diff --git a/src/client/src/tscSubquery.c b/src/client/src/tscSubquery.c
index f4b6ea2c9454460b8b899b237d9a16364e0be826..938ec09beb72ffca183089b407b09c61a1cc5dcf 100644
--- a/src/client/src/tscSubquery.c
+++ b/src/client/src/tscSubquery.c
@@ -96,7 +96,7 @@ static int64_t doTSBlockIntersect(SSqlObj* pSql, SJoinSupporter* pSupporter1, SJ
     tscInfo("%" PRId64 ", tags:%"PRId64" \t %" PRId64 ", tags:%"PRId64, elem1.ts, elem1.tag.i64Key, elem2.ts, elem2.tag.i64Key);
 #endif
 
-    int32_t res = tVariantCompare(&elem1.tag, &elem2.tag);
+    int32_t res = tVariantCompare(elem1.tag, elem2.tag);
     if (res == -1 || (res == 0 && tsCompare(order, elem1.ts, elem2.ts))) {
       if (!tsBufNextPos(pSupporter1->pTSBuf)) {
         break;
@@ -123,11 +123,9 @@ static int64_t doTSBlockIntersect(SSqlObj* pSql, SJoinSupporter* pSupporter1, SJ
           win->ekey = elem1.ts;
         }
         
-        tsBufAppend(output1, elem1.vnode, &elem1.tag, (const char*)&elem1.ts, sizeof(elem1.ts));
-        tsBufAppend(output2, elem2.vnode, &elem2.tag, (const char*)&elem2.ts, sizeof(elem2.ts));
+        tsBufAppend(output1, elem1.vnode, elem1.tag, (const char*)&elem1.ts, sizeof(elem1.ts));
+        tsBufAppend(output2, elem2.vnode, elem2.tag, (const char*)&elem2.ts, sizeof(elem2.ts));
 
-        tVariantDestroy(&elem1.tag);
-        tVariantDestroy(&elem2.tag);
       } else {
         pLimit->offset -= 1;
       }
diff --git a/src/query/inc/qTsbuf.h b/src/query/inc/qTsbuf.h
index fe5de8b25a15786194088d16e7194bd0d6624f05..6c2a955f47577a0da19f6520b2addc44e66b73ba 100644
--- a/src/query/inc/qTsbuf.h
+++ b/src/query/inc/qTsbuf.h
@@ -35,16 +35,9 @@ typedef struct STSList {
   int32_t len;
 } STSList;
 
-typedef struct STSRawBlock {
-  int32_t vnode;
-  int64_t tag;
-  TSKEY*  ts;
-  int32_t len;
-} STSRawBlock;
-
 typedef struct STSElem {
   TSKEY     ts;
-  tVariant  tag;
+  tVariant* tag;
   int32_t   vnode;
 } STSElem;
 
@@ -84,6 +77,7 @@ typedef struct STSBuf {
   char     path[PATH_MAX];
   uint32_t fileSize;
 
+  // todo use array
   STSVnodeBlockInfoEx* pData;
   uint32_t             numOfAlloc;
   uint32_t             numOfVnodes;
@@ -121,6 +115,7 @@ void tsBufFlush(STSBuf* pTSBuf);
 
 void    tsBufResetPos(STSBuf* pTSBuf);
 STSElem tsBufGetElem(STSBuf* pTSBuf);
+
 bool    tsBufNextPos(STSBuf* pTSBuf);
 
 STSElem tsBufGetElemStartPos(STSBuf* pTSBuf, int32_t vnodeId, tVariant* tag);
diff --git a/src/query/src/qExecutor.c b/src/query/src/qExecutor.c
index 4e7f065decaa176d2b03c4f162d849879b81b2bc..37394b9769104b9d5e3c48edc96ddb5391bede9d 100644
--- a/src/query/src/qExecutor.c
+++ b/src/query/src/qExecutor.c
@@ -1201,7 +1201,7 @@ static int32_t doTSJoinFilter(SQueryRuntimeEnv *pRuntimeEnv, int32_t offset) {
   SQLFunctionCtx *pCtx = pRuntimeEnv->pCtx;
 
   // compare tag first
-  if (tVariantCompare(&pCtx[0].tag, &elem.tag) != 0) {
+  if (tVariantCompare(&pCtx[0].tag, elem.tag) != 0) {
     return TS_JOIN_TAG_NOT_EQUALS;
   }
 
@@ -3888,7 +3888,6 @@ int32_t setAdditionalInfo(SQInfo *pQInfo, void* pTable, STableQueryInfo *pTableQ
           qError("QInfo:%p failed to find tag:%" PRId64 " in ts_comp", pQInfo, pTag->i64Key);
         }
 
-        tVariantDestroy(&elem.tag);
         return false;
       }
 
@@ -4815,7 +4814,6 @@ static bool multiTableMultioutputHelper(SQInfo *pQInfo, int32_t index) {
           qError("QInfo:%p failed to find tag:%"PRId64" in ts_comp", pQInfo, pTag->i64Key);
         }
 
-        tVariantDestroy(&elem.tag);
         return false;
       } else {
         STSCursor cur = tsBufGetCursor(pRuntimeEnv->pTSBuf);
@@ -4830,7 +4828,7 @@ static bool multiTableMultioutputHelper(SQInfo *pQInfo, int32_t index) {
       }
     } else {
       STSElem elem = tsBufGetElem(pRuntimeEnv->pTSBuf);
-      if (tVariantCompare(&elem.tag, &pRuntimeEnv->pCtx[0].tag) != 0) {
+      if (tVariantCompare(elem.tag, &pRuntimeEnv->pCtx[0].tag) != 0) {
 
         STSElem elem1 = tsBufGetElemStartPos(pRuntimeEnv->pTSBuf, pQInfo->vgId, pTag);
         // failed to find data with the specified tag value and vnodeId
@@ -4841,9 +4839,6 @@ static bool multiTableMultioutputHelper(SQInfo *pQInfo, int32_t index) {
             qError("QInfo:%p failed to find tag:%"PRId64" in ts_comp", pQInfo, pTag->i64Key);
           }
 
-          tVariantDestroy(&elem.tag);
-          tVariantDestroy(&elem1.tag);
-
           return false;
         } else {
           STSCursor cur = tsBufGetCursor(pRuntimeEnv->pTSBuf);
@@ -4854,7 +4849,6 @@ static bool multiTableMultioutputHelper(SQInfo *pQInfo, int32_t index) {
           }
         }
 
-        tVariantDestroy(&elem1.tag);
       } else {
         tsBufSetCursor(pRuntimeEnv->pTSBuf, &pRuntimeEnv->cur);
         STSCursor cur = tsBufGetCursor(pRuntimeEnv->pTSBuf);
@@ -4864,8 +4858,6 @@ static bool multiTableMultioutputHelper(SQInfo *pQInfo, int32_t index) {
           qDebug("QInfo:%p continue scan ts_comp file, tag:%"PRId64" blockIndex:%d, tsIndex:%d", pQInfo, pTag->i64Key, cur.blockIndex, cur.tsIndex);
         }
       }
-
-      tVariantDestroy(&elem.tag);
     }
   }
 
diff --git a/src/query/src/qTsbuf.c b/src/query/src/qTsbuf.c
index 42b6e3f6e082b696b9379352f6d4c788dc1c4977..ad29cef5c290f4a6bcd45f8a79828b0c14727dc0 100644
--- a/src/query/src/qTsbuf.c
+++ b/src/query/src/qTsbuf.c
@@ -702,7 +702,7 @@ STSElem tsBufGetElem(STSBuf* pTSBuf) {
   
   elem1.vnode = pTSBuf->pData[pCur->vgroupIndex].info.vnode;
   elem1.ts = *(TSKEY*)(pTSBuf->tsData.rawBuf + pCur->tsIndex * TSDB_KEYSIZE);
-  tVariantAssign(&elem1.tag, &pBlock->tag);
+  elem1.tag = &pBlock->tag;
 
   return elem1;
 }
@@ -913,8 +913,8 @@ void tsBufDisplay(STSBuf* pTSBuf) {
   
   while (tsBufNextPos(pTSBuf)) {
     STSElem elem = tsBufGetElem(pTSBuf);
-    if (elem.tag.nType == TSDB_DATA_TYPE_BIGINT) {
-      printf("%d-%" PRId64 "-%" PRId64 "\n", elem.vnode, elem.tag.i64Key, elem.ts);
+    if (elem.tag->nType == TSDB_DATA_TYPE_BIGINT) {
+      printf("%d-%" PRId64 "-%" PRId64 "\n", elem.vnode, elem.tag->i64Key, elem.ts);
     }
   }