diff --git a/src/client/src/tscSQLParser.c b/src/client/src/tscSQLParser.c
index b3b77e576cba156db38471b02199a5e6337e1b56..17ff4997b56cb9541851623a5935bfb86db7917d 100644
--- a/src/client/src/tscSQLParser.c
+++ b/src/client/src/tscSQLParser.c
@@ -820,7 +820,7 @@ int32_t parseSlidingClause(SSqlObj* pSql, SQueryInfo* pQueryInfo, SQuerySQL* pQu
   const char* msg1 = "sliding value no larger than the interval value";
   const char* msg2 = "sliding value can not less than 1% of interval value";
   const char* msg3 = "does not support sliding when interval is natural month/year";
-  const char* msg4 = "sliding not support yet in ordinary query";
+//  const char* msg4 = "sliding not support yet in ordinary query";
 
   const static int32_t INTERVAL_SLIDING_FACTOR = 100;
   SSqlCmd* pCmd = &pSql->cmd;
@@ -856,9 +856,9 @@ int32_t parseSlidingClause(SSqlObj* pSql, SQueryInfo* pQueryInfo, SQuerySQL* pQu
     return invalidSqlErrMsg(tscGetErrorMsgPayload(pCmd), msg2);
   }
 
-  if (pQueryInfo->interval.sliding != pQueryInfo->interval.interval && pSql->pStream == NULL) {
-    return invalidSqlErrMsg(tscGetErrorMsgPayload(pCmd), msg4);
-  }
+//  if (pQueryInfo->interval.sliding != pQueryInfo->interval.interval && pSql->pStream == NULL) {
+//    return invalidSqlErrMsg(tscGetErrorMsgPayload(pCmd), msg4);
+//  }
 
   return TSDB_CODE_SUCCESS;
 }
diff --git a/src/query/src/qExecutor.c b/src/query/src/qExecutor.c
index f3bedb141da2891756f5193e561913556a6df839..17c8955352906b78fe072ebb6047bb09bde53c3b 100644
--- a/src/query/src/qExecutor.c
+++ b/src/query/src/qExecutor.c
@@ -170,8 +170,6 @@ static void getNextTimeWindow(SQuery* pQuery, STimeWindow* tw) {
   tw->ekey -= 1;
 }
 
-#define GET_NEXT_TIMEWINDOW(_q, tw) getNextTimeWindow((_q), (tw))
-
 #define SET_STABLE_QUERY_OVER(_q) ((_q)->tableIndex = (int32_t)((_q)->tableqinfoGroupInfo.numOfTables))
 #define IS_STASBLE_QUERY_OVER(_q) ((_q)->tableIndex >= (int32_t)((_q)->tableqinfoGroupInfo.numOfTables))
 
@@ -827,7 +825,7 @@ static int32_t getNextQualifiedWindow(SQueryRuntimeEnv *pRuntimeEnv, STimeWindow
     TSKEY *primaryKeys, __block_search_fn_t searchFn, int32_t prevPosition) {
   SQuery *pQuery = pRuntimeEnv->pQuery;
 
-  GET_NEXT_TIMEWINDOW(pQuery, pNext);
+  getNextTimeWindow(pQuery, pNext);
 
   // next time window is not in current block
   if ((pNext->skey > pDataBlockInfo->window.ekey && QUERY_IS_ASC_QUERY(pQuery)) ||
@@ -1342,9 +1340,9 @@ static void rowwiseApplyFunctions(SQueryRuntimeEnv *pRuntimeEnv, SDataStatis *pS
       int32_t     index = pWindowResInfo->curIndex;
 
       while (1) {
-        GET_NEXT_TIMEWINDOW(pQuery, &nextWin);
+        getNextTimeWindow(pQuery, &nextWin);
         if ((nextWin.skey > pQuery->window.ekey && QUERY_IS_ASC_QUERY(pQuery)) ||
-            (nextWin.skey < pQuery->window.ekey && !QUERY_IS_ASC_QUERY(pQuery))) {
+            (nextWin.ekey < pQuery->window.ekey && !QUERY_IS_ASC_QUERY(pQuery))) {
           break;
         }
 
@@ -2202,7 +2200,7 @@ static bool overlapWithTimeWindow(SQuery* pQuery, SDataBlockInfo* pBlockInfo) {
     }
 
     while(1) {
-      GET_NEXT_TIMEWINDOW(pQuery, &w);
+      getNextTimeWindow(pQuery, &w);
       if (w.skey > pBlockInfo->window.ekey) {
         break;
       }
@@ -2221,7 +2219,7 @@ static bool overlapWithTimeWindow(SQuery* pQuery, SDataBlockInfo* pBlockInfo) {
     }
 
     while(1) {
-      GET_NEXT_TIMEWINDOW(pQuery, &w);
+      getNextTimeWindow(pQuery, &w);
       if (w.ekey < pBlockInfo->window.skey) {
         break;
       }
@@ -2536,7 +2534,7 @@ static int64_t doScanAllDataBlocks(SQueryRuntimeEnv *pRuntimeEnv) {
     setQueryStatus(pQuery, QUERY_COMPLETED);
   }
 
-  if (QUERY_IS_INTERVAL_QUERY(pQuery) && IS_MASTER_SCAN(pRuntimeEnv)) {
+  if (QUERY_IS_INTERVAL_QUERY(pQuery) && (IS_MASTER_SCAN(pRuntimeEnv)|| pRuntimeEnv->scanFlag == REPEAT_SCAN)) {
     if (Q_STATUS_EQUAL(pQuery->status, QUERY_COMPLETED)) {
       closeAllTimeWindow(&pRuntimeEnv->windowResInfo);
       pRuntimeEnv->windowResInfo.curIndex = pRuntimeEnv->windowResInfo.size - 1;  // point to the last time window
@@ -4354,14 +4352,17 @@ static bool skipTimeInterval(SQueryRuntimeEnv *pRuntimeEnv, TSKEY* start) {
     STimeWindow win = getActiveTimeWindow(pWindowResInfo, pWindowResInfo->prevSKey, pQuery);
 
     while (pQuery->limit.offset > 0) {
+      STimeWindow tw = win;
+
       if ((win.ekey <= blockInfo.window.ekey && QUERY_IS_ASC_QUERY(pQuery)) ||
           (win.ekey >= blockInfo.window.skey && !QUERY_IS_ASC_QUERY(pQuery))) {
         pQuery->limit.offset -= 1;
         pWindowResInfo->prevSKey = win.skey;
-      }
 
-      STimeWindow tw = win;
-      GET_NEXT_TIMEWINDOW(pQuery, &tw);
+        getNextTimeWindow(pQuery, &tw);
+      } else { // current window does not ended in current data block, try next data block
+        getNextTimeWindow(pQuery, &tw);
+      }
 
       if (pQuery->limit.offset == 0) {
         if ((tw.skey <= blockInfo.window.ekey && QUERY_IS_ASC_QUERY(pQuery)) ||
@@ -4414,16 +4415,60 @@ static bool skipTimeInterval(SQueryRuntimeEnv *pRuntimeEnv, TSKEY* start) {
         SArray *         pDataBlock = tsdbRetrieveDataBlock(pRuntimeEnv->pQueryHandle, NULL);
         SColumnInfoData *pColInfoData = taosArrayGet(pDataBlock, 0);
 
-        tw = win;
-        int32_t startPos =
-            getNextQualifiedWindow(pRuntimeEnv, &tw, &blockInfo, pColInfoData->pData, binarySearchForKey, -1);
-        assert(startPos >= 0);
+        if ((win.ekey > blockInfo.window.ekey && QUERY_IS_ASC_QUERY(pQuery)) ||
+            (win.ekey < blockInfo.window.skey && !QUERY_IS_ASC_QUERY(pQuery))) {
+          pQuery->limit.offset -= 1;
+        }
+
+        if (pQuery->limit.offset == 0) {
+          if ((tw.skey <= blockInfo.window.ekey && QUERY_IS_ASC_QUERY(pQuery)) ||
+              (tw.ekey >= blockInfo.window.skey && !QUERY_IS_ASC_QUERY(pQuery))) {
+            // load the data block and check data remaining in current data block
+            // TODO optimize performance
+            SArray *         pDataBlock = tsdbRetrieveDataBlock(pRuntimeEnv->pQueryHandle, NULL);
+            SColumnInfoData *pColInfoData = taosArrayGet(pDataBlock, 0);
+
+            tw = win;
+            int32_t startPos =
+                getNextQualifiedWindow(pRuntimeEnv, &tw, &blockInfo, pColInfoData->pData, binarySearchForKey, -1);
+            assert(startPos >= 0);
+
+            // set the abort info
+            pQuery->pos = startPos;
+
+            // reset the query start timestamp
+            pTableQueryInfo->win.skey = ((TSKEY *)pColInfoData->pData)[startPos];
+            pQuery->window.skey = pTableQueryInfo->win.skey;
+            *start = pTableQueryInfo->win.skey;
+
+            pWindowResInfo->prevSKey = tw.skey;
+            int32_t index = pRuntimeEnv->windowResInfo.curIndex;
+
+            int32_t numOfRes = tableApplyFunctionsOnBlock(pRuntimeEnv, &blockInfo, NULL, binarySearchForKey, pDataBlock);
+            pRuntimeEnv->windowResInfo.curIndex = index;  // restore the window index
+
+            qDebug("QInfo:%p check data block, brange:%" PRId64 "-%" PRId64 ", numOfRows:%d, numOfRes:%d, lastKey:%"PRId64,
+                   GET_QINFO_ADDR(pRuntimeEnv), blockInfo.window.skey, blockInfo.window.ekey, blockInfo.rows, numOfRes, pQuery->current->lastKey);
+
+            return true;
+          } else { // do nothing
+            *start = tw.skey;
+            pQuery->window.skey = tw.skey;
+            pWindowResInfo->prevSKey = tw.skey;
+            return true;
+          }
+        } else {
+          tw = win;
+          int32_t startPos =
+              getNextQualifiedWindow(pRuntimeEnv, &tw, &blockInfo, pColInfoData->pData, binarySearchForKey, -1);
+          assert(startPos >= 0);
 
-        // set the abort info
-        pQuery->pos = startPos;
-        pTableQueryInfo->lastKey = ((TSKEY *)pColInfoData->pData)[startPos];
-        pWindowResInfo->prevSKey = tw.skey;
-        win = tw;
+          // set the abort info
+          pQuery->pos = startPos;
+          pTableQueryInfo->lastKey = ((TSKEY *)pColInfoData->pData)[startPos];
+          pWindowResInfo->prevSKey = tw.skey;
+          win = tw;
+        }
       } else {
         break;  // offset is not 0, and next time window begins or ends in the next block.
       }
@@ -6926,7 +6971,6 @@ int32_t qDumpRetrieveResult(qinfo_t qinfo, SRetrieveTableRsp **pRsp, int32_t *co
 
   if (IS_QUERY_KILLED(pQInfo) || Q_STATUS_EQUAL(pQuery->status, QUERY_OVER)) {
     // here current thread hold the refcount, so it is safe to free tsdbQueryHandle.
-//    doFreeQueryHandle(pQInfo);
     *continueExec = false;
     (*pRsp)->completed = 1;  // notify no more result to client
   } else {
diff --git a/src/query/src/sql.c b/src/query/src/sql.c
index 9b8eb8fd41e9900b11f833de839b6c40c5626771..da2c56ee9e4ec3b4bb1ea9c323bdd4da39821048 100644
--- a/src/query/src/sql.c
+++ b/src/query/src/sql.c
@@ -2628,13 +2628,13 @@ static void yy_reduce(
 {yymsp[1].minor.yy216.limit = -1; yymsp[1].minor.yy216.offset = 0;}
         break;
       case 177: /* limit_opt ::= LIMIT signed */
-{printf("aa1, %d\n", yymsp[0].minor.yy207); yymsp[-1].minor.yy216.limit = yymsp[0].minor.yy207;  yymsp[-1].minor.yy216.offset = 0;}
+{yymsp[-1].minor.yy216.limit = yymsp[0].minor.yy207;  yymsp[-1].minor.yy216.offset = 0;}
         break;
       case 178: /* limit_opt ::= LIMIT signed OFFSET signed */
-{printf("aa2\n, %d\n", yymsp[-2].minor.yy207); yymsp[-3].minor.yy216.limit = yymsp[-2].minor.yy207;  yymsp[-3].minor.yy216.offset = yymsp[0].minor.yy207;}
+{yymsp[-3].minor.yy216.limit = yymsp[-2].minor.yy207;  yymsp[-3].minor.yy216.offset = yymsp[0].minor.yy207;}
         break;
       case 179: /* limit_opt ::= LIMIT signed COMMA signed */
-{printf("aa3\n, %d\n", yymsp[-2].minor.yy207); yymsp[-3].minor.yy216.limit = yymsp[0].minor.yy207;  yymsp[-3].minor.yy216.offset = yymsp[-2].minor.yy207;}
+{yymsp[-3].minor.yy216.limit = yymsp[0].minor.yy207;  yymsp[-3].minor.yy216.offset = yymsp[-2].minor.yy207;}
         break;
       case 181: /* slimit_opt ::= SLIMIT signed */
 {yymsp[-1].minor.yy216.limit = yymsp[0].minor.yy207;  yymsp[-1].minor.yy216.offset = 0;}
diff --git a/src/rpc/src/rpcTcp.c b/src/rpc/src/rpcTcp.c
index 7b32d3416d784b4cbc6e319a73664a28dd578d4d..bbabb5d47b2de104c9278adf713057b6f4531607 100644
--- a/src/rpc/src/rpcTcp.c
+++ b/src/rpc/src/rpcTcp.c
@@ -373,8 +373,8 @@ void *taosOpenTcpClientConnection(void *shandle, void *thandle, uint32_t ip, uin
     tDebug("%s %p TCP connection to 0x%x:%hu is created, localPort:%hu FD:%p numOfFds:%d", 
             pThreadObj->label, thandle, ip, port, localPort, pFdObj, pThreadObj->numOfFds);
   } else {
-    taosCloseSocket(fd);
     tError("%s failed to malloc client FdObj(%s)", pThreadObj->label, strerror(errno));
+    taosCloseSocket(fd);
   }
 
   return pFdObj;
diff --git a/tests/script/general/parser/sliding.sim b/tests/script/general/parser/sliding.sim
index ec0e31311afe1a08644aa28515071bced71ae0f0..b9fd66334d469b09812daac4d0ad15b8a2ac3a9c 100644
--- a/tests/script/general/parser/sliding.sim
+++ b/tests/script/general/parser/sliding.sim
@@ -4,6 +4,7 @@ system sh/deploy.sh -n dnode1 -i 1
 system sh/cfg.sh -n dnode1 -c walLevel -v 1
 system sh/cfg.sh -n dnode1 -c debugFlag -v 135
 system sh/cfg.sh -n dnode1 -c rpcDebugFlag -v 135
+system sh/cfg.sh -n dnode1 -c maxtablespervnode -v 4
 system sh/exec.sh -n dnode1 -s start
 sleep 1000
 sql connect
@@ -28,7 +29,7 @@ $mt = $mtPrefix . $i
 
 sql drop database if exists $db -x step1
 step1:
-sql create database if not exists $db maxtables 4 keep 36500
+sql create database if not exists $db  keep 36500
 sql use $db
 sql create table $mt (ts timestamp, c1 int, c2 float, c3 bigint, c4 smallint, c5 tinyint, c6 double, c7 bool, c8 binary(10), c9 nchar(9)) TAGS(t1 int, t2 binary(12))
 
@@ -169,19 +170,20 @@ if $data94 != 90 then
 endi
 
 sql select count(c2),last(c4) from sliding_tb0 interval(30s) sliding(10s) order by ts asc;
-if $row != 30 then
+if $row != 32 then
   return -1
 endi
 
-if $data00 != @00-01-01 00:00:00.000@ then
+if $data00 != @99-12-31 23:59:40.000@ then
+  print expect 12-31 23:59:40.000, actual: $data00
   return -1
 endi
 
-if $data01 != 1000 then
+if $data01 != 334 then
   return -1
 endi
 
-if $data02 != 99 then
+if $data02 != 33 then
   return -1
 endi
 
@@ -304,11 +306,11 @@ if $data13 != 9.810708435 then
 endi
 
 sql select count(c2),last(c4),stddev(c3) from sliding_tb0 interval(30s) sliding(20s) order by ts asc limit 100 offset 1;
-if $row != 14 then
+if $row != 15 then
  return -1
 endi
 
-if $data00 != @00-01-01 00:00:20.000@ then
+if $data00 != @00-01-01 00:00:00.000@ then
  return -1
 endi
 
@@ -316,7 +318,7 @@ if $data01 != 1000 then
  return -1
 endi
 
-if $data02 != 66 then
+if $data02 != 99 then
  return -1
 endi
 
@@ -324,7 +326,7 @@ if $data03 != 28.866070048 then
  return -1
 endi
 
-if $data90 != @00-01-01 00:03:20.000@ then
+if $data90 != @00-01-01 00:03:00.000@ then
  return -1
 endi
 
@@ -332,113 +334,158 @@ if $data91 != 1000 then
  return -1
 endi
 
-if $data92 != 66 then
+if $data92 != 99 then
  return -1
 endi
 
-sql select count(c2),last(c4),stddev(c3) from sliding_tb0 interval(30s) sliding(20s) order by ts asc limit 100 offset 14;
-if $row != 1 then
+sql select count(c2),last(c4),stddev(c3) from sliding_tb0 interval(30s) sliding(20s) order by ts asc limit 100 offset 5;
+if $row != 11 then
  return -1
 endi
 
-sql select count(c2),last(c4),stddev(c3),spread(c3) from sliding_tb0 where c2 = 0 interval(30s) order by ts desc;
+sql select count(c2),last(c4),stddev(c3) from sliding_tb0 interval(30s) sliding(20s) order by ts asc limit 100 offset 6;
 if $row != 10 then
  return -1
 endi
 
-#00-01-01 00:04:30.000|                   10|       0|              0.000000000|              0.000000000|
-if $data00 != @00-01-01 00:04:30.000@ then
+sql select count(c2),last(c4),stddev(c3) from sliding_tb0 interval(30s) sliding(20s) order by ts asc limit 100 offset 7;
+if $row != 9 then
  return -1
 endi
 
-if $data01 != 10 then
+sql select count(c2),last(c4),stddev(c3) from sliding_tb0 interval(30s) sliding(20s) order by ts asc limit 100 offset 8;
+if $row != 8 then
  return -1
 endi
 
-if $data02 != 0 then
+sql select count(c2),last(c4),stddev(c3) from sliding_tb0 interval(30s) sliding(20s) order by ts asc limit 100 offset 9;
+if $row != 7 then
  return -1
 endi
 
-if $data03 != 0.000000000 then
+sql select count(c2),last(c4),stddev(c3) from sliding_tb0 interval(30s) sliding(20s) order by ts asc limit 100 offset 10;
+if $row != 6 then
  return -1
 endi
 
-sql select count(c2),last(c4),stddev(c3),spread(c3) from sliding_tb0 where c2 = 0 interval(30s) sliding(20s) order by ts desc limit 1 offset 15;
+sql select count(c2),last(c4),stddev(c3) from sliding_tb0 interval(30s) sliding(20s) order by ts asc limit 100 offset 11;
+if $row != 5 then
+ return -1
+endi
+
+sql select count(c2),last(c4),stddev(c3) from sliding_tb0 interval(30s) sliding(20s) order by ts asc limit 100 offset 12;
+if $row != 4 then
+ return -1
+endi
+
+sql select count(c2),last(c4),stddev(c3) from sliding_tb0 interval(30s) sliding(20s) order by ts asc limit 100 offset 13;
+if $row != 3 then
+ return -1
+endi
+
+sql select count(c2),last(c4),stddev(c3) from sliding_tb0 interval(30s) sliding(20s) order by ts asc limit 100 offset 14;
+if $row != 2 then
+ return -1
+endi
+
+sql select count(c2),last(c4),stddev(c3) from sliding_tb0 interval(30s) sliding(20s) order by ts asc limit 100 offset 15;
+if $row != 1 then
+ return -1
+endi
+
+sql select count(c2),last(c4),stddev(c3) from sliding_tb0 interval(30s) sliding(20s) order by ts asc limit 100 offset 16;
 if $row != 0 then
  return -1
 endi
 
-sql select count(*),stddev(c1),count(c1),first(c2),last(c3) from sliding_tb0 where ts>'2000-1-1 00:00:00' and ts<'2000-1-1 00:00:01.002' and c2 >= 0 interval(30s) sliding(10a) order by ts asc limit 1000;
-if $row != 100 then
+sql select count(c2),last(c4),stddev(c3),spread(c3) from sliding_tb0 where c2 = 0 interval(30s) order by ts desc;
+if $row != 10 then
  return -1
 endi
 
-if $data00 != @00-01-01 00:00:00.000@ then
+#00-01-01 00:04:30.000|                   10|       0|              0.000000000|              0.000000000|
+if $data00 != @00-01-01 00:04:30.000@ then
  return -1
 endi
 
-if $data02 != 9.521904571 then
+if $data01 != 10 then
  return -1
 endi
 
-if $data05 != 33 then
+if $data02 != 0 then
  return -1
 endi
 
-if $data10 != @00-01-01 00:00:00.010@ then
+if $data03 != 0.000000000 then
  return -1
 endi
 
-if $data12 != 9.521904571 then
+sql select count(c2),last(c4),stddev(c3),spread(c3) from sliding_tb0 where c2 = 0 interval(30s) sliding(20s) order by ts desc limit 1 offset 15;
+if $row != 1 then
  return -1
 endi
 
-if $data15 != 33 then
+sql select count(c2),last(c4),stddev(c3),spread(c3) from sliding_tb0 where c2 = 0 interval(30s) sliding(20s) order by ts desc limit 1 offset 16;
+if $row != 0 then
  return -1
 endi
 
-if $data95 != 33 then
+sql select count(c2), first(c3),stddev(c4) from sliding_tb0 interval(10a) order by ts desc limit 10 offset 2;
+if $data00 != @00-01-01 00:04:59.910@ then
+  return -1
+endi
+
+sql select count(*),stddev(c1),count(c1),first(c2),last(c3) from sliding_tb0 where ts>'2000-1-1 00:00:00' and ts<'2000-1-1 00:00:01.002' and c2 >= 0 interval(30s) sliding(10s) order by ts asc limit 1000;
+if $row != 3 then
  return -1
 endi
 
-sql select count(*),stddev(c1),count(c1),first(c2),last(c3) from sliding_tb0 where ts>'2000-1-1 00:00:00' and ts<'2000-1-1 00:00:01.002' and c2 >= 0 interval(30s) sliding(10a) order by ts desc limit 1000;
-if $row != 100 then
+if $data00 != @99-12-31 23:59:40.000@ then
  return -1
 endi
 
-if $data00 != @00-01-01 00:00:00.990@ then
+if $data02 != 9.521904571 then
  return -1
 endi
 
-if $data01 != 1 then
+if $data05 != 33 then
+ return -1
+endi
+
+if $data10 != @99-12-31 23:59:50.000@ then
+ return -1
+endi
+
+if $data12 != 9.521904571 then
  return -1
 endi
 
-if $data02 != 0.000000000 then
+if $data15 != 33 then
  return -1
 endi
 
-if $data03 != 1 then
+if $data25 != 33 then
  return -1
 endi
 
-if $data90 != @00-01-01 00:00:00.900@ then
+sql select count(*),stddev(c1),count(c1),first(c2),last(c3) from sliding_tb0 where ts>'2000-1-1 00:00:00' and ts<'2000-1-1 00:00:01.002' and c2 >= 0 interval(30s) sliding(10s) order by ts desc limit 1000;
+if $row != 1 then
  return -1
 endi
 
-if $data91 != 4 then
+if $data00 != @99-12-31 23:59:40.000@ then
  return -1
 endi
 
-if $data92 != 1.118033989 then
+if $data01 != 33 then
  return -1
 endi
 
-if $data93 != 4 then
+if $data02 != 9.521904571 then
  return -1
 endi
 
-if $data94 != 30.00000 then
+if $data03 != 33 then
  return -1
 endi
 
@@ -457,5 +504,7 @@ sql_error select sum(c1) from sliding_tb0 interval(0)  sliding(0);
 sql_error select sum(c1) from sliding_tb0 interval(0m)  sliding(0m);
 sql_error select sum(c1) from sliding_tb0 interval(m)  sliding(m);
 sql_error select sum(c1) from sliding_tb0 sliding(4m);
+sql_error select count(*) from sliding_tb0 interval(1s) sliding(10s);
+sql_error select count(*) from sliding_tb0 interval(10s) sliding(10a);
 
 system sh/exec.sh -n dnode1 -s stop -x SIGINT