diff --git a/src/kit/taosdump/taosdump.c b/src/kit/taosdump/taosdump.c
index f89dc6cb78..588d21574b 100644
--- a/src/kit/taosdump/taosdump.c
+++ b/src/kit/taosdump/taosdump.c
@@ -698,79 +698,97 @@ int32_t taosSaveTableOfMetricToTempFile(TAOS *taosCon, char* metric, struct argu
 
   sprintf(tmpCommand, "select tbname from %s", metric);
   
-  TAOS_RES *result = taos_query(taosCon, tmpCommand);
-  int32_t code = taos_errno(result);
+  TAOS_RES *res = taos_query(taosCon, tmpCommand);
+  int32_t code = taos_errno(res);
   if (code != 0) {
     fprintf(stderr, "failed to run command %s\n", tmpCommand);
     free(tmpCommand);
-    taos_free_result(result);
+    taos_free_result(res);
+    return -1;
+  }
+  free(tmpCommand);
+
+  char     tmpBuf[TSDB_FILENAME_LEN + 1];
+  memset(tmpBuf, 0, TSDB_FILENAME_LEN);
+  sprintf(tmpBuf, ".select-tbname.tmp");
+  fd = open(tmpBuf, O_RDWR | O_CREAT | O_TRUNC, S_IRWXU | S_IRGRP | S_IXGRP | S_IROTH);
+  if (fd == -1) {
+    fprintf(stderr, "failed to open temp file: %s\n", tmpBuf);
+    taos_free_result(res);
     return -1;
   }
 
-  int table_batch = arguments->table_batch;
-  int affectdRows =  taos_affected_rows(result);
-  if (affectdRows <= 0) {
-    free(tmpCommand);
-    taos_free_result(result);
-    return -1;
-  }
-
-  int maxNumOfThread = affectdRows / table_batch + 1;
-  if (maxNumOfThread > 2 * g_numOfCores) {
-    maxNumOfThread = 2 * g_numOfCores;
-  }
-
-  table_batch = affectdRows / maxNumOfThread + 1;
-
-  TAOS_FIELD *fields = taos_fetch_fields(result);
-
-  int32_t  numOfTable  = 0;
-  int32_t  numOfThread = *totalNumOfThread;
-  char     tmpFileName[TSDB_FILENAME_LEN + 1];
-  while ((row = taos_fetch_row(result)) != NULL) {
-    if (0 == numOfTable) {
-      memset(tmpFileName, 0, TSDB_FILENAME_LEN);
-      sprintf(tmpFileName, ".tables.tmp.%d", numOfThread);
-      fd = open(tmpFileName, O_RDWR | O_CREAT, S_IRWXU | S_IRGRP | S_IXGRP | S_IROTH);
-      if (fd == -1) {
-        fprintf(stderr, "failed to open temp file: %s\n", tmpFileName);
-        taos_free_result(result);
-        for (int32_t loopCnt = 0; loopCnt < numOfThread; loopCnt++) {
-          sprintf(tmpFileName, ".tables.tmp.%d", loopCnt);
-          (void)remove(tmpFileName);
-        }
-        free(tmpCommand);
-        return -1;
-      }
-      
-      numOfThread++;
-    }
+  TAOS_FIELD *fields = taos_fetch_fields(res);
   
+  int32_t  numOfTable  = 0;
+  while ((row = taos_fetch_row(res)) != NULL) {  
+
     memset(&tableRecord, 0, sizeof(STableRecord));
     tstrncpy(tableRecord.name, (char *)row[0], fields[0].bytes);
     tstrncpy(tableRecord.metric, metric, TSDB_TABLE_NAME_LEN);
-
-    taosWrite(fd, &tableRecord, sizeof(STableRecord));
-
+    
+    taosWrite(fd, &tableRecord, sizeof(STableRecord));    
     numOfTable++;
-
-    if (numOfTable >= table_batch) {
-      numOfTable = 0;
-      close(fd);
-      fd = -1;
-    }
   }
+  taos_free_result(res);
+  lseek(fd, 0, SEEK_SET);
+  
+  int maxThreads = arguments->thread_num;
+  int tableOfPerFile ;
+  if (numOfTable <= arguments->thread_num) {
+    tableOfPerFile = 1;
+    maxThreads = numOfTable;
+  } else {
+    tableOfPerFile = numOfTable / arguments->thread_num;
+    if (0 != numOfTable % arguments->thread_num) {
+      tableOfPerFile += 1;
+    }    
+  }
+
+  char* tblBuf = (char*)calloc(1, tableOfPerFile * sizeof(STableRecord));
+  if (NULL == tblBuf){
+    fprintf(stderr, "failed to calloc %" PRIzu "\n", tableOfPerFile * sizeof(STableRecord));      
+    close(fd);
+    return -1;
+  }
+  
+  int32_t  numOfThread = *totalNumOfThread;
+  int      subFd = -1;
+  for (; numOfThread < maxThreads; numOfThread++) {
+    memset(tmpBuf, 0, TSDB_FILENAME_LEN);
+    sprintf(tmpBuf, ".tables.tmp.%d", numOfThread);
+    subFd = open(tmpBuf, O_RDWR | O_CREAT | O_TRUNC, S_IRWXU | S_IRGRP | S_IXGRP | S_IROTH);
+    if (subFd == -1) {
+      fprintf(stderr, "failed to open temp file: %s\n", tmpBuf);
+      for (int32_t loopCnt = 0; loopCnt < numOfThread; loopCnt++) {
+        sprintf(tmpBuf, ".tables.tmp.%d", loopCnt);
+        (void)remove(tmpBuf);
+      }
+      sprintf(tmpBuf, ".select-tbname.tmp");
+      (void)remove(tmpBuf);      
+      close(fd);
+      return -1;
+    }
+
+    // read tableOfPerFile for fd, write to subFd
+    ssize_t readLen = read(fd, tblBuf, tableOfPerFile * sizeof(STableRecord));
+    if (readLen <= 0) {
+      close(subFd);
+      break;
+    }
+    taosWrite(subFd, tblBuf, readLen);
+    close(subFd);
+  }
+
+  sprintf(tmpBuf, ".select-tbname.tmp");
+  (void)remove(tmpBuf);
   
   if (fd >= 0) {
     close(fd);
     fd = -1;
-  }
-  
-  taos_free_result(result);
+  }  
 
   *totalNumOfThread = numOfThread;
- 
-  free(tmpCommand);
 
   return 0;
 }
@@ -1443,57 +1461,80 @@ int taosDumpDb(SDbInfo *dbInfo, struct arguments *arguments, FILE *fp, TAOS *tao
     return -1;
   }
 
-  int table_batch = arguments->table_batch;
-  int affectdRows =  taos_affected_rows(res);
-  if (affectdRows <= 0) {
+  char tmpBuf[TSDB_FILENAME_LEN + 1];
+  memset(tmpBuf, 0, TSDB_FILENAME_LEN);
+  sprintf(tmpBuf, ".show-tables.tmp");
+  fd = open(tmpBuf, O_RDWR | O_CREAT | O_TRUNC, S_IRWXU | S_IRGRP | S_IXGRP | S_IROTH);
+  if (fd == -1) {
+    fprintf(stderr, "failed to open temp file: %s\n", tmpBuf);
     taos_free_result(res);
     return -1;
   }
 
-  int maxNumOfThread = affectdRows / table_batch + 1;
-  if (maxNumOfThread > 2 * g_numOfCores) {
-    maxNumOfThread = 2 * g_numOfCores;
-  }
-
-  table_batch = affectdRows / maxNumOfThread + 1;
-
   TAOS_FIELD *fields = taos_fetch_fields(res);
-
-  int32_t  numOfTable  = 0;
-  int32_t  numOfThread = 0;
-  char     tmpBuf[TSDB_FILENAME_LEN + 1];
-  while ((row = taos_fetch_row(res)) != NULL) {
-    if (0 == numOfTable) {
-      memset(tmpBuf, 0, TSDB_FILENAME_LEN);
-      sprintf(tmpBuf, ".tables.tmp.%d", numOfThread);
-      fd = open(tmpBuf, O_RDWR | O_CREAT | O_TRUNC, S_IRWXU | S_IRGRP | S_IXGRP | S_IROTH);
-      if (fd == -1) {
-        fprintf(stderr, "failed to open temp file: %s\n", tmpBuf);
-        taos_free_result(res);
-        for (int32_t loopCnt = 0; loopCnt < numOfThread; loopCnt++) {
-          sprintf(tmpBuf, ".tables.tmp.%d", loopCnt);
-          (void)remove(tmpBuf);
-        }
-        return -1;
-      }
-
-      numOfThread++;
-    }
   
+  int32_t  numOfTable  = 0;
+  while ((row = taos_fetch_row(res)) != NULL) {  
     memset(&tableRecord, 0, sizeof(STableRecord));
     tstrncpy(tableRecord.name, (char *)row[TSDB_SHOW_TABLES_NAME_INDEX], fields[TSDB_SHOW_TABLES_NAME_INDEX].bytes);
     tstrncpy(tableRecord.metric, (char *)row[TSDB_SHOW_TABLES_METRIC_INDEX], fields[TSDB_SHOW_TABLES_METRIC_INDEX].bytes);
-
+  
     taosWrite(fd, &tableRecord, sizeof(STableRecord));
-
+  
     numOfTable++;
-
-    if (numOfTable >= table_batch) {
-      numOfTable = 0;
-      close(fd);
-      fd = -1;
-    }
   }
+  taos_free_result(res);
+  lseek(fd, 0, SEEK_SET);
+
+  int maxThreads = tsArguments.thread_num;
+  int tableOfPerFile ;
+  if (numOfTable <= tsArguments.thread_num) {
+    tableOfPerFile = 1;
+    maxThreads = numOfTable;
+  } else {
+    tableOfPerFile = numOfTable / tsArguments.thread_num;
+    if (0 != numOfTable % tsArguments.thread_num) {
+      tableOfPerFile += 1;
+    }    
+  }
+
+  char* tblBuf = (char*)calloc(1, tableOfPerFile * sizeof(STableRecord));
+  if (NULL == tblBuf){
+    fprintf(stderr, "failed to calloc %" PRIzu "\n", tableOfPerFile * sizeof(STableRecord));
+    close(fd);
+    return -1;
+  }
+  
+  int32_t  numOfThread = 0;
+  int      subFd = -1;
+  for (numOfThread = 0; numOfThread < maxThreads; numOfThread++) {
+    memset(tmpBuf, 0, TSDB_FILENAME_LEN);
+    sprintf(tmpBuf, ".tables.tmp.%d", numOfThread);
+    subFd = open(tmpBuf, O_RDWR | O_CREAT | O_TRUNC, S_IRWXU | S_IRGRP | S_IXGRP | S_IROTH);
+    if (subFd == -1) {
+      fprintf(stderr, "failed to open temp file: %s\n", tmpBuf);
+      for (int32_t loopCnt = 0; loopCnt < numOfThread; loopCnt++) {
+        sprintf(tmpBuf, ".tables.tmp.%d", loopCnt);
+        (void)remove(tmpBuf);
+      }
+      sprintf(tmpBuf, ".show-tables.tmp");
+      (void)remove(tmpBuf);
+      close(fd);
+      return -1;
+    }
+
+    // read tableOfPerFile for fd, write to subFd
+    ssize_t readLen = read(fd, tblBuf, tableOfPerFile * sizeof(STableRecord));
+    if (readLen <= 0) {
+      close(subFd);
+      break;
+    }
+    taosWrite(subFd, tblBuf, readLen);
+    close(subFd);
+  }
+
+  sprintf(tmpBuf, ".show-tables.tmp");
+  (void)remove(tmpBuf);
 
   if (fd >= 0) {
     close(fd);