diff --git a/src/query/inc/qExecutor.h b/src/query/inc/qExecutor.h
index c91b835980429176483c23850e9887fe7aa48d5a..4cc90bce33ffb31557f5149e9a64e50d6f9dc0e4 100644
--- a/src/query/inc/qExecutor.h
+++ b/src/query/inc/qExecutor.h
@@ -283,12 +283,14 @@ enum OPERATOR_TYPE_E {
   OP_Arithmetic        = 7,
   OP_Groupby           = 8,
   OP_Limit             = 9,
-  OP_TimeWindow        = 10,
-  OP_SessionWindow     = 11,
-  OP_Fill              = 12,
-  OP_MultiTableAggregate     = 13,
-  OP_MultiTableTimeInterval  = 14,
-  OP_DummyInput        = 15,   //TODO remove it after fully refactor.
+  OP_SLimit            = 10,
+  OP_TimeWindow        = 11,
+  OP_SessionWindow     = 12,
+  OP_Fill              = 13,
+  OP_MultiTableAggregate     = 14,
+  OP_MultiTableTimeInterval  = 15,
+  OP_DummyInput        = 16,   //TODO remove it after fully refactor.
+  OP_MultiwayMerge     = 17,   // multi-way merge process for partial results from different vnodes
 };
 
 typedef struct SOperatorInfo {
@@ -434,6 +436,23 @@ typedef struct SSWindowOperatorInfo {
   int32_t        start;      // start row index
 } SSWindowOperatorInfo;
 
+SOperatorInfo* createDataBlocksOptScanInfo(void* pTsdbQueryHandle, SQueryRuntimeEnv* pRuntimeEnv, int32_t repeatTime, int32_t reverseTime);
+SOperatorInfo* createTableScanOperator(void* pTsdbQueryHandle, SQueryRuntimeEnv* pRuntimeEnv, int32_t repeatTime);
+SOperatorInfo* createTableSeqScanOperator(void* pTsdbQueryHandle, SQueryRuntimeEnv* pRuntimeEnv);
+
+SOperatorInfo* createAggregateOperatorInfo(SQueryRuntimeEnv* pRuntimeEnv, SOperatorInfo* upstream, SExprInfo* pExpr, int32_t numOfOutput);
+SOperatorInfo* createArithOperatorInfo(SQueryRuntimeEnv* pRuntimeEnv, SOperatorInfo* upstream, SExprInfo* pExpr, int32_t numOfOutput);
+SOperatorInfo* createLimitOperatorInfo(SQueryRuntimeEnv* pRuntimeEnv, SOperatorInfo* upstream);
+SOperatorInfo* createTimeIntervalOperatorInfo(SQueryRuntimeEnv* pRuntimeEnv, SOperatorInfo* upstream, SExprInfo* pExpr, int32_t numOfOutput);
+SOperatorInfo* createSWindowOperatorInfo(SQueryRuntimeEnv* pRuntimeEnv, SOperatorInfo* upstream, SExprInfo* pExpr, int32_t numOfOutput);
+SOperatorInfo* createFillOperatorInfo(SQueryRuntimeEnv* pRuntimeEnv, SOperatorInfo* upstream, SExprInfo* pExpr, int32_t numOfOutput);
+SOperatorInfo* createGroupbyOperatorInfo(SQueryRuntimeEnv* pRuntimeEnv, SOperatorInfo* upstream, SExprInfo* pExpr, int32_t numOfOutput);
+SOperatorInfo* createMultiTableAggOperatorInfo(SQueryRuntimeEnv* pRuntimeEnv, SOperatorInfo* upstream, SExprInfo* pExpr, int32_t numOfOutput);
+SOperatorInfo* createMultiTableTimeIntervalOperatorInfo(SQueryRuntimeEnv* pRuntimeEnv, SOperatorInfo* upstream, SExprInfo* pExpr, int32_t numOfOutput);
+SOperatorInfo* createTagScanOperatorInfo(SQueryRuntimeEnv* pRuntimeEnv, SExprInfo* pExpr, int32_t numOfOutput);
+SOperatorInfo* createTableBlockInfoScanOperator(void* pTsdbQueryHandle, SQueryRuntimeEnv* pRuntimeEnv);
+
+
 void freeParam(SQueryParam *param);
 int32_t convertQueryMsg(SQueryTableMsg *pQueryMsg, SQueryParam* param);
 int32_t createQueryFunc(SQueriedTableInfo* pTableInfo, int32_t numOfOutput, SExprInfo** pExprInfo,
diff --git a/src/query/src/qExecutor.c b/src/query/src/qExecutor.c
index 0c5686b21612457cdd0f2000a5806bbaab2b69cb..3bd398cfa96e86ee6aec2bff742eeeffff4d7527 100644
--- a/src/query/src/qExecutor.c
+++ b/src/query/src/qExecutor.c
@@ -156,22 +156,6 @@ static void setTableScanFilterOperatorInfo(STableScanInfo* pTableScanInfo, SOper
 
 static int32_t getNumOfScanTimes(SQueryAttr* pQueryAttr);
 
-static SOperatorInfo* createDataBlocksOptScanInfo(void* pTsdbQueryHandle, SQueryRuntimeEnv* pRuntimeEnv, int32_t repeatTime, int32_t reverseTime);
-static SOperatorInfo* createTableScanOperator(void* pTsdbQueryHandle, SQueryRuntimeEnv* pRuntimeEnv, int32_t repeatTime);
-static SOperatorInfo* createTableSeqScanOperator(void* pTsdbQueryHandle, SQueryRuntimeEnv* pRuntimeEnv);
-
-static SOperatorInfo* createAggregateOperatorInfo(SQueryRuntimeEnv* pRuntimeEnv, SOperatorInfo* upstream, SExprInfo* pExpr, int32_t numOfOutput);
-static SOperatorInfo* createArithOperatorInfo(SQueryRuntimeEnv* pRuntimeEnv, SOperatorInfo* upstream, SExprInfo* pExpr, int32_t numOfOutput);
-static SOperatorInfo* createLimitOperatorInfo(SQueryRuntimeEnv* pRuntimeEnv, SOperatorInfo* upstream);
-static SOperatorInfo* createTimeIntervalOperatorInfo(SQueryRuntimeEnv* pRuntimeEnv, SOperatorInfo* upstream, SExprInfo* pExpr, int32_t numOfOutput);
-static SOperatorInfo* createSWindowOperatorInfo(SQueryRuntimeEnv* pRuntimeEnv, SOperatorInfo* upstream, SExprInfo* pExpr, int32_t numOfOutput);
-static SOperatorInfo* createFillOperatorInfo(SQueryRuntimeEnv* pRuntimeEnv, SOperatorInfo* upstream, SExprInfo* pExpr, int32_t numOfOutput);
-static SOperatorInfo* createGroupbyOperatorInfo(SQueryRuntimeEnv* pRuntimeEnv, SOperatorInfo* upstream, SExprInfo* pExpr, int32_t numOfOutput);
-static SOperatorInfo* createMultiTableAggOperatorInfo(SQueryRuntimeEnv* pRuntimeEnv, SOperatorInfo* upstream, SExprInfo* pExpr, int32_t numOfOutput);
-static SOperatorInfo* createMultiTableTimeIntervalOperatorInfo(SQueryRuntimeEnv* pRuntimeEnv, SOperatorInfo* upstream, SExprInfo* pExpr, int32_t numOfOutput);
-static SOperatorInfo* createTagScanOperatorInfo(SQueryRuntimeEnv* pRuntimeEnv, SExprInfo* pExpr, int32_t numOfOutput);
-static SOperatorInfo* createTableBlockInfoScanOperator(void* pTsdbQueryHandle, SQueryRuntimeEnv* pRuntimeEnv);
-
 static void destroyBasicOperatorInfo(void* param, int32_t numOfOutput);
 static void destroySFillOperatorInfo(void* param, int32_t numOfOutput);
 static void destroyGroupbyOperatorInfo(void* param, int32_t numOfOutput);
@@ -4350,7 +4334,7 @@ void setTableScanFilterOperatorInfo(STableScanInfo* pTableScanInfo, SOperatorInf
   }
 }
 
-static SOperatorInfo* createDataBlocksOptScanInfo(void* pTsdbQueryHandle, SQueryRuntimeEnv* pRuntimeEnv, int32_t repeatTime, int32_t reverseTime) {
+SOperatorInfo* createDataBlocksOptScanInfo(void* pTsdbQueryHandle, SQueryRuntimeEnv* pRuntimeEnv, int32_t repeatTime, int32_t reverseTime) {
   assert(repeatTime > 0);
 
   STableScanInfo* pInfo = calloc(1, sizeof(STableScanInfo));
@@ -4862,7 +4846,7 @@ static void destroyOperatorInfo(SOperatorInfo* pOperator) {
   tfree(pOperator);
 }
 
-static SOperatorInfo* createAggregateOperatorInfo(SQueryRuntimeEnv* pRuntimeEnv, SOperatorInfo* upstream, SExprInfo* pExpr, int32_t numOfOutput) {
+SOperatorInfo* createAggregateOperatorInfo(SQueryRuntimeEnv* pRuntimeEnv, SOperatorInfo* upstream, SExprInfo* pExpr, int32_t numOfOutput) {
   SAggOperatorInfo* pInfo = calloc(1, sizeof(SAggOperatorInfo));
 
   SQueryAttr* pQueryAttr = pRuntimeEnv->pQueryAttr;