diff --git a/src/client/src/tscSubquery.c b/src/client/src/tscSubquery.c
index 2e7e02cfd5..1a138f2b48 100644
--- a/src/client/src/tscSubquery.c
+++ b/src/client/src/tscSubquery.c
@@ -2812,7 +2812,6 @@ static void tscAllDataRetrievedFromDnode(SRetrieveSupport *trsupport, SSqlObj* p
       pParentSql->self, pState->numOfSub, pState->numOfRetrievedRows);
   
   SQueryInfo *pPQueryInfo = tscGetQueryInfo(&pParentSql->cmd);
-  tscClearInterpInfo(pPQueryInfo);
   
   code = tscCreateGlobalMerger(trsupport->pExtMemBuffer, pState->numOfSub, pDesc, pPQueryInfo, &pParentSql->res.pMerger, pParentSql->self);
   pParentSql->res.code = code;
diff --git a/src/query/src/qAggMain.c b/src/query/src/qAggMain.c
index 6eadedcaf3..14d3f4e417 100644
--- a/src/query/src/qAggMain.c
+++ b/src/query/src/qAggMain.c
@@ -3670,6 +3670,8 @@ static void interp_function_impl(SQLFunctionCtx *pCtx) {
     return;
   }
 
+  bool ascQuery = (pCtx->order == TSDB_ORDER_ASC);
+
   if (pCtx->inputType == TSDB_DATA_TYPE_TIMESTAMP) {
     *(TSKEY *)pCtx->pOutput = pCtx->startTs;
   } else if (type == TSDB_FILL_NULL) {
@@ -3677,7 +3679,7 @@ static void interp_function_impl(SQLFunctionCtx *pCtx) {
   } else if (type == TSDB_FILL_SET_VALUE) {
     tVariantDump(&pCtx->param[1], pCtx->pOutput, pCtx->inputType, true);
   } else {
-    if (pCtx->start.key != INT64_MIN && pCtx->start.key < pCtx->startTs && pCtx->end.key > pCtx->startTs) {
+    if (pCtx->start.key != INT64_MIN && ((ascQuery && pCtx->start.key <= pCtx->startTs && pCtx->end.key >= pCtx->startTs) || ((!ascQuery) && pCtx->start.key >= pCtx->startTs && pCtx->end.key <= pCtx->startTs))) {
       if (type == TSDB_FILL_PREV) {
         if (IS_NUMERIC_TYPE(pCtx->inputType) || pCtx->inputType == TSDB_DATA_TYPE_BOOL) {
           SET_TYPED_DATA(pCtx->pOutput, pCtx->inputType, pCtx->start.val);
@@ -3716,13 +3718,14 @@ static void interp_function_impl(SQLFunctionCtx *pCtx) {
       TSKEY skey = GET_TS_DATA(pCtx, 0);
 
       if (type == TSDB_FILL_PREV) {
-        if (skey > pCtx->startTs) {
+        if ((ascQuery && skey > pCtx->startTs) || ((!ascQuery) && skey < pCtx->startTs)) {
           return;
         }
 
         if (pCtx->size > 1) {
           TSKEY ekey = GET_TS_DATA(pCtx, 1);
-          if (ekey > skey && ekey <= pCtx->startTs) {
+          if ((ascQuery &&  ekey > skey && ekey <= pCtx->startTs) ||
+             ((!ascQuery) && ekey < skey && ekey >= pCtx->startTs)){
             skey = ekey;
           }
         }
@@ -3731,10 +3734,10 @@ static void interp_function_impl(SQLFunctionCtx *pCtx) {
         TSKEY ekey = skey;
         char* val = NULL;
         
-        if (ekey < pCtx->startTs) {
+        if ((ascQuery && ekey < pCtx->startTs) || ((!ascQuery) && ekey > pCtx->startTs)) {
           if (pCtx->size > 1) {
             ekey = GET_TS_DATA(pCtx, 1);
-            if (ekey < pCtx->startTs) {
+            if ((ascQuery && ekey < pCtx->startTs) || ((!ascQuery) && ekey > pCtx->startTs)) {
               return;
             }
 
@@ -3755,12 +3758,11 @@ static void interp_function_impl(SQLFunctionCtx *pCtx) {
         TSKEY ekey = GET_TS_DATA(pCtx, 1);
       
         // no data generated yet
-        if (!(skey < pCtx->startTs && ekey > pCtx->startTs)) {
+        if ((ascQuery && !(skey <= pCtx->startTs && ekey >= pCtx->startTs))
+           || ((!ascQuery) && !(skey >= pCtx->startTs && ekey <= pCtx->startTs))) {
           return;
         }
         
-        assert(pCtx->start.key == INT64_MIN && skey < pCtx->startTs && ekey > pCtx->startTs);
-        
         char *start = GET_INPUT_DATA(pCtx, 0);
         char *end = GET_INPUT_DATA(pCtx, 1);
 
diff --git a/src/query/src/qExecutor.c b/src/query/src/qExecutor.c
index b1fb2add1b..bb16b74d3d 100644
--- a/src/query/src/qExecutor.c
+++ b/src/query/src/qExecutor.c
@@ -1595,6 +1595,7 @@ static void hashAllIntervalAgg(SOperatorInfo* pOperatorInfo, SResultRowInfo* pRe
   SResultRow* pResult = NULL;
   int32_t forwardStep = 0;
   int32_t ret = 0;
+  STimeWindow preWin = win;
 
   while (1) {
     // null data, failed to allocate more memory buffer
@@ -1609,12 +1610,13 @@ static void hashAllIntervalAgg(SOperatorInfo* pOperatorInfo, SResultRowInfo* pRe
 
     // window start(end) key interpolation
     doWindowBorderInterpolation(pOperatorInfo, pSDataBlock, pInfo->pCtx, pResult, &win, startPos, forwardStep);
-    doApplyFunctions(pRuntimeEnv, pInfo->pCtx, &win, startPos, forwardStep, tsCols, pSDataBlock->info.rows, numOfOutput);
-
+    doApplyFunctions(pRuntimeEnv, pInfo->pCtx, ascQuery ? &win : &preWin, startPos, forwardStep, tsCols, pSDataBlock->info.rows, numOfOutput);
+    preWin = win;
+    
     int32_t prevEndPos = (forwardStep - 1) * step + startPos;
     startPos = getNextQualifiedWindow(pQueryAttr, &win, &pSDataBlock->info, tsCols, binarySearchForKey, prevEndPos);
     if (startPos < 0) {
-      if (win.skey <= pQueryAttr->window.ekey) {
+      if ((ascQuery && win.skey <= pQueryAttr->window.ekey) || ((!ascQuery) && win.ekey >= pQueryAttr->window.ekey)) {
         int32_t code = setResultOutputBufByKey(pRuntimeEnv, pResultRowInfo, pSDataBlock->info.tid, &win, masterScan, &pResult, tableGroupId,
                                                pInfo->pCtx, numOfOutput, pInfo->rowCellInfoOffset);
         if (code != TSDB_CODE_SUCCESS || pResult == NULL) {
@@ -1625,7 +1627,7 @@ static void hashAllIntervalAgg(SOperatorInfo* pOperatorInfo, SResultRowInfo* pRe
         
         // window start(end) key interpolation
         doWindowBorderInterpolation(pOperatorInfo, pSDataBlock, pInfo->pCtx, pResult, &win, startPos, forwardStep);
-        doApplyFunctions(pRuntimeEnv, pInfo->pCtx, &win, startPos, forwardStep, tsCols, pSDataBlock->info.rows, numOfOutput);
+        doApplyFunctions(pRuntimeEnv, pInfo->pCtx, ascQuery ? &win : &preWin, startPos, forwardStep, tsCols, pSDataBlock->info.rows, numOfOutput);
       }
       
       break;
diff --git a/src/query/src/qPlan.c b/src/query/src/qPlan.c
index b8a5ee7699..ad286f7afa 100644
--- a/src/query/src/qPlan.c
+++ b/src/query/src/qPlan.c
@@ -693,7 +693,7 @@ SArray* createGlobalMergePlan(SQueryAttr* pQueryAttr) {
   }
 
   // fill operator
-  if (pQueryAttr->fillType != TSDB_FILL_NONE && (!pQueryAttr->pointInterpQuery)) {
+  if (pQueryAttr->fillType != TSDB_FILL_NONE && pQueryAttr->interval.interval > 0) {
     op = OP_Fill;
     taosArrayPush(plan, &op);
   }
diff --git a/tests/script/general/parser/interp_test.sim b/tests/script/general/parser/interp_test.sim
index 845afb0173..5a2021dcfc 100644
--- a/tests/script/general/parser/interp_test.sim
+++ b/tests/script/general/parser/interp_test.sim
@@ -930,8 +930,254 @@ if $data44 != @18-11-25 19:06:00.000@ then
 endi
 
 
+sql select interp(c1) from intp_stb0 where ts >= '2018-09-17 20:35:00.000' and ts <= '2018-09-17 20:42:00.000' interval(1m) fill(linear);
+if $rows != 8 then
+  return -1
+endi
+if $data00 != @18-09-17 20:35:00.000@  then
+  return -1
+endi
+if $data01 != NULL  then
+  return -1
+endi
+if $data10 != @18-09-17 20:36:00.000@  then
+  return -1
+endi
+if $data11 != NULL then
+  return -1
+endi
+if $data20 != @18-09-17 20:37:00.000@  then
+  return -1
+endi
+if $data21 != NULL then
+  return -1
+endi
+if $data30 != @18-09-17 20:38:00.000@  then
+  return -1
+endi
+if $data31 != NULL then
+  return -1
+endi
+if $data40 != @18-09-17 20:39:00.000@  then
+  return -1
+endi
+if $data41 != NULL then
+  return -1
+endi
+if $data50 != @18-09-17 20:40:00.000@  then
+  return -1
+endi
+if $data51 != 0 then
+  return -1
+endi
+if $data60 != @18-09-17 20:41:00.000@  then
+  return -1
+endi
+if $data61 != NULL then
+  return -1
+endi
+if $data70 != @18-09-17 20:42:00.000@  then
+  return -1
+endi
+if $data71 != NULL then
+  return -1
+endi
 
 
+sql select interp(c1) from intp_stb0 where ts >= '2018-09-17 20:35:00.000' and ts <= '2018-09-17 20:42:00.000' interval(1m) fill(linear) order by ts desc;
+if $rows != 8 then
+  return -1
+endi
+if $data00 != @18-09-17 20:42:00.000@  then
+  return -1
+endi
+if $data01 != NULL  then
+  return -1
+endi
+if $data10 != @18-09-17 20:41:00.000@  then
+  return -1
+endi
+if $data11 != NULL then
+  return -1
+endi
+if $data20 != @18-09-17 20:40:00.000@  then
+  return -1
+endi
+if $data21 != 0 then
+  return -1
+endi
+if $data30 != @18-09-17 20:39:00.000@  then
+  return -1
+endi
+if $data31 != NULL then
+  return -1
+endi
+if $data40 != @18-09-17 20:38:00.000@  then
+  return -1
+endi
+if $data41 != NULL then
+  return -1
+endi
+if $data50 != @18-09-17 20:37:00.000@  then
+  return -1
+endi
+if $data51 != NULL then
+  return -1
+endi
+if $data60 != @18-09-17 20:36:00.000@  then
+  return -1
+endi
+if $data61 != NULL then
+  return -1
+endi
+if $data70 != @18-09-17 20:35:00.000@  then
+  return -1
+endi
+if $data71 != NULL then
+  return -1
+endi
+
+sql  select interp(c3) from intp_stb0 where ts >= '2018-09-17 20:35:00.000' and ts <= '2018-09-17 20:50:00.000' interval(2m) fill(linear) order by ts;
+if $rows != 9 then
+  return -1
+endi
+if $data00 != @18-09-17 20:34:00.000@  then
+  return -1
+endi
+if $data01 != NULL  then
+  return -1
+endi
+if $data10 != @18-09-17 20:36:00.000@  then
+  return -1
+endi
+if $data11 != NULL then
+  return -1
+endi
+if $data20 != @18-09-17 20:38:00.000@  then
+  return -1
+endi
+if $data21 != NULL then
+  return -1
+endi
+if $data30 != @18-09-17 20:40:00.000@  then
+  return -1
+endi
+if $data31 != 0.00000 then
+  return -1
+endi
+if $data40 != @18-09-17 20:42:00.000@  then
+  return -1
+endi
+if $data41 != 0.20000 then
+  return -1
+endi
+if $data50 != @18-09-17 20:44:00.000@  then
+  return -1
+endi
+if $data51 != 0.40000 then
+  return -1
+endi
+if $data60 != @18-09-17 20:46:00.000@  then
+  return -1
+endi
+if $data61 != 0.60000 then
+  return -1
+endi
+if $data70 != @18-09-17 20:48:00.000@  then
+  return -1
+endi
+if $data71 != 0.80000 then
+  return -1
+endi
+if $data80 != @18-09-17 20:50:00.000@  then
+  return -1
+endi
+if $data81 != 1.00000 then
+  return -1
+endi
+
+
+sql select interp(c3) from intp_stb0 where ts >= '2018-09-17 20:35:00.000' and ts <= '2018-09-17 20:50:00.000' interval(3m) fill(linear) order by ts;
+if $rows != 6 then
+  return -1
+endi
+if $data00 != @18-09-17 20:33:00.000@  then
+  return -1
+endi
+if $data01 != NULL  then
+  return -1
+endi
+if $data10 != @18-09-17 20:36:00.000@  then
+  return -1
+endi
+if $data11 != NULL then
+  return -1
+endi
+if $data20 != @18-09-17 20:39:00.000@  then
+  return -1
+endi
+if $data21 != NULL then
+  return -1
+endi
+if $data30 != @18-09-17 20:42:00.000@  then
+  return -1
+endi
+if $data31 != 0.20000 then
+  return -1
+endi
+if $data40 != @18-09-17 20:45:00.000@  then
+  return -1
+endi
+if $data41 != 0.50000 then
+  return -1
+endi
+if $data50 != @18-09-17 20:48:00.000@  then
+  return -1
+endi
+if $data51 != 0.80000 then
+  return -1
+endi
+
+sql select interp(c3) from intp_stb0 where ts >= '2018-09-17 20:35:00.000' and ts <= '2018-09-17 20:50:00.000' interval(3m) fill(linear) order by ts desc;
+if $rows != 6 then
+  return -1
+endi
+if $data00 != @18-09-17 20:48:00.000@  then
+  return -1
+endi
+if $data01 != 0.80000 then
+  return -1
+endi
+if $data10 != @18-09-17 20:45:00.000@  then
+  return -1
+endi
+if $data11 != 0.50000 then
+  return -1
+endi
+if $data20 != @18-09-17 20:42:00.000@  then
+  return -1
+endi
+if $data21 != 0.20000 then
+  return -1
+endi
+if $data30 != @18-09-17 20:39:00.000@  then
+  return -1
+endi
+if $data31 != NULL then
+  return -1
+endi
+if $data40 != @18-09-17 20:36:00.000@  then
+  return -1
+endi
+if $data41 != NULL then
+  return -1
+endi
+if $data50 != @18-09-17 20:33:00.000@  then
+  return -1
+endi
+if $data51 != NULL  then
+  return -1
+endi