlockDataFrom->aColData[iColDataFrom] : NULL;
@@ -1082,12 +1096,11 @@ int32_t tBlockDataAppendRow(SBlockData *pBlockData, TSDBROW *pRow, STSchema *pTS
   if (code) goto _exit;
   pBlockData->aTSKEY[pBlockData->nRow] = TSDBROW_TS(pRow);
 
-  SColVal cv = {0};
   if (pRow->type == TSDBROW_ROW_FMT) {
-    code = tRowAppendToColData(pRow->pTSRow, pTSchema, pBlockData->aColData, pBlockData->nColData);
+    code = tRowUpsertColData(pRow->pTSRow, pTSchema, pBlockData->aColData, pBlockData->nColData, 0 /* append */);
     if (code) goto _exit;
   } else if (pRow->type == TSDBROW_COL_FMT) {
-    code = tBlockDataAppendBlockRow(pBlockData, pRow->pBlockData, pRow->iRow);
+    code = tBlockDataUpsertBlockRow(pBlockData, pRow->pBlockData, pRow->iRow, 0 /* append */);
     if (code) goto _exit;
   } else {
     ASSERT(0);
@@ -1097,15 +1110,44 @@ int32_t tBlockDataAppendRow(SBlockData *pBlockData, TSDBROW *pRow, STSchema *pTS
 _exit:
   return code;
 }
+static int32_t tBlockDataUpdateRow(SBlockData *pBlockData, TSDBROW *pRow, STSchema *pTSchema) {
+  int32_t code = 0;
+
+  // version
+  int64_t lversion = pBlockData->aVersion[pBlockData->nRow - 1];
+  int64_t rversion = TSDBROW_VERSION(pRow);
+  ASSERT(lversion != rversion);
+  if (rversion > lversion) {
+    pBlockData->aVersion[pBlockData->nRow - 1] = rversion;
+  }
 
-int32_t tBlockDataAppendRowEx(SBlockData *pBlockData, TSDBROW *pRow, STSchema *pTSchema, int64_t uid) {
+  // update other rows
+  if (pRow->type == TSDBROW_ROW_FMT) {
+    code = tRowUpsertColData(pRow->pTSRow, pTSchema, pBlockData->aColData, pBlockData->nColData,
+                             (rversion > lversion) ? 1 : -1 /* update */);
+    if (code) goto _exit;
+  } else if (pRow->type == TSDBROW_COL_FMT) {
+    code = tBlockDataUpsertBlockRow(pBlockData, pRow->pBlockData, pRow->iRow, (rversion > lversion) ? 1 : -1);
+    if (code) goto _exit;
+  } else {
+    ASSERT(0);
+  }
+
+_exit:
+  return code;
+}
+
+int32_t tBlockDataUpsertRow(SBlockData *pBlockData, TSDBROW *pRow, STSchema *pTSchema, int64_t uid) {
   int32_t code = 0;
 
   ASSERT(pBlockData->suid || pBlockData->uid);
 
   if (pBlockData->nRow == 0) {
     pBlockData->uid = uid;
-  } else if (pBlockData->uid && pBlockData->uid != uid) {
+    return tBlockDataAppendRow(pBlockData, pRow, pTSchema, uid);
+  }
+
+  if (pBlockData->uid && pBlockData->uid != uid) {
     ASSERT(pBlockData->suid);
 
     code = tRealloc((uint8_t **)&pBlockData->aUid, sizeof(int64_t) * (pBlockData->nRow + 1));
@@ -1118,7 +1160,13 @@ int32_t tBlockDataAppendRowEx(SBlockData *pBlockData, TSDBROW *pRow, STSchema *p
     pBlockData->uid = 0;
   }
 
-  return tBlockDataAppendRow(pBlockData, pRow, pTSchema, uid);
+  // decide append/update row
+  int64_t luid = pBlockData->uid ? pBlockData->uid : pBlockData->aUid[pBlockData->nRow - 1];
+  if (luid == uid && pBlockData->aTSKEY[pBlockData->nRow - 1] == TSDBROW_TS(pRow)) {
+    return tBlockDataUpdateRow(pBlockData, pRow, pTSchema);
+  } else {
+    return tBlockDataAppendRow(pBlockData, pRow, pTSchema, uid);
+  }
 }
 
 void tBlockDataGetColData(SBlockData *pBlockData, int16_t cid, SColData **ppColData) {