diff --git a/src/query/inc/qExecutor.h b/src/query/inc/qExecutor.h
index 5d570821cb6608fb382398e146766eb1f8aff284..85b1509aca1205c876456174983fb4feff7a2d12 100644
--- a/src/query/inc/qExecutor.h
+++ b/src/query/inc/qExecutor.h
@@ -190,6 +190,7 @@ typedef struct SQInfo {
   int32_t          code;   // error code to returned to client
   int64_t          owner; // if it is in execution
   void*            tsdb;
+  int32_t          ref;   // tsdb mem/immem ref count 
   int32_t          vgId;
   STableGroupInfo  tableGroupInfo;       // table <tid, last_key> list  SArray<STableKeyInfo>
   STableGroupInfo  tableqinfoGroupInfo;  // this is a group array list, including SArray<STableQueryInfo*> structure
diff --git a/src/tsdb/inc/tsdbMain.h b/src/tsdb/inc/tsdbMain.h
index 256b8189f8fc69345b27fdf702fb705d22ac3c10..989e29737512f154deb0771bf69c8ca1a5583e7c 100644
--- a/src/tsdb/inc/tsdbMain.h
+++ b/src/tsdb/inc/tsdbMain.h
@@ -425,8 +425,8 @@ SListNode*    tsdbAllocBufBlockFromPool(STsdbRepo* pRepo);
 int   tsdbInsertRowToMem(STsdbRepo* pRepo, SDataRow row, STable* pTable);
 int   tsdbRefMemTable(STsdbRepo* pRepo, SMemTable* pMemTable);
 int   tsdbUnRefMemTable(STsdbRepo* pRepo, SMemTable* pMemTable);
-int   tsdbTakeMemSnapshot(STsdbRepo* pRepo, SMemTable** pMem, SMemTable** pIMem);
-void  tsdbUnTakeMemSnapShot(STsdbRepo* pRepo, SMemTable* pMem, SMemTable* pIMem);
+int   tsdbTakeMemSnapshot(STsdbRepo* pRepo, SMemTable** pMem, SMemTable** pIMem, bool ref);
+void  tsdbUnTakeMemSnapShot(STsdbRepo* pRepo, SMemTable* pMem, SMemTable* pIMem, bool unRef);
 void* tsdbAllocBytes(STsdbRepo* pRepo, int bytes);
 int   tsdbAsyncCommit(STsdbRepo* pRepo);
 int   tsdbLoadDataFromCache(STable* pTable, SSkipListIterator* pIter, TSKEY maxKey, int maxRowsToRead, SDataCols* pCols,
@@ -576,4 +576,4 @@ void             tsdbFreeScanHandle(STsdbScanHandle* pScanHandle);
 }
 #endif
 
-#endif
\ No newline at end of file
+#endif
diff --git a/src/tsdb/src/tsdbMemTable.c b/src/tsdb/src/tsdbMemTable.c
index 4cf8ddd4bd8df396352ad66b8499552018d5d322..a667c89f4253df0ec1b91174588af18ee020ab5d 100644
--- a/src/tsdb/src/tsdbMemTable.c
+++ b/src/tsdb/src/tsdbMemTable.c
@@ -171,30 +171,36 @@ int tsdbUnRefMemTable(STsdbRepo *pRepo, SMemTable *pMemTable) {
   return 0;
 }
 
-int tsdbTakeMemSnapshot(STsdbRepo *pRepo, SMemTable **pMem, SMemTable **pIMem) {
+int tsdbTakeMemSnapshot(STsdbRepo *pRepo, SMemTable **pMem, SMemTable **pIMem, bool ref) {
   if (tsdbLockRepo(pRepo) < 0) return -1;
+    *pMem = pRepo->mem;
+    *pIMem = pRepo->imem;
 
-  *pMem = pRepo->mem;
-  *pIMem = pRepo->imem;
-  tsdbRefMemTable(pRepo, *pMem);
-  tsdbRefMemTable(pRepo, *pIMem);
+    if (ref) {
+      tsdbRefMemTable(pRepo, *pMem);
+      tsdbRefMemTable(pRepo, *pIMem);
+    }
 
   if (tsdbUnlockRepo(pRepo) < 0) return -1;
 
-  if (*pMem != NULL) taosRLockLatch(&((*pMem)->latch));
+  if (*pMem != NULL) {
+    if (ref) taosRLockLatch(&((*pMem)->latch));
+  }
 
   tsdbDebug("vgId:%d take memory snapshot, pMem %p pIMem %p", REPO_ID(pRepo), *pMem, *pIMem);
   return 0;
 }
 
-void tsdbUnTakeMemSnapShot(STsdbRepo *pRepo, SMemTable *pMem, SMemTable *pIMem) {
+void tsdbUnTakeMemSnapShot(STsdbRepo *pRepo, SMemTable *pMem, SMemTable *pIMem, bool unRef) {
   if (pMem != NULL) {
-    taosRUnLockLatch(&(pMem->latch));
-    tsdbUnRefMemTable(pRepo, pMem);
+    if (unRef) {
+      taosRUnLockLatch(&(pMem->latch));
+      tsdbUnRefMemTable(pRepo, pMem);
+    }
   }
 
   if (pIMem != NULL) {
-    tsdbUnRefMemTable(pRepo, pIMem);
+    if (unRef) tsdbUnRefMemTable(pRepo, pIMem);
   }
 }
 
@@ -780,4 +786,4 @@ static int tsdbAdjustMemMaxTables(SMemTable *pMemTable, int maxTables) {
   taosTFree(tData);
 
   return 0;
-}
\ No newline at end of file
+}
diff --git a/src/tsdb/src/tsdbRead.c b/src/tsdb/src/tsdbRead.c
index f0a2694b608363518c76b63d2e1e674330fba2fa..b21e5273e1e2a53b1c4fcbce26f4da7f47286b2c 100644
--- a/src/tsdb/src/tsdbRead.c
+++ b/src/tsdb/src/tsdbRead.c
@@ -20,6 +20,7 @@
 #include "exception.h"
 
 #include "../../query/inc/qAst.h"  // todo move to common module
+#include "../../query/inc/qExecutor.h"
 #include "tlosertree.h"
 #include "tsdb.h"
 #include "tsdbMain.h"
@@ -203,8 +204,8 @@ TsdbQueryHandleT* tsdbQueryTables(TSDB_REPO_T* tsdb, STsdbQueryCond* pCond, STab
   if (tsdbInitReadHelper(&pQueryHandle->rhelper, (STsdbRepo*) tsdb) != 0) {
     goto out_of_memory;
   }
-
-  tsdbTakeMemSnapshot(pQueryHandle->pTsdb, &pQueryHandle->mem, &pQueryHandle->imem);
+  SQInfo *pQInfo = (SQInfo *)(pQueryHandle->qinfo);
+  tsdbTakeMemSnapshot(pQueryHandle->pTsdb, &pQueryHandle->mem, &pQueryHandle->imem, pQInfo->ref++ == 0);
 
   size_t sizeOfGroup = taosArrayGetSize(groupList->pGroupList);
   assert(sizeOfGroup >= 1 && pCond != NULL && pCond->numOfCols > 0);
@@ -1939,14 +1940,15 @@ bool tsdbNextDataBlock(TsdbQueryHandleT* pHandle) {
       pSecQueryHandle->checkFiles  = true;
       pSecQueryHandle->activeIndex = 0;
       pSecQueryHandle->outputCapacity = ((STsdbRepo*)pSecQueryHandle->pTsdb)->config.maxRowsPerFileBlock;
+      pSecQueryHandle->qinfo       = pQueryHandle->qinfo; 
 
       if (tsdbInitReadHelper(&pSecQueryHandle->rhelper, (STsdbRepo*) pSecQueryHandle->pTsdb) != 0) {
         terrno = TSDB_CODE_TDB_OUT_OF_MEMORY;
         free(pSecQueryHandle);
         return false;
       }
-
-      tsdbTakeMemSnapshot(pSecQueryHandle->pTsdb, &pSecQueryHandle->mem, &pSecQueryHandle->imem);
+      SQInfo *pQInfo = (SQInfo *)(pSecQueryHandle->qinfo); 
+      tsdbTakeMemSnapshot(pSecQueryHandle->pTsdb, &pSecQueryHandle->mem, &pSecQueryHandle->imem, (pQInfo->ref++ == 0));
 
       // allocate buffer in order to load data blocks from file
       int32_t numOfCols = (int32_t)(QH_GET_NUM_OF_COLS(pQueryHandle));
@@ -2707,7 +2709,8 @@ void tsdbCleanupQueryHandle(TsdbQueryHandleT queryHandle) {
   taosTFree(pQueryHandle->statis);
 
   // todo check error
-  tsdbUnTakeMemSnapShot(pQueryHandle->pTsdb, pQueryHandle->mem, pQueryHandle->imem);
+  SQInfo *qInfo = (SQInfo *)(pQueryHandle->qinfo);
+  tsdbUnTakeMemSnapShot(pQueryHandle->pTsdb, pQueryHandle->mem, pQueryHandle->imem, --qInfo->ref == 0);
 
   tsdbDestroyHelper(&pQueryHandle->rhelper);