diff --git a/source/dnode/mnode/impl/src/mndStb.c b/source/dnode/mnode/impl/src/mndStb.c
index 8b708c3e0f6f06c1e784f3a7e3807371041716b8..dff0ef261fc4b655d13b43ad6f2b3222a0f356b7 100644
--- a/source/dnode/mnode/impl/src/mndStb.c
+++ b/source/dnode/mnode/impl/src/mndStb.c
@@ -2742,7 +2742,7 @@ void mndExtractTbNameFromStbFullName(const char *stbFullName, char *dst, int32_t
 //      varDataSetLen(stbName, strlen(&stbName[VARSTR_HEADER_SIZE]));
 //
 //      SColumnInfoData *pColInfo = taosArrayGet(pBlock->pDataBlock, cols++);
-//      colDataAppend(pColInfo, numOfRows, (const char *)stbName, false);
+//      colDataSetVal(pColInfo, numOfRows, (const char *)stbName, false);
 //
 //      char db[TSDB_DB_NAME_LEN + VARSTR_HEADER_SIZE] = {0};
 //      tNameFromString(&name, pStb->db, T_NAME_ACCT | T_NAME_DB);
@@ -2750,29 +2750,29 @@ void mndExtractTbNameFromStbFullName(const char *stbFullName, char *dst, int32_t
 //      varDataSetLen(db, strlen(varDataVal(db)));
 //
 //      pColInfo = taosArrayGet(pBlock->pDataBlock, cols++);
-//      colDataAppend(pColInfo, numOfRows, (const char *)db, false);
+//      colDataSetVal(pColInfo, numOfRows, (const char *)db, false);
 //
 //      pColInfo = taosArrayGet(pBlock->pDataBlock, cols++);
-//      colDataAppend(pColInfo, numOfRows, (const char *)&pStb->createdTime, false);
+//      colDataSetVal(pColInfo, numOfRows, (const char *)&pStb->createdTime, false);
 //
 //      pColInfo = taosArrayGet(pBlock->pDataBlock, cols++);
-//      colDataAppend(pColInfo, numOfRows, (const char *)&pStb->numOfColumns, false);
+//      colDataSetVal(pColInfo, numOfRows, (const char *)&pStb->numOfColumns, false);
 //
 //      pColInfo = taosArrayGet(pBlock->pDataBlock, cols++);
-//      colDataAppend(pColInfo, numOfRows, (const char *)&pStb->numOfTags, false);
+//      colDataSetVal(pColInfo, numOfRows, (const char *)&pStb->numOfTags, false);
 //
 //      pColInfo = taosArrayGet(pBlock->pDataBlock, cols++);
-//      colDataAppend(pColInfo, numOfRows, (const char *)&pStb->updateTime, false);  // number of tables
+//      colDataSetVal(pColInfo, numOfRows, (const char *)&pStb->updateTime, false);  // number of tables
 //
 //      pColInfo = taosArrayGet(pBlock->pDataBlock, cols++);
 //      if (pStb->commentLen > 0) {
 //        char comment[TSDB_TB_COMMENT_LEN + VARSTR_HEADER_SIZE] = {0};
 //        STR_TO_VARSTR(comment, pStb->comment);
-//        colDataAppend(pColInfo, numOfRows, comment, false);
+//        colDataSetVal(pColInfo, numOfRows, comment, false);
 //      } else if (pStb->commentLen == 0) {
 //        char comment[VARSTR_HEADER_SIZE + VARSTR_HEADER_SIZE] = {0};
 //        STR_TO_VARSTR(comment, "");
-//        colDataAppend(pColInfo, numOfRows, comment, false);
+//        colDataSetVal(pColInfo, numOfRows, comment, false);
 //      } else {
 //        colDataSetNULL(pColInfo, numOfRows);
 //      }
@@ -2782,14 +2782,14 @@ void mndExtractTbNameFromStbFullName(const char *stbFullName, char *dst, int32_t
 //      varDataSetLen(watermark, strlen(varDataVal(watermark)));
 //
 //      pColInfo = taosArrayGet(pBlock->pDataBlock, cols++);
-//      colDataAppend(pColInfo, numOfRows, (const char *)watermark, false);
+//      colDataSetVal(pColInfo, numOfRows, (const char *)watermark, false);
 //
 //      char maxDelay[64 + VARSTR_HEADER_SIZE] = {0};
 //      sprintf(varDataVal(maxDelay), "%" PRId64 "a,%" PRId64 "a", pStb->maxdelay[0], pStb->maxdelay[1]);
 //      varDataSetLen(maxDelay, strlen(varDataVal(maxDelay)));
 //
 //      pColInfo = taosArrayGet(pBlock->pDataBlock, cols++);
-//      colDataAppend(pColInfo, numOfRows, (const char *)maxDelay, false);
+//      colDataSetVal(pColInfo, numOfRows, (const char *)maxDelay, false);
 //
 //      char    rollup[160 + VARSTR_HEADER_SIZE] = {0};
 //      int32_t rollupNum = (int32_t)taosArrayGetSize(pStb->pFuncs);
@@ -2808,7 +2808,7 @@ void mndExtractTbNameFromStbFullName(const char *stbFullName, char *dst, int32_t
 //      varDataSetLen(rollup, strlen(varDataVal(rollup)));
 //
 //      pColInfo = taosArrayGet(pBlock->pDataBlock, cols++);
-//      colDataAppend(pColInfo, numOfRows, (const char *)rollup, false);
+//      colDataSetVal(pColInfo, numOfRows, (const char *)rollup, false);
 //
 //      numOfRows++;
 //      sdbRelease(pSdb, pStb);
@@ -3067,20 +3067,20 @@ static int32_t buildDbColsInfoBlock(const SSDataBlock *p, const SSysTableMeta *p
     for (int32_t j = 0; j < pm->colNum; j++) {
       // table name
       SColumnInfoData *pColInfoData = taosArrayGet(p->pDataBlock, 0);
-      colDataAppend(pColInfoData, numOfRows, tName, false);
+      colDataSetVal(pColInfoData, numOfRows, tName, false);
 
       // database name
       pColInfoData = taosArrayGet(p->pDataBlock, 1);
-      colDataAppend(pColInfoData, numOfRows, dName, false);
+      colDataSetVal(pColInfoData, numOfRows, dName, false);
 
       pColInfoData = taosArrayGet(p->pDataBlock, 2);
-      colDataAppend(pColInfoData, numOfRows, typeName, false);
+      colDataSetVal(pColInfoData, numOfRows, typeName, false);
 
       // col name
       char colName[TSDB_COL_NAME_LEN + VARSTR_HEADER_SIZE] = {0};
       STR_TO_VARSTR(colName, pm->schema[j].name);
       pColInfoData = taosArrayGet(p->pDataBlock, 3);
-      colDataAppend(pColInfoData, numOfRows, colName, false);
+      colDataSetVal(pColInfoData, numOfRows, colName, false);
 
       // col type
       int8_t colType = pm->schema[j].type;
@@ -3095,10 +3095,10 @@ static int32_t buildDbColsInfoBlock(const SSDataBlock *p, const SSysTableMeta *p
                               (int32_t)((pm->schema[j].bytes - VARSTR_HEADER_SIZE) / TSDB_NCHAR_SIZE));
       }
       varDataSetLen(colTypeStr, colTypeLen);
-      colDataAppend(pColInfoData, numOfRows, (char *)colTypeStr, false);
+      colDataSetVal(pColInfoData, numOfRows, (char *)colTypeStr, false);
 
       pColInfoData = taosArrayGet(p->pDataBlock, 5);
-      colDataAppend(pColInfoData, numOfRows, (const char *)&pm->schema[j].bytes, false);
+      colDataSetVal(pColInfoData, numOfRows, (const char *)&pm->schema[j].bytes, false);
       for (int32_t k = 6; k <= 8; ++k) {
         pColInfoData = taosArrayGet(p->pDataBlock, k);
         colDataSetNULL(pColInfoData, numOfRows);
@@ -3192,19 +3192,19 @@ static int32_t mndRetrieveStbCol(SRpcMsg *pReq, SShowObj *pShow, SSDataBlock *pB
     for (int i = 0; i < pStb->numOfColumns; i++) {
       int32_t          cols = 0;
       SColumnInfoData *pColInfo = taosArrayGet(pBlock->pDataBlock, cols++);
-      colDataAppend(pColInfo, numOfRows, (const char *)stbName, false);
+      colDataSetVal(pColInfo, numOfRows, (const char *)stbName, false);
 
       pColInfo = taosArrayGet(pBlock->pDataBlock, cols++);
-      colDataAppend(pColInfo, numOfRows, (const char *)db, false);
+      colDataSetVal(pColInfo, numOfRows, (const char *)db, false);
 
       pColInfo = taosArrayGet(pBlock->pDataBlock, cols++);
-      colDataAppend(pColInfo, numOfRows, typeName, false);
+      colDataSetVal(pColInfo, numOfRows, typeName, false);
 
       // col name
       char colName[TSDB_COL_NAME_LEN + VARSTR_HEADER_SIZE] = {0};
       STR_TO_VARSTR(colName, pStb->pColumns[i].name);
       pColInfo = taosArrayGet(pBlock->pDataBlock, cols++);
-      colDataAppend(pColInfo, numOfRows, colName, false);
+      colDataSetVal(pColInfo, numOfRows, colName, false);
 
       // col type
       int8_t colType = pStb->pColumns[i].type;
@@ -3219,10 +3219,10 @@ static int32_t mndRetrieveStbCol(SRpcMsg *pReq, SShowObj *pShow, SSDataBlock *pB
                               (int32_t)((pStb->pColumns[i].bytes - VARSTR_HEADER_SIZE) / TSDB_NCHAR_SIZE));
       }
       varDataSetLen(colTypeStr, colTypeLen);
-      colDataAppend(pColInfo, numOfRows, (char *)colTypeStr, false);
+      colDataSetVal(pColInfo, numOfRows, (char *)colTypeStr, false);
 
       pColInfo = taosArrayGet(pBlock->pDataBlock, cols++);
-      colDataAppend(pColInfo, numOfRows, (const char *)&pStb->pColumns[i].bytes, false);
+      colDataSetVal(pColInfo, numOfRows, (const char *)&pStb->pColumns[i].bytes, false);
       while (cols < pShow->numOfColumns) {
         pColInfo = taosArrayGet(pBlock->pDataBlock, cols++);
         colDataSetNULL(pColInfo, numOfRows);
diff --git a/source/dnode/vnode/src/tq/tqRead.c b/source/dnode/vnode/src/tq/tqRead.c
index 1fbdb255281d731478da87fbc00c26e0bb17a618..9b6d97d6e2030fdf089cef14c6c590629d647bad 100644
--- a/source/dnode/vnode/src/tq/tqRead.c
+++ b/source/dnode/vnode/src/tq/tqRead.c
@@ -503,6 +503,74 @@ int32_t tqMaskBlock(SSchemaWrapper* pDst, SSDataBlock* pBlock, const SSchemaWrap
   return 0;
 }
 
+static int32_t buildResSDataBlock(SSDataBlock* pBlock, SSchemaWrapper* pSchema, const SArray* pColIdList) {
+  if (blockDataGetNumOfCols(pBlock) > 0) {
+    return TSDB_CODE_SUCCESS;
+  }
+
+  int32_t numOfCols = taosArrayGetSize(pColIdList);
+
+  if (numOfCols == 0) {  // all columns are required
+    for (int32_t i = 0; i < pSchema->nCols; ++i) {
+      SSchema*        pColSchema = &pSchema->pSchema[i];
+      SColumnInfoData colInfo = createColumnInfoData(pColSchema->type, pColSchema->bytes, pColSchema->colId);
+
+      int32_t code = blockDataAppendColInfo(pBlock, &colInfo);
+      if (code != TSDB_CODE_SUCCESS) {
+        blockDataFreeRes(pBlock);
+        return TSDB_CODE_OUT_OF_MEMORY;
+      }
+    }
+  } else {
+    if (numOfCols > pSchema->nCols) {
+      numOfCols = pSchema->nCols;
+    }
+
+    int32_t i = 0;
+    int32_t j = 0;
+    while (i < pSchema->nCols && j < numOfCols) {
+      SSchema* pColSchema = &pSchema->pSchema[i];
+      col_id_t colIdSchema = pColSchema->colId;
+
+      col_id_t colIdNeed = *(col_id_t*)taosArrayGet(pColIdList, j);
+      if (colIdSchema < colIdNeed) {
+        i++;
+      } else if (colIdSchema > colIdNeed) {
+        j++;
+      } else {
+        SColumnInfoData colInfo = createColumnInfoData(pColSchema->type, pColSchema->bytes, pColSchema->colId);
+        int32_t         code = blockDataAppendColInfo(pBlock, &colInfo);
+        if (code != TSDB_CODE_SUCCESS) {
+          return -1;
+        }
+        i++;
+        j++;
+      }
+    }
+  }
+
+  return TSDB_CODE_SUCCESS;
+}
+
+static int32_t doSetVal(SColumnInfoData* pColumnInfoData, int32_t rowIndex, SColVal* pColVal) {
+  int32_t code = TSDB_CODE_SUCCESS;
+
+  if (IS_STR_DATA_TYPE(pColVal->type)) {
+    char val[65535 + 2] = {0};
+    if (pColVal->value.pData != NULL) {
+      memcpy(varDataVal(val), pColVal->value.pData, pColVal->value.nData);
+      varDataSetLen(val, pColVal->value.nData);
+      code = colDataSetVal(pColumnInfoData, rowIndex, val, !COL_VAL_IS_VALUE(pColVal));
+    } else {
+      colDataSetNULL(pColumnInfoData, rowIndex);
+    }
+  } else {
+    code = colDataSetVal(pColumnInfoData, rowIndex, (void*)&pColVal->value.val, !COL_VAL_IS_VALUE(pColVal));
+  }
+
+  return code;
+}
+
 int32_t tqRetrieveDataBlock(STqReader* pReader, SSubmitTbData** pSubmitTbDataRet) {
   tqDebug("tq reader retrieve data block %p, index:%d", pReader->msg.msgStr, pReader->nextBlk);
 
@@ -538,53 +606,11 @@ int32_t tqRetrieveDataBlock(STqReader* pReader, SSubmitTbData** pSubmitTbDataRet
     pReader->cachedSchemaSuid = suid;
     pReader->cachedSchemaVer = sversion;
 
-    SSchemaWrapper* pSchemaWrapper = pReader->pSchemaWrapper;
-    if (blockDataGetNumOfCols(pBlock) > 0) {
-      blockDataDestroy(pReader->pResBlock);
-      pReader->pResBlock = createDataBlock();
-      pBlock = pReader->pResBlock;
-
-      pBlock->info.id.uid = uid;
-      pBlock->info.version = pReader->msg.ver;
-    }
-
-    int32_t numOfCols = taosArrayGetSize(pReader->pColIdList);
-    if (numOfCols == 0) {  // all columns are required
-      for (int32_t i = 0; i < pSchemaWrapper->nCols; ++i) {
-        SSchema*        pColSchema = &pSchemaWrapper->pSchema[i];
-        SColumnInfoData colInfo = createColumnInfoData(pColSchema->type, pColSchema->bytes, pColSchema->colId);
-
-        int32_t code = blockDataAppendColInfo(pBlock, &colInfo);
-        if (code != TSDB_CODE_SUCCESS) {
-          blockDataFreeRes(pBlock);
-          return -1;
-        }
-      }
-    } else {
-      if (numOfCols > pSchemaWrapper->nCols) {
-        numOfCols = pSchemaWrapper->nCols;
-      }
-
-      int32_t i = 0;
-      int32_t j = 0;
-      while (i < pSchemaWrapper->nCols && j < numOfCols) {
-        SSchema* pColSchema = &pSchemaWrapper->pSchema[i];
-        col_id_t colIdSchema = pColSchema->colId;
-
-        col_id_t colIdNeed = *(col_id_t*)taosArrayGet(pReader->pColIdList, j);
-        if (colIdSchema < colIdNeed) {
-          i++;
-        } else if (colIdSchema > colIdNeed) {
-          j++;
-        } else {
-          SColumnInfoData colInfo = createColumnInfoData(pColSchema->type, pColSchema->bytes, pColSchema->colId);
-          int32_t         code = blockDataAppendColInfo(pBlock, &colInfo);
-          if (code != TSDB_CODE_SUCCESS) {
-            return -1;
-          }
-          i++;
-          j++;
-        }
+    ASSERT(pReader->cachedSchemaVer == pReader->pSchemaWrapper->version);
+    if (blockDataGetNumOfCols(pBlock) == 0) {
+      int32_t code = buildResSDataBlock(pReader->pResBlock, pReader->pSchemaWrapper, pReader->pColIdList);
+      if (code != TSDB_CODE_SUCCESS) {
+        return code;
       }
     }
   }
@@ -632,30 +658,15 @@ int32_t tqRetrieveDataBlock(STqReader* pReader, SSubmitTbData** pSubmitTbDataRet
       } else if (pCol->cid == pColData->info.colId) {
         for (int32_t i = 0; i < pCol->nVal; i++) {
           tColDataGetValue(pCol, i, &colVal);
-          if (IS_STR_DATA_TYPE(colVal.type)) {
-            if (colVal.value.pData != NULL) {
-              char val[65535 + 2] = {0};
-              memcpy(varDataVal(val), colVal.value.pData, colVal.value.nData);
-              varDataSetLen(val, colVal.value.nData);
-              if (colDataAppend(pColData, i, val, !COL_VAL_IS_VALUE(&colVal)) < 0) {
-                return -1;
-              }
-            } else {
-              colDataSetNULL(pColData, i);
-            }
-          } else {
-            if (colDataAppend(pColData, i, (void*)&colVal.value.val, !COL_VAL_IS_VALUE(&colVal)) < 0) {
-              return -1;
-            }
+          int32_t code = doSetVal(pColData, i, &colVal);
+          if (code != TSDB_CODE_SUCCESS) {
+            return code;
           }
         }
         sourceIdx++;
         targetIdx++;
       } else {
-        for (int32_t i = 0; i < pCol->nVal; i++) {
-          colDataSetNULL(pColData, i);
-        }
-
+        colDataSetNNULL(pColData, 0, pCol->nVal);
         targetIdx++;
       }
     }
@@ -681,21 +692,9 @@ int32_t tqRetrieveDataBlock(STqReader* pReader, SSubmitTbData** pSubmitTbDataRet
             sourceIdx++;
             continue;
           } else if (colVal.cid == pColData->info.colId) {
-            if (IS_STR_DATA_TYPE(colVal.type)) {
-              if (colVal.value.pData != NULL) {
-                char val[65535 + 2] = {0};
-                memcpy(varDataVal(val), colVal.value.pData, colVal.value.nData);
-                varDataSetLen(val, colVal.value.nData);
-                if (colDataAppend(pColData, i, val, !COL_VAL_IS_VALUE(&colVal)) < 0) {
-                  return -1;
-                }
-              } else {
-                colDataSetNULL(pColData, i);
-              }
-            } else {
-              if (colDataAppend(pColData, i, (void*)&colVal.value.val, !COL_VAL_IS_VALUE(&colVal)) < 0) {
-                return -1;
-              }
+            int32_t code = doSetVal(pColData, i, &colVal);
+            if (code != TSDB_CODE_SUCCESS) {
+              return code;
             }
 
             sourceIdx++;
@@ -833,14 +832,14 @@ int32_t tqRetrieveTaosxBlock(STqReader* pReader, SArray* blocks, SArray* schemas
               char val[65535 + 2];
               memcpy(varDataVal(val), colVal.value.pData, colVal.value.nData);
               varDataSetLen(val, colVal.value.nData);
-              if (colDataAppend(pColData, curRow - lastRow, val, !COL_VAL_IS_VALUE(&colVal)) < 0) {
+              if (colDataSetVal(pColData, curRow - lastRow, val, !COL_VAL_IS_VALUE(&colVal)) < 0) {
                 goto FAIL;
               }
             } else {
               colDataSetNULL(pColData, curRow - lastRow);
             }
           } else {
-            if (colDataAppend(pColData, curRow - lastRow, (void*)&colVal.value.val, !COL_VAL_IS_VALUE(&colVal)) < 0) {
+            if (colDataSetVal(pColData, curRow - lastRow, (void*)&colVal.value.val, !COL_VAL_IS_VALUE(&colVal)) < 0) {
               goto FAIL;
             }
           }
@@ -930,14 +929,14 @@ int32_t tqRetrieveTaosxBlock(STqReader* pReader, SArray* blocks, SArray* schemas
               char val[65535 + 2];
               memcpy(varDataVal(val), colVal.value.pData, colVal.value.nData);
               varDataSetLen(val, colVal.value.nData);
-              if (colDataAppend(pColData, curRow - lastRow, val, !COL_VAL_IS_VALUE(&colVal)) < 0) {
+              if (colDataSetVal(pColData, curRow - lastRow, val, !COL_VAL_IS_VALUE(&colVal)) < 0) {
                 goto FAIL;
               }
             } else {
               colDataSetNULL(pColData, curRow - lastRow);
             }
           } else {
-            if (colDataAppend(pColData, curRow - lastRow, (void*)&colVal.value.val, !COL_VAL_IS_VALUE(&colVal)) < 0) {
+            if (colDataSetVal(pColData, curRow - lastRow, (void*)&colVal.value.val, !COL_VAL_IS_VALUE(&colVal)) < 0) {
               goto FAIL;
             }
           }