diff --git a/src/client/src/tscParseInsert.c b/src/client/src/tscParseInsert.c
index 125e28f17778baead6b2be8d8409f2259d7d77e5..0750abdf6ff991d8c19eb63b77c5ba9ff9ddfb03 100644
--- a/src/client/src/tscParseInsert.c
+++ b/src/client/src/tscParseInsert.c
@@ -762,35 +762,32 @@ void tscSortRemoveDataBlockDupRowsRaw(STableDataBlocks *dataBuf) {
   if (!dataBuf->ordered) {
     char *pBlockData = pBlocks->data;
     qsort(pBlockData, pBlocks->numOfRows, dataBuf->rowSize, rowDataCompar);
+    dataBuf->ordered = true;
 
-    int32_t i = 0;
-    int32_t j = 1;
-
-    while (j < pBlocks->numOfRows) {
-      TSKEY ti = *(TSKEY *)(pBlockData + dataBuf->rowSize * i);
-      TSKEY tj = *(TSKEY *)(pBlockData + dataBuf->rowSize * j);
+    if(tsClientMerge) {
+      int32_t i = 0;
+      int32_t j = 1;
+      while (j < pBlocks->numOfRows) {
+        TSKEY ti = *(TSKEY *)(pBlockData + dataBuf->rowSize * i);
+        TSKEY tj = *(TSKEY *)(pBlockData + dataBuf->rowSize * j);
 
-      if (ti == tj) {
-        if (dataBuf->pTableMeta && dataBuf->pTableMeta->tableInfo.update != TD_ROW_DISCARD_UPDATE) {
-          memmove(pBlockData + dataBuf->rowSize * i, pBlockData + dataBuf->rowSize * j, dataBuf->rowSize);
+        if (ti == tj) {
+          if (dataBuf->pTableMeta && dataBuf->pTableMeta->tableInfo.update != TD_ROW_DISCARD_UPDATE) {
+            memmove(pBlockData + dataBuf->rowSize * i, pBlockData + dataBuf->rowSize * j, dataBuf->rowSize);
+          }
+          ++j;
+          continue;
         }
 
+        int32_t nextPos = (++i);
+        if (nextPos != j) {
+          memmove(pBlockData + dataBuf->rowSize * nextPos, pBlockData + dataBuf->rowSize * j, dataBuf->rowSize);
+        }
         ++j;
-        continue;
-      }
-
-      int32_t nextPos = (++i);
-      if (nextPos != j) {
-        memmove(pBlockData + dataBuf->rowSize * nextPos, pBlockData + dataBuf->rowSize * j, dataBuf->rowSize);
-      }
-
-      ++j;
+      }      
+      pBlocks->numOfRows = i + 1;
+      dataBuf->size = sizeof(SSubmitBlk) + dataBuf->rowSize * pBlocks->numOfRows;
     }
-
-    dataBuf->ordered = true;
-
-    pBlocks->numOfRows = i + 1;
-    dataBuf->size = sizeof(SSubmitBlk) + dataBuf->rowSize * pBlocks->numOfRows;
   }
 
   dataBuf->prevTS = INT64_MIN;
@@ -836,32 +833,33 @@ int tscSortRemoveDataBlockDupRows(STableDataBlocks *dataBuf, SBlockKeyInfo *pBlk
   if (!dataBuf->ordered) {
     pBlkKeyTuple = pBlkKeyInfo->pKeyTuple;
     qsort(pBlkKeyTuple, nRows, sizeof(SBlockKeyTuple), rowDataCompar);
+    dataBuf->ordered = true;
 
-    pBlkKeyTuple = pBlkKeyInfo->pKeyTuple;
-    int32_t i = 0;
-    int32_t j = 1;
-    while (j < nRows) {
-      TSKEY ti = (pBlkKeyTuple + i)->skey;
-      TSKEY tj = (pBlkKeyTuple + j)->skey;
-
-      if (ti == tj) {
-        if (dataBuf->pTableMeta && dataBuf->pTableMeta->tableInfo.update != TD_ROW_DISCARD_UPDATE) {
-          memmove(pBlkKeyTuple + i, pBlkKeyTuple + j, sizeof(SBlockKeyTuple));
+    if(tsClientMerge) {
+      pBlkKeyTuple = pBlkKeyInfo->pKeyTuple;
+      int32_t i = 0;
+      int32_t j = 1;
+      while (j < nRows) {
+        TSKEY ti = (pBlkKeyTuple + i)->skey;
+        TSKEY tj = (pBlkKeyTuple + j)->skey;
+
+        if (ti == tj) {
+          if (dataBuf->pTableMeta && dataBuf->pTableMeta->tableInfo.update != TD_ROW_DISCARD_UPDATE) {
+            memmove(pBlkKeyTuple + i, pBlkKeyTuple + j, sizeof(SBlockKeyTuple));
+          }
+
+          ++j;
+          continue;
         }
 
+        int32_t nextPos = (++i);
+        if (nextPos != j) {
+          memmove(pBlkKeyTuple + nextPos, pBlkKeyTuple + j, sizeof(SBlockKeyTuple));
+        }
         ++j;
-        continue;
-      }
-
-      int32_t nextPos = (++i);
-      if (nextPos != j) {
-        memmove(pBlkKeyTuple + nextPos, pBlkKeyTuple + j, sizeof(SBlockKeyTuple));
       }
-      ++j;
-    }
-
-    dataBuf->ordered = true;
-    pBlocks->numOfRows = i + 1;
+      pBlocks->numOfRows = i + 1;
+    } 
   }
 
   dataBuf->size = sizeof(SSubmitBlk) + pBlocks->numOfRows * extendedRowSize;
diff --git a/src/common/inc/tglobal.h b/src/common/inc/tglobal.h
index a384cf6e70485b8f7d1b06b7f7e86ba92776b547..1e1e2617a953e6d4156e3032266bc8b1bdf8090d 100644
--- a/src/common/inc/tglobal.h
+++ b/src/common/inc/tglobal.h
@@ -209,6 +209,8 @@ extern int32_t wDebugFlag;
 extern int32_t cqDebugFlag;
 extern int32_t debugFlag;
 
+int8_t tsClientMerge;
+
 #ifdef TD_TSZ
 // lossy 
 extern char lossyColumns[];
@@ -219,6 +221,7 @@ extern uint32_t curRange;
 extern char Compressor[];
 #endif
 
+
 typedef struct {
   char dir[TSDB_FILENAME_LEN];
   int  level;
diff --git a/src/common/src/tglobal.c b/src/common/src/tglobal.c
index 876eb4fa92bada1d22e0e43b6d6532d31a0b913c..f1a7e4f7fd12a85ed1b8b503db35fba7211fc788 100644
--- a/src/common/src/tglobal.c
+++ b/src/common/src/tglobal.c
@@ -254,6 +254,8 @@ int32_t tsdbDebugFlag = 131;
 int32_t cqDebugFlag = 131;
 int32_t fsDebugFlag = 135;
 
+int8_t tsClientMerge = 0;
+
 #ifdef TD_TSZ
 //
 // lossy compress 6
@@ -1581,6 +1583,16 @@ static void doInitGlobalConfig(void) {
   cfg.unitType = TAOS_CFG_UTYPE_NONE;
   taosInitConfigOption(cfg);
 
+  cfg.option = "clientMerge";
+  cfg.ptr = &tsClientMerge;
+  cfg.valType = TAOS_CFG_VTYPE_INT8;
+  cfg.cfgType = TSDB_CFG_CTYPE_B_CONFIG | TSDB_CFG_CTYPE_B_SHOW;
+  cfg.minValue = 0;
+  cfg.maxValue = 1;
+  cfg.ptrLength = 1;
+  cfg.unitType = TAOS_CFG_UTYPE_NONE;
+  taosInitConfigOption(cfg);
+
 #ifdef TD_TSZ
   // lossy compress
   cfg.option = "lossyColumns";
diff --git a/src/query/src/qExecutor.c b/src/query/src/qExecutor.c
index 42787f22190e3fd7685af6598b51fc9c9699d0c2..73c93dba83530b0bb2cfc79552ba953f309a77b1 100644
--- a/src/query/src/qExecutor.c
+++ b/src/query/src/qExecutor.c
@@ -1296,9 +1296,6 @@ static void projectApplyFunctions(SQueryRuntimeEnv *pRuntimeEnv, SQLFunctionCtx
     if (pCtx[k].currentStage == MERGE_STAGE) {
       pCtx[k].order = TSDB_ORDER_ASC;
     }
-
-    pCtx[k].startTs = pQueryAttr->window.skey;
-
     if (pCtx[k].functionId < 0) {
       // load the script and exec
       SUdfInfo* pUdfInfo = pRuntimeEnv->pUdfInfo;
diff --git a/src/util/inc/tconfig.h b/src/util/inc/tconfig.h
index 5bd69aece2ffa2166c268b437549c95a30608383..d6a1cb113a43874ee77b096e75959e02e4aa6747 100644
--- a/src/util/inc/tconfig.h
+++ b/src/util/inc/tconfig.h
@@ -20,7 +20,7 @@
 extern "C" {
 #endif
 
-#define TSDB_CFG_MAX_NUM    119  
+#define TSDB_CFG_MAX_NUM    120  
 #define TSDB_CFG_PRINT_LEN  23
 #define TSDB_CFG_OPTION_LEN 24
 #define TSDB_CFG_VALUE_LEN  41
diff --git a/src/util/src/tskiplist.c b/src/util/src/tskiplist.c
index 98fd9c094cba3e779c9f203fdacc548a3bda5ef4..9f00b1750bdba64d06c51a9eb6d7de81bf725d1a 100644
--- a/src/util/src/tskiplist.c
+++ b/src/util/src/tskiplist.c
@@ -163,6 +163,10 @@ void tSkipListPutBatchByIter(SSkipList *pSkipList, void *iter, iter_next_fn_t it
       for (int i = 0; i < pSkipList->maxLevel; i++) {
         forward[i] = SL_NODE_GET_BACKWARD_POINTER(pSkipList->pTail, i);
       }
+    } else if(compare == 0) {
+      // same need special deal
+      forward[0] = SL_NODE_GET_BACKWARD_POINTER(SL_NODE_GET_BACKWARD_POINTER(pSkipList->pTail,0),0);
+      hasDup = true;
     } else {
       SSkipListNode *px = pSkipList->pHead;
       for (int i = pSkipList->maxLevel - 1; i >= 0; --i) {