diff --git a/Jenkinsfile b/Jenkinsfile
index c262aa50f7970cf637c73595917d0fbc3df827b4..4410d81be6974fc246f50044cbc142076212677b 100644
--- a/Jenkinsfile
+++ b/Jenkinsfile
@@ -5,29 +5,7 @@ pipeline {
       WKC= '/var/lib/jenkins/workspace/TDinternal/community'
   }
   stages {
-    stage('build TDengine') {
-      agent{label 'master'}
-      steps {
-        sh '''
-        cd ${WKC}
-        git checkout develop
-        git pull
-        git submodule update
-        cd ${WK}
-        git checkout develop
-        git pull
-        export TZ=Asia/Harbin
-        date
-        rm -rf ${WK}/debug
-        mkdir debug
-        cd debug
-        #cmake .. > /dev/null
-        #make > /dev/null
-        '''
-      }
-    }
-
-    stage('Parallel test stage') {
+      stage('Parallel test stage') {
       parallel {
         stage('pytest') {
           agent{label 'master'}
diff --git a/src/balance/src/balance.c b/src/balance/src/balance.c
index fc1853f3d818be80f14728e3cce16c60e0e61123..0fa4b3f34615aad3fb749d44cb27b3feab10f49c 100644
--- a/src/balance/src/balance.c
+++ b/src/balance/src/balance.c
@@ -126,6 +126,8 @@ int32_t balanceAllocVnodes(SVgObj *pVgroup) {
 
   balanceAccquireDnodeList();
 
+  mDebug("db:%s, try alloc %d vnodes to vgroup, dnodes total:%d, avail:%d", pVgroup->dbName, pVgroup->numOfVnodes,
+         mnodeGetDnodesNum(), tsBalanceDnodeListSize);
   for (int32_t i = 0; i < pVgroup->numOfVnodes; ++i) {
     for (; dnode < tsBalanceDnodeListSize; ++dnode) {
       SDnodeObj *pDnode = tsBalanceDnodeList[dnode];
@@ -135,17 +137,33 @@ int32_t balanceAllocVnodes(SVgObj *pVgroup) {
         pVnodeGid->pDnode = pDnode;
         dnode++;
         vnodes++;
+        mDebug("dnode:%d, is selected, vnodeIndex:%d", pDnode->dnodeId, i);
         break;
+      } else {
+        mDebug("dnode:%d, is not selected, status:%s vnodes:%d disk:%fGB role:%d", pDnode->dnodeId,
+               mnodeGetDnodeStatusStr(pDnode->status), pDnode->openVnodes, pDnode->diskAvailable,
+               pDnode->alternativeRole);
       }
     }
   }
 
   if (vnodes != pVgroup->numOfVnodes) {
-    mDebug("vgId:%d, db:%s need vnodes:%d, but alloc:%d, free them", pVgroup->vgId, pVgroup->dbName,
-           pVgroup->numOfVnodes, vnodes);
     balanceReleaseDnodeList();
     balanceUnLock();
 
+    mDebug("db:%s, need vnodes:%d, but alloc:%d", pVgroup->dbName, pVgroup->numOfVnodes, vnodes);
+
+    void *     pIter = NULL;
+    SDnodeObj *pDnode = NULL;
+    while (1) {
+      pIter = mnodeGetNextDnode(pIter, &pDnode);
+      if (pDnode == NULL) break;
+      mDebug("dnode:%d, status:%s vnodes:%d disk:%fGB role:%d", pDnode->dnodeId, mnodeGetDnodeStatusStr(pDnode->status),
+             pDnode->openVnodes, pDnode->diskAvailable, pDnode->alternativeRole);
+      mnodeDecDnodeRef(pDnode);
+    }
+    sdbFreeIter(pIter);
+
     if (mnodeGetOnlineDnodesNum() == 0) {
       return TSDB_CODE_MND_NOT_READY;
     } else {
@@ -553,7 +571,8 @@ static void balanceCheckDnodeAccess() {
       if (pDnode->status != TAOS_DN_STATUS_DROPPING && pDnode->status != TAOS_DN_STATUS_OFFLINE) {
         pDnode->status = TAOS_DN_STATUS_OFFLINE;
         pDnode->offlineReason = TAOS_DN_OFF_STATUS_MSG_TIMEOUT;
-        mInfo("dnode:%d, set to offline state", pDnode->dnodeId);
+        mInfo("dnode:%d, set to offline state, access seq:%d, last seq:%d", pDnode->dnodeId, tsAccessSquence,
+              pDnode->lastAccess);
         balanceSetVgroupOffline(pDnode);
       }
     }
diff --git a/src/client/src/tscFunctionImpl.c b/src/client/src/tscFunctionImpl.c
index 60e9596ec41ce41f5d727d3016663b752dc32fd0..1b4f92d3fc9fc78951e23eaec4c438d7522bf7f1 100644
--- a/src/client/src/tscFunctionImpl.c
+++ b/src/client/src/tscFunctionImpl.c
@@ -2445,8 +2445,8 @@ static bool percentile_function_setup(SQLFunctionCtx *pCtx) {
   // in the first round, get the min-max value of all involved data
   SResultInfo *pResInfo = GET_RES_INFO(pCtx);
   SPercentileInfo *pInfo = pResInfo->interResultBuf;
-  pInfo->minval = DBL_MAX;
-  pInfo->maxval = -DBL_MAX;
+  SET_DOUBLE_VAL(&pInfo->minval, DBL_MAX);
+  SET_DOUBLE_VAL(&pInfo->maxval, -DBL_MAX);
   pInfo->numOfElems = 0;
 
   return true;
@@ -2461,12 +2461,12 @@ static void percentile_function(SQLFunctionCtx *pCtx) {
   // the first stage, only acquire the min/max value
   if (pInfo->stage == 0) {
     if (pCtx->preAggVals.isSet) {
-      if (pInfo->minval > pCtx->preAggVals.statis.min) {
-        pInfo->minval = (double)pCtx->preAggVals.statis.min;
+      if (GET_DOUBLE_VAL(&pInfo->minval) > pCtx->preAggVals.statis.min) {
+        SET_DOUBLE_VAL(&pInfo->minval, (double)pCtx->preAggVals.statis.min);
       }
 
-      if (pInfo->maxval < pCtx->preAggVals.statis.max) {
-        pInfo->maxval = (double)pCtx->preAggVals.statis.max;
+      if (GET_DOUBLE_VAL(&pInfo->maxval) < pCtx->preAggVals.statis.max) {
+        SET_DOUBLE_VAL(&pInfo->maxval, (double)pCtx->preAggVals.statis.max);
       }
 
       pInfo->numOfElems += (pCtx->size - pCtx->preAggVals.statis.numOfNull);
@@ -2500,12 +2500,12 @@ static void percentile_function(SQLFunctionCtx *pCtx) {
             break;
         }
 
-        if (v < pInfo->minval) {
-          pInfo->minval = v;
+        if (v < GET_DOUBLE_VAL(&pInfo->minval)) {
+          SET_DOUBLE_VAL(&pInfo->minval, v);
         }
 
-        if (v > pInfo->maxval) {
-          pInfo->maxval = v;
+        if (v > GET_DOUBLE_VAL(&pInfo->maxval)) {
+          SET_DOUBLE_VAL(&pInfo->maxval, v);
         }
 
         pInfo->numOfElems += 1;
@@ -2564,12 +2564,12 @@ static void percentile_function_f(SQLFunctionCtx *pCtx, int32_t index) {
         break;
     }
 
-    if (v < pInfo->minval) {
-      pInfo->minval = v;
+    if (v < GET_DOUBLE_VAL(&pInfo->minval)) {
+      SET_DOUBLE_VAL(&pInfo->minval, v);
     }
 
-    if (v > pInfo->maxval) {
-      pInfo->maxval = v;
+    if (v > GET_DOUBLE_VAL(&pInfo->maxval)) {
+      SET_DOUBLE_VAL(&pInfo->maxval, v);
     }
 
     pInfo->numOfElems += 1;
@@ -2609,7 +2609,7 @@ static void percentile_next_step(SQLFunctionCtx *pCtx) {
     }
 
     pInfo->stage += 1;
-    pInfo->pMemBucket = tMemBucketCreate(pCtx->inputBytes, pCtx->inputType, pInfo->minval, pInfo->maxval);
+    pInfo->pMemBucket = tMemBucketCreate(pCtx->inputBytes, pCtx->inputType, GET_DOUBLE_VAL(&pInfo->minval), GET_DOUBLE_VAL(&pInfo->maxval));
   } else {
     pResInfo->complete = true;
   }
diff --git a/src/inc/taosdef.h b/src/inc/taosdef.h
index 01a4ed32f11e2badd6bda7ffdf862195c408dcbd..aee60da20147c674979540aa73da5ac101fae7f0 100644
--- a/src/inc/taosdef.h
+++ b/src/inc/taosdef.h
@@ -194,9 +194,9 @@ static FORCE_INLINE bool isNull(const char *val, int32_t type) {
     case TSDB_DATA_TYPE_DOUBLE:
       return *(uint64_t *)val == TSDB_DATA_DOUBLE_NULL;
     case TSDB_DATA_TYPE_NCHAR:
-      return *(uint32_t*) varDataVal(val) == TSDB_DATA_NCHAR_NULL;
+      return varDataLen(val) == sizeof(int32_t) && *(uint32_t*) varDataVal(val) == TSDB_DATA_NCHAR_NULL;
     case TSDB_DATA_TYPE_BINARY:
-      return *(uint8_t *) varDataVal(val) == TSDB_DATA_BINARY_NULL;
+      return varDataLen(val) == sizeof(int8_t) && *(uint8_t *) varDataVal(val) == TSDB_DATA_BINARY_NULL;
     default:
       return false;
   };
diff --git a/src/mnode/src/mnodeDnode.c b/src/mnode/src/mnodeDnode.c
index 33a869a35325787de18b883634d4efa70cfd7144..1cd861e22303d5f6f0dcb75c7ef83cf66696578f 100644
--- a/src/mnode/src/mnodeDnode.c
+++ b/src/mnode/src/mnodeDnode.c
@@ -471,7 +471,8 @@ static int32_t mnodeProcessDnodeStatusMsg(SMnodeMsg *pMsg) {
              mnodeGetClusterId());
       return TSDB_CODE_MND_INVALID_CLUSTER_ID;
     } else {
-      mTrace("dnode:%d, status received, access times %d", pDnode->dnodeId, pDnode->lastAccess);
+      mTrace("dnode:%d, status received, access times %d openVnodes:%d:%d", pDnode->dnodeId, pDnode->lastAccess,
+             htons(pStatus->openVnodes), pDnode->openVnodes);
     }
   }
 
diff --git a/src/mnode/src/mnodeTable.c b/src/mnode/src/mnodeTable.c
index ca9d6cff96827ad1b6893019b680c619bea42840..1a1ff878a5e58982c5e720140b0c74c83e0db3e5 100644
--- a/src/mnode/src/mnodeTable.c
+++ b/src/mnode/src/mnodeTable.c
@@ -2409,14 +2409,16 @@ static void mnodeProcessCreateChildTableRsp(SRpcMsg *rpcMsg) {
     }
   } else {
     if (mnodeMsg->retry++ < 10) {
-      mDebug("app:%p:%p, table:%s, create table rsp received, need retry, times:%d result:%s thandle:%p",
-             mnodeMsg->rpcMsg.ahandle, mnodeMsg, pTable->info.tableId, mnodeMsg->retry, tstrerror(rpcMsg->code),
-             mnodeMsg->rpcMsg.handle);
+      mDebug("app:%p:%p, table:%s, create table rsp received, need retry, times:%d vgId:%d sid:%d uid:%" PRIu64
+             " result:%s thandle:%p",
+             mnodeMsg->rpcMsg.ahandle, mnodeMsg, pTable->info.tableId, mnodeMsg->retry, pTable->vgId, pTable->sid,
+             pTable->uid, tstrerror(rpcMsg->code), mnodeMsg->rpcMsg.handle);
 
       dnodeDelayReprocessMnodeWriteMsg(mnodeMsg);
     } else {
-      mError("app:%p:%p, table:%s, failed to create in dnode, result:%s thandle:%p", mnodeMsg->rpcMsg.ahandle, mnodeMsg,
-             pTable->info.tableId, tstrerror(rpcMsg->code), mnodeMsg->rpcMsg.handle);
+      mError("app:%p:%p, table:%s, failed to create in dnode, vgId:%d sid:%d uid:%" PRIu64 ", result:%s thandle:%p",
+             mnodeMsg->rpcMsg.ahandle, mnodeMsg, pTable->info.tableId, pTable->vgId, pTable->sid, pTable->uid,
+             tstrerror(rpcMsg->code), mnodeMsg->rpcMsg.handle);
 
       SSdbOper oper = {.type = SDB_OPER_GLOBAL, .table = tsChildTableSdb, .pObj = pTable};
       sdbDeleteRow(&oper);
diff --git a/src/mnode/src/mnodeVgroup.c b/src/mnode/src/mnodeVgroup.c
index 69b9224d4ff774abb9ac047acac28f5b9d4e2022..28e4d179202e2d54bef669bbc80cadcfe85d3d17 100644
--- a/src/mnode/src/mnodeVgroup.c
+++ b/src/mnode/src/mnodeVgroup.c
@@ -270,31 +270,34 @@ void mnodeUpdateVgroup(SVgObj *pVgroup) {
   Traverse all vgroups on mnode, if there no such vgId on a dnode, so send msg to this dnode for re-creating this vgId/vnode 
 */
 void mnodeCheckUnCreatedVgroup(SDnodeObj *pDnode, SVnodeLoad *pVloads, int32_t openVnodes) {
-  SVnodeLoad *pNextV = NULL;
-
   void *pIter = NULL;
   while (1) {
     SVgObj *pVgroup;
     pIter = mnodeGetNextVgroup(pIter, &pVgroup);
     if (pVgroup == NULL) break;
 
-    pNextV = pVloads;
-    int32_t i;
-    for (i = 0; i < openVnodes; ++i) {
-      if ((pVgroup->vnodeGid[i].pDnode == pDnode) && (pVgroup->vgId == pNextV->vgId)) {
-        break;
-      }
-      pNextV++;
-    }
-
-    if (i == openVnodes) {
-      if (pVgroup->status == TAOS_VG_STATUS_CREATING || pVgroup->status == TAOS_VG_STATUS_DROPPING) {
-        mDebug("vgId:%d, not exist in dnode:%d and status is %s, do nothing", pVgroup->vgId, pDnode->dnodeId,
-               vgroupStatus[pVgroup->status]);
-      } else {
-        mDebug("vgId:%d, not exist in dnode:%d and status is %s, send create msg", pVgroup->vgId, pDnode->dnodeId,
-               vgroupStatus[pVgroup->status]);
-        mnodeSendCreateVgroupMsg(pVgroup, NULL);
+    for (int v = 0; v < pVgroup->numOfVnodes; ++v) {
+      if (pVgroup->vnodeGid[v].dnodeId == pDnode->dnodeId) {
+        // vgroup should have a vnode on this dnode
+        bool have = false;
+        for (int32_t i = 0; i < openVnodes; ++i) {
+          SVnodeLoad *pVload = pVloads + i;
+          if (pVgroup->vgId == pVload->vgId) {
+            have = true;
+            break;
+          }
+        }
+
+        if (have) continue;
+
+        if (pVgroup->status == TAOS_VG_STATUS_CREATING || pVgroup->status == TAOS_VG_STATUS_DROPPING) {
+          mDebug("vgId:%d, not exist in dnode:%d and status is %s, do nothing", pVgroup->vgId, pDnode->dnodeId,
+                 vgroupStatus[pVgroup->status]);
+        } else {
+          mDebug("vgId:%d, not exist in dnode:%d and status is %s, send create msg", pVgroup->vgId, pDnode->dnodeId,
+                 vgroupStatus[pVgroup->status]);
+          mnodeSendCreateVgroupMsg(pVgroup, NULL);
+        }
       }
     }
 
@@ -302,7 +305,6 @@ void mnodeCheckUnCreatedVgroup(SDnodeObj *pDnode, SVnodeLoad *pVloads, int32_t o
   }
 
   sdbFreeIter(pIter);
-  return;
 }
 
 void mnodeUpdateVgroupStatus(SVgObj *pVgroup, SDnodeObj *pDnode, SVnodeLoad *pVload) {
diff --git a/src/tsdb/src/tsdbRead.c b/src/tsdb/src/tsdbRead.c
index 670555a9f064e46f08d52b6909a77865d9e43748..b785a60b1ea1006b43a98b6853287d865d8d192a 100644
--- a/src/tsdb/src/tsdbRead.c
+++ b/src/tsdb/src/tsdbRead.c
@@ -2284,7 +2284,7 @@ void filterPrepare(void* expr, void* param) {
   if (pInfo->optr == TSDB_RELATION_IN) {
     pInfo->q = (char*) pCond->arr;
   } else {
-    pInfo->q = calloc(1, pSchema->bytes);
+    pInfo->q = calloc(1, pSchema->bytes + TSDB_NCHAR_SIZE);   // to make sure tonchar does not cause invalid write, since the '\0' needs at least sizeof(wchar_t) space.
     tVariantDump(pCond, pInfo->q, pSchema->type, true);
   }
 }
diff --git a/tests/pytest/fulltest.sh b/tests/pytest/fulltest.sh
index b679942054c000050271fcb96328d18adea60b42..fd973b8b7604c9c6b7148a336ca1ac082cd1b548 100755
--- a/tests/pytest/fulltest.sh
+++ b/tests/pytest/fulltest.sh
@@ -172,23 +172,23 @@ python3 testNoCompress.py
 python3 testMinTablesPerVnode.py
 
 # functions
-python3 ./test.py -f functions/function_avg.py
-python3 ./test.py -f functions/function_bottom.py
-python3 ./test.py -f functions/function_count.py
-python3 ./test.py -f functions/function_diff.py
-python3 ./test.py -f functions/function_first.py
-python3 ./test.py -f functions/function_last.py
-python3 ./test.py -f functions/function_last_row.py
-python3 ./test.py -f functions/function_leastsquares.py
-python3 ./test.py -f functions/function_max.py
-python3 ./test.py -f functions/function_min.py
-python3 ./test.py -f functions/function_operations.py
+python3 ./test.py -f functions/function_avg.py -r 1
+python3 ./test.py -f functions/function_bottom.py -r 1
+python3 ./test.py -f functions/function_count.py -r 1
+python3 ./test.py -f functions/function_diff.py -r 1
+python3 ./test.py -f functions/function_first.py -r 1
+python3 ./test.py -f functions/function_last.py -r 1
+python3 ./test.py -f functions/function_last_row.py -r 1
+python3 ./test.py -f functions/function_leastsquares.py -r 1
+python3 ./test.py -f functions/function_max.py -r 1
+python3 ./test.py -f functions/function_min.py -r 1
+python3 ./test.py -f functions/function_operations.py -r 1 
 python3 ./test.py -f functions/function_percentile.py
-python3 ./test.py -f functions/function_spread.py
-python3 ./test.py -f functions/function_stddev.py
-python3 ./test.py -f functions/function_sum.py
-python3 ./test.py -f functions/function_top.py
-#python3 ./test.py -f functions/function_twa.py
+python3 ./test.py -f functions/function_spread.py -r 1
+python3 ./test.py -f functions/function_stddev.py -r 1
+python3 ./test.py -f functions/function_sum.py -r 1
+python3 ./test.py -f functions/function_top.py -r 1
+#python3 ./test.py -f functions/function_twa.py -r 1
 python3 queryCount.py
 python3 ./test.py -f query/queryGroupbyWithInterval.py
 python3 client/twoClients.py
@@ -200,4 +200,4 @@ python3 test.py -f tools/taosdemo.py
 # subscribe
 python3 test.py -f subscribe/singlemeter.py
 #python3 test.py -f subscribe/stability.py
-python3 test.py -f subscribe/supertable.py
\ No newline at end of file
+python3 test.py -f subscribe/supertable.py
diff --git a/tests/pytest/functions/function_avg_restart.py b/tests/pytest/functions/function_avg_restart.py
new file mode 100644
index 0000000000000000000000000000000000000000..56b99cdf910869b5bc4f5bd93da208943b1b026e
--- /dev/null
+++ b/tests/pytest/functions/function_avg_restart.py
@@ -0,0 +1,73 @@
+###################################################################
+#           Copyright (c) 2016 by TAOS Technologies, Inc.
+#                     All rights reserved.
+#
+#  This file is proprietary and confidential to TAOS Technologies.
+#  No part of this file may be reproduced, stored, transmitted,
+#  disclosed or used in any form or by any means other than as
+#  expressly provided by the written permission from Jianhui Tao
+#
+###################################################################
+
+# -*- coding: utf-8 -*-
+
+import sys
+import taos
+from util.log import *
+from util.cases import *
+from util.sql import *
+import numpy as np
+
+
+class TDTestCase:
+    def init(self, conn, logSql):
+        tdLog.debug("start to execute %s" % __file__)
+        tdSql.init(conn.cursor())
+
+        self.rowNum = 10
+        self.ts = 1537146000000
+        
+    def run(self):
+        tdSql.execute("use db")
+
+        intData = []        
+        floatData = []
+
+        #tdSql.execute('''create table test(ts timestamp, col1 tinyint, col2 smallint, col3 int, col4 bigint, col5 float, col6 double, 
+        #            col7 bool, col8 binary(20), col9 nchar(20)) tags(loc nchar(20))''')
+        #tdSql.execute("create table test1 using test tags('beijing')")
+        for i in range(self.rowNum):
+            #tdSql.execute("insert into test1 values(%d, %d, %d, %d, %d, %f, %f, %d, 'taosdata%d', '涛思数据%d')" 
+            #            % (self.ts + i, i + 1, i + 1, i + 1, i + 1, i + 0.1, i + 0.1, i % 2, i + 1, i + 1))
+            intData.append(i + 1)            
+            floatData.append(i + 0.1)                        
+
+        # average verifacation 
+        tdSql.error("select avg(ts) from test")
+        tdSql.error("select avg(ts) from test1")
+        tdSql.error("select avg(col7) from test")
+        tdSql.error("select avg(col7) from test1")
+        tdSql.error("select avg(col8) from test")
+        tdSql.error("select avg(col8) from test1")
+        tdSql.error("select avg(col9) from test")
+        tdSql.error("select avg(col9) from test1")
+
+        tdSql.query("select avg(col1) from test")
+        tdSql.checkData(0, 0, np.average(intData))
+        tdSql.query("select avg(col2) from test")
+        tdSql.checkData(0, 0, np.average(intData))
+        tdSql.query("select avg(col3) from test")
+        tdSql.checkData(0, 0, np.average(intData))
+        tdSql.query("select avg(col4) from test")
+        tdSql.checkData(0, 0, np.average(intData))
+        tdSql.query("select avg(col5) from test")
+        tdSql.checkData(0, 0, np.average(floatData))              
+        tdSql.query("select avg(col6) from test")
+        tdSql.checkData(0, 0, np.average(floatData))              
+
+    def stop(self):
+        tdSql.close()
+        tdLog.success("%s successfully executed" % __file__)
+
+tdCases.addWindows(__file__, TDTestCase())
+tdCases.addLinux(__file__, TDTestCase())
diff --git a/tests/pytest/functions/function_bottom_restart.py b/tests/pytest/functions/function_bottom_restart.py
new file mode 100644
index 0000000000000000000000000000000000000000..74eb044645ffa6a54e286dd11d022672575a38db
--- /dev/null
+++ b/tests/pytest/functions/function_bottom_restart.py
@@ -0,0 +1,93 @@
+###################################################################
+#           Copyright (c) 2016 by TAOS Technologies, Inc.
+#                     All rights reserved.
+#
+#  This file is proprietary and confidential to TAOS Technologies.
+#  No part of this file may be reproduced, stored, transmitted,
+#  disclosed or used in any form or by any means other than as
+#  expressly provided by the written permission from Jianhui Tao
+#
+###################################################################
+
+# -*- coding: utf-8 -*-
+
+import sys
+import taos
+from util.log import *
+from util.cases import *
+from util.sql import *
+import numpy as np
+
+
+class TDTestCase:
+    def init(self, conn, logSql):
+        tdLog.debug("start to execute %s" % __file__)
+        tdSql.init(conn.cursor())
+
+        self.rowNum = 10
+        self.ts = 1537146000000
+        
+    def run(self):
+        tdSql.execute("use db")    
+
+        #tdSql.execute('''create table test(ts timestamp, col1 tinyint, col2 smallint, col3 int, col4 bigint, col5 float, col6 double, 
+        #            col7 bool, col8 binary(20), col9 nchar(20)) tags(loc nchar(20))''')
+        #tdSql.execute("create table test1 using test tags('beijing')")
+        #for i in range(self.rowNum):
+        #    tdSql.execute("insert into test1 values(%d, %d, %d, %d, %d, %f, %f, %d, 'taosdata%d', '涛思数据%d')" 
+        #                % (self.ts + i, i + 1, i + 1, i + 1, i + 1, i + 0.1, i + 0.1, i % 2, i + 1, i + 1))                            
+
+        # bottom verifacation 
+        tdSql.error("select bottom(ts, 10) from test")
+        tdSql.error("select bottom(col1, 0) from test")
+        tdSql.error("select bottom(col1, 101) from test")
+        tdSql.error("select bottom(col2, 0) from test")
+        tdSql.error("select bottom(col2, 101) from test")
+        tdSql.error("select bottom(col3, 0) from test")
+        tdSql.error("select bottom(col3, 101) from test")
+        tdSql.error("select bottom(col4, 0) from test")
+        tdSql.error("select bottom(col4, 101) from test")
+        tdSql.error("select bottom(col5, 0) from test")
+        tdSql.error("select bottom(col5, 101) from test")
+        tdSql.error("select bottom(col6, 0) from test")
+        tdSql.error("select bottom(col6, 101) from test")        
+        tdSql.error("select bottom(col7, 10) from test")        
+        tdSql.error("select bottom(col8, 10) from test")
+        tdSql.error("select bottom(col9, 10) from test")
+
+        tdSql.query("select bottom(col1, 2) from test")
+        tdSql.checkRows(2)
+        tdSql.checkData(0, 1, 1)
+        tdSql.checkData(1, 1, 2)
+
+        tdSql.query("select bottom(col2, 2) from test")
+        tdSql.checkRows(2)
+        tdSql.checkData(0, 1, 1)
+        tdSql.checkData(1, 1, 2)
+
+        tdSql.query("select bottom(col3, 2) from test")
+        tdSql.checkRows(2)
+        tdSql.checkData(0, 1, 1)
+        tdSql.checkData(1, 1, 2)
+
+        tdSql.query("select bottom(col4, 2) from test")
+        tdSql.checkRows(2)
+        tdSql.checkData(0, 1, 1)
+        tdSql.checkData(1, 1, 2)
+
+        tdSql.query("select bottom(col5, 2) from test")
+        tdSql.checkRows(2)
+        tdSql.checkData(0, 1, 0.1)
+        tdSql.checkData(1, 1, 1.1)
+
+        tdSql.query("select bottom(col6, 2) from test")
+        tdSql.checkRows(2)
+        tdSql.checkData(0, 1, 0.1)
+        tdSql.checkData(1, 1, 1.1)
+                   
+    def stop(self):
+        tdSql.close()
+        tdLog.success("%s successfully executed" % __file__)
+
+tdCases.addWindows(__file__, TDTestCase())
+tdCases.addLinux(__file__, TDTestCase())
diff --git a/tests/pytest/functions/function_count_restart.py b/tests/pytest/functions/function_count_restart.py
new file mode 100644
index 0000000000000000000000000000000000000000..5eabb47d952a1a461b6fd5c976f3f2a8c294222b
--- /dev/null
+++ b/tests/pytest/functions/function_count_restart.py
@@ -0,0 +1,79 @@
+###################################################################
+#           Copyright (c) 2016 by TAOS Technologies, Inc.
+#                     All rights reserved.
+#
+#  This file is proprietary and confidential to TAOS Technologies.
+#  No part of this file may be reproduced, stored, transmitted,
+#  disclosed or used in any form or by any means other than as
+#  expressly provided by the written permission from Jianhui Tao
+#
+###################################################################
+
+# -*- coding: utf-8 -*-
+
+import sys
+import taos
+from util.log import *
+from util.cases import *
+from util.sql import *
+import numpy as np
+
+
+class TDTestCase:
+    def init(self, conn, logSql):
+        tdLog.debug("start to execute %s" % __file__)
+        tdSql.init(conn.cursor())
+
+        self.rowNum = 10
+        self.ts = 1537146000000
+        
+    def run(self):
+        tdSql.execute("use db")
+
+        #tdSql.execute('''create table test(ts timestamp, col1 tinyint, col2 smallint, col3 int, col4 bigint, col5 float, col6 double, 
+        #            col7 bool, col8 binary(20), col9 nchar(20)) tags(loc nchar(20))''')
+        #tdSql.execute("create table test1 using test tags('beijing')")
+        #for i in range(self.rowNum):
+        #    tdSql.execute("insert into test1 values(%d, %d, %d, %d, %d, %f, %f, %d, 'taosdata%d', '涛思数据%d')" 
+        #                % (self.ts + i, i + 1, i + 1, i + 1, i + 1, i + 0.1, i + 0.1, i % 2, i + 1, i + 1))
+        
+        # Count verifacation
+        tdSql.query("select count(*) from test")        
+        tdSql.checkData(0, 0, 11)
+
+        tdSql.query("select count(ts) from test")        
+        tdSql.checkData(0, 0, 11)                        
+        tdSql.query("select count(col1) from test")        
+        tdSql.checkData(0, 0, 11)
+        tdSql.query("select count(col2) from test")        
+        tdSql.checkData(0, 0, 11)
+        tdSql.query("select count(col3) from test")        
+        tdSql.checkData(0, 0, 11)
+        tdSql.query("select count(col4) from test")        
+        tdSql.checkData(0, 0, 11)
+        tdSql.query("select count(col5) from test")        
+        tdSql.checkData(0, 0, 11)
+        tdSql.query("select count(col6) from test")        
+        tdSql.checkData(0, 0, 11)
+        tdSql.query("select count(col7) from test")        
+        tdSql.checkData(0, 0, 11)
+        tdSql.query("select count(col8) from test")        
+        tdSql.checkData(0, 0, 11)
+        tdSql.query("select count(col9) from test")        
+        tdSql.checkData(0, 0, 11)
+
+        #tdSql.execute("alter table test add column col10 int")
+        #tdSql.query("select count(col10) from test")        
+        #tdSql.checkRows(0)
+
+        ##tdSql.execute("insert into test1 values(now, 1, 2, 3, 4, 1.1, 2.2, false, 'test', 'test' 1)")
+        tdSql.query("select count(col10) from test")        
+        tdSql.checkData(0, 0, 1)        
+              
+    def stop(self):
+        tdSql.close()
+        tdLog.success("%s successfully executed" % __file__)
+
+
+tdCases.addWindows(__file__, TDTestCase())
+tdCases.addLinux(__file__, TDTestCase())
diff --git a/tests/pytest/functions/function_diff_restart.py b/tests/pytest/functions/function_diff_restart.py
new file mode 100644
index 0000000000000000000000000000000000000000..870ee03fc94cbd8dbf5e858726cd52b09010a884
--- /dev/null
+++ b/tests/pytest/functions/function_diff_restart.py
@@ -0,0 +1,99 @@
+###################################################################
+#           Copyright (c) 2016 by TAOS Technologies, Inc.
+#                     All rights reserved.
+#
+#  This file is proprietary and confidential to TAOS Technologies.
+#  No part of this file may be reproduced, stored, transmitted,
+#  disclosed or used in any form or by any means other than as
+#  expressly provided by the written permission from Jianhui Tao
+#
+###################################################################
+
+# -*- coding: utf-8 -*-
+
+import sys
+import taos
+from util.log import *
+from util.cases import *
+from util.sql import *
+import numpy as np
+
+
+class TDTestCase:
+    def init(self, conn, logSql):
+        tdLog.debug("start to execute %s" % __file__)
+        tdSql.init(conn.cursor())
+
+        self.rowNum = 10
+        self.ts = 1537146000000
+        
+    def run(self):
+        tdSql.execute("use db")
+
+        #tdSql.execute('''create table test(ts timestamp, col1 tinyint, col2 smallint, col3 int, col4 bigint, col5 float, col6 double, 
+        #            col7 bool, col8 binary(20), col9 nchar(20)) tags(loc nchar(20))''')
+        #tdSql.execute("create table test1 using test tags('beijing')")
+        #tdSql.execute("insert into test1 values(%d, 0, 0, 0, 0, 0.0, 0.0, False, ' ', ' ')" % (self.ts - 1))
+        
+        # diff verifacation 
+        #tdSql.query("select diff(col1) from test1")
+        #tdSql.checkRows(0)
+        #
+        #tdSql.query("select diff(col2) from test1")
+        #tdSql.checkRows(0)
+
+        #tdSql.query("select diff(col3) from test1")
+        #tdSql.checkRows(0)
+
+        #tdSql.query("select diff(col4) from test1")
+        #tdSql.checkRows(0)
+
+        #tdSql.query("select diff(col5) from test1")
+        #tdSql.checkRows(0)
+
+        #tdSql.query("select diff(col6) from test1")
+        #tdSql.checkRows(0)
+
+        #for i in range(self.rowNum):
+        #    tdSql.execute("insert into test1 values(%d, %d, %d, %d, %d, %f, %f, %d, 'taosdata%d', '涛思数据%d')" 
+        #                % (self.ts + i, i + 1, i + 1, i + 1, i + 1, i + 0.1, i + 0.1, i % 2, i + 1, i + 1))                                
+        
+        tdSql.error("select diff(ts) from test")
+        tdSql.error("select diff(ts) from test1")
+        tdSql.error("select diff(col1) from test")
+        tdSql.error("select diff(col2) from test")
+        tdSql.error("select diff(col3) from test")
+        tdSql.error("select diff(col4) from test")
+        tdSql.error("select diff(col5) from test")
+        tdSql.error("select diff(col6) from test")
+        tdSql.error("select diff(col7) from test")     
+        tdSql.error("select diff(col7) from test1")               
+        tdSql.error("select diff(col8) from test") 
+        tdSql.error("select diff(col8) from test1")
+        tdSql.error("select diff(col9) from test")        
+        tdSql.error("select diff(col9) from test1")
+        
+        tdSql.query("select diff(col1) from test1")
+        tdSql.checkRows(10)
+
+        tdSql.query("select diff(col2) from test1")
+        tdSql.checkRows(10)
+
+        tdSql.query("select diff(col3) from test1")
+        tdSql.checkRows(10)
+
+        tdSql.query("select diff(col4) from test1")
+        tdSql.checkRows(10)
+
+        tdSql.query("select diff(col5) from test1")
+        tdSql.checkRows(10)
+
+        tdSql.query("select diff(col6) from test1")
+        tdSql.checkRows(10)
+        
+    def stop(self):
+        tdSql.close()
+        tdLog.success("%s successfully executed" % __file__)
+
+tdCases.addWindows(__file__, TDTestCase())
+tdCases.addLinux(__file__, TDTestCase())
diff --git a/tests/pytest/functions/function_first_restart.py b/tests/pytest/functions/function_first_restart.py
new file mode 100644
index 0000000000000000000000000000000000000000..31904c3cde6e1237472aac5767037e5e53e08a47
--- /dev/null
+++ b/tests/pytest/functions/function_first_restart.py
@@ -0,0 +1,78 @@
+###################################################################
+#           Copyright (c) 2016 by TAOS Technologies, Inc.
+#                     All rights reserved.
+#
+#  This file is proprietary and confidential to TAOS Technologies.
+#  No part of this file may be reproduced, stored, transmitted,
+#  disclosed or used in any form or by any means other than as
+#  expressly provided by the written permission from Jianhui Tao
+#
+###################################################################
+
+# -*- coding: utf-8 -*-
+
+import sys
+import taos
+from util.log import *
+from util.cases import *
+from util.sql import *
+import numpy as np
+
+
+class TDTestCase:
+    def init(self, conn, logSql):
+        tdLog.debug("start to execute %s" % __file__)
+        tdSql.init(conn.cursor())
+
+        self.rowNum = 10
+        self.ts = 1537146000000
+        
+    def run(self):
+        tdSql.execute("use db")
+
+        tdSql.query("select first(*) from test1")
+        tdSql.checkRows(1)
+        tdSql.checkData(0, 1, 1)
+
+        tdSql.query("select first(col1) from test1")
+        tdSql.checkRows(1)
+        tdSql.checkData(0, 0, 1)
+
+        tdSql.query("select first(col2) from test1")
+        tdSql.checkRows(1)
+        tdSql.checkData(0, 0, 1)
+
+        tdSql.query("select first(col3) from test1")
+        tdSql.checkRows(1)
+        tdSql.checkData(0, 0, 1)
+
+        tdSql.query("select first(col4) from test1")
+        tdSql.checkRows(1)
+        tdSql.checkData(0, 0, 1)
+
+        tdSql.query("select first(col5) from test1")
+        tdSql.checkRows(1)
+        tdSql.checkData(0, 0, 0.1)
+
+        tdSql.query("select first(col6) from test1")
+        tdSql.checkRows(1)
+        tdSql.checkData(0, 0, 0.1)
+
+        tdSql.query("select first(col7) from test1")
+        tdSql.checkRows(1)
+        tdSql.checkData(0, 0, False)
+
+        tdSql.query("select first(col8) from test1")
+        tdSql.checkRows(1)
+        tdSql.checkData(0, 0, 'taosdata1')
+
+        tdSql.query("select first(col9) from test1")
+        tdSql.checkRows(1)
+        tdSql.checkData(0, 0, '涛思数据1')
+                
+    def stop(self):
+        tdSql.close()
+        tdLog.success("%s successfully executed" % __file__)
+
+tdCases.addWindows(__file__, TDTestCase())
+tdCases.addLinux(__file__, TDTestCase())
diff --git a/tests/pytest/functions/function_last_restart.py b/tests/pytest/functions/function_last_restart.py
new file mode 100644
index 0000000000000000000000000000000000000000..69a588d28de7081da4469e9a407be1b68d07f82a
--- /dev/null
+++ b/tests/pytest/functions/function_last_restart.py
@@ -0,0 +1,78 @@
+###################################################################
+#           Copyright (c) 2016 by TAOS Technologies, Inc.
+#                     All rights reserved.
+#
+#  This file is proprietary and confidential to TAOS Technologies.
+#  No part of this file may be reproduced, stored, transmitted,
+#  disclosed or used in any form or by any means other than as
+#  expressly provided by the written permission from Jianhui Tao
+#
+###################################################################
+
+# -*- coding: utf-8 -*-
+
+import sys
+import taos
+from util.log import *
+from util.cases import *
+from util.sql import *
+import numpy as np
+
+
+class TDTestCase:
+    def init(self, conn, logSql):
+        tdLog.debug("start to execute %s" % __file__)
+        tdSql.init(conn.cursor())
+
+        self.rowNum = 10
+        self.ts = 1537146000000
+        
+    def run(self):
+        tdSql.execute("use db")
+
+        tdSql.query("select last(*) from test1")
+        tdSql.checkRows(1)
+        tdSql.checkData(0, 1, 10)
+
+        tdSql.query("select last(col1) from test1")
+        tdSql.checkRows(1)
+        tdSql.checkData(0, 0, 10)
+
+        tdSql.query("select last(col2) from test1")
+        tdSql.checkRows(1)
+        tdSql.checkData(0, 0, 10)
+
+        tdSql.query("select last(col3) from test1")
+        tdSql.checkRows(1)
+        tdSql.checkData(0, 0, 10)
+
+        tdSql.query("select last(col4) from test1")
+        tdSql.checkRows(1)
+        tdSql.checkData(0, 0, 10)
+
+        tdSql.query("select last(col5) from test1")
+        tdSql.checkRows(1)
+        tdSql.checkData(0, 0, 9.1)
+
+        tdSql.query("select last(col6) from test1")
+        tdSql.checkRows(1)
+        tdSql.checkData(0, 0, 9.1)
+
+        tdSql.query("select last(col7) from test1")
+        tdSql.checkRows(1)
+        tdSql.checkData(0, 0, True)
+
+        tdSql.query("select last(col8) from test1")
+        tdSql.checkRows(1)
+        tdSql.checkData(0, 0, 'taosdata10')
+
+        tdSql.query("select last(col9) from test1")
+        tdSql.checkRows(1)
+        tdSql.checkData(0, 0, '涛思数据10')
+                
+    def stop(self):
+        tdSql.close()
+        tdLog.success("%s successfully executed" % __file__)
+
+tdCases.addWindows(__file__, TDTestCase())
+tdCases.addLinux(__file__, TDTestCase())
diff --git a/tests/pytest/functions/function_last_row_restart.py b/tests/pytest/functions/function_last_row_restart.py
new file mode 100644
index 0000000000000000000000000000000000000000..1043a8809d640d5b57f808d83799f1f497776233
--- /dev/null
+++ b/tests/pytest/functions/function_last_row_restart.py
@@ -0,0 +1,78 @@
+###################################################################
+#           Copyright (c) 2016 by TAOS Technologies, Inc.
+#                     All rights reserved.
+#
+#  This file is proprietary and confidential to TAOS Technologies.
+#  No part of this file may be reproduced, stored, transmitted,
+#  disclosed or used in any form or by any means other than as
+#  expressly provided by the written permission from Jianhui Tao
+#
+###################################################################
+
+# -*- coding: utf-8 -*-
+
+import sys
+import taos
+from util.log import *
+from util.cases import *
+from util.sql import *
+import numpy as np
+
+
+class TDTestCase:
+    def init(self, conn, logSql):
+        tdLog.debug("start to execute %s" % __file__)
+        tdSql.init(conn.cursor())
+
+        self.rowNum = 10
+        self.ts = 1537146000000
+        
+    def run(self):
+        tdSql.execute("use db")
+
+        tdSql.query("select last_row(*) from test1")
+        tdSql.checkRows(1)
+        tdSql.checkData(0, 1, 10)
+
+        tdSql.query("select last_row(col1) from test1")
+        tdSql.checkRows(1)
+        tdSql.checkData(0, 0, 10)
+
+        tdSql.query("select last_row(col2) from test1")
+        tdSql.checkRows(1)
+        tdSql.checkData(0, 0, 10)
+
+        tdSql.query("select last_row(col3) from test1")
+        tdSql.checkRows(1)
+        tdSql.checkData(0, 0, 10)
+
+        tdSql.query("select last_row(col4) from test1")
+        tdSql.checkRows(1)
+        tdSql.checkData(0, 0, 10)
+
+        tdSql.query("select last_row(col5) from test1")
+        tdSql.checkRows(1)
+        tdSql.checkData(0, 0, 9.1)
+
+        tdSql.query("select last_row(col6) from test1")
+        tdSql.checkRows(1)
+        tdSql.checkData(0, 0, 9.1)
+
+        tdSql.query("select last_row(col7) from test1")
+        tdSql.checkRows(1)
+        tdSql.checkData(0, 0, True)
+
+        tdSql.query("select last_row(col8) from test1")
+        tdSql.checkRows(1)
+        tdSql.checkData(0, 0, 'taosdata10')
+
+        tdSql.query("select last_row(col9) from test1")
+        tdSql.checkRows(1)
+        tdSql.checkData(0, 0, '涛思数据10')
+                
+    def stop(self):
+        tdSql.close()
+        tdLog.success("%s successfully executed" % __file__)
+
+tdCases.addWindows(__file__, TDTestCase())
+tdCases.addLinux(__file__, TDTestCase())
diff --git a/tests/pytest/functions/function_leastsquares_restart.py b/tests/pytest/functions/function_leastsquares_restart.py
new file mode 100644
index 0000000000000000000000000000000000000000..0221dc0aed865882e375f90c44f52b391d1ffee5
--- /dev/null
+++ b/tests/pytest/functions/function_leastsquares_restart.py
@@ -0,0 +1,68 @@
+###################################################################
+#           Copyright (c) 2016 by TAOS Technologies, Inc.
+#                     All rights reserved.
+#
+#  This file is proprietary and confidential to TAOS Technologies.
+#  No part of this file may be reproduced, stored, transmitted,
+#  disclosed or used in any form or by any means other than as
+#  expressly provided by the written permission from Jianhui Tao
+#
+###################################################################
+
+# -*- coding: utf-8 -*-
+
+import sys
+import taos
+from util.log import *
+from util.cases import *
+from util.sql import *
+import numpy as np
+
+
+class TDTestCase:
+    def init(self, conn, logSql):
+        tdLog.debug("start to execute %s" % __file__)
+        tdSql.init(conn.cursor())
+
+        self.rowNum = 10
+        self.ts = 1537146000000
+        
+    def run(self):
+        tdSql.execute("use db")
+
+        # leastsquares verifacation 
+        tdSql.error("select leastsquares(ts, 1, 1) from test1")
+        tdSql.error("select leastsquares(col1, 1, 1) from test")
+        tdSql.error("select leastsquares(col2, 1, 1) from test")
+        tdSql.error("select leastsquares(col3, 1, 1) from test")
+        tdSql.error("select leastsquares(col4, 1, 1) from test")
+        tdSql.error("select leastsquares(col5, 1, 1) from test")
+        tdSql.error("select leastsquares(col6, 1, 1) from test")
+        tdSql.error("select leastsquares(col7, 1, 1) from test1")
+        tdSql.error("select leastsquares(col8, 1, 1) from test1")
+        tdSql.error("select leastsquares(col9, 1, 1) from test1")
+                
+        tdSql.query("select leastsquares(col1, 1, 1) from test1")
+        tdSql.checkData(0, 0, '{slop:1.000000, intercept:0.000000}')
+
+        tdSql.query("select leastsquares(col2, 1, 1) from test1")
+        tdSql.checkData(0, 0, '{slop:1.000000, intercept:0.000000}')
+
+        tdSql.query("select leastsquares(col3, 1, 1) from test1")
+        tdSql.checkData(0, 0, '{slop:1.000000, intercept:0.000000}')
+
+        tdSql.query("select leastsquares(col4, 1, 1) from test1")
+        tdSql.checkData(0, 0, '{slop:1.000000, intercept:0.000000}')
+
+        tdSql.query("select leastsquares(col5, 1, 1) from test1")
+        tdSql.checkData(0, 0, '{slop:1.000000, intercept:-0.900000}')
+
+        tdSql.query("select leastsquares(col6, 1, 1) from test1")
+        tdSql.checkData(0, 0, '{slop:1.000000, intercept:-0.900000}')
+
+    def stop(self):
+        tdSql.close()
+        tdLog.success("%s successfully executed" % __file__)
+
+tdCases.addWindows(__file__, TDTestCase())
+tdCases.addLinux(__file__, TDTestCase())
diff --git a/tests/pytest/functions/function_max_restart.py b/tests/pytest/functions/function_max_restart.py
new file mode 100644
index 0000000000000000000000000000000000000000..8d1827561758f1ceebffab877aabd6cd79166d42
--- /dev/null
+++ b/tests/pytest/functions/function_max_restart.py
@@ -0,0 +1,76 @@
+###################################################################
+#           Copyright (c) 2016 by TAOS Technologies, Inc.
+#                     All rights reserved.
+#
+#  This file is proprietary and confidential to TAOS Technologies.
+#  No part of this file may be reproduced, stored, transmitted,
+#  disclosed or used in any form or by any means other than as
+#  expressly provided by the written permission from Jianhui Tao
+#
+###################################################################
+
+# -*- coding: utf-8 -*-
+
+import sys
+import taos
+from util.log import *
+from util.cases import *
+from util.sql import *
+import numpy as np
+
+
+class TDTestCase:
+    def init(self, conn, logSql):
+        tdLog.debug("start to execute %s" % __file__)
+        tdSql.init(conn.cursor())
+
+        self.rowNum = 10
+        self.ts = 1537146000000
+        
+    def run(self):
+        tdSql.execute("use db") 
+
+        intData = []        
+        floatData = []
+
+        #tdSql.execute('''create table test(ts timestamp, col1 tinyint, col2 smallint, col3 int, col4 bigint, col5 float, col6 double, 
+        #             col7 bool, col8 binary(20), col9 nchar(20)) tags(loc nchar(20))''')
+        #tdSql.execute("create table test1 using test tags('beijing')")
+        for i in range(self.rowNum):
+            intData.append(i + 1)            
+            floatData.append(i + 0.1)                        
+
+        # max verifacation 
+        tdSql.error("select max(ts) from test")
+        tdSql.error("select max(ts) from test1")
+        tdSql.error("select max(col7) from test")
+        tdSql.error("select max(col7) from test1")
+        tdSql.error("select max(col8) from test")
+        tdSql.error("select max(col8) from test1")
+        tdSql.error("select max(col9) from test")
+        tdSql.error("select max(col9) from test1")
+        
+        tdSql.query("select max(col1) from test1")
+        tdSql.checkData(0, 0, np.max(intData))
+
+        tdSql.query("select max(col2) from test1")
+        tdSql.checkData(0, 0, np.max(intData))
+
+        tdSql.query("select max(col3) from test1")
+        tdSql.checkData(0, 0, np.max(intData))
+
+        tdSql.query("select max(col4) from test1")
+        tdSql.checkData(0, 0, np.max(intData))
+        
+        tdSql.query("select max(col5) from test1")
+        tdSql.checkData(0, 0, np.max(floatData))
+
+        tdSql.query("select max(col6) from test1")
+        tdSql.checkData(0, 0, np.max(floatData))
+        
+    def stop(self):
+        tdSql.close()
+        tdLog.success("%s successfully executed" % __file__)
+
+tdCases.addWindows(__file__, TDTestCase())
+tdCases.addLinux(__file__, TDTestCase())
diff --git a/tests/pytest/functions/function_min_restart.py b/tests/pytest/functions/function_min_restart.py
new file mode 100644
index 0000000000000000000000000000000000000000..c8329bffa5525c2386d264010acf7231059e344d
--- /dev/null
+++ b/tests/pytest/functions/function_min_restart.py
@@ -0,0 +1,73 @@
+###################################################################
+#           Copyright (c) 2016 by TAOS Technologies, Inc.
+#                     All rights reserved.
+#
+#  This file is proprietary and confidential to TAOS Technologies.
+#  No part of this file may be reproduced, stored, transmitted,
+#  disclosed or used in any form or by any means other than as
+#  expressly provided by the written permission from Jianhui Tao
+#
+###################################################################
+
+# -*- coding: utf-8 -*-
+
+import sys
+import taos
+from util.log import *
+from util.cases import *
+from util.sql import *
+import numpy as np
+
+
+class TDTestCase:
+    def init(self, conn, logSql):
+        tdLog.debug("start to execute %s" % __file__)
+        tdSql.init(conn.cursor())
+
+        self.rowNum = 10
+        self.ts = 1537146000000
+        
+    def run(self):
+        tdSql.execute("use db")
+
+        intData = []        
+        floatData = []
+
+        for i in range(self.rowNum):
+            intData.append(i + 1)            
+            floatData.append(i + 0.1)                        
+
+        # min verifacation 
+        tdSql.error("select min(ts) from test")
+        tdSql.error("select min(ts) from test1")
+        tdSql.error("select min(col7) from test")
+        tdSql.error("select min(col7) from test1")
+        tdSql.error("select min(col8) from test")
+        tdSql.error("select min(col8) from test1")
+        tdSql.error("select min(col9) from test")
+        tdSql.error("select min(col9) from test1")
+        
+        tdSql.query("select min(col1) from test1")
+        tdSql.checkData(0, 0, np.min(intData))
+
+        tdSql.query("select min(col2) from test1")
+        tdSql.checkData(0, 0, np.min(intData))
+
+        tdSql.query("select min(col3) from test1")
+        tdSql.checkData(0, 0, np.min(intData))
+
+        tdSql.query("select min(col4) from test1")
+        tdSql.checkData(0, 0, np.min(intData))
+        
+        tdSql.query("select min(col5) from test1")
+        tdSql.checkData(0, 0, np.min(floatData))
+
+        tdSql.query("select min(col6) from test1")
+        tdSql.checkData(0, 0, np.min(floatData))
+        
+    def stop(self):
+        tdSql.close()
+        tdLog.success("%s successfully executed" % __file__)
+
+tdCases.addWindows(__file__, TDTestCase())
+tdCases.addLinux(__file__, TDTestCase())
diff --git a/tests/pytest/functions/function_operations_restart.py b/tests/pytest/functions/function_operations_restart.py
new file mode 100644
index 0000000000000000000000000000000000000000..6e3990264cb91d8c063fe638a5f77231ef7be424
--- /dev/null
+++ b/tests/pytest/functions/function_operations_restart.py
@@ -0,0 +1,70 @@
+###################################################################
+#           Copyright (c) 2016 by TAOS Technologies, Inc.
+#                     All rights reserved.
+#
+#  This file is proprietary and confidential to TAOS Technologies.
+#  No part of this file may be reproduced, stored, transmitted,
+#  disclosed or used in any form or by any means other than as
+#  expressly provided by the written permission from Jianhui Tao
+#
+###################################################################
+
+# -*- coding: utf-8 -*-
+
+import sys
+import taos
+from util.log import *
+from util.cases import *
+from util.sql import *
+import numpy as np
+
+
+class TDTestCase:
+    def init(self, conn, logSql):
+        tdLog.debug("start to execute %s" % __file__)
+        tdSql.init(conn.cursor())
+
+        self.rowNum = 10
+        self.ts = 1537146000000
+        
+    def run(self):
+        tdSql.execute("use db")
+
+        # min verifacation 
+        tdSql.error("select ts + col1 from test")
+        tdSql.error("select ts + col1 from test1")
+        tdSql.error("select col1 + col7 from test")
+        tdSql.error("select col1 + col7 from test1")
+        tdSql.error("select col1 + col8 from test")
+        tdSql.error("select col1 + col8 from test1")
+        tdSql.error("select col1 + col9 from test")
+        tdSql.error("select col1 + col9 from test1")
+
+        tdSql.query("select col1 + col2 from test1")
+        tdSql.checkRows(11)
+        tdSql.checkData(0, 0, 2.0)        
+
+        tdSql.query("select col1 + col2 * col3 + col3 / col4 + col5 + col6 from test1")
+        tdSql.checkRows(11)
+        tdSql.checkData(0, 0, 3.2)
+
+        #tdSql.execute("insert into test1(ts, col1) values(%d, 11)" % (self.ts + 11))
+        tdSql.query("select col1 + col2 from test1")
+        tdSql.checkRows(11)
+        tdSql.checkData(10, 0, None)
+        
+        tdSql.query("select col1 + col2 * col3 from test1")
+        tdSql.checkRows(11)
+        tdSql.checkData(10, 0, None)
+
+        tdSql.query("select col1 + col2 * col3 + col3 / col4 + col5 + col6 from test1")
+        tdSql.checkRows(11)
+        tdSql.checkData(10, 0, None)
+
+
+    def stop(self):
+        tdSql.close()
+        tdLog.success("%s successfully executed" % __file__)
+
+tdCases.addWindows(__file__, TDTestCase())
+tdCases.addLinux(__file__, TDTestCase())
diff --git a/tests/pytest/functions/function_percentile_restart.py b/tests/pytest/functions/function_percentile_restart.py
new file mode 100644
index 0000000000000000000000000000000000000000..ade10282dedd655bc7ccb912a30a2a3e88a72223
--- /dev/null
+++ b/tests/pytest/functions/function_percentile_restart.py
@@ -0,0 +1,136 @@
+###################################################################
+#           Copyright (c) 2016 by TAOS Technologies, Inc.
+#                     All rights reserved.
+#
+#  This file is proprietary and confidential to TAOS Technologies.
+#  No part of this file may be reproduced, stored, transmitted,
+#  disclosed or used in any form or by any means other than as
+#  expressly provided by the written permission from Jianhui Tao
+#
+###################################################################
+
+# -*- coding: utf-8 -*-
+
+import sys
+import taos
+from util.log import *
+from util.cases import *
+from util.sql import *
+import numpy as np
+
+
+class TDTestCase:
+    def init(self, conn, logSql):
+        tdLog.debug("start to execute %s" % __file__)
+        tdSql.init(conn.cursor())
+
+        self.rowNum = 10
+        self.ts = 1537146000000
+        
+    def run(self):
+        tdSql.execute("use db")
+
+        intData = []        
+        floatData = []
+
+        for i in range(self.rowNum):
+            intData.append(i + 1)            
+            floatData.append(i + 0.1)                        
+
+        # percentile verifacation 
+        tdSql.error("select percentile(ts 20) from test")
+        tdSql.error("select apercentile(ts 20) from test")
+        tdSql.error("select percentile(col7 20) from test")
+        tdSql.error("select apercentile(col7 20) from test")
+        tdSql.error("select percentile(col8 20) from test")        
+        tdSql.error("select apercentile(col8 20) from test")
+        tdSql.error("select percentile(col9 20) from test")
+        tdSql.error("select apercentile(col9 20) from test")        
+
+        tdSql.query("select percentile(col1, 0) from test")        
+        tdSql.checkData(0, 0, np.percentile(intData, 0))
+        tdSql.query("select apercentile(col1, 0) from test")
+        print("apercentile result: %s" % tdSql.getData(0, 0))
+        tdSql.query("select percentile(col1, 50) from test")
+        tdSql.checkData(0, 0, np.percentile(intData, 50))
+        tdSql.query("select apercentile(col1, 50) from test")
+        print("apercentile result: %s" % tdSql.getData(0, 0))
+        tdSql.query("select percentile(col1, 100) from test")
+        tdSql.checkData(0, 0, np.percentile(intData, 100))
+        tdSql.query("select apercentile(col1, 100) from test")
+        print("apercentile result: %s" % tdSql.getData(0, 0))  
+
+        tdSql.query("select percentile(col2, 0) from test")
+        tdSql.checkData(0, 0, np.percentile(intData, 0))
+        tdSql.query("select apercentile(col2, 0) from test")
+        print("apercentile result: %s" % tdSql.getData(0, 0))
+        tdSql.query("select percentile(col2, 50) from test")
+        tdSql.checkData(0, 0, np.percentile(intData, 50))
+        tdSql.query("select apercentile(col2, 50) from test")
+        print("apercentile result: %s" % tdSql.getData(0, 0))
+        tdSql.query("select percentile(col2, 100) from test")
+        tdSql.checkData(0, 0, np.percentile(intData, 100)) 
+        tdSql.query("select apercentile(col2, 100) from test")
+        print("apercentile result: %s" % tdSql.getData(0, 0))
+
+        tdSql.query("select percentile(col3, 0) from test")
+        tdSql.checkData(0, 0, np.percentile(intData, 0))
+        tdSql.query("select apercentile(col3, 0) from test")
+        print("apercentile result: %s" % tdSql.getData(0, 0))
+        tdSql.query("select percentile(col3, 50) from test")
+        tdSql.checkData(0, 0, np.percentile(intData, 50))
+        tdSql.query("select apercentile(col3, 50) from test")
+        print("apercentile result: %s" % tdSql.getData(0, 0))
+        tdSql.query("select percentile(col3, 100) from test")
+        tdSql.checkData(0, 0, np.percentile(intData, 100))
+        tdSql.query("select apercentile(col3, 100) from test")
+        print("apercentile result: %s" % tdSql.getData(0, 0))
+
+        tdSql.query("select percentile(col4, 0) from test")
+        tdSql.checkData(0, 0, np.percentile(intData, 0))
+        tdSql.query("select apercentile(col4, 0) from test")
+        print("apercentile result: %s" % tdSql.getData(0, 0))
+        tdSql.query("select percentile(col4, 50) from test")
+        tdSql.checkData(0, 0, np.percentile(intData, 50))
+        tdSql.query("select apercentile(col4, 50) from test")
+        print("apercentile result: %s" % tdSql.getData(0, 0))
+        tdSql.query("select percentile(col4, 100) from test")
+        tdSql.checkData(0, 0, np.percentile(intData, 100)) 
+        tdSql.query("select apercentile(col4, 100) from test")
+        print("apercentile result: %s" % tdSql.getData(0, 0))
+
+        tdSql.query("select percentile(col5, 0) from test")        
+        print("query result: %s" % tdSql.getData(0, 0))
+        print("array result: %s" % np.percentile(floatData, 0))
+        tdSql.query("select apercentile(col5, 0) from test")
+        print("apercentile result: %s" % tdSql.getData(0, 0))
+        tdSql.query("select percentile(col5, 50) from test")
+        print("query result: %s" % tdSql.getData(0, 0))
+        print("array result: %s" % np.percentile(floatData, 50))
+        tdSql.query("select apercentile(col5, 50) from test")
+        print("apercentile result: %s" % tdSql.getData(0, 0))        
+        tdSql.query("select percentile(col5, 100) from test")
+        print("query result: %s" % tdSql.getData(0, 0))
+        print("array result: %s" % np.percentile(floatData, 100)) 
+        tdSql.query("select apercentile(col5, 100) from test")
+        print("apercentile result: %s" % tdSql.getData(0, 0))     
+
+        tdSql.query("select percentile(col6, 0) from test")
+        tdSql.checkData(0, 0, np.percentile(floatData, 0))
+        tdSql.query("select apercentile(col6, 0) from test")
+        print("apercentile result: %s" % tdSql.getData(0, 0))
+        tdSql.query("select percentile(col6, 50) from test")
+        tdSql.checkData(0, 0, np.percentile(floatData, 50))
+        tdSql.query("select apercentile(col6, 50) from test")
+        print("apercentile result: %s" % tdSql.getData(0, 0))
+        tdSql.query("select percentile(col6, 100) from test")
+        tdSql.checkData(0, 0, np.percentile(floatData, 100)) 
+        tdSql.query("select apercentile(col6, 100) from test")
+        print("apercentile result: %s" % tdSql.getData(0, 0))       
+
+    def stop(self):
+        tdSql.close()
+        tdLog.success("%s successfully executed" % __file__)
+
+tdCases.addWindows(__file__, TDTestCase())
+tdCases.addLinux(__file__, TDTestCase())
diff --git a/tests/pytest/functions/function_spread_restart.py b/tests/pytest/functions/function_spread_restart.py
new file mode 100644
index 0000000000000000000000000000000000000000..ba71da0a18ac2e1e2a1ead6ab3de9ff5cae6a600
--- /dev/null
+++ b/tests/pytest/functions/function_spread_restart.py
@@ -0,0 +1,69 @@
+###################################################################
+#           Copyright (c) 2016 by TAOS Technologies, Inc.
+#                     All rights reserved.
+#
+#  This file is proprietary and confidential to TAOS Technologies.
+#  No part of this file may be reproduced, stored, transmitted,
+#  disclosed or used in any form or by any means other than as
+#  expressly provided by the written permission from Jianhui Tao
+#
+###################################################################
+
+# -*- coding: utf-8 -*-
+
+import sys
+import taos
+from util.log import *
+from util.cases import *
+from util.sql import *
+import numpy as np
+
+
+class TDTestCase:
+    def init(self, conn, logSql):
+        tdLog.debug("start to execute %s" % __file__)
+        tdSql.init(conn.cursor())
+
+        self.rowNum = 10
+        self.ts = 1537146000000
+        
+    def run(self):
+        tdSql.execute("use db")        
+       
+        tdSql.error("select spread(col7) from test")     
+        tdSql.error("select spread(col7) from test1")               
+        tdSql.error("select spread(col8) from test") 
+        tdSql.error("select spread(col8) from test1")
+        tdSql.error("select spread(col9) from test")        
+        tdSql.error("select spread(col9) from test1")
+        
+        tdSql.query("select spread(col1) from test1")
+        tdSql.checkRows(1)
+        tdSql.checkData(0, 0, 10)
+
+        tdSql.query("select spread(col2) from test1")
+        tdSql.checkRows(1)
+        tdSql.checkData(0, 0, 10)
+
+        tdSql.query("select spread(col3) from test1")
+        tdSql.checkRows(1)
+        tdSql.checkData(0, 0, 10)
+
+        tdSql.query("select spread(col4) from test1")
+        tdSql.checkRows(1)
+        tdSql.checkData(0, 0, 10)
+
+        tdSql.query("select spread(col5) from test1")
+        tdSql.checkRows(1)
+        tdSql.checkData(0, 0, 9.1)
+
+        tdSql.query("select spread(col6) from test1")
+        tdSql.checkRows(1)
+        tdSql.checkData(0, 0, 9.1)
+        
+    def stop(self):
+        tdSql.close()
+        tdLog.success("%s successfully executed" % __file__)
+
+tdCases.addWindows(__file__, TDTestCase())
+tdCases.addLinux(__file__, TDTestCase())
diff --git a/tests/pytest/functions/function_stddev_restart.py b/tests/pytest/functions/function_stddev_restart.py
new file mode 100644
index 0000000000000000000000000000000000000000..ec413b94b20a89c210131188d2a09e38cdbc721c
--- /dev/null
+++ b/tests/pytest/functions/function_stddev_restart.py
@@ -0,0 +1,75 @@
+###################################################################
+#           Copyright (c) 2016 by TAOS Technologies, Inc.
+#                     All rights reserved.
+#
+#  This file is proprietary and confidential to TAOS Technologies.
+#  No part of this file may be reproduced, stored, transmitted,
+#  disclosed or used in any form or by any means other than as
+#  expressly provided by the written permission from Jianhui Tao
+#
+###################################################################
+
+# -*- coding: utf-8 -*-
+
+import sys
+import taos
+from util.log import *
+from util.cases import *
+from util.sql import *
+import numpy as np
+
+
+class TDTestCase:
+    def init(self, conn, logSql):
+        tdLog.debug("start to execute %s" % __file__)
+        tdSql.init(conn.cursor())
+
+        self.rowNum = 10
+        self.ts = 1537146000000
+        
+    def run(self):
+        tdSql.execute("use db")
+
+        intData = []        
+        floatData = []
+
+        for i in range(self.rowNum):
+            intData.append(i + 1)            
+            floatData.append(i + 0.1)                        
+
+        # stddev verifacation 
+        tdSql.error("select stddev(ts) from test1")
+        tdSql.error("select stddev(col1) from test")
+        tdSql.error("select stddev(col2) from test")
+        tdSql.error("select stddev(col3) from test")
+        tdSql.error("select stddev(col4) from test")
+        tdSql.error("select stddev(col5) from test")
+        tdSql.error("select stddev(col6) from test")
+        tdSql.error("select stddev(col7) from test1")
+        tdSql.error("select stddev(col8) from test1")
+        tdSql.error("select stddev(col9) from test1")
+
+        tdSql.query("select stddev(col1) from test1")
+        tdSql.checkData(0, 0, np.std(intData))
+
+        tdSql.query("select stddev(col2) from test1")
+        tdSql.checkData(0, 0, np.std(intData))
+
+        tdSql.query("select stddev(col3) from test1")
+        tdSql.checkData(0, 0, np.std(intData))
+
+        tdSql.query("select stddev(col4) from test1")
+        tdSql.checkData(0, 0, np.std(intData))
+
+        tdSql.query("select stddev(col5) from test1")
+        tdSql.checkData(0, 0, np.std(floatData))
+
+        tdSql.query("select stddev(col6) from test1")
+        tdSql.checkData(0, 0, np.std(floatData))
+            
+    def stop(self):
+        tdSql.close()
+        tdLog.success("%s successfully executed" % __file__)
+
+tdCases.addWindows(__file__, TDTestCase())
+tdCases.addLinux(__file__, TDTestCase())
diff --git a/tests/pytest/functions/function_sum_restart.py b/tests/pytest/functions/function_sum_restart.py
new file mode 100644
index 0000000000000000000000000000000000000000..7fd9ae7dd419faa7f9e00f5a043a0c5e2c3d5f03
--- /dev/null
+++ b/tests/pytest/functions/function_sum_restart.py
@@ -0,0 +1,64 @@
+###################################################################
+#           Copyright (c) 2016 by TAOS Technologies, Inc.
+#                     All rights reserved.
+#
+#  This file is proprietary and confidential to TAOS Technologies.
+#  No part of this file may be reproduced, stored, transmitted,
+#  disclosed or used in any form or by any means other than as
+#  expressly provided by the written permission from Jianhui Tao
+#
+###################################################################
+
+# -*- coding: utf-8 -*-
+
+import sys
+import taos
+from util.log import *
+from util.cases import *
+from util.sql import *
+import numpy as np
+
+
+class TDTestCase:
+    def init(self, conn, logSql):
+        tdLog.debug("start to execute %s" % __file__)
+        tdSql.init(conn.cursor())
+
+        self.rowNum = 10
+        self.ts = 1537146000000
+        
+    def run(self):
+        tdSql.execute("use db")
+
+        intData = []        
+        floatData = []
+
+        for i in range(self.rowNum):
+            intData.append(i + 1)            
+            floatData.append(i + 0.1)                        
+
+        # sum verifacation 
+        tdSql.error("select sum(ts) from test")
+        tdSql.error("select sum(col7) from test")
+        tdSql.error("select sum(col8) from test")
+        tdSql.error("select sum(col9) from test")
+
+        tdSql.query("select sum(col1) from test")
+        tdSql.checkData(0, 0, np.sum(intData))
+        tdSql.query("select sum(col2) from test")
+        tdSql.checkData(0, 0, np.sum(intData))
+        tdSql.query("select sum(col3) from test")
+        tdSql.checkData(0, 0, np.sum(intData))
+        tdSql.query("select sum(col4) from test")
+        tdSql.checkData(0, 0, np.sum(intData))
+        tdSql.query("select sum(col5) from test")
+        tdSql.checkData(0, 0, np.sum(floatData)) 
+        tdSql.query("select sum(col6) from test")
+        tdSql.checkData(0, 0, np.sum(floatData))              
+
+    def stop(self):
+        tdSql.close()
+        tdLog.success("%s successfully executed" % __file__)
+
+tdCases.addWindows(__file__, TDTestCase())
+tdCases.addLinux(__file__, TDTestCase())
diff --git a/tests/pytest/functions/function_top_restart.py b/tests/pytest/functions/function_top_restart.py
new file mode 100644
index 0000000000000000000000000000000000000000..5ae96a2505f98a1bfe4ce8602e098c5217816fda
--- /dev/null
+++ b/tests/pytest/functions/function_top_restart.py
@@ -0,0 +1,93 @@
+###################################################################
+#           Copyright (c) 2016 by TAOS Technologies, Inc.
+#                     All rights reserved.
+#
+#  This file is proprietary and confidential to TAOS Technologies.
+#  No part of this file may be reproduced, stored, transmitted,
+#  disclosed or used in any form or by any means other than as
+#  expressly provided by the written permission from Jianhui Tao
+#
+###################################################################
+
+# -*- coding: utf-8 -*-
+
+import sys
+import taos
+from util.log import *
+from util.cases import *
+from util.sql import *
+import numpy as np
+
+
+class TDTestCase:
+    def init(self, conn, logSql):
+        tdLog.debug("start to execute %s" % __file__)
+        tdSql.init(conn.cursor())
+
+        self.rowNum = 10
+        self.ts = 1537146000000
+        
+    def run(self):
+        tdSql.execute("use db")
+
+        intData = []        
+        floatData = []
+
+        for i in range(self.rowNum):
+            intData.append(i + 1)            
+            floatData.append(i + 0.1)                        
+
+        # top verifacation 
+        tdSql.error("select top(ts, 10) from test")
+        tdSql.error("select top(col1, 0) from test")
+        tdSql.error("select top(col1, 101) from test")
+        tdSql.error("select top(col2, 0) from test")
+        tdSql.error("select top(col2, 101) from test")
+        tdSql.error("select top(col3, 0) from test")
+        tdSql.error("select top(col3, 101) from test")
+        tdSql.error("select top(col4, 0) from test")
+        tdSql.error("select top(col4, 101) from test")
+        tdSql.error("select top(col5, 0) from test")
+        tdSql.error("select top(col5, 101) from test")
+        tdSql.error("select top(col6, 0) from test")
+        tdSql.error("select top(col6, 101) from test")        
+        tdSql.error("select top(col7, 10) from test")        
+        tdSql.error("select top(col8, 10) from test")
+        tdSql.error("select top(col9, 10) from test")
+
+        tdSql.query("select top(col1, 2) from test")
+        tdSql.checkRows(2)
+        tdSql.checkData(0, 1, 9)
+        tdSql.checkData(1, 1, 10)
+
+        tdSql.query("select top(col2, 2) from test")
+        tdSql.checkRows(2)
+        tdSql.checkData(0, 1, 9)
+        tdSql.checkData(1, 1, 10)
+
+        tdSql.query("select top(col3, 2) from test")
+        tdSql.checkRows(2)
+        tdSql.checkData(0, 1, 9)
+        tdSql.checkData(1, 1, 10)
+
+        tdSql.query("select top(col4, 2) from test")
+        tdSql.checkRows(2)
+        tdSql.checkData(0, 1, 9)
+        tdSql.checkData(1, 1, 10)
+
+        tdSql.query("select top(col5, 2) from test")
+        tdSql.checkRows(2)
+        tdSql.checkData(0, 1, 8.1)
+        tdSql.checkData(1, 1, 9.1)
+
+        tdSql.query("select top(col6, 2) from test")
+        tdSql.checkRows(2)
+        tdSql.checkData(0, 1, 8.1)
+        tdSql.checkData(1, 1, 9.1)
+                   
+    def stop(self):
+        tdSql.close()
+        tdLog.success("%s successfully executed" % __file__)
+
+tdCases.addWindows(__file__, TDTestCase())
+tdCases.addLinux(__file__, TDTestCase())
diff --git a/tests/pytest/functions/function_twa_restart.py b/tests/pytest/functions/function_twa_restart.py
new file mode 100644
index 0000000000000000000000000000000000000000..2025e3c9ddcdd41aa18db949e5db0d059090e469
--- /dev/null
+++ b/tests/pytest/functions/function_twa_restart.py
@@ -0,0 +1,130 @@
+###################################################################
+#           Copyright (c) 2016 by TAOS Technologies, Inc.
+#                     All rights reserved.
+#
+#  This file is proprietary and confidential to TAOS Technologies.
+#  No part of this file may be reproduced, stored, transmitted,
+#  disclosed or used in any form or by any means other than as
+#  expressly provided by the written permission from Jianhui Tao
+#
+###################################################################
+
+# -*- coding: utf-8 -*-
+
+import sys
+import taos
+from util.log import *
+from util.cases import *
+from util.sql import *
+import numpy as np
+
+
+class TDTestCase:
+    def init(self, conn, logSql):
+        tdLog.debug("start to execute %s" % __file__)
+        tdSql.init(conn.cursor())
+
+        self.rowNum = 10
+        self.ts = 1537146000000
+        
+    def run(self):
+        tdSql.execute("use db")
+
+        intData = []        
+        floatData = []
+
+        for i in range(self.rowNum):
+            intData.append(i + 1)            
+            floatData.append(i + 0.1)                        
+
+        # twa verifacation 
+        tdSql.error("select twa(ts) from test")
+        tdSql.error("select twa(ts) from test1")
+
+        tdSql.error("select twa(col1) from test")
+        tdSql.error("select twa(col1) from test1")
+
+        tdSql.error("select twa(col2) from test")
+        tdSql.error("select twa(col2) from test1")
+
+        tdSql.error("select twa(col3) from test")
+        tdSql.error("select twa(col3) from test1")
+
+        tdSql.error("select twa(col4) from test")
+        tdSql.error("select twa(col4) from test1")
+
+        tdSql.error("select twa(col5) from test")
+        tdSql.error("select twa(col5) from test1")
+
+        tdSql.error("select twa(col6) from test")
+        tdSql.error("select twa(col6) from test1")        
+
+        tdSql.error("select twa(col7) from test")
+        tdSql.error("select twa(col7) from test1")
+
+        tdSql.error("select twa(col8) from test")
+        tdSql.error("select twa(col8) from test1")
+
+        tdSql.error("select twa(col9) from test")
+        tdSql.error("select twa(col9) from test1")
+
+        tdSql.error("select twa(col1) from test where ts > %d" % self.ts)
+        tdSql.error("select twa(col1) from test1 where ts > %d" % self.ts)
+
+        tdSql.error("select twa(col2) from test where ts > %d" % self.ts)
+        tdSql.error("select twa(col2) from test1 where ts > %d" % self.ts)
+
+        tdSql.error("select twa(col3) from test where ts > %d" % self.ts)
+        tdSql.error("select twa(col3) from test1 where ts > %d" % self.ts)
+
+        tdSql.error("select twa(col4) from test where ts > %d" % self.ts)
+        tdSql.error("select twa(col4) from test1 where ts > %d" % self.ts)
+            
+        tdSql.error("select twa(col5) from test where ts > %d" % self.ts)
+        tdSql.error("select twa(col5) from test1 where ts > %d" % self.ts)
+
+        tdSql.error("select twa(col6) from test where ts > %d" % self.ts)
+        tdSql.error("select twa(col6) from test1 where ts > %d" % self.ts)
+
+        tdSql.error("select twa(col1) from test where ts < %d" % (self.ts + self.rowNum))
+        tdSql.error("select twa(col1) from test1 where ts < %d" % (self.ts + self.rowNum))
+
+        tdSql.error("select twa(col2) from test where ts < %d" % (self.ts + self.rowNum))
+        tdSql.error("select twa(col2) from test1 where ts < %d" % (self.ts + self.rowNum))
+
+        tdSql.error("select twa(col3) from test where ts < %d" % (self.ts + self.rowNum))
+        tdSql.error("select twa(col3) from test1 where ts < %d" % (self.ts + self.rowNum))
+
+        tdSql.error("select twa(col4) from test where ts < %d" % (self.ts + self.rowNum))
+        tdSql.error("select twa(col4) from test1 where ts < %d" % (self.ts + self.rowNum))
+
+        tdSql.error("select twa(col5) from test where ts < %d" % (self.ts + self.rowNum))
+        tdSql.error("select twa(col5) from test1 where ts < %d" % (self.ts + self.rowNum))
+
+        tdSql.error("select twa(col6) from test where ts < %d" % (self.ts + self.rowNum))
+        tdSql.error("select twa(col6) from test1 where ts < %d" % (self.ts + self.rowNum))
+        
+        tdSql.query("select twa(col1) from test where ts > %d  and ts < %d" % (self.ts, self.ts + self.rowNum))
+        tdSql.query("select twa(col1) from test1 where ts > %d  and ts < %d" % (self.ts, self.ts + self.rowNum))
+
+        tdSql.query("select twa(col2) from test where ts > %d  and ts < %d" % (self.ts, self.ts + self.rowNum))
+        tdSql.query("select twa(col2) from test1 where ts > %d  and ts < %d" % (self.ts, self.ts + self.rowNum))
+
+        tdSql.query("select twa(col3) from test where ts > %d  and ts < %d" % (self.ts, self.ts + self.rowNum))
+        tdSql.query("select twa(col3) from test1 where ts > %d  and ts < %d" % (self.ts, self.ts + self.rowNum))
+
+        tdSql.query("select twa(col4) from test where ts > %d  and ts < %d" % (self.ts, self.ts + self.rowNum)) 
+        tdSql.query("select twa(col4) from test1 where ts > %d  and ts < %d" % (self.ts, self.ts + self.rowNum))
+
+        tdSql.query("select twa(col5) from test where ts > %d  and ts < %d" % (self.ts, self.ts + self.rowNum)) 
+        tdSql.query("select twa(col5) from test1 where ts > %d  and ts < %d" % (self.ts, self.ts + self.rowNum))
+
+        tdSql.query("select twa(col6) from test where ts > %d  and ts < %d" % (self.ts, self.ts + self.rowNum))         
+        tdSql.query("select twa(col6) from test1 where ts > %d  and ts < %d" % (self.ts, self.ts + self.rowNum))
+
+    def stop(self):
+        tdSql.close()
+        tdLog.success("%s successfully executed" % __file__)
+
+tdCases.addWindows(__file__, TDTestCase())
+tdCases.addLinux(__file__, TDTestCase())
diff --git a/tests/pytest/test.py b/tests/pytest/test.py
index 678bd873368325d97783fac1e0f94cd76be38cef..a2c35444b55fea9df55e46b4c81a9150b642b452 100644
--- a/tests/pytest/test.py
+++ b/tests/pytest/test.py
@@ -16,6 +16,7 @@
 import sys
 import getopt
 import subprocess
+import time
 from distutils.log import warn as printf
 
 from util.log import *
@@ -33,7 +34,8 @@ if __name__ == "__main__":
     valgrind = 0
     logSql = True
     stop = 0
-    opts, args = getopt.gnu_getopt(sys.argv[1:], 'f:p:m:l:scgh', [
+    restart = False
+    opts, args = getopt.gnu_getopt(sys.argv[1:], 'f:p:m:l:scghr', [
         'file=', 'path=', 'master', 'logSql', 'stop', 'cluster', 'valgrind', 'help'])
     for key, value in opts:
         if key in ['-h', '--help']:
@@ -46,8 +48,12 @@ if __name__ == "__main__":
             tdLog.printNoPrefix('-s stop All dnodes')
             tdLog.printNoPrefix('-c Test Cluster Flag')
             tdLog.printNoPrefix('-g valgrind Test Flag')
+            tdLog.printNoPrefix('-r taosd restart test')
             sys.exit(0)
 
+        if key in ['-r', '--restart']: 
+            restart = True
+
         if key in ['-f', '--file']:
             fileName = value
 
@@ -138,5 +144,19 @@ if __name__ == "__main__":
             tdCases.runAllLinux(conn)
         else:
             tdCases.runOneLinux(conn, fileName)
-
+    if restart:
+        if fileName == "all":
+            tdLog.info("not need to query ")
+        else:    
+            sp = fileName.rsplit(".", 1)
+            if len(sp) == 2 and sp[1] == "py":
+                tdDnodes.stopAll()
+                tdDnodes.start(1)
+                time.sleep(1)            
+                conn = taos.connect( host, config=tdDnodes.getSimCfgPath())
+                tdLog.info("Procedures for tdengine deployed in %s" % (host))
+                tdLog.info("query test after taosd restart")
+                tdCases.runOneLinux(conn, sp[0] + "_" + "restart.py")
+            else:
+                tdLog.info("not need to query")
     conn.close()
diff --git a/tests/script/general/insert/query_block1_memory.sim b/tests/script/general/insert/query_block1_memory.sim
index 83509ad5b0de17500f87591f5cb0a9c3a3c21438..bec9190f9b93044d4321b96d6604209cbc78daba 100644
--- a/tests/script/general/insert/query_block1_memory.sim
+++ b/tests/script/general/insert/query_block1_memory.sim
@@ -30,9 +30,11 @@ print =============== step 1
 $x = $N
 $y = $N / 2
 while $x > $y
-  $ms = $x . m 
+  $z = $x * 60000
+  $ms = 1601481600000 - $z
+
   $xt = - . $x 
-  sql insert into $tb values (now - $ms , -$x ) 
+  sql insert into $tb values ($ms , -$x ) 
   $x = $x - 1
 endw 
 
@@ -45,8 +47,10 @@ endi
 $x = $N / 2
 $y = $N
 while $x < $y
-  $ms = $x . m 
-  sql insert into $tb values (now + $ms , $x ) 
+  $z = $x * 60000
+  $ms = 1601481600000 + $z
+
+  sql insert into $tb values ($ms , $x ) 
   $x = $x + 1
 endw 
 sql select * from $tb
@@ -60,14 +64,14 @@ print =============== step 2
 $N1 = $N + 1
 $result1 = $N / 2
 $result2 = $N
-$step = $N1 . m
-
-$start1 = now- . $step
-$start2 = now
-$start3 = now+ . $step
-$end1 = now- . $step
-$end2 = now
-$end3 = now+ . $step
+$step = $N1 * 60000
+
+$start1 = 1601481600000 -  $step
+$start2 = 1601481600000
+$start3 = 1601481600000 + $step
+$end1 = 1601481600000 -  $step
+$end2 = 1601481600000
+$end3 = 1601481600000 +  $step
 
 sql select * from $tb where ts < $start1 and ts > $end1
 if $rows != 0 then 
diff --git a/tests/script/general/parser/where.sim b/tests/script/general/parser/where.sim
index e609dda652304846081c28a43ed6745be3806eb3..5cac3f47235c1321d740e373d0f5828f076c31c7 100644
--- a/tests/script/general/parser/where.sim
+++ b/tests/script/general/parser/where.sim
@@ -33,7 +33,8 @@ while $i < $tbNum
 
   $x = 0
   while $x < $rowNum
-    $ms = $x . m
+    $y = $x * 60000
+    $ms = 1600099200000 + $y
     $c = $x / 100
     $c = $c * 100
     $c = $x - $c
@@ -41,7 +42,7 @@ while $i < $tbNum
     $binary = $binary . '
     $nchar = 'nchar . $c
     $nchar = $nchar . '
-    sql insert into $tb values (now + $ms , $c , $c , $c , $c , $c , $c , $c , $binary , $nchar )
+    sql insert into $tb values ($ms , $c , $c , $c , $c , $c , $c , $c , $binary , $nchar )
     $x = $x + 1
   endw
 
@@ -299,7 +300,8 @@ while $i < 1
 
   $x = 0
   while $x < 10000
-    $ms = $x . m
+    $y = $x * 60000
+    $ms = 1601481600000 + $y
     $c = $x / 100
     $c = $c * 100
     $c = $x - $c
@@ -307,7 +309,7 @@ while $i < 1
     $binary = $binary . '
     $nchar = 'nchar . $c
     $nchar = $nchar . '
-    sql insert into $tb values (now + $ms , null , null , null , null , null , null , null , null , null )
+    sql insert into $tb values ($ms , null , null , null , null , null , null , null , null , null )
     $x = $x + 1
   endw
 
diff --git a/tests/script/general/stream/table_n.sim b/tests/script/general/stream/table_n.sim
index d1b4a87a9ea641a8f4d58e0d9fc61bd9ac7c7477..a336772a9819ec54607265913eb65c26a2ec1a28 100644
--- a/tests/script/general/stream/table_n.sim
+++ b/tests/script/general/stream/table_n.sim
@@ -289,3 +289,5 @@ endi
 if $data09 != 20 then 
   return -1
 endi
+
+system sh/exec.sh -n dnode1 -s stop -x SIGINT
\ No newline at end of file
diff --git a/tests/script/unique/cluster/vgroup100.sim b/tests/script/unique/cluster/vgroup100.sim
index 7879c5529efa242cabcc37ce93791bc50e7197e5..68a5bad6b32dc23c667900707d3e9027ac943077 100644
--- a/tests/script/unique/cluster/vgroup100.sim
+++ b/tests/script/unique/cluster/vgroup100.sim
@@ -29,6 +29,9 @@ system sh/exec.sh -n dnode3 -s start
 
 sleep 3000
 
+$maxNum = 102
+$maxNum = 12
+
 $x = 0
 show2: 
 	$x = $x + 1
@@ -58,7 +61,7 @@ endi
 
 print ============================== step3
 $count = 2
-while $count < 102
+while $count < $maxNum
   $db = d . $count
   $tb = $db . .t
   $tb2 = $db . .t2
@@ -73,7 +76,7 @@ endw
 print ============================== step4
 
 $count = 2
-while $count < 102
+while $count < $maxNum
   $db = d . $count
   $tb = $db . .t
   sql select * from $tb
@@ -131,7 +134,7 @@ show8:
 	endi
 
 $count = 2
-while $count < 102
+while $count < $maxNum
   $db = d . $count
   $tb = $db . .t
   sql select * from $tb