diff --git a/src/client/src/tscFunctionImpl.c b/src/client/src/tscFunctionImpl.c
index e0bd76233399b389c75aba4c28c04bdb8b1ac0f8..affa4aee8367b412442085d25ddd751dd0019b17 100644
--- a/src/client/src/tscFunctionImpl.c
+++ b/src/client/src/tscFunctionImpl.c
@@ -3978,7 +3978,7 @@ static void interp_function(SQLFunctionCtx *pCtx) {
           if (isNull(data1, srcType) || isNull(data2, srcType)) {
             setNull(pCtx->aOutputBuf, srcType, pCtx->inputBytes);
           } else {
-            taosDoLinearInterpolation(pCtx->outputType, &point1, &point2, &point);
+            taosGetLinearInterpolationVal(pCtx->outputType, &point1, &point2, &point);
           }
         } else if (srcType == TSDB_DATA_TYPE_FLOAT) {
           point1.val = data1;
@@ -3987,7 +3987,7 @@ static void interp_function(SQLFunctionCtx *pCtx) {
           if (isNull(data1, srcType) || isNull(data2, srcType)) {
             setNull(pCtx->aOutputBuf, srcType, pCtx->inputBytes);
           } else {
-            taosDoLinearInterpolation(pCtx->outputType, &point1, &point2, &point);
+            taosGetLinearInterpolationVal(pCtx->outputType, &point1, &point2, &point);
           }
         
         } else {
diff --git a/src/client/src/tscSQLParser.c b/src/client/src/tscSQLParser.c
index f7aaf830666e586d5ebd485011f3e94ddf47aeeb..f497263f2acf9f426d822950ea6279be9e3183ff 100644
--- a/src/client/src/tscSQLParser.c
+++ b/src/client/src/tscSQLParser.c
@@ -2758,6 +2758,7 @@ int32_t parseGroupbyClause(SQueryInfo* pQueryInfo, tVariantList* pList, SSqlCmd*
   const char* msg1 = "too many columns in group by clause";
   const char* msg2 = "invalid column name in group by clause";
   const char* msg3 = "columns from one table allowed as group by columns";
+  const char* msg4 = "join query does not support group by";
   const char* msg7 = "not support group by expression";
   const char* msg8 = "not allowed column type for group by";
   const char* msg9 = "tags not allowed for table query";
@@ -2778,6 +2779,10 @@ int32_t parseGroupbyClause(SQueryInfo* pQueryInfo, tVariantList* pList, SSqlCmd*
     return invalidSqlErrMsg(tscGetErrorMsgPayload(pCmd), msg1);
   }
 
+  if (pQueryInfo->numOfTables > 1) {
+    return invalidSqlErrMsg(tscGetErrorMsgPayload(pCmd), msg4);
+  }
+
   STableMeta* pTableMeta = NULL;
   SSchema*    pSchema = NULL;
   SSchema     s = tscGetTbnameColumnSchema();
diff --git a/src/client/src/tscServer.c b/src/client/src/tscServer.c
index 1584afe706e21d1a16e4ab914297aadaccbbf1b3..b7d3a22596154e847924d2ee7be683bee1031cfe 100644
--- a/src/client/src/tscServer.c
+++ b/src/client/src/tscServer.c
@@ -882,7 +882,7 @@ int tscBuildQueryMsg(SSqlObj *pSql, SSqlInfo *pInfo) {
   if (pQueryInfo->tsBuf != NULL) {
     // note: here used the index instead of actual vnode id.
     int32_t vnodeIndex = pTableMetaInfo->vgroupIndex;
-    int32_t code = dumpFileBlockByVnodeId(pQueryInfo->tsBuf, vnodeIndex, pMsg, &pQueryMsg->tsLen, &pQueryMsg->tsNumOfBlocks);
+    int32_t code = dumpFileBlockByGroupId(pQueryInfo->tsBuf, vnodeIndex, pMsg, &pQueryMsg->tsLen, &pQueryMsg->tsNumOfBlocks);
     if (code != TSDB_CODE_SUCCESS) {
       return code;
     }
diff --git a/src/client/src/tscSubquery.c b/src/client/src/tscSubquery.c
index 5139f7bd80fd23ef8e1115f65b675d6bf2800675..9905de279e5deecc17f5e8cbbad5148694663555 100644
--- a/src/client/src/tscSubquery.c
+++ b/src/client/src/tscSubquery.c
@@ -156,8 +156,8 @@ 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.id, elem1.tag, (const char*)&elem1.ts, sizeof(elem1.ts));
+            tsBufAppend(output2, elem2.id, elem2.tag, (const char*)&elem2.ts, sizeof(elem2.ts));
           } else {
             pLimit->offset -= 1;//offset apply to projection?
           }
@@ -193,8 +193,8 @@ static int64_t doTSBlockIntersect(SSqlObj* pSql, SJoinSupporter* pSupporter1, SJ
   TSKEY et = taosGetTimestampUs();
   tscDebug("%p input1:%" PRId64 ", input2:%" PRId64 ", final:%" PRId64 " in %d vnodes for secondary query after ts blocks "
            "intersecting, skey:%" PRId64 ", ekey:%" PRId64 ", numOfVnode:%d, elapsed time:%" PRId64 " us",
-           pSql, numOfInput1, numOfInput2, output1->numOfTotal, output1->numOfVnodes, win->skey, win->ekey,
-           tsBufGetNumOfVnodes(output1), et - st);
+           pSql, numOfInput1, numOfInput2, output1->numOfTotal, output1->numOfGroups, win->skey, win->ekey,
+           tsBufGetNumOfGroup(output1), et - st);
 
   return output1->numOfTotal;
 }
@@ -282,7 +282,7 @@ static UNUSED_FUNC bool needSecondaryQuery(SQueryInfo* pQueryInfo) {
 static void filterVgroupTables(SQueryInfo* pQueryInfo, SArray* pVgroupTables) {
   int32_t  num = 0;
   int32_t* list = NULL;
-  tsBufGetVnodeIdList(pQueryInfo->tsBuf, &num, &list);
+  tsBufGetGroupIdList(pQueryInfo->tsBuf, &num, &list);
 
   // The virtual node, of which all tables are disqualified after the timestamp intersection,
   // is removed to avoid next stage query.
@@ -314,7 +314,7 @@ static void filterVgroupTables(SQueryInfo* pQueryInfo, SArray* pVgroupTables) {
 static SArray* buildVgroupTableByResult(SQueryInfo* pQueryInfo, SArray* pVgroupTables) {
   int32_t  num = 0;
   int32_t* list = NULL;
-  tsBufGetVnodeIdList(pQueryInfo->tsBuf, &num, &list);
+  tsBufGetGroupIdList(pQueryInfo->tsBuf, &num, &list);
 
   size_t numOfGroups = taosArrayGetSize(pVgroupTables);
 
diff --git a/src/query/inc/qFill.h b/src/query/inc/qFill.h
index 329ea9a789cf7e5c8963788c68981b63ccb234e3..1b5aca77c4d08bc2b51f1147279a7df64476c8e2 100644
--- a/src/query/inc/qFill.h
+++ b/src/query/inc/qFill.h
@@ -49,7 +49,6 @@ typedef struct SFillInfo {
   int32_t numOfTags;            // number of tags
   int32_t numOfCols;            // number of columns, including the tags columns
   int32_t rowSize;              // size of each row
-//  char ** pTags;                // tags value for current interpolation
   SFillTagColInfo* pTags;       // tags value for filling gap
   SInterval interval;
   char *  prevValues;           // previous row of data, to generate the interpolation results
@@ -83,7 +82,7 @@ int64_t getFilledNumOfRes(SFillInfo* pFillInfo, int64_t ekey, int32_t maxNumOfRo
 
 int32_t taosNumOfRemainRows(SFillInfo *pFillInfo);
 
-int taosDoLinearInterpolation(int32_t type, SPoint *point1, SPoint *point2, SPoint *point);
+int32_t taosGetLinearInterpolationVal(int32_t type, SPoint *point1, SPoint *point2, SPoint *point);
 
 int64_t taosGenerateDataBlock(SFillInfo* pFillInfo, tFilePage** output, int32_t capacity);
 
diff --git a/src/query/inc/qTsbuf.h b/src/query/inc/qTsbuf.h
index 73b18f8915122305cca4a45604986f2e5593e274..90bd64336fdeed91deb68b9b490224a7fb29bc80 100644
--- a/src/query/inc/qTsbuf.h
+++ b/src/query/inc/qTsbuf.h
@@ -26,7 +26,7 @@ extern "C" {
 
 #define MEM_BUF_SIZE (1 << 20)
 #define TS_COMP_FILE_MAGIC 0x87F5EC4C
-#define TS_COMP_FILE_VNODE_MAX 512
+#define TS_COMP_FILE_GROUP_MAX 512
 
 typedef struct STSList {
   char*   rawBuf;
@@ -38,7 +38,7 @@ typedef struct STSList {
 typedef struct STSElem {
   TSKEY     ts;
   tVariant* tag;
-  int32_t   vnode;
+  int32_t   id;
 } STSElem;
 
 typedef struct STSCursor {
@@ -60,17 +60,17 @@ typedef struct STSBlock {
  * The size of buffer file should not be greater than 2G,
  * and the offset of int32_t type is enough
  */
-typedef struct STSVnodeBlockInfo {
-  int32_t vnode;       // vnode id
+typedef struct STSGroupBlockInfo {
+  int32_t id;          // group id
   int32_t offset;      // offset set value in file
   int32_t numOfBlocks; // number of total blocks
   int32_t compLen;     // compressed size
-} STSVnodeBlockInfo;
+} STSGroupBlockInfo;
 
-typedef struct STSVnodeBlockInfoEx {
-  STSVnodeBlockInfo info;
+typedef struct STSGroupBlockInfoEx {
+  STSGroupBlockInfo info;
   int32_t           len;  // length before compress
-} STSVnodeBlockInfoEx;
+} STSGroupBlockInfoEx;
 
 typedef struct STSBuf {
   FILE*    f;
@@ -78,9 +78,9 @@ typedef struct STSBuf {
   uint32_t fileSize;
 
   // todo use array
-  STSVnodeBlockInfoEx* pData;
+  STSGroupBlockInfoEx* pData;
   uint32_t             numOfAlloc;
-  uint32_t             numOfVnodes;
+  uint32_t             numOfGroups;
 
   char*     assistBuf;
   int32_t   bufSize;
@@ -94,22 +94,22 @@ typedef struct STSBuf {
 
 typedef struct STSBufFileHeader {
   uint32_t magic;       // file magic number
-  uint32_t numOfVnode;  // number of vnode stored in current file
+  uint32_t numOfGroup;  // number of group stored in current file
   int32_t  tsOrder;     // timestamp order in current file
 } STSBufFileHeader;
 
 STSBuf* tsBufCreate(bool autoDelete, int32_t order);
 STSBuf* tsBufCreateFromFile(const char* path, bool autoDelete);
-STSBuf* tsBufCreateFromCompBlocks(const char* pData, int32_t numOfBlocks, int32_t len, int32_t tsOrder, int32_t vnodeId);
+STSBuf* tsBufCreateFromCompBlocks(const char* pData, int32_t numOfBlocks, int32_t len, int32_t tsOrder, int32_t id);
 
 void* tsBufDestroy(STSBuf* pTSBuf);
 
-void    tsBufAppend(STSBuf* pTSBuf, int32_t vnodeId, tVariant* tag, const char* pData, int32_t len);
+void    tsBufAppend(STSBuf* pTSBuf, int32_t id, tVariant* tag, const char* pData, int32_t len);
 int32_t tsBufMerge(STSBuf* pDestBuf, const STSBuf* pSrcBuf);
 
 STSBuf* tsBufClone(STSBuf* pTSBuf);
 
-STSVnodeBlockInfo* tsBufGetVnodeBlockInfo(STSBuf* pTSBuf, int32_t vnodeId);
+STSGroupBlockInfo* tsBufGetGroupBlockInfo(STSBuf* pTSBuf, int32_t id);
 
 void tsBufFlush(STSBuf* pTSBuf);
 
@@ -118,7 +118,7 @@ STSElem tsBufGetElem(STSBuf* pTSBuf);
 
 bool    tsBufNextPos(STSBuf* pTSBuf);
 
-STSElem tsBufGetElemStartPos(STSBuf* pTSBuf, int32_t vnodeId, tVariant* tag);
+STSElem tsBufGetElemStartPos(STSBuf* pTSBuf, int32_t id, tVariant* tag);
 
 STSCursor tsBufGetCursor(STSBuf* pTSBuf);
 void      tsBufSetTraverseOrder(STSBuf* pTSBuf, int32_t order);
@@ -131,11 +131,11 @@ void tsBufSetCursor(STSBuf* pTSBuf, STSCursor* pCur);
  */
 void tsBufDisplay(STSBuf* pTSBuf);
 
-int32_t tsBufGetNumOfVnodes(STSBuf* pTSBuf);
+int32_t tsBufGetNumOfGroup(STSBuf* pTSBuf);
 
-void tsBufGetVnodeIdList(STSBuf* pTSBuf, int32_t* num, int32_t** vnodeId);
+void tsBufGetGroupIdList(STSBuf* pTSBuf, int32_t* num, int32_t** id);
 
-int32_t dumpFileBlockByVnodeId(STSBuf* pTSBuf, int32_t vnodeId, void* buf, int32_t* len, int32_t* numOfBlocks);
+int32_t dumpFileBlockByGroupId(STSBuf* pTSBuf, int32_t id, void* buf, int32_t* len, int32_t* numOfBlocks);
 
 STSElem tsBufFindElemStartPosByTag(STSBuf* pTSBuf, tVariant* pTag);
 
diff --git a/src/query/src/qAst.c b/src/query/src/qAst.c
index 893105e44ac4eb82843514cda20928d3e0dcdaf9..847a8b8eb601250866ed2e4f29b63941c3faa19d 100644
--- a/src/query/src/qAst.c
+++ b/src/query/src/qAst.c
@@ -609,7 +609,7 @@ int32_t intersect(SArray *pLeft, SArray *pRight, SArray *pFinalRes) {
 /*
  * traverse the result and apply the function to each item to check if the item is qualified or not
  */
-static void tArrayTraverse(tExprNode *pExpr, __result_filter_fn_t fp, SArray *pResult) {
+static UNUSED_FUNC void tArrayTraverse(tExprNode *pExpr, __result_filter_fn_t fp, SArray *pResult) {
   assert(pExpr->_node.pLeft->nodeType == TSQL_NODE_COL && pExpr->_node.pRight->nodeType == TSQL_NODE_VALUE && fp != NULL);
 
   //  scan the result array list and check for each item in the list
@@ -660,7 +660,7 @@ static bool filterItem(tExprNode *pExpr, const void *pItem, SExprTraverseSupp *p
  * @param pSchema   tag schemas
  * @param fp        filter callback function
  */
-static void exprTreeTraverseImpl(tExprNode *pExpr, SArray *pResult, SExprTraverseSupp *param) {
+static UNUSED_FUNC void exprTreeTraverseImpl(tExprNode *pExpr, SArray *pResult, SExprTraverseSupp *param) {
   size_t size = taosArrayGetSize(pResult);
   
   SArray* array = taosArrayInit(size, POINTER_BYTES);
@@ -733,10 +733,6 @@ void tExprTreeTraverse(tExprNode *pExpr, SSkipList *pSkipList, SArray *result, S
     assert(pLeft->nodeType == TSQL_NODE_COL && (pRight->nodeType == TSQL_NODE_VALUE || pRight->nodeType == TSQL_NODE_DUMMY));
 
     param->setupInfoFn(pExpr, param->pExtInfo);
-    if (pSkipList == NULL) {
-      tArrayTraverse(pExpr, param->nodeFilterFn, result);
-      return;
-    }
 
     tQueryInfo *pQueryInfo = pExpr->_node.info;
     if (pQueryInfo->indexed && pQueryInfo->optr != TSDB_RELATION_LIKE) {
@@ -748,49 +744,14 @@ void tExprTreeTraverse(tExprNode *pExpr, SSkipList *pSkipList, SArray *result, S
     return;
   }
 
-  // recursive traverse left child branch
+  // The value of hasPK is always 0.
   uint8_t weight = pLeft->_node.hasPK + pRight->_node.hasPK;
+  assert(weight == 0 && pSkipList != NULL && taosArrayGetSize(result) == 0);
 
-  if (weight == 0 ) {
-    if (taosArrayGetSize(result) > 0 && pSkipList == NULL) {
-    /**
-     * Perform the filter operation based on the initial filter result, which is obtained from filtering from index.
-     * Since no index presented, the filter operation is done by scan all elements in the result set.
-     *
-     * if the query is a high selectivity filter, only small portion of meters are retrieved.
-     */
-      exprTreeTraverseImpl(pExpr, result, param);
-    } else {
-      /**
-       * apply the hierarchical expression to every node in skiplist for find the qualified nodes
-       */
-      assert(taosArrayGetSize(result) == 0);
-      tSQLBinaryTraverseOnSkipList(pExpr, result, pSkipList, param);
-    }
-
-    return;
-  }
-  
-  if (weight == 2 || (weight == 1 && pExpr->_node.optr == TSDB_RELATION_OR)) {
-    SArray* rLeft  = taosArrayInit(10, POINTER_BYTES);
-    SArray* rRight = taosArrayInit(10, POINTER_BYTES);
-
-    tExprTreeTraverse(pLeft, pSkipList, rLeft, param);
-    tExprTreeTraverse(pRight, pSkipList, rRight, param);
-
-    if (pExpr->_node.optr == TSDB_RELATION_AND) {  // CROSS
-      intersect(rLeft, rRight, result);
-    } else if (pExpr->_node.optr == TSDB_RELATION_OR) {  // or
-      merge(rLeft, rRight, result);
-    } else {
-      assert(false);
-    }
-
-    taosArrayDestroy(rLeft);
-    taosArrayDestroy(rRight);
-    return;
-  }
+  //apply the hierarchical expression to every node in skiplist for find the qualified nodes
+  tSQLBinaryTraverseOnSkipList(pExpr, result, pSkipList, param);
 
+  #if 0
   /*
     * (weight == 1 && pExpr->nSQLBinaryOptr == TSDB_RELATION_AND) is handled here
     *
@@ -819,6 +780,7 @@ void tExprTreeTraverse(tExprNode *pExpr, SSkipList *pSkipList, SArray *result, S
     * So, we do not set the skip list index as a parameter
     */
   tExprTreeTraverse(pSecond, NULL, result, param);
+#endif
 }
 
 void tExprTreeCalcTraverse(tExprNode *pExprs, int32_t numOfRows, char *pOutput, void *param, int32_t order,
diff --git a/src/query/src/qExecutor.c b/src/query/src/qExecutor.c
index d65d01d1558795767a6ad497dea7312444f3686e..b365dc4283ccab8d6440a5c479102353870aa616 100644
--- a/src/query/src/qExecutor.c
+++ b/src/query/src/qExecutor.c
@@ -3843,7 +3843,7 @@ int32_t setAdditionalInfo(SQInfo *pQInfo, void* pTable, STableQueryInfo *pTableQ
       STSElem elem = tsBufGetElemStartPos(pRuntimeEnv->pTSBuf, pQInfo->vgId, &pTableQueryInfo->tag);
 
       // failed to find data with the specified tag value and vnodeId
-      if (elem.vnode < 0) {
+      if (!tsBufIsValidElem(&elem)) {
         if (pTag->nType == TSDB_DATA_TYPE_BINARY || pTag->nType == TSDB_DATA_TYPE_NCHAR) {
           qError("QInfo:%p failed to find tag:%s in ts_comp", pQInfo, pTag->pz);
         } else {
@@ -4777,7 +4777,7 @@ static bool multiTableMultioutputHelper(SQInfo *pQInfo, int32_t index) {
     if (pRuntimeEnv->cur.vgroupIndex == -1) {
       STSElem elem = tsBufGetElemStartPos(pRuntimeEnv->pTSBuf, pQInfo->vgId, pTag);
       // failed to find data with the specified tag value and vnodeId
-      if (elem.vnode < 0) {
+      if (!tsBufIsValidElem(&elem)) {
         if (pTag->nType == TSDB_DATA_TYPE_BINARY || pTag->nType == TSDB_DATA_TYPE_NCHAR) {
           qError("QInfo:%p failed to find tag:%s in ts_comp", pQInfo, pTag->pz);
         } else {
@@ -4802,7 +4802,7 @@ static bool multiTableMultioutputHelper(SQInfo *pQInfo, int32_t index) {
 
         STSElem elem1 = tsBufGetElemStartPos(pRuntimeEnv->pTSBuf, pQInfo->vgId, pTag);
         // failed to find data with the specified tag value and vnodeId
-        if (elem1.vnode < 0) {
+        if (!tsBufIsValidElem(&elem1)) {
           if (pTag->nType == TSDB_DATA_TYPE_BINARY || pTag->nType == TSDB_DATA_TYPE_NCHAR) {
             qError("QInfo:%p failed to find tag:%s in ts_comp", pQInfo, pTag->pz);
           } else {
diff --git a/src/query/src/qFill.c b/src/query/src/qFill.c
index 99fa3a8e0ffc9b53ae370d4e5860bf16a8988367..a219bd6abd928866b93d00ab2ed162c1ae9bc3f3 100644
--- a/src/query/src/qFill.c
+++ b/src/query/src/qFill.c
@@ -215,7 +215,7 @@ static double linearInterpolationImpl(double v1, double v2, double k1, double k2
   return v1 + (v2 - v1) * (k - k1) / (k2 - k1);
 }
 
-int taosDoLinearInterpolation(int32_t type, SPoint* point1, SPoint* point2, SPoint* point) {
+int32_t taosGetLinearInterpolationVal(int32_t type, SPoint* point1, SPoint* point2, SPoint* point) {
   switch (type) {
     case TSDB_DATA_TYPE_INT: {
       *(int32_t*)point->val = (int32_t)linearInterpolationImpl(*(int32_t*)point1->val, *(int32_t*)point2->val, (double)point1->key,
@@ -343,7 +343,7 @@ static void doFillResultImpl(SFillInfo* pFillInfo, tFilePage** data, int32_t* nu
         point1 = (SPoint){.key = *(TSKEY*)(prevValues), .val = prevValues + pCol->col.offset};
         point2 = (SPoint){.key = ts, .val = srcData[i] + pFillInfo->rowIdx * bytes};
         point  = (SPoint){.key = pFillInfo->start, .val = val1};
-        taosDoLinearInterpolation(type, &point1, &point2, &point);
+        taosGetLinearInterpolationVal(type, &point1, &point2, &point);
       }
 
       setTagsValue(pFillInfo, data, *num);
diff --git a/src/query/src/qTsbuf.c b/src/query/src/qTsbuf.c
index df9ea1db0367f18cf8d436636dc72d2ec67c4648..dd5297bc78308c53b3dcef500f23c4e03ad5c7b7 100644
--- a/src/query/src/qTsbuf.c
+++ b/src/query/src/qTsbuf.c
@@ -4,7 +4,7 @@
 #include "tutil.h"
 
 static int32_t getDataStartOffset();
-static void TSBufUpdateVnodeInfo(STSBuf* pTSBuf, int32_t index, STSVnodeBlockInfo* pBlockInfo);
+static void TSBufUpdateGroupInfo(STSBuf* pTSBuf, int32_t index, STSGroupBlockInfo* pBlockInfo);
 static STSBuf* allocResForTSBuf(STSBuf* pTSBuf);
 static int32_t STSBufUpdateHeader(STSBuf* pTSBuf, STSBufFileHeader* pHeader);
 
@@ -32,7 +32,7 @@ STSBuf* tsBufCreate(bool autoDelete, int32_t order) {
   }
   
   // update the header info
-  STSBufFileHeader header = {.magic = TS_COMP_FILE_MAGIC, .numOfVnode = pTSBuf->numOfVnodes, .tsOrder = TSDB_ORDER_ASC};
+  STSBufFileHeader header = {.magic = TS_COMP_FILE_MAGIC, .numOfGroup = pTSBuf->numOfGroups, .tsOrder = TSDB_ORDER_ASC};
   STSBufUpdateHeader(pTSBuf, &header);
   
   tsBufResetPos(pTSBuf);
@@ -75,9 +75,9 @@ STSBuf* tsBufCreateFromFile(const char* path, bool autoDelete) {
     return NULL;
   }
   
-  if (header.numOfVnode > pTSBuf->numOfAlloc) {
-    pTSBuf->numOfAlloc = header.numOfVnode;
-    STSVnodeBlockInfoEx* tmp = realloc(pTSBuf->pData, sizeof(STSVnodeBlockInfoEx) * pTSBuf->numOfAlloc);
+  if (header.numOfGroup > pTSBuf->numOfAlloc) {
+    pTSBuf->numOfAlloc = header.numOfGroup;
+    STSGroupBlockInfoEx* tmp = realloc(pTSBuf->pData, sizeof(STSGroupBlockInfoEx) * pTSBuf->numOfAlloc);
     if (tmp == NULL) {
       tsBufDestroy(pTSBuf);
       return NULL;
@@ -86,7 +86,7 @@ STSBuf* tsBufCreateFromFile(const char* path, bool autoDelete) {
     pTSBuf->pData = tmp;
   }
   
-  pTSBuf->numOfVnodes = header.numOfVnode;
+  pTSBuf->numOfGroups = header.numOfGroup;
   
   // check the ts order
   pTSBuf->tsOrder = header.tsOrder;
@@ -96,9 +96,9 @@ STSBuf* tsBufCreateFromFile(const char* path, bool autoDelete) {
     return NULL;
   }
   
-  size_t infoSize = sizeof(STSVnodeBlockInfo) * pTSBuf->numOfVnodes;
+  size_t infoSize = sizeof(STSGroupBlockInfo) * pTSBuf->numOfGroups;
   
-  STSVnodeBlockInfo* buf = (STSVnodeBlockInfo*)calloc(1, infoSize);
+  STSGroupBlockInfo* buf = (STSGroupBlockInfo*)calloc(1, infoSize);
   if (buf == NULL) {
     tsBufDestroy(pTSBuf);
     return NULL; 
@@ -109,9 +109,9 @@ STSBuf* tsBufCreateFromFile(const char* path, bool autoDelete) {
   UNUSED(sz);
   
   // the length value for each vnode is not kept in file, so does not set the length value
-  for (int32_t i = 0; i < pTSBuf->numOfVnodes; ++i) {
-    STSVnodeBlockInfoEx* pBlockList = &pTSBuf->pData[i];
-    memcpy(&pBlockList->info, &buf[i], sizeof(STSVnodeBlockInfo));
+  for (int32_t i = 0; i < pTSBuf->numOfGroups; ++i) {
+    STSGroupBlockInfoEx* pBlockList = &pTSBuf->pData[i];
+    memcpy(&pBlockList->info, &buf[i], sizeof(STSGroupBlockInfo));
   }
   free(buf);
   
@@ -131,8 +131,8 @@ STSBuf* tsBufCreateFromFile(const char* path, bool autoDelete) {
   pTSBuf->cur.order = TSDB_ORDER_ASC;
   pTSBuf->autoDelete = autoDelete;
   
-//  tscDebug("create tsBuf from file:%s, fd:%d, size:%d, numOfVnode:%d, autoDelete:%d", pTSBuf->path, fileno(pTSBuf->f),
-//           pTSBuf->fileSize, pTSBuf->numOfVnodes, pTSBuf->autoDelete);
+//  tscDebug("create tsBuf from file:%s, fd:%d, size:%d, numOfGroups:%d, autoDelete:%d", pTSBuf->path, fileno(pTSBuf->f),
+//           pTSBuf->fileSize, pTSBuf->numOfGroups, pTSBuf->autoDelete);
   
   return pTSBuf;
 }
@@ -162,53 +162,53 @@ void* tsBufDestroy(STSBuf* pTSBuf) {
   return NULL;
 }
 
-static STSVnodeBlockInfoEx* tsBufGetLastVnodeInfo(STSBuf* pTSBuf) {
-  int32_t last = pTSBuf->numOfVnodes - 1;
+static STSGroupBlockInfoEx* tsBufGetLastGroupInfo(STSBuf* pTSBuf) {
+  int32_t last = pTSBuf->numOfGroups - 1;
   
   assert(last >= 0);
   return &pTSBuf->pData[last];
 }
 
-static STSVnodeBlockInfoEx* addOneVnodeInfo(STSBuf* pTSBuf, int32_t vnodeId) {
-  if (pTSBuf->numOfAlloc <= pTSBuf->numOfVnodes) {
+static STSGroupBlockInfoEx* addOneGroupInfo(STSBuf* pTSBuf, int32_t id) {
+  if (pTSBuf->numOfAlloc <= pTSBuf->numOfGroups) {
     uint32_t newSize = (uint32_t)(pTSBuf->numOfAlloc * 1.5);
     assert((int32_t)newSize > pTSBuf->numOfAlloc);
     
-    STSVnodeBlockInfoEx* tmp = (STSVnodeBlockInfoEx*)realloc(pTSBuf->pData, sizeof(STSVnodeBlockInfoEx) * newSize);
+    STSGroupBlockInfoEx* tmp = (STSGroupBlockInfoEx*)realloc(pTSBuf->pData, sizeof(STSGroupBlockInfoEx) * newSize);
     if (tmp == NULL) {
       return NULL;
     }
     
     pTSBuf->pData = tmp;
     pTSBuf->numOfAlloc = newSize;
-    memset(&pTSBuf->pData[pTSBuf->numOfVnodes], 0, sizeof(STSVnodeBlockInfoEx) * (newSize - pTSBuf->numOfVnodes));
+    memset(&pTSBuf->pData[pTSBuf->numOfGroups], 0, sizeof(STSGroupBlockInfoEx) * (newSize - pTSBuf->numOfGroups));
   }
   
-  if (pTSBuf->numOfVnodes > 0) {
-    STSVnodeBlockInfoEx* pPrevBlockInfoEx = tsBufGetLastVnodeInfo(pTSBuf);
+  if (pTSBuf->numOfGroups > 0) {
+    STSGroupBlockInfoEx* pPrevBlockInfoEx = tsBufGetLastGroupInfo(pTSBuf);
     
     // update prev vnode length info in file
-    TSBufUpdateVnodeInfo(pTSBuf, pTSBuf->numOfVnodes - 1, &pPrevBlockInfoEx->info);
+    TSBufUpdateGroupInfo(pTSBuf, pTSBuf->numOfGroups - 1, &pPrevBlockInfoEx->info);
   }
   
   // set initial value for vnode block
-  STSVnodeBlockInfo* pBlockInfo = &pTSBuf->pData[pTSBuf->numOfVnodes].info;
-  pBlockInfo->vnode = vnodeId;
+  STSGroupBlockInfo* pBlockInfo = &pTSBuf->pData[pTSBuf->numOfGroups].info;
+  pBlockInfo->id = id;
   pBlockInfo->offset = pTSBuf->fileSize;
   assert(pBlockInfo->offset >= getDataStartOffset());
   
   // update vnode info in file
-  TSBufUpdateVnodeInfo(pTSBuf, pTSBuf->numOfVnodes, pBlockInfo);
+  TSBufUpdateGroupInfo(pTSBuf, pTSBuf->numOfGroups, pBlockInfo);
   
   // add one vnode info
-  pTSBuf->numOfVnodes += 1;
+  pTSBuf->numOfGroups += 1;
   
   // update the header info
   STSBufFileHeader header = {
-      .magic = TS_COMP_FILE_MAGIC, .numOfVnode = pTSBuf->numOfVnodes, .tsOrder = pTSBuf->tsOrder};
+      .magic = TS_COMP_FILE_MAGIC, .numOfGroup = pTSBuf->numOfGroups, .tsOrder = pTSBuf->tsOrder};
   
   STSBufUpdateHeader(pTSBuf, &header);
-  return tsBufGetLastVnodeInfo(pTSBuf);
+  return tsBufGetLastGroupInfo(pTSBuf);
 }
 
 static void shrinkBuffer(STSList* ptsData) {
@@ -279,10 +279,10 @@ static void writeDataToDisk(STSBuf* pTSBuf) {
   
   pTSBuf->tsData.len = 0;
   
-  STSVnodeBlockInfoEx* pVnodeBlockInfoEx = tsBufGetLastVnodeInfo(pTSBuf);
+  STSGroupBlockInfoEx* pGroupBlockInfoEx = tsBufGetLastGroupInfo(pTSBuf);
   
-  pVnodeBlockInfoEx->info.compLen += blockSize;
-  pVnodeBlockInfoEx->info.numOfBlocks += 1;
+  pGroupBlockInfoEx->info.compLen += blockSize;
+  pGroupBlockInfoEx->info.numOfBlocks += 1;
   
   shrinkBuffer(&pTSBuf->tsData);
 }
@@ -413,20 +413,20 @@ static int32_t setCheckTSOrder(STSBuf* pTSBuf, const char* pData, int32_t len) {
   return TSDB_CODE_SUCCESS;
 }
 
-void tsBufAppend(STSBuf* pTSBuf, int32_t vnodeId, tVariant* tag, const char* pData, int32_t len) {
-  STSVnodeBlockInfoEx* pBlockInfo = NULL;
+void tsBufAppend(STSBuf* pTSBuf, int32_t id, tVariant* tag, const char* pData, int32_t len) {
+  STSGroupBlockInfoEx* pBlockInfo = NULL;
   STSList*             ptsData = &pTSBuf->tsData;
   
-  if (pTSBuf->numOfVnodes == 0 || tsBufGetLastVnodeInfo(pTSBuf)->info.vnode != vnodeId) {
+  if (pTSBuf->numOfGroups == 0 || tsBufGetLastGroupInfo(pTSBuf)->info.id != id) {
     writeDataToDisk(pTSBuf);
     shrinkBuffer(ptsData);
     
-    pBlockInfo = addOneVnodeInfo(pTSBuf, vnodeId);
+    pBlockInfo = addOneGroupInfo(pTSBuf, id);
   } else {
-    pBlockInfo = tsBufGetLastVnodeInfo(pTSBuf);
+    pBlockInfo = tsBufGetLastGroupInfo(pTSBuf);
   }
   
-  assert(pBlockInfo->info.vnode == vnodeId);
+  assert(pBlockInfo->info.id == id);
 
   if ((tVariantCompare(&pTSBuf->block.tag, tag) != 0) && ptsData->len > 0) {
     // new arrived data with different tags value, save current value into disk first
@@ -464,23 +464,23 @@ void tsBufFlush(STSBuf* pTSBuf) {
   writeDataToDisk(pTSBuf);
   shrinkBuffer(&pTSBuf->tsData);
   
-  STSVnodeBlockInfoEx* pBlockInfoEx = tsBufGetLastVnodeInfo(pTSBuf);
+  STSGroupBlockInfoEx* pBlockInfoEx = tsBufGetLastGroupInfo(pTSBuf);
   
   // update prev vnode length info in file
-  TSBufUpdateVnodeInfo(pTSBuf, pTSBuf->numOfVnodes - 1, &pBlockInfoEx->info);
+  TSBufUpdateGroupInfo(pTSBuf, pTSBuf->numOfGroups - 1, &pBlockInfoEx->info);
   
   // save the ts order into header
   STSBufFileHeader header = {
-      .magic = TS_COMP_FILE_MAGIC, .numOfVnode = pTSBuf->numOfVnodes, .tsOrder = pTSBuf->tsOrder};
+      .magic = TS_COMP_FILE_MAGIC, .numOfGroup = pTSBuf->numOfGroups, .tsOrder = pTSBuf->tsOrder};
   STSBufUpdateHeader(pTSBuf, &header);
   
   fsync(fileno(pTSBuf->f));
 }
 
-static int32_t tsBufFindVnodeById(STSVnodeBlockInfoEx* pVnodeInfoEx, int32_t numOfVnodes, int32_t vnodeId) {
+static int32_t tsBufFindGroupById(STSGroupBlockInfoEx* pGroupInfoEx, int32_t numOfGroups, int32_t id) {
   int32_t j = -1;
-  for (int32_t i = 0; i < numOfVnodes; ++i) {
-    if (pVnodeInfoEx[i].info.vnode == vnodeId) {
+  for (int32_t i = 0; i < numOfGroups; ++i) {
+    if (pGroupInfoEx[i].info.id == id) {
       j = i;
       break;
     }
@@ -490,7 +490,7 @@ static int32_t tsBufFindVnodeById(STSVnodeBlockInfoEx* pVnodeInfoEx, int32_t num
 }
 
 // todo opt performance by cache blocks info
-static int32_t tsBufFindBlock(STSBuf* pTSBuf, STSVnodeBlockInfo* pBlockInfo, int32_t blockIndex) {
+static int32_t tsBufFindBlock(STSBuf* pTSBuf, STSGroupBlockInfo* pBlockInfo, int32_t blockIndex) {
   if (fseek(pTSBuf->f, pBlockInfo->offset, SEEK_SET) != 0) {
     return -1;
   }
@@ -517,7 +517,7 @@ static int32_t tsBufFindBlock(STSBuf* pTSBuf, STSVnodeBlockInfo* pBlockInfo, int
   return 0;
 }
 
-static int32_t tsBufFindBlockByTag(STSBuf* pTSBuf, STSVnodeBlockInfo* pBlockInfo, tVariant* tag) {
+static int32_t tsBufFindBlockByTag(STSBuf* pTSBuf, STSGroupBlockInfo* pBlockInfo, tVariant* tag) {
   bool decomp = false;
   
   int64_t offset = 0;
@@ -544,14 +544,14 @@ static int32_t tsBufFindBlockByTag(STSBuf* pTSBuf, STSVnodeBlockInfo* pBlockInfo
   return -1;
 }
 
-static void tsBufGetBlock(STSBuf* pTSBuf, int32_t vnodeIndex, int32_t blockIndex) {
-  STSVnodeBlockInfo* pBlockInfo = &pTSBuf->pData[vnodeIndex].info;
+static void tsBufGetBlock(STSBuf* pTSBuf, int32_t groupIndex, int32_t blockIndex) {
+  STSGroupBlockInfo* pBlockInfo = &pTSBuf->pData[groupIndex].info;
   if (pBlockInfo->numOfBlocks <= blockIndex) {
     assert(false);
   }
   
   STSCursor* pCur = &pTSBuf->cur;
-  if (pCur->vgroupIndex == vnodeIndex && ((pCur->blockIndex <= blockIndex && pCur->order == TSDB_ORDER_ASC) ||
+  if (pCur->vgroupIndex == groupIndex && ((pCur->blockIndex <= blockIndex && pCur->order == TSDB_ORDER_ASC) ||
       (pCur->blockIndex >= blockIndex && pCur->order == TSDB_ORDER_DESC))) {
     int32_t i = 0;
     bool    decomp = false;
@@ -586,13 +586,13 @@ static void tsBufGetBlock(STSBuf* pTSBuf, int32_t vnodeIndex, int32_t blockIndex
   
   assert((pTSBuf->tsData.len / TSDB_KEYSIZE == pBlock->numOfElem) && (pTSBuf->tsData.allocSize >= pTSBuf->tsData.len));
   
-  pCur->vgroupIndex = vnodeIndex;
+  pCur->vgroupIndex = groupIndex;
   pCur->blockIndex = blockIndex;
   
   pCur->tsIndex = (pCur->order == TSDB_ORDER_ASC) ? 0 : pBlock->numOfElem - 1;
 }
 
-static int32_t doUpdateVnodeInfo(STSBuf* pTSBuf, int64_t offset, STSVnodeBlockInfo* pVInfo) {
+static int32_t doUpdateGroupInfo(STSBuf* pTSBuf, int64_t offset, STSGroupBlockInfo* pVInfo) {
   if (offset < 0 || offset >= getDataStartOffset()) {
     return -1;
   }
@@ -601,12 +601,12 @@ static int32_t doUpdateVnodeInfo(STSBuf* pTSBuf, int64_t offset, STSVnodeBlockIn
     return -1;
   }
 
-  fwrite(pVInfo, sizeof(STSVnodeBlockInfo), 1, pTSBuf->f);
+  fwrite(pVInfo, sizeof(STSGroupBlockInfo), 1, pTSBuf->f);
   return 0;
 }
 
-STSVnodeBlockInfo* tsBufGetVnodeBlockInfo(STSBuf* pTSBuf, int32_t vnodeId) {
-  int32_t j = tsBufFindVnodeById(pTSBuf->pData, pTSBuf->numOfVnodes, vnodeId);
+STSGroupBlockInfo* tsBufGetGroupBlockInfo(STSBuf* pTSBuf, int32_t id) {
+  int32_t j = tsBufFindGroupById(pTSBuf->pData, pTSBuf->numOfGroups, id);
   if (j == -1) {
     return NULL;
   }
@@ -615,7 +615,7 @@ STSVnodeBlockInfo* tsBufGetVnodeBlockInfo(STSBuf* pTSBuf, int32_t vnodeId) {
 }
 
 int32_t STSBufUpdateHeader(STSBuf* pTSBuf, STSBufFileHeader* pHeader) {
-  if ((pTSBuf->f == NULL) || pHeader == NULL || pHeader->numOfVnode == 0 || pHeader->magic != TS_COMP_FILE_MAGIC) {
+  if ((pTSBuf->f == NULL) || pHeader == NULL || pHeader->numOfGroup == 0 || pHeader->magic != TS_COMP_FILE_MAGIC) {
     return -1;
   }
 
@@ -631,7 +631,7 @@ int32_t STSBufUpdateHeader(STSBuf* pTSBuf, STSBufFileHeader* pHeader) {
 }
 
 bool tsBufNextPos(STSBuf* pTSBuf) {
-  if (pTSBuf == NULL || pTSBuf->numOfVnodes == 0) {
+  if (pTSBuf == NULL || pTSBuf->numOfGroups == 0) {
     return false;
   }
   
@@ -650,16 +650,16 @@ bool tsBufNextPos(STSBuf* pTSBuf) {
       }
       
     } else {  // get the last timestamp record in the last block of the last vnode
-      assert(pTSBuf->numOfVnodes > 0);
+      assert(pTSBuf->numOfGroups > 0);
       
-      int32_t vnodeIndex = pTSBuf->numOfVnodes - 1;
-      pCur->vgroupIndex = vnodeIndex;
+      int32_t groupIndex = pTSBuf->numOfGroups - 1;
+      pCur->vgroupIndex = groupIndex;
       
-      int32_t            vnodeId = pTSBuf->pData[pCur->vgroupIndex].info.vnode;
-      STSVnodeBlockInfo* pBlockInfo = tsBufGetVnodeBlockInfo(pTSBuf, vnodeId);
+      int32_t            id = pTSBuf->pData[pCur->vgroupIndex].info.id;
+      STSGroupBlockInfo* pBlockInfo = tsBufGetGroupBlockInfo(pTSBuf, id);
       int32_t            blockIndex = pBlockInfo->numOfBlocks - 1;
       
-      tsBufGetBlock(pTSBuf, vnodeIndex, blockIndex);
+      tsBufGetBlock(pTSBuf, groupIndex, blockIndex);
       
       pCur->tsIndex = pTSBuf->block.numOfElem - 1;
       if (pTSBuf->block.numOfElem == 0) {
@@ -678,12 +678,12 @@ bool tsBufNextPos(STSBuf* pTSBuf) {
     
     if ((pCur->order == TSDB_ORDER_ASC && pCur->tsIndex >= pTSBuf->block.numOfElem - 1) ||
         (pCur->order == TSDB_ORDER_DESC && pCur->tsIndex <= 0)) {
-      int32_t vnodeId = pTSBuf->pData[pCur->vgroupIndex].info.vnode;
+      int32_t id = pTSBuf->pData[pCur->vgroupIndex].info.id;
       
-      STSVnodeBlockInfo* pBlockInfo = tsBufGetVnodeBlockInfo(pTSBuf, vnodeId);
+      STSGroupBlockInfo* pBlockInfo = tsBufGetGroupBlockInfo(pTSBuf, id);
       if (pBlockInfo == NULL || (pCur->blockIndex >= pBlockInfo->numOfBlocks - 1 && pCur->order == TSDB_ORDER_ASC) ||
           (pCur->blockIndex <= 0 && pCur->order == TSDB_ORDER_DESC)) {
-        if ((pCur->vgroupIndex >= pTSBuf->numOfVnodes - 1 && pCur->order == TSDB_ORDER_ASC) ||
+        if ((pCur->vgroupIndex >= pTSBuf->numOfGroups - 1 && pCur->order == TSDB_ORDER_ASC) ||
             (pCur->vgroupIndex <= 0 && pCur->order == TSDB_ORDER_DESC)) {
           pCur->vgroupIndex = -1;
           return false;
@@ -719,7 +719,7 @@ void tsBufResetPos(STSBuf* pTSBuf) {
 }
 
 STSElem tsBufGetElem(STSBuf* pTSBuf) {
-  STSElem elem1 = {.vnode = -1};
+  STSElem elem1 = {.id = -1};
   if (pTSBuf == NULL) {
     return elem1;
   }
@@ -731,7 +731,7 @@ STSElem tsBufGetElem(STSBuf* pTSBuf) {
 
   STSBlock* pBlock = &pTSBuf->block;
   
-  elem1.vnode = pTSBuf->pData[pCur->vgroupIndex].info.vnode;
+  elem1.id = pTSBuf->pData[pCur->vgroupIndex].info.id;
   elem1.ts = *(TSKEY*)(pTSBuf->tsData.rawBuf + pCur->tsIndex * TSDB_KEYSIZE);
   elem1.tag = &pBlock->tag;
 
@@ -742,34 +742,34 @@ STSElem tsBufGetElem(STSBuf* pTSBuf) {
  * current only support ts comp data from two vnode merge
  * @param pDestBuf
  * @param pSrcBuf
- * @param vnodeId
+ * @param id
  * @return
  */
 int32_t tsBufMerge(STSBuf* pDestBuf, const STSBuf* pSrcBuf) {
-  if (pDestBuf == NULL || pSrcBuf == NULL || pSrcBuf->numOfVnodes <= 0) {
+  if (pDestBuf == NULL || pSrcBuf == NULL || pSrcBuf->numOfGroups <= 0) {
     return 0;
   }
   
-  if (pDestBuf->numOfVnodes + pSrcBuf->numOfVnodes > TS_COMP_FILE_VNODE_MAX) {
+  if (pDestBuf->numOfGroups + pSrcBuf->numOfGroups > TS_COMP_FILE_GROUP_MAX) {
     return -1;
   }
   
   // src can only have one vnode index
-  assert(pSrcBuf->numOfVnodes == 1);
+  assert(pSrcBuf->numOfGroups == 1);
 
   // there are data in buffer, flush to disk first
   tsBufFlush(pDestBuf);
   
   // compared with the last vnode id
-  int32_t vnodeId = tsBufGetLastVnodeInfo((STSBuf*) pSrcBuf)->info.vnode;
-  if (vnodeId != tsBufGetLastVnodeInfo(pDestBuf)->info.vnode) {
-    int32_t oldSize = pDestBuf->numOfVnodes;
-    int32_t newSize = oldSize + pSrcBuf->numOfVnodes;
+  int32_t id = tsBufGetLastGroupInfo((STSBuf*) pSrcBuf)->info.id;
+  if (id != tsBufGetLastGroupInfo(pDestBuf)->info.id) {
+    int32_t oldSize = pDestBuf->numOfGroups;
+    int32_t newSize = oldSize + pSrcBuf->numOfGroups;
     
     if (pDestBuf->numOfAlloc < newSize) {
       pDestBuf->numOfAlloc = newSize;
       
-      STSVnodeBlockInfoEx* tmp = realloc(pDestBuf->pData, sizeof(STSVnodeBlockInfoEx) * newSize);
+      STSGroupBlockInfoEx* tmp = realloc(pDestBuf->pData, sizeof(STSGroupBlockInfoEx) * newSize);
       if (tmp == NULL) {
         return -1;
       }
@@ -778,23 +778,23 @@ int32_t tsBufMerge(STSBuf* pDestBuf, const STSBuf* pSrcBuf) {
     }
     
     // directly copy the vnode index information
-    memcpy(&pDestBuf->pData[oldSize], pSrcBuf->pData, (size_t)pSrcBuf->numOfVnodes * sizeof(STSVnodeBlockInfoEx));
+    memcpy(&pDestBuf->pData[oldSize], pSrcBuf->pData, (size_t)pSrcBuf->numOfGroups * sizeof(STSGroupBlockInfoEx));
     
     // set the new offset value
-    for (int32_t i = 0; i < pSrcBuf->numOfVnodes; ++i) {
-      STSVnodeBlockInfoEx* pBlockInfoEx = &pDestBuf->pData[i + oldSize];
+    for (int32_t i = 0; i < pSrcBuf->numOfGroups; ++i) {
+      STSGroupBlockInfoEx* pBlockInfoEx = &pDestBuf->pData[i + oldSize];
       pBlockInfoEx->info.offset = (pSrcBuf->pData[i].info.offset - getDataStartOffset()) + pDestBuf->fileSize;
-      pBlockInfoEx->info.vnode = vnodeId;
+      pBlockInfoEx->info.id = id;
     }
     
-    pDestBuf->numOfVnodes = newSize;
+    pDestBuf->numOfGroups = newSize;
   } else {
-    STSVnodeBlockInfoEx* pBlockInfoEx = tsBufGetLastVnodeInfo(pDestBuf);
+    STSGroupBlockInfoEx* pBlockInfoEx = tsBufGetLastGroupInfo(pDestBuf);
     
     pBlockInfoEx->len += pSrcBuf->pData[0].len;
     pBlockInfoEx->info.numOfBlocks += pSrcBuf->pData[0].info.numOfBlocks;
     pBlockInfoEx->info.compLen += pSrcBuf->pData[0].info.compLen;
-    pBlockInfoEx->info.vnode = vnodeId;
+    pBlockInfoEx->info.id = id;
   }
   
   int32_t r = fseek(pDestBuf->f, 0, SEEK_END);
@@ -827,23 +827,23 @@ int32_t tsBufMerge(STSBuf* pDestBuf, const STSBuf* pSrcBuf) {
   
   assert(pDestBuf->fileSize == oldSize + size);
   
-//  tscDebug("tsBuf merge success, %p, path:%s, fd:%d, file size:%d, numOfVnode:%d, autoDelete:%d", pDestBuf,
-//           pDestBuf->path, fileno(pDestBuf->f), pDestBuf->fileSize, pDestBuf->numOfVnodes, pDestBuf->autoDelete);
+//  tscDebug("tsBuf merge success, %p, path:%s, fd:%d, file size:%d, numOfGroups:%d, autoDelete:%d", pDestBuf,
+//           pDestBuf->path, fileno(pDestBuf->f), pDestBuf->fileSize, pDestBuf->numOfGroups, pDestBuf->autoDelete);
   
   return 0;
 }
 
-STSBuf* tsBufCreateFromCompBlocks(const char* pData, int32_t numOfBlocks, int32_t len, int32_t order, int32_t vnodeId) {
+STSBuf* tsBufCreateFromCompBlocks(const char* pData, int32_t numOfBlocks, int32_t len, int32_t order, int32_t id) {
   STSBuf* pTSBuf = tsBufCreate(true, order);
   
-  STSVnodeBlockInfo* pBlockInfo = &(addOneVnodeInfo(pTSBuf, 0)->info);
+  STSGroupBlockInfo* pBlockInfo = &(addOneGroupInfo(pTSBuf, 0)->info);
   pBlockInfo->numOfBlocks = numOfBlocks;
   pBlockInfo->compLen = len;
   pBlockInfo->offset = getDataStartOffset();
-  pBlockInfo->vnode = vnodeId;
+  pBlockInfo->id = id;
   
   // update prev vnode length info in file
-  TSBufUpdateVnodeInfo(pTSBuf, pTSBuf->numOfVnodes - 1, pBlockInfo);
+  TSBufUpdateGroupInfo(pTSBuf, pTSBuf->numOfGroups - 1, pBlockInfo);
   
   int32_t ret = fseek(pTSBuf->f, pBlockInfo->offset, SEEK_SET);
   UNUSED(ret);
@@ -855,7 +855,7 @@ STSBuf* tsBufCreateFromCompBlocks(const char* pData, int32_t numOfBlocks, int32_
   assert(order == TSDB_ORDER_ASC || order == TSDB_ORDER_DESC);
   
   STSBufFileHeader header = {
-      .magic = TS_COMP_FILE_MAGIC, .numOfVnode = pTSBuf->numOfVnodes, .tsOrder = pTSBuf->tsOrder};
+      .magic = TS_COMP_FILE_MAGIC, .numOfGroup = pTSBuf->numOfGroups, .tsOrder = pTSBuf->tsOrder};
   STSBufUpdateHeader(pTSBuf, &header);
   
   fsync(fileno(pTSBuf->f));
@@ -863,14 +863,14 @@ STSBuf* tsBufCreateFromCompBlocks(const char* pData, int32_t numOfBlocks, int32_
   return pTSBuf;
 }
 
-STSElem tsBufGetElemStartPos(STSBuf* pTSBuf, int32_t vnodeId, tVariant* tag) {
-  STSElem elem = {.vnode = -1};
+STSElem tsBufGetElemStartPos(STSBuf* pTSBuf, int32_t id, tVariant* tag) {
+  STSElem elem = {.id = -1};
   
   if (pTSBuf == NULL) {
     return elem;
   }
   
-  int32_t j = tsBufFindVnodeById(pTSBuf->pData, pTSBuf->numOfVnodes, vnodeId);
+  int32_t j = tsBufFindGroupById(pTSBuf->pData, pTSBuf->numOfGroups, id);
   if (j == -1) {
     return elem;
   }
@@ -879,7 +879,7 @@ STSElem tsBufGetElemStartPos(STSBuf* pTSBuf, int32_t vnodeId, tVariant* tag) {
   //  tsBufDisplay(pTSBuf);
   
   STSCursor*         pCur = &pTSBuf->cur;
-  STSVnodeBlockInfo* pBlockInfo = &pTSBuf->pData[j].info;
+  STSGroupBlockInfo* pBlockInfo = &pTSBuf->pData[j].info;
   
   int32_t blockIndex = tsBufFindBlockByTag(pTSBuf, pBlockInfo, tag);
   if (blockIndex < 0) {
@@ -935,7 +935,7 @@ STSBuf* tsBufClone(STSBuf* pTSBuf) {
 
 void tsBufDisplay(STSBuf* pTSBuf) {
   printf("-------start of ts comp file-------\n");
-  printf("number of vnode:%d\n", pTSBuf->numOfVnodes);
+  printf("number of vnode:%d\n", pTSBuf->numOfGroups);
   
   int32_t old = pTSBuf->cur.order;
   pTSBuf->cur.order = TSDB_ORDER_ASC;
@@ -945,7 +945,7 @@ 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);
+      printf("%d-%" PRId64 "-%" PRId64 "\n", elem.id, elem.tag->i64Key, elem.ts);
     }
   }
   
@@ -954,20 +954,20 @@ void tsBufDisplay(STSBuf* pTSBuf) {
 }
 
 static int32_t getDataStartOffset() {
-  return sizeof(STSBufFileHeader) + TS_COMP_FILE_VNODE_MAX * sizeof(STSVnodeBlockInfo);
+  return sizeof(STSBufFileHeader) + TS_COMP_FILE_GROUP_MAX * sizeof(STSGroupBlockInfo);
 }
 
 // update prev vnode length info in file
-static void TSBufUpdateVnodeInfo(STSBuf* pTSBuf, int32_t index, STSVnodeBlockInfo* pBlockInfo) {
-  int32_t offset = sizeof(STSBufFileHeader) + index * sizeof(STSVnodeBlockInfo);
-  doUpdateVnodeInfo(pTSBuf, offset, pBlockInfo);
+static void TSBufUpdateGroupInfo(STSBuf* pTSBuf, int32_t index, STSGroupBlockInfo* pBlockInfo) {
+  int32_t offset = sizeof(STSBufFileHeader) + index * sizeof(STSGroupBlockInfo);
+  doUpdateGroupInfo(pTSBuf, offset, pBlockInfo);
 }
 
 static STSBuf* allocResForTSBuf(STSBuf* pTSBuf) {
-  const int32_t INITIAL_VNODEINFO_SIZE = 4;
+  const int32_t INITIAL_GROUPINFO_SIZE = 4;
   
-  pTSBuf->numOfAlloc = INITIAL_VNODEINFO_SIZE;
-  pTSBuf->pData = calloc(pTSBuf->numOfAlloc, sizeof(STSVnodeBlockInfoEx));
+  pTSBuf->numOfAlloc = INITIAL_GROUPINFO_SIZE;
+  pTSBuf->pData = calloc(pTSBuf->numOfAlloc, sizeof(STSGroupBlockInfoEx));
   if (pTSBuf->pData == NULL) {
     tsBufDestroy(pTSBuf);
     return NULL;
@@ -999,35 +999,35 @@ static STSBuf* allocResForTSBuf(STSBuf* pTSBuf) {
   return pTSBuf;
 }
 
-int32_t tsBufGetNumOfVnodes(STSBuf* pTSBuf) {
+int32_t tsBufGetNumOfGroup(STSBuf* pTSBuf) {
   if (pTSBuf == NULL) {
     return 0;
   }
 
-  return pTSBuf->numOfVnodes;
+  return pTSBuf->numOfGroups;
 }
 
-void tsBufGetVnodeIdList(STSBuf* pTSBuf, int32_t* num, int32_t** vnodeId) {
-  int32_t size = tsBufGetNumOfVnodes(pTSBuf);
+void tsBufGetGroupIdList(STSBuf* pTSBuf, int32_t* num, int32_t** id) {
+  int32_t size = tsBufGetNumOfGroup(pTSBuf);
   if (num != NULL) {
     *num = size;
   }
 
-  *vnodeId = NULL;
+  *id = NULL;
   if (size == 0) {
     return;
   }
 
-  (*vnodeId) = malloc(tsBufGetNumOfVnodes(pTSBuf) * sizeof(int32_t));
+  (*id) = malloc(tsBufGetNumOfGroup(pTSBuf) * sizeof(int32_t));
 
   for(int32_t i = 0; i < size; ++i) {
-    (*vnodeId)[i] = pTSBuf->pData[i].info.vnode;
+    (*id)[i] = pTSBuf->pData[i].info.id;
   }
 }
 
-int32_t dumpFileBlockByVnodeId(STSBuf* pTSBuf, int32_t vnodeIndex, void* buf, int32_t* len, int32_t* numOfBlocks) {
-  assert(vnodeIndex >= 0 && vnodeIndex < pTSBuf->numOfVnodes);
-  STSVnodeBlockInfo *pBlockInfo = &pTSBuf->pData[vnodeIndex].info;
+int32_t dumpFileBlockByGroupId(STSBuf* pTSBuf, int32_t groupIndex, void* buf, int32_t* len, int32_t* numOfBlocks) {
+  assert(groupIndex >= 0 && groupIndex < pTSBuf->numOfGroups);
+  STSGroupBlockInfo *pBlockInfo = &pTSBuf->pData[groupIndex].info;
 
   *len = 0;
   *numOfBlocks = 0;
@@ -1052,11 +1052,11 @@ int32_t dumpFileBlockByVnodeId(STSBuf* pTSBuf, int32_t vnodeIndex, void* buf, in
 }
 
 STSElem tsBufFindElemStartPosByTag(STSBuf* pTSBuf, tVariant* pTag) {
-  STSElem el = {.vnode = -1};
+  STSElem el = {.id = -1};
 
-  for (int32_t i = 0; i < pTSBuf->numOfVnodes; ++i) {
-    el = tsBufGetElemStartPos(pTSBuf, pTSBuf->pData[i].info.vnode, pTag);
-    if (el.vnode == pTSBuf->pData[i].info.vnode) {
+  for (int32_t i = 0; i < pTSBuf->numOfGroups; ++i) {
+    el = tsBufGetElemStartPos(pTSBuf, pTSBuf->pData[i].info.id, pTag);
+    if (el.id == pTSBuf->pData[i].info.id) {
       return el;
     }
   }
@@ -1065,5 +1065,5 @@ STSElem tsBufFindElemStartPosByTag(STSBuf* pTSBuf, tVariant* pTag) {
 }
 
 bool tsBufIsValidElem(STSElem* pElem) {
-  return pElem->vnode >= 0;
+  return pElem->id >= 0;
 }
diff --git a/src/query/tests/tsBufTest.cpp b/src/query/tests/tsBufTest.cpp
index 2892af397960df6c1730f17209a02aa227887439..bada3194bd90e30de465dceaef07742cf6e8ac07 100644
--- a/src/query/tests/tsBufTest.cpp
+++ b/src/query/tests/tsBufTest.cpp
@@ -42,7 +42,7 @@ void simpleTest() {
 
   EXPECT_EQ(pTSBuf->tsData.len, sizeof(int64_t) * num);
   EXPECT_EQ(tVariantCompare(&pTSBuf->block.tag, &t), 0);
-  EXPECT_EQ(pTSBuf->numOfVnodes, 1);
+  EXPECT_EQ(pTSBuf->numOfGroups, 1);
 
   tsBufFlush(pTSBuf);
   EXPECT_EQ(pTSBuf->tsData.len, 0);
@@ -69,7 +69,7 @@ void largeTSTest() {
   // the data has been flush to disk, no data in cache
   EXPECT_EQ(pTSBuf->tsData.len, 0);
   EXPECT_EQ(tVariantCompare(&pTSBuf->block.tag, &t), 0);
-  EXPECT_EQ(pTSBuf->numOfVnodes, 1);
+  EXPECT_EQ(pTSBuf->numOfGroups, 1);
   EXPECT_EQ(pTSBuf->tsOrder, TSDB_ORDER_ASC);
 
   tsBufFlush(pTSBuf);
@@ -105,7 +105,7 @@ void multiTagsTest() {
   EXPECT_EQ(pTSBuf->tsData.len, num * sizeof(int64_t));
 
   EXPECT_EQ(pTSBuf->block.tag.i64Key, numOfTags - 1);
-  EXPECT_EQ(pTSBuf->numOfVnodes, 1);
+  EXPECT_EQ(pTSBuf->numOfGroups, 1);
 
   tsBufFlush(pTSBuf);
   EXPECT_EQ(pTSBuf->tsData.len, 0);
@@ -139,7 +139,7 @@ void multiVnodeTagsTest() {
       start += step * num;
     }
 
-    EXPECT_EQ(pTSBuf->numOfVnodes, j + 1);
+    EXPECT_EQ(pTSBuf->numOfGroups, j + 1);
   }
 
   EXPECT_EQ(pTSBuf->tsOrder, TSDB_ORDER_ASC);
@@ -184,7 +184,7 @@ void loadDataTest() {
       start += step * num;
     }
 
-    EXPECT_EQ(pTSBuf->numOfVnodes, j + 1);
+    EXPECT_EQ(pTSBuf->numOfGroups, j + 1);
   }
 
   EXPECT_EQ(pTSBuf->tsOrder, TSDB_ORDER_ASC);
@@ -203,7 +203,7 @@ void loadDataTest() {
   // create from exists file
   STSBuf* pNewBuf = tsBufCreateFromFile(pTSBuf->path, false);
   EXPECT_EQ(pNewBuf->tsOrder, pTSBuf->tsOrder);
-  EXPECT_EQ(pNewBuf->numOfVnodes, numOfVnode);
+  EXPECT_EQ(pNewBuf->numOfGroups, numOfVnode);
   EXPECT_EQ(pNewBuf->fileSize, pTSBuf->fileSize);
 
   EXPECT_EQ(pNewBuf->pData[0].info.offset, pTSBuf->pData[0].info.offset);
@@ -269,7 +269,7 @@ void TSTraverse() {
       start += step * num;
     }
 
-    EXPECT_EQ(pTSBuf->numOfVnodes, j + 1);
+    EXPECT_EQ(pTSBuf->numOfGroups, j + 1);
   }
 
   tsBufResetPos(pTSBuf);
@@ -304,7 +304,7 @@ void TSTraverse() {
   int32_t totalOutput = 10;
   while (1) {
     STSElem elem = tsBufGetElem(pTSBuf);
-    printf("%d-%" PRIu64 "-%" PRIu64 "\n", elem.vnode, elem.tag->i64Key, elem.ts);
+    printf("%d-%" PRIu64 "-%" PRIu64 "\n", elem.id, elem.tag->i64Key, elem.ts);
 
     if (!tsBufNextPos(pTSBuf)) {
       break;
@@ -352,7 +352,7 @@ void TSTraverse() {
   totalOutput = 10;
   while (1) {
     STSElem elem = tsBufGetElem(pTSBuf);
-    printf("%d-%" PRIu64 "-%" PRIu64 "\n", elem.vnode, elem.tag->i64Key, elem.ts);
+    printf("%d-%" PRIu64 "-%" PRIu64 "\n", elem.id, elem.tag->i64Key, elem.ts);
 
     if (!tsBufNextPos(pTSBuf)) {
       break;
@@ -427,7 +427,7 @@ void mergeDiffVnodeBufferTest() {
   tsBufFlush(pTSBuf2);
 
   tsBufMerge(pTSBuf1, pTSBuf2);
-  EXPECT_EQ(pTSBuf1->numOfVnodes, 2);
+  EXPECT_EQ(pTSBuf1->numOfGroups, 2);
   EXPECT_EQ(pTSBuf1->numOfTotal, numOfTags * 2 * num);
 
   tsBufDisplay(pTSBuf1);
@@ -472,7 +472,7 @@ void mergeIdenticalVnodeBufferTest() {
   tsBufFlush(pTSBuf2);
 
   tsBufMerge(pTSBuf1, pTSBuf2);
-  EXPECT_EQ(pTSBuf1->numOfVnodes, 2);
+  EXPECT_EQ(pTSBuf1->numOfGroups, 2);
   EXPECT_EQ(pTSBuf1->numOfTotal, numOfTags * 2 * num);
 
   tsBufResetPos(pTSBuf1);
@@ -482,12 +482,12 @@ void mergeIdenticalVnodeBufferTest() {
     STSElem elem = tsBufGetElem(pTSBuf1);
 
     if (count++ < numOfTags * num) {
-      EXPECT_EQ(elem.vnode, 12);
+      EXPECT_EQ(elem.id, 12);
     } else {
-      EXPECT_EQ(elem.vnode, 77);
+      EXPECT_EQ(elem.id, 77);
     }
 
-    printf("%d-%" PRIu64 "-%" PRIu64 "\n", elem.vnode, elem.tag->i64Key, elem.ts);
+    printf("%d-%" PRIu64 "-%" PRIu64 "\n", elem.id, elem.tag->i64Key, elem.ts);
   }
 
   tsBufDestroy(pTSBuf1);