diff --git a/src/client/inc/tsclient.h b/src/client/inc/tsclient.h
index c482375bff19e007fe2ece0eacc7ae8370696019..f5dfdaf779bd24a702ec859e8eb6f3ccfad8a20c 100644
--- a/src/client/inc/tsclient.h
+++ b/src/client/inc/tsclient.h
@@ -333,7 +333,7 @@ typedef struct STscObj {
   char               superAuth : 1;
   uint32_t           connId;
   uint64_t           rid;      // ref ID returned by taosAddRef
-  struct SSqlObj *   pHb;
+  int64_t            hbrid;
   struct SSqlObj *   sqlList;
   struct SSqlStream *streamList;
   void*              pDnodeConn;
@@ -373,7 +373,7 @@ typedef struct SSqlObj {
   struct SSqlObj **pSubs;
 
   struct SSqlObj  *prev, *next;
-  struct SSqlObj **self;
+  int64_t          self;
 } SSqlObj;
 
 typedef struct SSqlStream {
@@ -507,7 +507,7 @@ static FORCE_INLINE void tscGetResultColumnChr(SSqlRes* pRes, SFieldInfo* pField
 }
 
 extern SCacheObj*    tscMetaCache;
-extern SCacheObj*    tscObjCache;
+extern int           tscObjRef;
 extern void *    tscTmr;
 extern void *    tscQhandle;
 extern int       tscKeepConn[];
diff --git a/src/client/src/tscLocal.c b/src/client/src/tscLocal.c
index 538e652f3c6577098363565a4e76fa637b60709c..4c28adc261f6b83b3c1bbb68d3dd3d56e6007fc9 100644
--- a/src/client/src/tscLocal.c
+++ b/src/client/src/tscLocal.c
@@ -825,8 +825,11 @@ static int32_t tscProcessClientVer(SSqlObj *pSql) {
 static int32_t tscProcessServStatus(SSqlObj *pSql) {
   STscObj* pObj = pSql->pTscObj;
 
-  if (pObj->pHb != NULL) {
-    if (pObj->pHb->res.code == TSDB_CODE_RPC_NETWORK_UNAVAIL) {
+  SSqlObj* pHb = (SSqlObj*)taosAcquireRef(tscObjRef, pObj->hbrid);
+  if (pHb != NULL) {
+    int32_t code = pHb->res.code;
+    taosReleaseRef(tscObjRef, pObj->hbrid);
+    if (code == TSDB_CODE_RPC_NETWORK_UNAVAIL) {
       pSql->res.code = TSDB_CODE_RPC_NETWORK_UNAVAIL;
       return pSql->res.code;
     }
diff --git a/src/client/src/tscServer.c b/src/client/src/tscServer.c
index 9735e26ece0ee107fe7e9464d050d7fb6c665dbe..5d3b86caf33295292944f5eded6fd2cc94d42ba9 100644
--- a/src/client/src/tscServer.c
+++ b/src/client/src/tscServer.c
@@ -175,10 +175,10 @@ void tscProcessHeartBeatRsp(void *param, TAOS_RES *tres, int code) {
       if (pRsp->streamId) tscKillStream(pObj, htonl(pRsp->streamId));
     }
   } else {
-    tscDebug("%p heartbeat failed, code:%s", pObj->pHb, tstrerror(code));
+    tscDebug("%" PRId64 " heartbeat failed, code:%s", pObj->hbrid, tstrerror(code));
   }
 
-  if (pObj->pHb != NULL) {
+  if (pObj->hbrid != 0) {
     int32_t waitingDuring = tsShellActivityTimer * 500;
     tscDebug("%p send heartbeat in %dms", pSql, waitingDuring);
 
@@ -193,20 +193,12 @@ void tscProcessActivityTimer(void *handle, void *tmrId) {
   STscObj *pObj = taosAcquireRef(tscRefId, rid);
   if (pObj == NULL) return; 
 
-  SSqlObj* pHB = pObj->pHb;
-
-  void** p = taosCacheAcquireByKey(tscObjCache, &pHB, sizeof(TSDB_CACHE_PTR_TYPE));
-  if (p == NULL) {
-    tscWarn("%p HB object has been released already", pHB);
-    taosReleaseRef(tscRefId, pObj->rid);
-    return;
-  }
-
-  assert(*pHB->self == pHB);
+  SSqlObj* pHB = taosAcquireRef(tscObjRef, pObj->hbrid);
+  assert(pHB->self == pObj->hbrid);
 
   pHB->retry = 0;
   int32_t code = tscProcessSql(pHB);
-  taosCacheRelease(tscObjCache, (void**) &p, false);
+  taosReleaseRef(tscObjRef, pObj->hbrid);
 
   if (code != TSDB_CODE_SUCCESS) {
     tscError("%p failed to sent HB to server, reason:%s", pHB, tstrerror(code));
@@ -236,7 +228,7 @@ int tscSendMsgToServer(SSqlObj *pSql) {
       .msgType = pSql->cmd.msgType,
       .pCont   = pMsg,
       .contLen = pSql->cmd.payloadLen,
-      .ahandle = pSql,
+      .ahandle = (void*)pSql->self,
       .handle  = NULL,
       .code    = 0
   };
@@ -247,26 +239,24 @@ int tscSendMsgToServer(SSqlObj *pSql) {
 
 void tscProcessMsgFromServer(SRpcMsg *rpcMsg, SRpcEpSet *pEpSet) {
   TSDB_CACHE_PTR_TYPE handle = (TSDB_CACHE_PTR_TYPE) rpcMsg->ahandle;
-  void** p = taosCacheAcquireByKey(tscObjCache, &handle, sizeof(TSDB_CACHE_PTR_TYPE));
-  if (p == NULL) {
+  SSqlObj* pSql = (SSqlObj*)taosAcquireRef(tscObjRef, handle);
+  if (pSql == NULL) {
     rpcFreeCont(rpcMsg->pCont);
     return;
   }
-
-  SSqlObj* pSql = *p;
-  assert(pSql != NULL);
+  assert(pSql->self == handle);
 
   STscObj *pObj = pSql->pTscObj;
   SSqlRes *pRes = &pSql->res;
   SSqlCmd *pCmd = &pSql->cmd;
 
-  assert(*pSql->self == pSql);
   pSql->rpcRid = -1;
 
   if (pObj->signature != pObj) {
     tscDebug("%p DB connection is closed, cmd:%d pObj:%p signature:%p", pSql, pCmd->command, pObj, pObj->signature);
 
-    taosCacheRelease(tscObjCache, (void**) &p, true);
+    taosRemoveRef(tscObjRef, pSql->self);
+    taosReleaseRef(tscObjRef, pSql->self);
     rpcFreeCont(rpcMsg->pCont);
     return;
   }
@@ -276,10 +266,8 @@ void tscProcessMsgFromServer(SRpcMsg *rpcMsg, SRpcEpSet *pEpSet) {
     tscDebug("%p sqlObj needs to be released or DB connection is closed, cmd:%d type:%d, pObj:%p signature:%p",
         pSql, pCmd->command, pQueryInfo->type, pObj, pObj->signature);
 
-    void** p1 = p;
-    taosCacheRelease(tscObjCache, (void**) &p1, false);
-
-    taosCacheRelease(tscObjCache, (void**) &p, true);
+    taosRemoveRef(tscObjRef, pSql->self);
+    taosReleaseRef(tscObjRef, pSql->self);
     rpcFreeCont(rpcMsg->pCont);
     return;
   }
@@ -322,7 +310,7 @@ void tscProcessMsgFromServer(SRpcMsg *rpcMsg, SRpcEpSet *pEpSet) {
 
       // if there is an error occurring, proceed to the following error handling procedure.
       if (rpcMsg->code == TSDB_CODE_TSC_ACTION_IN_PROGRESS) {
-        taosCacheRelease(tscObjCache, (void**) &p, false);
+        taosReleaseRef(tscObjRef, pSql->self);
         rpcFreeCont(rpcMsg->pCont);
         return;
       }
@@ -390,11 +378,10 @@ void tscProcessMsgFromServer(SRpcMsg *rpcMsg, SRpcEpSet *pEpSet) {
     (*pSql->fp)(pSql->param, pSql, rpcMsg->code);
   }
 
-  void** p1 = p;
-  taosCacheRelease(tscObjCache, (void**) &p1, false);
+  taosReleaseRef(tscObjRef, pSql->self);
 
   if (shouldFree) { // in case of table-meta/vgrouplist query, automatically free it
-    taosCacheRelease(tscObjCache, (void **)&p, true);
+    taosRemoveRef(tscObjRef, pSql->self);
     tscDebug("%p sqlObj is automatically freed", pSql);
   }
 
@@ -2020,7 +2007,7 @@ int tscProcessShowRsp(SSqlObj *pSql) {
 
 // TODO multithread problem
 static void createHBObj(STscObj* pObj) {
-  if (pObj->pHb != NULL) {
+  if (pObj->hbrid != 0) {
     return;
   }
 
@@ -2052,7 +2039,7 @@ static void createHBObj(STscObj* pObj) {
   registerSqlObj(pSql);
   tscDebug("%p HB is allocated, pObj:%p", pSql, pObj);
 
-  pObj->pHb = pSql;
+  pObj->hbrid = pSql->self;
 }
 
 int tscProcessConnectRsp(SSqlObj *pSql) {
diff --git a/src/client/src/tscSql.c b/src/client/src/tscSql.c
index de0177647234d0b63fa21a3b0fe2ec5763f40da3..dcca63ff0ebc2b6939c1bfa074ddfad15e5f6560 100644
--- a/src/client/src/tscSql.c
+++ b/src/client/src/tscSql.c
@@ -276,8 +276,8 @@ void taos_close(TAOS *taos) {
   pObj->signature = NULL;
   taosTmrStopA(&(pObj->pTimer));
 
-  SSqlObj* pHb = pObj->pHb;
-  if (pHb != NULL && atomic_val_compare_exchange_ptr(&pObj->pHb, pHb, 0) == pHb) {
+  SSqlObj* pHb = (SSqlObj*)taosAcquireRef(tscObjRef, pObj->hbrid);
+  if (pHb != NULL) {
     if (pHb->rpcRid > 0) {  // wait for rsp from dnode
       rpcCancelRequest(pHb->rpcRid);
       pHb->rpcRid = -1;
@@ -285,6 +285,7 @@ void taos_close(TAOS *taos) {
 
     tscDebug("%p HB is freed", pHb);
     taos_free_result(pHb);
+    taosReleaseRef(tscObjRef, pHb->self);
   }
 
   int32_t ref = T_REF_DEC(pObj);
@@ -606,8 +607,7 @@ void taos_free_result(TAOS_RES *res) {
   bool freeNow = tscKillQueryInDnode(pSql);
   if (freeNow) {
     tscDebug("%p free sqlObj in cache", pSql);
-    SSqlObj** p = pSql->self;
-    taosCacheRelease(tscObjCache, (void**) &p, true);
+    taosReleaseRef(tscObjRef, pSql->self);
   }
 }
 
@@ -700,13 +700,7 @@ static void tscKillSTableQuery(SSqlObj *pSql) {
       continue;
     }
 
-    void** p = taosCacheAcquireByKey(tscObjCache, &pSub, sizeof(TSDB_CACHE_PTR_TYPE));
-    if (p == NULL) {
-      continue;
-    }
-
-    SSqlObj* pSubObj = (SSqlObj*) (*p);
-    assert(pSubObj->self == (SSqlObj**) p);
+    SSqlObj* pSubObj = pSub;
 
     pSubObj->res.code = TSDB_CODE_TSC_QUERY_CANCELLED;
     if (pSubObj->rpcRid > 0) {
@@ -715,7 +709,7 @@ static void tscKillSTableQuery(SSqlObj *pSql) {
     }
 
     tscQueueAsyncRes(pSubObj);
-    taosCacheRelease(tscObjCache, (void**) &p, false);
+    taosReleaseRef(tscObjRef, pSubObj->self);
   }
 
   tscDebug("%p super table query cancelled", pSql);
diff --git a/src/client/src/tscSub.c b/src/client/src/tscSub.c
index a782b53e75513a14b4fe3c297adb077e769ceecd..043e78a9f3c85fa57f776c2212415e12565e3685 100644
--- a/src/client/src/tscSub.c
+++ b/src/client/src/tscSub.c
@@ -179,8 +179,8 @@ static SSub* tscCreateSubscription(STscObj* pObj, const char* topic, const char*
 fail:
   tscError("tscCreateSubscription failed at line %d, reason: %s", line, tstrerror(code));
   if (pSql != NULL) {
-    if (pSql->self != NULL) {
-      taos_free_result(pSql);
+    if (pSql->self != 0) {
+      taosReleaseRef(tscObjRef, pSql->self);
     } else {
       tscFreeSqlObj(pSql);
     }
diff --git a/src/client/src/tscSubquery.c b/src/client/src/tscSubquery.c
index 6ebbeeef411f8922662e7045027cf55410cbf89d..819a323db5e947df46158b9665c0f5d5c491f532 100644
--- a/src/client/src/tscSubquery.c
+++ b/src/client/src/tscSubquery.c
@@ -2198,6 +2198,9 @@ int32_t tscHandleInsertRetry(SSqlObj* pSql) {
   STableDataBlocks* pTableDataBlock = taosArrayGetP(pCmd->pDataBlocks, pSupporter->index);
   int32_t code = tscCopyDataBlockToPayload(pSql, pTableDataBlock);
 
+  // free the data block created from insert sql string
+  pCmd->pDataBlocks = tscDestroyBlockArrayList(pCmd->pDataBlocks);
+
   if ((pRes->code = code)!= TSDB_CODE_SUCCESS) {
     tscQueueAsyncRes(pSql);
     return code;  // here the pSql may have been released already.
diff --git a/src/client/src/tscSystem.c b/src/client/src/tscSystem.c
index 9e9a00550a4497ae11cbdffe48991c2fd7b742d6..91eabda78b8082355e9b48b0cf52c5495304710b 100644
--- a/src/client/src/tscSystem.c
+++ b/src/client/src/tscSystem.c
@@ -15,7 +15,7 @@
 
 #include "os.h"
 #include "taosmsg.h"
-#include "tcache.h"
+#include "tref.h"
 #include "trpc.h"
 #include "tsystem.h"
 #include "ttimer.h"
@@ -31,7 +31,7 @@
 
 // global, not configurable
 SCacheObj*  tscMetaCache;
-SCacheObj*  tscObjCache;
+int     tscObjRef = -1;
 void *  tscTmr;
 void *  tscQhandle;
 void *  tscCheckDiskUsageTmr;
@@ -144,7 +144,7 @@ void taos_init_imp(void) {
   int64_t refreshTime = 10; // 10 seconds by default
   if (tscMetaCache == NULL) {
     tscMetaCache = taosCacheInit(TSDB_DATA_TYPE_BINARY, refreshTime, false, tscFreeTableMetaHelper, "tableMeta");
-    tscObjCache = taosCacheInit(TSDB_CACHE_PTR_KEY, refreshTime / 2, false, tscFreeRegisteredSqlObj, "sqlObj");
+    tscObjRef = taosOpenRef(4096, tscFreeRegisteredSqlObj);
   }
 
   tscRefId = taosOpenRef(200, tscCloseTscObj);
@@ -167,9 +167,9 @@ void taos_cleanup(void) {
     taosCacheCleanup(m);
   }
 
-  m = tscObjCache;
-  if (m != NULL && atomic_val_compare_exchange_ptr(&tscObjCache, m, 0) == m) {
-    taosCacheCleanup(m);
+  int refId = atomic_exchange_32(&tscObjRef, -1);
+  if (refId != -1) {
+    taosCloseRef(refId);
   }
 
   m = tscQhandle;
diff --git a/src/client/src/tscUtil.c b/src/client/src/tscUtil.c
index d22c2588cca37d03b10c506856426068fcf79a78..af17f9b45729ea244a36b76218a0f1aed6de7db0 100644
--- a/src/client/src/tscUtil.c
+++ b/src/client/src/tscUtil.c
@@ -447,20 +447,18 @@ static void tscFreeSubobj(SSqlObj* pSql) {
 void tscFreeRegisteredSqlObj(void *pSql) {
   assert(pSql != NULL);
 
-  SSqlObj** p = (SSqlObj**)pSql;
-  STscObj* pTscObj = (*p)->pTscObj;
+  SSqlObj* p = *(SSqlObj**)pSql;
+  STscObj* pTscObj = p->pTscObj;
 
-  assert((*p)->self != 0 && (*p)->self == (p));
-
-  SSqlObj* ptr = *p;
-  tscFreeSqlObj(*p);
+  assert(p->self != 0);
+  tscFreeSqlObj(p);
 
   int32_t ref = T_REF_DEC(pTscObj);
   assert(ref >= 0);
 
-  tscDebug("%p free sqlObj completed, tscObj:%p ref:%d", ptr, pTscObj, ref);
+  tscDebug("%p free sqlObj completed, tscObj:%p ref:%d", p, pTscObj, ref);
   if (ref == 0) {
-    tscDebug("%p all sqlObj freed, free tscObj:%p", ptr, pTscObj);
+    tscDebug("%p all sqlObj freed, free tscObj:%p", p, pTscObj);
     taosRemoveRef(tscRefId, pTscObj->rid);
   }
 }
@@ -840,7 +838,6 @@ int32_t tscMergeTableDataBlocks(SSqlObj* pSql, SArray* pTableDataBlockList) {
 
     // the length does not include the SSubmitBlk structure
     pBlocks->dataLen = htonl(finalLen);
-
     dataBuf->numOfTables += 1;
   }
 
@@ -1565,19 +1562,6 @@ void tscGetSrcColumnInfo(SSrcColumnInfo* pColInfo, SQueryInfo* pQueryInfo) {
   }
 }
 
-void tscSetFreeHeatBeat(STscObj* pObj) {
-  if (pObj == NULL || pObj->signature != pObj || pObj->pHb == NULL) {
-    return;
-  }
-
-  SSqlObj* pHeatBeat = pObj->pHb;
-  assert(pHeatBeat == pHeatBeat->signature);
-
-  // to denote the heart-beat timer close connection and free all allocated resources
-  SQueryInfo* pQueryInfo = tscGetQueryInfoDetail(&pHeatBeat->cmd, 0);
-  pQueryInfo->type = TSDB_QUERY_TYPE_FREE_RESOURCE;
-}
-
 /*
  * the following four kinds of SqlObj should not be freed
  * 1. SqlObj for stream computing
@@ -1596,7 +1580,7 @@ bool tscShouldBeFreed(SSqlObj* pSql) {
   }
   
   STscObj* pTscObj = pSql->pTscObj;
-  if (pSql->pStream != NULL || pTscObj->pHb == pSql || pSql->pSubscription != NULL) {
+  if (pSql->pStream != NULL || pTscObj->hbrid == pSql->self || pSql->pSubscription != NULL) {
     return false;
   }
 
@@ -1888,13 +1872,10 @@ void tscResetForNextRetrieve(SSqlRes* pRes) {
 }
 
 void registerSqlObj(SSqlObj* pSql) {
-  int32_t DEFAULT_LIFE_TIME = 2 * 600 * 1000;  // 1200 sec
-
   int32_t ref = T_REF_INC(pSql->pTscObj);
   tscDebug("%p add to tscObj:%p, ref:%d", pSql, pSql->pTscObj, ref);
 
-  TSDB_CACHE_PTR_TYPE p = (TSDB_CACHE_PTR_TYPE) pSql;
-  pSql->self = taosCachePut(tscObjCache, &p, sizeof(TSDB_CACHE_PTR_TYPE), &p, sizeof(TSDB_CACHE_PTR_TYPE), DEFAULT_LIFE_TIME);
+  pSql->self = taosAddRef(tscObjRef, pSql);
 }
 
 SSqlObj* createSimpleSubObj(SSqlObj* pSql, void (*fp)(), void* param, int32_t cmd) {