diff --git a/README-CN.md b/README-CN.md
index 53abc5c006445f33053c6364227efb11e0f7823b..2b1790f4bbd5cb9862c62c450cb6cb484526cbb0 100644
--- a/README-CN.md
+++ b/README-CN.md
@@ -175,7 +175,7 @@ cd TDengine
 ```bash
 mkdir debug
 cd debug
-cmake .. -DBUILD_TOOLS=true
+cmake .. -DBUILD_TOOLS=true -DBUILD_CONTRIB=true
 make
 ```
 
diff --git a/README.md b/README.md
index 73df4fb187fedcfdd93dafec7e95f7ccfe0da465..a8c20ea3f606e2b68b76c5c203bb02b20b588105 100644
--- a/README.md
+++ b/README.md
@@ -183,7 +183,7 @@ It equals to execute following commands:
 ```bash
 mkdir debug
 cd debug
-cmake .. -DBUILD_TOOLS=true
+cmake .. -DBUILD_TOOLS=true -DBUILD_CONTRIB=true
 make
 ```
 
diff --git a/build.sh b/build.sh
index 78f08afa7a772e2a9f05178244f2443e0ec45925..04ca7a11a0d8907b63848504beeb6ff96db73dd3 100755
--- a/build.sh
+++ b/build.sh
@@ -4,5 +4,5 @@ if [ ! -d debug ]; then
     mkdir debug || echo -e "failed to make directory for build"
 fi
 
-cd debug && cmake .. -DBUILD_TOOLS=true && make
+cd debug && cmake .. -DBUILD_TOOLS=true -DBUILD_CONTRIB=true && make
 
diff --git a/source/libs/executor/src/timewindowoperator.c b/source/libs/executor/src/timewindowoperator.c
index 8839cef3149a968d576d76f9e33b6cf4cbd6f58d..03f24919f28396e5ed16bcf40571f9ec1a46c4da 100644
--- a/source/libs/executor/src/timewindowoperator.c
+++ b/source/libs/executor/src/timewindowoperator.c
@@ -3574,6 +3574,7 @@ static SSDataBlock* doStreamSessionAgg(SOperatorInfo* pOperator) {
   SStreamSessionAggOperatorInfo* pInfo = pOperator->info;
   SOptrBasicInfo*                pBInfo = &pInfo->binfo;
   SStreamAggSupporter*           pAggSup = &pInfo->streamAggSup;
+  qDebug("===stream=== stream session agg");
   if (pOperator->status == OP_EXEC_DONE) {
     return NULL;
   } else if (pOperator->status == OP_RES_TO_RETURN) {
@@ -3736,6 +3737,7 @@ void streamSessionReloadState(SOperatorInfo* pOperator) {
     setSessionOutputBuf(pAggSup, pSeKeyBuf[i].win.skey, pSeKeyBuf[i].win.ekey, pSeKeyBuf[i].groupId, &winInfo);
     int32_t winNum = compactSessionWindow(pOperator, &winInfo, pInfo->pStUpdated, pInfo->pStDeleted, true);
     if (winNum > 0) {
+      qDebug("===stream=== reload state. save result %" PRId64 ", %" PRIu64, winInfo.sessionWin.win.skey, winInfo.sessionWin.groupId);
       if (pInfo->twAggSup.calTrigger == STREAM_TRIGGER_AT_ONCE) {
         saveResult(winInfo, pInfo->pStUpdated);
       } else if (pInfo->twAggSup.calTrigger == STREAM_TRIGGER_WINDOW_CLOSE) {
@@ -3754,7 +3756,7 @@ void streamSessionReloadState(SOperatorInfo* pOperator) {
   SOperatorInfo* downstream = pOperator->pDownstream[0];
   if (downstream->fpSet.reloadStreamStateFn) {
     downstream->fpSet.reloadStreamStateFn(downstream);
-  } 
+  }
 }
 
 SOperatorInfo* createStreamSessionAggOperatorInfo(SOperatorInfo* downstream, SPhysiNode* pPhyNode,
@@ -3863,6 +3865,7 @@ static SSDataBlock* doStreamSessionSemiAgg(SOperatorInfo* pOperator) {
   SExprSupp*                     pSup = &pOperator->exprSupp;
   SStreamAggSupporter*           pAggSup = &pInfo->streamAggSup;
 
+  qDebug("===stream=== stream session semi agg");
   if (pOperator->status == OP_EXEC_DONE) {
     return NULL;
   }
diff --git a/source/libs/stream/src/streamExec.c b/source/libs/stream/src/streamExec.c
index 34370ebce9a8962b6a5c81fd3de112753d779471..d3ab7e820a59a33195f62d685c7c02f82b1260e7 100644
--- a/source/libs/stream/src/streamExec.c
+++ b/source/libs/stream/src/streamExec.c
@@ -364,6 +364,15 @@ static int32_t streamDoTransferStateToStreamTask(SStreamTask* pTask) {
 
   // 7. pause allowed.
   streamTaskEnablePause(pStreamTask);
+  if (taosQueueEmpty(pTask->inputQueue->queue)) {
+    SStreamRefDataBlock* pItem = taosAllocateQitem(sizeof(SStreamRefDataBlock), DEF_QITEM, 0);;
+    SSDataBlock* pDelBlock = createSpecialDataBlock(STREAM_DELETE_DATA);
+    pDelBlock->info.rows = 0;
+    pDelBlock->info.version = 0;
+    pItem->type = STREAM_INPUT__REF_DATA_BLOCK;
+    pItem->pBlock = pDelBlock;
+    tAppendDataToInputQueue(pTask, (SStreamQueueItem*)pItem);
+  }
 
   streamSchedExec(pStreamTask);
   streamMetaReleaseTask(pMeta, pStreamTask);