diff --git a/include/common/tmsg.h b/include/common/tmsg.h
index 15daa97dbf..1f7ec3be1e 100644
--- a/include/common/tmsg.h
+++ b/include/common/tmsg.h
@@ -1089,6 +1089,10 @@ static FORCE_INLINE void* tDeserializeSMVSubscribeReq(void* buf, SMVSubscribeReq
   return buf;
 }
 
+typedef struct SMqTmrMsg {
+  int32_t reserved;
+} SMqTmrMsg;
+
 typedef struct {
   int64_t status;
 } SMVSubscribeRsp;
@@ -1548,6 +1552,25 @@ static FORCE_INLINE void* tDecodeSMqSetCVgReq(void* buf, SMqSetCVgReq* pReq) {
   return buf;
 }
 
+typedef struct SMqCVConsumeReq {
+  int64_t reqId;
+  int64_t offset;
+  int64_t clientId;
+  char    topicName[TSDB_TOPIC_FNAME_LEN];
+  char    cgroup[TSDB_CONSUMER_GROUP_LEN];
+} SMqCVConsumeReq;
+
+typedef struct SMqCVConsumeRsp {
+  int64_t reqId;
+  int64_t clientId;
+  int64_t committedOffset;
+  int64_t receiveOffset;
+  int64_t rspOffset;
+  int32_t skipLogNum;
+  int32_t bodyLen;
+  char    topicName[TSDB_TOPIC_FNAME_LEN];
+  char    body[];
+} SMqCvConsumeRsp;
 
 #ifdef __cplusplus
 }
diff --git a/include/common/tmsgdef.h b/include/common/tmsgdef.h
index f16dbd1f22..8cfc634346 100644
--- a/include/common/tmsgdef.h
+++ b/include/common/tmsgdef.h
@@ -140,6 +140,7 @@ enum {
   TD_DEF_MSG_TYPE(TDMT_MND_ALTER_TOPIC, "mnode-alter-topic", NULL, NULL)
   TD_DEF_MSG_TYPE(TDMT_MND_DROP_TOPIC, "mnode-drop-topic", NULL, NULL)
   TD_DEF_MSG_TYPE(TDMT_MND_SUBSCRIBE, "mnode-subscribe", SCMSubscribeReq, SCMSubscribeRsp)
+  TD_DEF_MSG_TYPE(TDMT_MND_MQ_TIMER, "mnode-timer", SMqTmrMsg, SMqTmrMsg)
 
   // Requests handled by VNODE
   TD_NEW_MSG_SEG(TDMT_VND_MSG)
@@ -173,6 +174,7 @@ enum {
   TD_DEF_MSG_TYPE(TDMT_VND_QUERY_CONTINUE, "vnode-query-continue", NULL, NULL)
 
   TD_DEF_MSG_TYPE(TDMT_VND_SUBSCRIBE, "vnode-subscribe", SMVSubscribeReq, SMVSubscribeRsp)
+  TD_DEF_MSG_TYPE(TDMT_VND_CONSUME, "vnode-consume", SMqCVConsumeReq, SMqCVConsumeRsp)
 
 
   // Requests handled by QNODE
diff --git a/include/libs/function/functionMgt.h b/include/libs/function/functionMgt.h
new file mode 100644
index 0000000000..3c365335be
--- /dev/null
+++ b/include/libs/function/functionMgt.h
@@ -0,0 +1,66 @@
+/*
+ * Copyright (c) 2019 TAOS Data, Inc. <jhtao@taosdata.com>
+ *
+ * This program is free software: you can use, redistribute, and/or modify
+ * it under the terms of the GNU Affero General Public License, version 3
+ * or later ("AGPL"), as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef _TD_FUNCTION_MGT_H_
+#define _TD_FUNCTION_MGT_H_
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#include "nodes.h"
+
+struct SQLFunctionCtx;
+struct SResultRowEntryInfo;
+struct STimeWindow;
+
+typedef struct SFuncExecEnv {
+  int32_t calcMemSize;
+} SFuncExecEnv;
+
+typedef void* FuncMgtHandle;
+typedef bool (*FExecGetEnv)(SFunctionNode* pFunc, SFuncExecEnv* pEnv);
+typedef bool (*FExecInit)(struct SQLFunctionCtx *pCtx, struct SResultRowEntryInfo* pResultCellInfo);
+typedef void (*FExecProcess)(struct SQLFunctionCtx *pCtx);
+typedef void (*FExecFinalize)(struct SQLFunctionCtx *pCtx);
+
+typedef struct SFuncExecFuncs {
+  FExecGetEnv getEnv;
+  FExecInit init;
+  FExecProcess process;
+  FExecFinalize finalize;
+} SFuncExecFuncs;
+
+int32_t fmFuncMgtInit();
+
+int32_t fmGetHandle(FuncMgtHandle* pHandle);
+
+int32_t fmGetFuncId(FuncMgtHandle handle, const char* name);
+int32_t fmGetFuncResultType(FuncMgtHandle handle, SFunctionNode* pFunc);
+bool fmIsAggFunc(int32_t funcId);
+bool fmIsStringFunc(int32_t funcId);
+bool fmIsTimestampFunc(int32_t funcId);
+bool fmIsTimelineFunc(int32_t funcId);
+bool fmIsTimeorderFunc(int32_t funcId);
+bool fmIsNonstandardSQLFunc(int32_t funcId);
+int32_t fmFuncScanType(int32_t funcId);
+
+int32_t fmGetFuncExecFuncs(FuncMgtHandle handle, int32_t funcId, SFuncExecFuncs* pFpSet);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif  // _TD_FUNCTION_MGT_H_
diff --git a/include/nodes/nodes.h b/include/nodes/nodes.h
new file mode 100644
index 0000000000..e6b41adf14
--- /dev/null
+++ b/include/nodes/nodes.h
@@ -0,0 +1,271 @@
+/*
+ * Copyright (c) 2019 TAOS Data, Inc. <jhtao@taosdata.com>
+ *
+ * This program is free software: you can use, redistribute, and/or modify
+ * it under the terms of the GNU Affero General Public License, version 3
+ * or later ("AGPL"), as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef _TD_NODES_H_
+#define _TD_NODES_H_
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#include "tarray.h"
+#include "tdef.h"
+
+typedef enum ENodeType {
+  QUERY_NODE_COLUMN = 1,
+  QUERY_NODE_VALUE,
+  QUERY_NODE_OPERATOR,
+  QUERY_NODE_LOGIC_CONDITION,
+  QUERY_NODE_IS_NULL_CONDITION,
+  QUERY_NODE_FUNCTION,
+  QUERY_NODE_REAL_TABLE,
+  QUERY_NODE_TEMP_TABLE,
+  QUERY_NODE_JOIN_TABLE,
+  QUERY_NODE_GROUPING_SET,
+  QUERY_NODE_ORDER_BY_EXPR,
+  QUERY_NODE_STATE_WINDOW,
+  QUERY_NODE_SESSION_WINDOW,
+  QUERY_NODE_INTERVAL_WINDOW,
+
+  QUERY_NODE_SET_OPERATOR,
+  QUERY_NODE_SELECT_STMT
+} ENodeType;
+
+/**
+ * The first field of a node of any type is guaranteed to be the ENodeType.
+ * Hence the type of any node can be gotten by casting it to SNode. 
+ */
+typedef struct SNode {
+  ENodeType type;
+} SNode;
+
+#define nodeType(nodeptr) (((const SNode*)(nodeptr))->type)
+
+typedef struct SDataType {
+  uint8_t type;
+  uint8_t precision;
+  uint8_t scale;
+  int32_t bytes;
+} SDataType;
+
+typedef struct SExprNode {
+  ENodeType nodeType;
+  SDataType resType;
+  char aliasName[TSDB_COL_NAME_LEN];
+} SExprNode;
+
+typedef enum EColumnType {
+  COLUMN_TYPE_COLUMN = 1,
+  COLUMN_TYPE_TAG
+} EColumnType;
+
+typedef struct SColumnNode {
+  SExprNode node; // QUERY_NODE_COLUMN
+  int16_t colId;
+  EColumnType colType; // column or tag
+  char dbName[TSDB_DB_NAME_LEN];
+  char tableName[TSDB_TABLE_NAME_LEN];
+  char colName[TSDB_COL_NAME_LEN];
+} SColumnNode;
+
+typedef struct SValueNode {
+  SExprNode type; // QUERY_NODE_VALUE
+  char* literal;
+} SValueNode;
+
+typedef enum EOperatorType {
+  // arithmetic operator
+  OP_TYPE_ADD = 1,
+  OP_TYPE_SUB,
+  OP_TYPE_MULTI,
+  OP_TYPE_DIV,
+  OP_TYPE_MOD,
+
+  // comparison operator
+  OP_TYPE_GREATER_THAN,
+  OP_TYPE_GREATER_EQUAL,
+  OP_TYPE_LOWER_THAN,
+  OP_TYPE_LOWER_EQUAL,
+  OP_TYPE_EQUAL,
+  OP_TYPE_NOT_EQUAL,
+  OP_TYPE_IN,
+  OP_TYPE_NOT_IN,
+  OP_TYPE_LIKE,
+  OP_TYPE_NOT_LIKE,
+  OP_TYPE_MATCH,
+  OP_TYPE_NMATCH,
+
+  // json operator
+  OP_TYPE_JSON_GET_VALUE,
+  OP_TYPE_JSON_CONTAINS
+} EOperatorType;
+
+typedef struct SOperatorNode {
+  SExprNode type; // QUERY_NODE_OPERATOR
+  EOperatorType opType;
+  SNode* pLeft;
+  SNode* pRight;
+} SOperatorNode;
+
+typedef enum ELogicConditionType {
+  LOGIC_COND_TYPE_AND,
+  LOGIC_COND_TYPE_OR,
+  LOGIC_COND_TYPE_NOT,
+} ELogicConditionType;
+
+typedef struct SLogicConditionNode {
+  ENodeType type; // QUERY_NODE_LOGIC_CONDITION
+  ELogicConditionType condType;
+  SArray* pParameterList;
+} SLogicConditionNode;
+
+typedef struct SIsNullCondNode {
+  ENodeType type; // QUERY_NODE_IS_NULL_CONDITION
+  SNode* pExpr;
+  bool isNot;
+} SIsNullCondNode;
+
+typedef struct SFunctionNode {
+  SExprNode type; // QUERY_NODE_FUNCTION
+  char functionName[TSDB_FUNC_NAME_LEN];
+  int32_t funcId;
+  SArray* pParameterList; // SNode
+} SFunctionNode;
+
+typedef struct STableNode {
+  ENodeType type;
+  char tableName[TSDB_TABLE_NAME_LEN];
+  char tableAliasName[TSDB_COL_NAME_LEN];
+} STableNode;
+
+typedef struct SRealTableNode {
+  STableNode type; // QUERY_NODE_REAL_TABLE
+  char dbName[TSDB_DB_NAME_LEN];
+} SRealTableNode;
+
+typedef struct STempTableNode {
+  STableNode type; // QUERY_NODE_TEMP_TABLE
+  SNode* pSubquery;
+} STempTableNode;
+
+typedef enum EJoinType {
+  JOIN_TYPE_INNER = 1
+} EJoinType;
+
+typedef struct SJoinTableNode {
+  STableNode type; // QUERY_NODE_JOIN_TABLE
+  EJoinType joinType;
+  SNode* pLeft;
+  SNode* pRight;
+  SNode* pOnCond;
+} SJoinTableNode;
+
+typedef enum EGroupingSetType {
+  GP_TYPE_NORMAL = 1
+} EGroupingSetType;
+
+typedef struct SGroupingSetNode {
+  ENodeType type; // QUERY_NODE_GROUPING_SET
+  EGroupingSetType groupingSetType;
+  SArray* pParameterList; 
+} SGroupingSetNode;
+
+typedef enum EOrder {
+  ORDER_ASC = 1,
+  ORDER_DESC
+} EOrder;
+
+typedef enum ENullOrder {
+  NULL_ORDER_FIRST = 1,
+  NULL_ORDER_LAST
+} ENullOrder;
+
+typedef struct SOrderByExprNode {
+  ENodeType type; // QUERY_NODE_ORDER_BY_EXPR
+  SNode* pExpr;
+  EOrder order;
+  ENullOrder nullOrder;
+} SOrderByExprNode;
+
+typedef struct SLimitInfo {
+  uint64_t limit;
+  uint64_t offset;
+} SLimitInfo;
+
+typedef struct SStateWindowNode {
+  ENodeType type; // QUERY_NODE_STATE_WINDOW
+  SNode* pCol;
+} SStateWindowNode;
+
+typedef struct SSessionWindowNode {
+  ENodeType type; // QUERY_NODE_SESSION_WINDOW
+  int64_t gap;             // gap between two session window(in microseconds)
+  SNode* pCol;
+} SSessionWindowNode;
+
+typedef struct SIntervalWindowNode {
+  ENodeType type; // QUERY_NODE_INTERVAL_WINDOW
+  int64_t interval;
+  int64_t sliding;
+  int64_t offset;
+} SIntervalWindowNode;
+
+typedef struct SSelectStmt {
+  ENodeType type; // QUERY_NODE_SELECT_STMT
+  bool isDistinct;
+  SArray* pProjectionList; // SNode
+  SNode* pFromTable;
+  SNode* pWhereCond;
+  SArray* pPartitionByList; // SNode
+  SNode* pWindowClause;
+  SArray* pGroupByList; // SGroupingSetNode
+  SArray* pOrderByList; // SOrderByExprNode
+  SLimitInfo limit;
+  SLimitInfo slimit;
+} SSelectStmt;
+
+typedef enum ESetOperatorType {
+  SET_OP_TYPE_UNION_ALL = 1
+} ESetOperatorType;
+
+typedef struct SSetOperator {
+  ENodeType type; // QUERY_NODE_SET_OPERATOR
+  ESetOperatorType opType;
+  SNode* pLeft;
+  SNode* pRight;
+} SSetOperator;
+
+typedef bool (*FQueryNodeWalker)(SNode* pNode, void* pContext);
+
+bool nodeArrayWalker(SArray* pArray, FQueryNodeWalker walker, void* pContext);
+bool nodeTreeWalker(SNode* pNode, FQueryNodeWalker walker, void* pContext);
+
+bool stmtWalker(SNode* pNode, FQueryNodeWalker walker, void* pContext);
+
+bool nodeEqual(const SNode* a, const SNode* b);
+
+void cloneNode(const SNode* pNode);
+
+int32_t nodeToString(const SNode* pNode, char** pStr, int32_t* pLen);
+int32_t stringToNode(const char* pStr, SNode** pNode);
+
+bool isTimeorderQuery(const SNode* pQuery);
+bool isTimelineQuery(const SNode* pQuery);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /*_TD_NODES_H_*/
diff --git a/source/CMakeLists.txt b/source/CMakeLists.txt
index 2833b329a7..fbf045b99c 100644
--- a/source/CMakeLists.txt
+++ b/source/CMakeLists.txt
@@ -3,4 +3,5 @@ add_subdirectory(util)
 add_subdirectory(common)
 add_subdirectory(libs)
 add_subdirectory(client)
-add_subdirectory(dnode)
\ No newline at end of file
+add_subdirectory(dnode)
+add_subdirectory(nodes)
\ No newline at end of file
diff --git a/source/client/test/clientTests.cpp b/source/client/test/clientTests.cpp
index 4361131f01..64fdacc597 100644
--- a/source/client/test/clientTests.cpp
+++ b/source/client/test/clientTests.cpp
@@ -148,30 +148,30 @@ TEST(testCase, connect_Test) {
 //  taos_close(pConn);
 //}
 //
-//TEST(testCase, create_db_Test) {
-  //TAOS* pConn = taos_connect("localhost", "root", "taosdata", NULL, 0);
-  //assert(pConn != NULL);
+TEST(testCase, create_db_Test) {
+  TAOS* pConn = taos_connect("localhost", "root", "taosdata", NULL, 0);
+  assert(pConn != NULL);
 
-  //TAOS_RES* pRes = taos_query(pConn, "create database abc1 vgroups 2");
-  //if (taos_errno(pRes) != 0) {
-    //printf("error in create db, reason:%s\n", taos_errstr(pRes));
-  //}
+  TAOS_RES* pRes = taos_query(pConn, "create database abc1 vgroups 2");
+  if (taos_errno(pRes) != 0) {
+    printf("error in create db, reason:%s\n", taos_errstr(pRes));
+  }
 
-  //TAOS_FIELD* pFields = taos_fetch_fields(pRes);
-  //ASSERT_TRUE(pFields == NULL);
+  TAOS_FIELD* pFields = taos_fetch_fields(pRes);
+  ASSERT_TRUE(pFields == NULL);
 
-  //int32_t numOfFields = taos_num_fields(pRes);
-  //ASSERT_EQ(numOfFields, 0);
+  int32_t numOfFields = taos_num_fields(pRes);
+  ASSERT_EQ(numOfFields, 0);
 
-  //taos_free_result(pRes);
+  taos_free_result(pRes);
+
+  pRes = taos_query(pConn, "create database abc1 vgroups 4");
+  if (taos_errno(pRes) != 0) {
+    printf("error in create db, reason:%s\n", taos_errstr(pRes));
+  }
+  taos_close(pConn);
+}
 
-  //pRes = taos_query(pConn, "create database abc1 vgroups 4");
-  //if (taos_errno(pRes) != 0) {
-    //printf("error in create db, reason:%s\n", taos_errstr(pRes));
-  //}
-  //taos_close(pConn);
-//}
-//
 //TEST(testCase, create_dnode_Test) {
 //  TAOS* pConn = taos_connect("localhost", "root", "taosdata", NULL, 0);
 //  assert(pConn != NULL);
diff --git a/source/dnode/mgmt/impl/src/dndTransport.c b/source/dnode/mgmt/impl/src/dndTransport.c
index ab4ae4ac53..f4fda75bd8 100644
--- a/source/dnode/mgmt/impl/src/dndTransport.c
+++ b/source/dnode/mgmt/impl/src/dndTransport.c
@@ -100,7 +100,7 @@ static void dndInitMsgFp(STransMgmt *pMgmt) {
   pMgmt->msgFp[TMSG_INDEX(TDMT_MND_VGROUP_LIST)] = dndProcessMnodeReadMsg;
   pMgmt->msgFp[TMSG_INDEX(TDMT_MND_KILL_QUERY)] = dndProcessMnodeWriteMsg;
   pMgmt->msgFp[TMSG_INDEX(TDMT_MND_KILL_CONN)] = dndProcessMnodeWriteMsg;
-  pMgmt->msgFp[TMSG_INDEX(TDMT_MND_HEARTBEAT)] = dndProcessMnodeReadMsg;
+  pMgmt->msgFp[TMSG_INDEX(TDMT_MND_HEARTBEAT)] = dndProcessMnodeWriteMsg;
   pMgmt->msgFp[TMSG_INDEX(TDMT_MND_SHOW)] = dndProcessMnodeReadMsg;
   pMgmt->msgFp[TMSG_INDEX(TDMT_MND_SHOW_RETRIEVE)] = dndProcessMnodeReadMsg;
   pMgmt->msgFp[TMSG_INDEX(TDMT_MND_STATUS)] = dndProcessMnodeReadMsg;
diff --git a/source/dnode/mnode/impl/inc/mndDef.h b/source/dnode/mnode/impl/inc/mndDef.h
index 45759117b5..ed88b42d39 100644
--- a/source/dnode/mnode/impl/inc/mndDef.h
+++ b/source/dnode/mnode/impl/inc/mndDef.h
@@ -354,6 +354,7 @@ typedef struct SMqSubscribeObj {
   char    key[TSDB_SUBSCRIBE_KEY_LEN];
   int32_t epoch;
   //TODO: replace with priority queue
+  int32_t nextConsumerIdx;
   SArray* availConsumer;        // SArray<int64_t> (consumerId)
   SArray* assigned;             // SArray<SMqConsumerEp>
   SArray* unassignedConsumer;   // SArray<SMqConsumerEp>
diff --git a/source/dnode/mnode/impl/inc/mndInt.h b/source/dnode/mnode/impl/inc/mndInt.h
index d2107b9d07..29ccd43622 100644
--- a/source/dnode/mnode/impl/inc/mndInt.h
+++ b/source/dnode/mnode/impl/inc/mndInt.h
@@ -80,6 +80,7 @@ typedef struct SMnode {
   SReplica          replicas[TSDB_MAX_REPLICA];
   tmr_h             timer;
   tmr_h             transTimer;
+  tmr_h             mqTimer;
   char             *path;
   SMnodeCfg         cfg;
   int64_t           checkTime;
diff --git a/source/dnode/mnode/impl/src/mndSubscribe.c b/source/dnode/mnode/impl/src/mndSubscribe.c
index 52f33fa89c..e786a8972c 100644
--- a/source/dnode/mnode/impl/src/mndSubscribe.c
+++ b/source/dnode/mnode/impl/src/mndSubscribe.c
@@ -13,13 +13,13 @@
  * along with this program. If not, see <http://www.gnu.org/licenses/>.
  */
 
+#include "mndSubscribe.h"
 #include "mndConsumer.h"
 #include "mndDb.h"
 #include "mndDnode.h"
 #include "mndMnode.h"
 #include "mndShow.h"
 #include "mndStb.h"
-#include "mndSubscribe.h"
 #include "mndTopic.h"
 #include "mndTrans.h"
 #include "mndUser.h"
@@ -40,6 +40,10 @@ static int32_t mndProcessSubscribeReq(SMnodeMsg *pMsg);
 static int32_t mndProcessSubscribeRsp(SMnodeMsg *pMsg);
 static int32_t mndProcessSubscribeInternalReq(SMnodeMsg *pMsg);
 static int32_t mndProcessSubscribeInternalRsp(SMnodeMsg *pMsg);
+static int32_t mndProcessMqTimerMsg(SMnodeMsg *pMsg);
+
+static int mndBuildMqSetConsumerVgReq(SMnode *pMnode, STrans *pTrans, SMqConsumerObj *pConsumer,
+                                      SMqConsumerTopic *pConsumerTopic, SMqTopicObj *pTopic);
 
 int32_t mndInitSubscribe(SMnode *pMnode) {
   SSdbTable table = {.sdbType = SDB_SUBSCRIBE,
@@ -54,9 +58,90 @@ int32_t mndInitSubscribe(SMnode *pMnode) {
   /*mndSetMsgHandle(pMnode, TDMT_MND_SUBSCRIBE_RSP, mndProcessSubscribeRsp);*/
   /*mndSetMsgHandle(pMnode, TDMT_VND_SUBSCRIBE, mndProcessSubscribeInternalReq);*/
   mndSetMsgHandle(pMnode, TDMT_VND_SUBSCRIBE_RSP, mndProcessSubscribeInternalRsp);
+  mndSetMsgHandle(pMnode, TDMT_MND_MQ_TIMER, mndProcessMqTimerMsg);
   return sdbSetTable(pMnode->pSdb, table);
 }
 
+static int32_t mndSplitSubscribeKey(char *key, char **topic, char **cgroup) {
+  int i = 0;
+  while (key[i] != ':') {
+    i++;
+  }
+  key[i] = 0;
+  *topic = strdup(key);
+  key[i] = ':';
+  *cgroup = strdup(&key[i + 1]);
+  return 0;
+}
+
+static int32_t mndProcessMqTimerMsg(SMnodeMsg *pMsg) {
+  SMnode          *pMnode = pMsg->pMnode;
+  SSdb            *pSdb = pMnode->pSdb;
+  SMqSubscribeObj *pSub = NULL;
+  void            *pIter = sdbFetch(pSdb, SDB_SUBSCRIBE, NULL, (void **)&pSub);
+  int              sz;
+  while (pIter != NULL) {
+    if ((sz = taosArrayGetSize(pSub->unassignedVg)) > 0) {
+      char *topic = NULL;
+      char *cgroup = NULL;
+      mndSplitSubscribeKey(pSub->key, &topic, &cgroup);
+
+      SMqTopicObj *pTopic = mndAcquireTopic(pMnode, topic);
+
+      // create trans
+      STrans *pTrans = mndTransCreate(pMnode, TRN_POLICY_RETRY, &pMsg->rpcMsg);
+      for (int i = 0; i < sz; i++) {
+        int64_t        consumerId = *(int64_t *)taosArrayGet(pSub->availConsumer, pSub->nextConsumerIdx);
+        SMqConsumerEp *pCEp = taosArrayPop(pSub->unassignedVg);
+        pCEp->consumerId = consumerId;
+        taosArrayPush(pSub->assigned, pCEp);
+        pSub->nextConsumerIdx++;
+
+        // build msg
+        SMqSetCVgReq req = {
+            .vgId = pCEp->vgId,
+            .consumerId = consumerId,
+        };
+        strcpy(req.cGroup, cgroup);
+        strcpy(req.topicName, topic);
+        strcpy(req.sql, pTopic->sql);
+        strcpy(req.logicalPlan, pTopic->logicalPlan);
+        strcpy(req.physicalPlan, pTopic->physicalPlan);
+        int32_t tlen = tEncodeSMqSetCVgReq(NULL, &req);
+        void   *reqStr = malloc(tlen);
+        if (reqStr == NULL) {
+          terrno = TSDB_CODE_OUT_OF_MEMORY;
+          return -1;
+        }
+        void *abuf = reqStr;
+        tEncodeSMqSetCVgReq(abuf, &req);
+
+        // persist msg
+        STransAction action = {0};
+        action.epSet = pCEp->epset;
+        action.pCont = reqStr;
+        action.contLen = tlen;
+        action.msgType = TDMT_VND_MQ_SET_CONN;
+        mndTransAppendRedoAction(pTrans, &action);
+
+        // persist raw
+        SSdbRaw *pRaw = mndSubActionEncode(pSub);
+        mndTransAppendRedolog(pTrans, pRaw);
+
+        tfree(topic);
+        tfree(cgroup);
+      }
+      if (mndTransPrepare(pMnode, pTrans) != 0) {
+        mError("trans:%d, failed to prepare since %s", pTrans->id, terrstr());
+      }
+      mndReleaseTopic(pMnode, pTopic);
+      mndTransDrop(pTrans);
+    }
+    pIter = sdbFetch(pSdb, SDB_SUBSCRIBE, NULL, (void **)&pSub);
+  }
+  return 0;
+}
+
 static int mndInitUnassignedVg(SMnode *pMnode, SMqTopicObj *pTopic, SArray *unassignedVg) {
   SMqConsumerEp CEp;
   CEp.lastConsumerHbTs = CEp.lastVgHbTs = -1;
@@ -76,7 +161,7 @@ static int mndInitUnassignedVg(SMnode *pMnode, SMqTopicObj *pTopic, SArray *unas
 }
 
 static int mndBuildMqSetConsumerVgReq(SMnode *pMnode, STrans *pTrans, SMqConsumerObj *pConsumer,
-                                      SMqConsumerTopic *pConsumerTopic) {
+                                      SMqConsumerTopic *pConsumerTopic, SMqTopicObj *pTopic) {
   int32_t sz = taosArrayGetSize(pConsumerTopic->pVgInfo);
   for (int32_t i = 0; i < sz; i++) {
     int32_t      vgId = *(int32_t *)taosArrayGet(pConsumerTopic->pVgInfo, i);
@@ -86,7 +171,10 @@ static int mndBuildMqSetConsumerVgReq(SMnode *pMnode, STrans *pTrans, SMqConsume
         .consumerId = pConsumer->consumerId,
     };
     strcpy(req.cGroup, pConsumer->cgroup);
-    strcpy(req.topicName, pConsumerTopic->name);
+    strcpy(req.topicName, pTopic->name);
+    strcpy(req.sql, pTopic->sql);
+    strcpy(req.logicalPlan, pTopic->logicalPlan);
+    strcpy(req.physicalPlan, pTopic->physicalPlan);
     int32_t tlen = tEncodeSMqSetCVgReq(NULL, &req);
     void   *reqStr = malloc(tlen);
     if (reqStr == NULL) {
@@ -94,7 +182,7 @@ static int mndBuildMqSetConsumerVgReq(SMnode *pMnode, STrans *pTrans, SMqConsume
       return -1;
     }
     void *abuf = reqStr;
-    tEncodeSMqSetCVgReq(abuf, &req);
+    tEncodeSMqSetCVgReq(&abuf, &req);
 
     STransAction action = {0};
     action.epSet = mndGetVgroupEpset(pMnode, pVgObj);
@@ -278,20 +366,20 @@ static int32_t mndProcessSubscribeReq(SMnodeMsg *pMsg) {
 
   int i = 0, j = 0;
   while (i < newTopicNum || j < oldTopicNum) {
-    char* newTopicName = NULL;
-    char* oldTopicName = NULL;
+    char *newTopicName = NULL;
+    char *oldTopicName = NULL;
     if (i >= newTopicNum) {
       // encode unset topic msg to all vnodes related to that topic
-      oldTopicName = ((SMqConsumerTopic*)taosArrayGet(oldSub, j))->name;
+      oldTopicName = ((SMqConsumerTopic *)taosArrayGet(oldSub, j))->name;
       j++;
     } else if (j >= oldTopicNum) {
       newTopicName = taosArrayGet(newSub, i);
       i++;
     } else {
       newTopicName = taosArrayGet(newSub, i);
-      oldTopicName = ((SMqConsumerTopic*)taosArrayGet(oldSub, j))->name;
+      oldTopicName = ((SMqConsumerTopic *)taosArrayGet(oldSub, j))->name;
 
-      int   comp = compareLenPrefixedStr(newTopicName, oldTopicName);
+      int comp = compareLenPrefixedStr(newTopicName, oldTopicName);
       if (comp == 0) {
         // do nothing
         oldTopicName = newTopicName = NULL;
@@ -374,19 +462,25 @@ static int32_t mndProcessSubscribeReq(SMnodeMsg *pMsg) {
         // set unassigned vg
         mndInitUnassignedVg(pMnode, pTopic, pSub->unassignedVg);
       }
+      taosArrayPush(pSub->availConsumer, &consumerId);
+
+      // TODO: no need
       SMqConsumerTopic *pConsumerTopic = tNewConsumerTopic(consumerId, pTopic, pSub);
       taosArrayPush(pConsumer->topics, pConsumerTopic);
 
       if (taosArrayGetSize(pConsumerTopic->pVgInfo) > 0) {
         int32_t vgId = *(int32_t *)taosArrayGetLast(pConsumerTopic->pVgInfo);
         // send setmsg to vnode
-        if (mndBuildMqSetConsumerVgReq(pMnode, pTrans, pConsumer, pConsumerTopic) < 0) {
+        if (mndBuildMqSetConsumerVgReq(pMnode, pTrans, pConsumer, pConsumerTopic, pTopic) < 0) {
           // TODO
           return -1;
         }
       }
       taosArrayDestroy(pConsumerTopic->pVgInfo);
       free(pConsumerTopic);
+      SSdbRaw *pRaw = mndSubActionEncode(pSub);
+      /*sdbSetRawStatus(pRaw, SDB_STATUS_READY);*/
+      mndTransAppendRedolog(pTrans, pRaw);
 #if 0
       SMqCGroup *pGroup = taosHashGet(pTopic->cgroups, consumerGroup, cgroupLen);
       if (pGroup == NULL) {
@@ -448,7 +542,10 @@ static int32_t mndProcessSubscribeReq(SMnodeMsg *pMsg) {
   return 0;
 }
 
-static int32_t mndProcessSubscribeInternalRsp(SMnodeMsg *pMsg) { return 0; }
+static int32_t mndProcessSubscribeInternalRsp(SMnodeMsg *pRsp) {
+  mndTransProcessRsp(pRsp);
+  return 0;
+}
 
 static int32_t mndProcessConsumerMetaMsg(SMnodeMsg *pMsg) {
   SMnode        *pMnode = pMsg->pMnode;
diff --git a/source/dnode/mnode/impl/src/mnode.c b/source/dnode/mnode/impl/src/mnode.c
index cab30702ea..e57ee3eabc 100644
--- a/source/dnode/mnode/impl/src/mnode.c
+++ b/source/dnode/mnode/impl/src/mnode.c
@@ -18,6 +18,7 @@
 #include "mndAuth.h"
 #include "mndBnode.h"
 #include "mndCluster.h"
+#include "mndConsumer.h"
 #include "mndDb.h"
 #include "mndDnode.h"
 #include "mndFunc.h"
@@ -27,6 +28,7 @@
 #include "mndShow.h"
 #include "mndSnode.h"
 #include "mndStb.h"
+#include "mndSubscribe.h"
 #include "mndSync.h"
 #include "mndTelem.h"
 #include "mndTopic.h"
@@ -69,15 +71,15 @@ static void mndTransReExecute(void *param, void *tmrId) {
   taosTmrReset(mndTransReExecute, 3000, pMnode, pMnode->timer, &pMnode->transTimer);
 }
 
-static void mndCalMqRebalance(void* param, void* tmrId) {
-  SMnode* pMnode = param;
+static void mndCalMqRebalance(void *param, void *tmrId) {
+  SMnode *pMnode = param;
   if (mndIsMaster(pMnode)) {
-    // iterate cgroup, cal rebalance
-    // sync with raft
-    // write sdb
+    SMqTmrMsg *pMsg = rpcMallocCont(sizeof(SMqTmrMsg));
+    SRpcMsg    rpcMsg = {.msgType = TDMT_MND_MQ_TIMER, .pCont = pMsg, .contLen = sizeof(SMqTmrMsg)};
+    pMnode->putReqToMWriteQFp(pMnode->pDnode, &rpcMsg);
   }
 
-  taosTmrReset(mndCalMqRebalance, 3000, pMnode, pMnode->timer, &pMnode->transTimer);
+  taosTmrReset(mndCalMqRebalance, 3000, pMnode, pMnode->timer, &pMnode->mqTimer);
 }
 
 static int32_t mndInitTimer(SMnode *pMnode) {
@@ -95,6 +97,11 @@ static int32_t mndInitTimer(SMnode *pMnode) {
     return -1;
   }
 
+  if (taosTmrReset(mndCalMqRebalance, 3000, pMnode, pMnode->timer, &pMnode->mqTimer)) {
+    terrno = TSDB_CODE_OUT_OF_MEMORY;
+    return -1;
+  }
+
   return 0;
 }
 
@@ -102,6 +109,8 @@ static void mndCleanupTimer(SMnode *pMnode) {
   if (pMnode->timer != NULL) {
     taosTmrStop(pMnode->transTimer);
     pMnode->transTimer = NULL;
+    taosTmrStop(pMnode->mqTimer);
+    pMnode->mqTimer = NULL;
     taosTmrCleanUp(pMnode->timer);
     pMnode->timer = NULL;
   }
@@ -171,6 +180,8 @@ static int32_t mndInitSteps(SMnode *pMnode) {
   if (mndAllocStep(pMnode, "mnode-auth", mndInitAuth, mndCleanupAuth) != 0) return -1;
   if (mndAllocStep(pMnode, "mnode-acct", mndInitAcct, mndCleanupAcct) != 0) return -1;
   if (mndAllocStep(pMnode, "mnode-topic", mndInitTopic, mndCleanupTopic) != 0) return -1;
+  if (mndAllocStep(pMnode, "mnode-consumer", mndInitConsumer, mndCleanupConsumer) != 0) return -1;
+  if (mndAllocStep(pMnode, "mnode-subscribe", mndInitSubscribe, mndCleanupSubscribe) != 0) return -1;
   if (mndAllocStep(pMnode, "mnode-vgroup", mndInitVgroup, mndCleanupVgroup) != 0) return -1;
   if (mndAllocStep(pMnode, "mnode-stb", mndInitStb, mndCleanupStb) != 0) return -1;
   if (mndAllocStep(pMnode, "mnode-db", mndInitDb, mndCleanupDb) != 0) return -1;
@@ -377,7 +388,7 @@ SMnodeMsg *mndInitMsg(SMnode *pMnode, SRpcMsg *pRpcMsg) {
     return NULL;
   }
 
-  if (pRpcMsg->msgType != TDMT_MND_TRANS) {
+  if (pRpcMsg->msgType != TDMT_MND_TRANS && pRpcMsg->msgType != TDMT_MND_MQ_TIMER) {
     SRpcConnInfo connInfo = {0};
     if ((pRpcMsg->msgType & 1U) && rpcGetConnInfo(pRpcMsg->handle, &connInfo) != 0) {
       taosFreeQitem(pMsg);
diff --git a/source/dnode/vnode/CMakeLists.txt b/source/dnode/vnode/CMakeLists.txt
index 9dc4bb1873..75734d2d29 100644
--- a/source/dnode/vnode/CMakeLists.txt
+++ b/source/dnode/vnode/CMakeLists.txt
@@ -25,6 +25,7 @@ target_link_libraries(
     PUBLIC bdb
     PUBLIC tfs
     PUBLIC wal
+    PUBLIC scheduler
     PUBLIC qworker
 )
 
diff --git a/source/dnode/vnode/inc/tq.h b/source/dnode/vnode/inc/tq.h
index 8089826a80..1a41a02673 100644
--- a/source/dnode/vnode/inc/tq.h
+++ b/source/dnode/vnode/inc/tq.h
@@ -18,14 +18,15 @@
 
 #include "common.h"
 #include "mallocator.h"
+#include "meta.h"
 #include "os.h"
+#include "scheduler.h"
 #include "taoserror.h"
-#include "tmsg.h"
 #include "tlist.h"
+#include "tmsg.h"
 #include "trpc.h"
 #include "ttimer.h"
 #include "tutil.h"
-#include "meta.h"
 
 #ifdef __cplusplus
 extern "C" {
@@ -150,15 +151,40 @@ typedef struct STqListHandle {
 } STqList;
 
 typedef struct STqGroup {
-  int64_t clientId;
-  int64_t cgId;
-  void*   ahandle;
-  int32_t topicNum;
+  int64_t      clientId;
+  int64_t      cgId;
+  void*        ahandle;
+  int32_t      topicNum;
   STqList*     head;
   SList*       topicList;  // SList<STqTopic>
   STqRspHandle rspHandle;
 } STqGroup;
 
+typedef struct STqTaskItem {
+  int32_t       status;
+  void*         dst;
+  SSubQueryMsg* pMsg;
+} STqTaskItem;
+
+// new version
+typedef struct STqBuffer {
+  int64_t     firstOffset;
+  int64_t     lastOffset;
+  STqTaskItem output[TQ_BUFFER_SIZE];
+} STqBuffer;
+
+typedef struct STqClientHandle {
+  int64_t   clientId;
+  char      topicName[TSDB_TOPIC_FNAME_LEN];
+  char      cGroup[TSDB_TOPIC_FNAME_LEN];
+  char*     sql;
+  char*     logicalPlan;
+  char*     physicalPlan;
+  int64_t   committedOffset;
+  int64_t   currentOffset;
+  STqBuffer buffer;
+} STqClientHandle;
+
 typedef struct STqQueryMsg {
   STqMsgItem*         item;
   struct STqQueryMsg* next;
@@ -253,7 +279,7 @@ typedef struct STqMetaStore {
   // a table head
   STqMetaList* unpersistHead;
   // topics that are not connectted
-  STqMetaList*   unconnectTopic;
+  STqMetaList* unconnectTopic;
 
   // TODO:temporaral use, to be replaced by unified tfile
   int fileFd;
@@ -316,24 +342,22 @@ const void* tqDeserializeGroup(const STqSerializedHead*, STqGroup**);
 static int tqQueryExecuting(int32_t status) { return status; }
 
 typedef struct STqReadHandle {
-  int64_t ver;
-  SSubmitMsg* pMsg;
-  SSubmitBlk* pBlock;
+  int64_t        ver;
+  SSubmitMsg*    pMsg;
+  SSubmitBlk*    pBlock;
   SSubmitMsgIter msgIter;
   SSubmitBlkIter blkIter;
-  SMeta* pMeta;
+  SMeta*         pMeta;
 } STqReadHandle;
 
 typedef struct SSubmitBlkScanInfo {
-  
 } SSubmitBlkScanInfo;
 
-STqReadHandle* tqInitSubmitMsgScanner(SMeta* pMeta, SSubmitMsg *pMsg);
-bool tqNextDataBlock(STqReadHandle* pHandle);
-int tqRetrieveDataBlockInfo(STqReadHandle* pHandle, SDataBlockInfo *pBlockInfo);
-//return SArray<SColumnInfoData>
-SArray *tqRetrieveDataBlock(STqReadHandle* pHandle, SArray* pColumnIdList);
-//int tqLoadDataBlock(SExecTaskInfo* pTaskInfo, SSubmitBlkScanInfo* pSubmitBlkScanInfo, SSDataBlock* pBlock, uint32_t status);
+STqReadHandle* tqInitSubmitMsgScanner(SMeta* pMeta, SSubmitMsg* pMsg);
+bool           tqNextDataBlock(STqReadHandle* pHandle);
+int            tqRetrieveDataBlockInfo(STqReadHandle* pHandle, SDataBlockInfo* pBlockInfo);
+// return SArray<SColumnInfoData>
+SArray* tqRetrieveDataBlock(STqReadHandle* pHandle, SArray* pColumnIdList);
 
 #ifdef __cplusplus
 }
diff --git a/source/dnode/vnode/src/inc/vnd.h b/source/dnode/vnode/src/inc/vnd.h
index 6b99b71b62..be32ed6829 100644
--- a/source/dnode/vnode/src/inc/vnd.h
+++ b/source/dnode/vnode/src/inc/vnd.h
@@ -177,4 +177,4 @@ bool            vmaIsFull(SVMemAllocator* pVMA);
 }
 #endif
 
-#endif /*_TD_VNODE_DEF_H_*/
\ No newline at end of file
+#endif /*_TD_VNODE_DEF_H_*/
diff --git a/source/dnode/vnode/src/vnd/vnodeQuery.c b/source/dnode/vnode/src/vnd/vnodeQuery.c
index 0d7e322b70..943465558a 100644
--- a/source/dnode/vnode/src/vnd/vnodeQuery.c
+++ b/source/dnode/vnode/src/vnd/vnodeQuery.c
@@ -55,6 +55,8 @@ int vnodeProcessFetchReq(SVnode *pVnode, SRpcMsg *pMsg, SRpcMsg **pRsp) {
       //      return qWorkerProcessShowFetchMsg(pVnode->pMeta, pVnode->pQuery, pMsg);
     case TDMT_VND_TABLE_META:
       return vnodeGetTableMeta(pVnode, pMsg, pRsp);
+    case TDMT_VND_CONSUME:
+      return 0;
     default:
       vError("unknown msg type:%d in fetch queue", pMsg->msgType);
       return TSDB_CODE_VND_APP_ERROR;
diff --git a/source/dnode/vnode/src/vnd/vnodeWrite.c b/source/dnode/vnode/src/vnd/vnodeWrite.c
index bb863d6ed0..2f3a4d5409 100644
--- a/source/dnode/vnode/src/vnd/vnodeWrite.c
+++ b/source/dnode/vnode/src/vnd/vnodeWrite.c
@@ -14,6 +14,7 @@
  */
 
 #include "vnd.h"
+#include "tq.h"
 
 int vnodeProcessNoWalWMsgs(SVnode *pVnode, SRpcMsg *pMsg) {
   switch (pMsg->msgType) {
@@ -108,6 +109,40 @@ int vnodeApplyWMsg(SVnode *pVnode, SRpcMsg *pMsg, SRpcMsg **pRsp) {
         // TODO: handle error
       }
       break;
+    case TDMT_VND_MQ_SET_CONN: {
+      char* reqStr = ptr;
+      SMqSetCVgReq req;
+      tDecodeSMqSetCVgReq(reqStr, &req);
+      STqClientHandle* pHandle = calloc(sizeof(STqClientHandle), 1);
+      if (pHandle == NULL) {
+        // TODO: handle error
+      }
+      strcpy(pHandle->topicName, req.topicName); 
+      strcpy(pHandle->cGroup, req.cGroup); 
+      strcpy(pHandle->sql, req.sql);
+      strcpy(pHandle->logicalPlan, req.logicalPlan);
+      strcpy(pHandle->physicalPlan, req.physicalPlan);
+      SArray *pArray;
+      //TODO: deserialize to SQueryDag
+      SQueryDag *pDag;
+      // convert to task
+      if (schedulerConvertDagToTaskList(pDag, &pArray) < 0) {
+        // TODO: handle error
+      }
+      ASSERT(taosArrayGetSize(pArray) == 0);
+      STaskInfo *pInfo = taosArrayGet(pArray, 0);
+      SArray* pTasks;
+      schedulerCopyTask(pInfo, &pTasks, TQ_BUFFER_SIZE);
+      pHandle->buffer.firstOffset = -1;
+      pHandle->buffer.lastOffset = -1;
+      for (int i = 0; i < TQ_BUFFER_SIZE; i++) {
+        SSubQueryMsg* pMsg = taosArrayGet(pTasks, i);
+        pHandle->buffer.output[i].pMsg = pMsg;
+        pHandle->buffer.output[i].status = 0;
+      }
+      // write mq meta
+    }
+      break;
     default:
       ASSERT(0);
       break;
diff --git a/source/libs/function/CMakeLists.txt b/source/libs/function/CMakeLists.txt
index a4aa7025e4..9f700dbb3c 100644
--- a/source/libs/function/CMakeLists.txt
+++ b/source/libs/function/CMakeLists.txt
@@ -8,5 +8,5 @@ target_include_directories(
 
 target_link_libraries(
     function
-    PRIVATE os util common
+    PRIVATE os util common nodes
 )
\ No newline at end of file
diff --git a/source/libs/function/inc/functionMgtInt.h b/source/libs/function/inc/functionMgtInt.h
new file mode 100644
index 0000000000..9b9d82f0e1
--- /dev/null
+++ b/source/libs/function/inc/functionMgtInt.h
@@ -0,0 +1,76 @@
+/*
+ * Copyright (c) 2019 TAOS Data, Inc. <jhtao@taosdata.com>
+ *
+ * This program is free software: you can use, redistribute, and/or modify
+ * it under the terms of the GNU Affero General Public License, version 3
+ * or later ("AGPL"), as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef _TD_FUNCTION_MGT_INT_H_
+#define _TD_FUNCTION_MGT_INT_H_
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#include "functionMgt.h"
+
+#define FUNC_MGT_DATA_TYPE_MASK(n)    (1 << n)
+
+#define FUNC_MGT_DATA_TYPE_NULL       0
+#define FUNC_MGT_DATA_TYPE_BOOL       FUNC_MGT_DATA_TYPE_MASK(0)
+#define FUNC_MGT_DATA_TYPE_TINYINT    FUNC_MGT_DATA_TYPE_MASK(1)
+#define FUNC_MGT_DATA_TYPE_SMALLINT   FUNC_MGT_DATA_TYPE_MASK(2)
+#define FUNC_MGT_DATA_TYPE_INT        FUNC_MGT_DATA_TYPE_MASK(3)
+#define FUNC_MGT_DATA_TYPE_BIGINT     FUNC_MGT_DATA_TYPE_MASK(4)
+#define FUNC_MGT_DATA_TYPE_FLOAT      FUNC_MGT_DATA_TYPE_MASK(5)
+#define FUNC_MGT_DATA_TYPE_DOUBLE     FUNC_MGT_DATA_TYPE_MASK(6)
+#define FUNC_MGT_DATA_TYPE_BINARY     FUNC_MGT_DATA_TYPE_MASK(7)
+#define FUNC_MGT_DATA_TYPE_TIMESTAMP  FUNC_MGT_DATA_TYPE_MASK(8)
+#define FUNC_MGT_DATA_TYPE_NCHAR      FUNC_MGT_DATA_TYPE_MASK(9)
+#define FUNC_MGT_DATA_TYPE_UTINYINT   FUNC_MGT_DATA_TYPE_MASK(10)
+#define FUNC_MGT_DATA_TYPE_USMALLINT  FUNC_MGT_DATA_TYPE_MASK(11)
+#define FUNC_MGT_DATA_TYPE_UINT       FUNC_MGT_DATA_TYPE_MASK(12)
+#define FUNC_MGT_DATA_TYPE_UBIGINT    FUNC_MGT_DATA_TYPE_MASK(13)
+#define FUNC_MGT_DATA_TYPE_VARCHAR    FUNC_MGT_DATA_TYPE_MASK(14)
+#define FUNC_MGT_DATA_TYPE_VARBINARY  FUNC_MGT_DATA_TYPE_MASK(15)
+#define FUNC_MGT_DATA_TYPE_JSON       FUNC_MGT_DATA_TYPE_MASK(16)
+#define FUNC_MGT_DATA_TYPE_DECIMAL    FUNC_MGT_DATA_TYPE_MASK(17)
+#define FUNC_MGT_DATA_TYPE_BLOB       FUNC_MGT_DATA_TYPE_MASK(18)
+
+#define FUNC_MGT_EXACT_NUMERIC_DATA_TYPE \
+  (FUNC_MGT_DATA_TYPE_TINYINT | FUNC_MGT_DATA_TYPE_SMALLINT | FUNC_MGT_DATA_TYPE_INT | FUNC_MGT_DATA_TYPE_BIGINT \
+      | FUNC_MGT_DATA_TYPE_UTINYINT | FUNC_MGT_DATA_TYPE_USMALLINT | FUNC_MGT_DATA_TYPE_UINT | FUNC_MGT_DATA_TYPE_UBIGINT)
+
+#define FUNC_MGT_APPRO_NUMERIC_DATA_TYPE (FUNC_MGT_DATA_TYPE_FLOAT | FUNC_MGT_DATA_TYPE_DOUBLE)
+
+#define FUNC_MGT_NUMERIC_DATA_TYPE (FUNC_MGT_EXACT_NUMERIC_DATA_TYPE | FUNC_MGT_APPRO_NUMERIC_DATA_TYPE)
+
+typedef void* FuncDef;
+
+typedef struct SFuncElement {
+  FuncDef (*defineFunc)();
+} SFuncElement;
+
+extern const SFuncElement gBuiltinFuncs[];
+
+FuncDef createFuncDef(const char* name, int32_t maxNumOfParams);
+FuncDef setOneParamSignature(FuncDef def, int64_t resDataType, int64_t paramDataType);
+FuncDef setTwoParamsSignature(FuncDef def, int64_t resDataType, int64_t p1DataType, int64_t p2DataType);
+FuncDef setFollowParamSignature(FuncDef def, int64_t paramDataType);
+FuncDef setFollowParamsSignature(FuncDef def, int64_t p1DataType, int64_t p2DataType, int32_t followNo);
+
+FuncDef setExecFuncs(FuncDef def, FExecGetEnv getEnv, FExecInit init, FExecProcess process, FExecFinalize finalize);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif  // _TD_FUNCTION_MGT_INT_H_
diff --git a/source/libs/function/inc/taggfunction.h b/source/libs/function/inc/taggfunction.h
index 41c7309a18..9192c19951 100644
--- a/source/libs/function/inc/taggfunction.h
+++ b/source/libs/function/inc/taggfunction.h
@@ -95,6 +95,10 @@ static FORCE_INLINE void initResultRowEntry(SResultRowEntryInfo *pResInfo, int32
   memset(GET_ROWCELL_INTERBUF(pResInfo), 0, bufLen);
 }
 
+#include "functionMgtInt.h"
+
+FuncDef defineCount();
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/source/libs/function/src/buildins.c b/source/libs/function/src/buildins.c
new file mode 100644
index 0000000000..ea2e9f3f2f
--- /dev/null
+++ b/source/libs/function/src/buildins.c
@@ -0,0 +1,21 @@
+/*
+ * Copyright (c) 2019 TAOS Data, Inc. <jhtao@taosdata.com>
+ *
+ * This program is free software: you can use, redistribute, and/or modify
+ * it under the terms of the GNU Affero General Public License, version 3
+ * or later ("AGPL"), as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "functionMgtInt.h"
+#include "taggfunction.h"
+
+const SFuncElement gBuiltinFuncs[] = {
+  {.defineFunc = defineCount}
+};
diff --git a/source/libs/function/src/functionMgt.c b/source/libs/function/src/functionMgt.c
new file mode 100644
index 0000000000..c6ed2c8c03
--- /dev/null
+++ b/source/libs/function/src/functionMgt.c
@@ -0,0 +1,80 @@
+/*
+ * Copyright (c) 2019 TAOS Data, Inc. <jhtao@taosdata.com>
+ *
+ * This program is free software: you can use, redistribute, and/or modify
+ * it under the terms of the GNU Affero General Public License, version 3
+ * or later ("AGPL"), as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "functionMgt.h"
+
+#include "functionMgtInt.h"
+#include "taos.h"
+#include "taoserror.h"
+#include "thash.h"
+
+typedef struct SFuncMgtService {
+  SHashObj* pFuncNameHashTable;
+} SFuncMgtService;
+
+static SFuncMgtService gFunMgtService;
+
+int32_t fmFuncMgtInit() {
+  gFunMgtService.pFuncNameHashTable = taosHashInit(128, taosGetDefaultHashFunction(TSDB_DATA_TYPE_BINARY), true, HASH_NO_LOCK);
+  if (NULL == gFunMgtService.pFuncNameHashTable) {
+    return TSDB_CODE_FAILED;
+  }
+  return TSDB_CODE_SUCCESS;
+}
+
+typedef struct SFuncDef {
+  char name[TSDB_FUNC_NAME_LEN];
+  int32_t maxNumOfParams;
+  SFuncExecFuncs execFuncs;
+} SFuncDef ;
+
+FuncDef createFuncDef(const char* name, int32_t maxNumOfParams) {
+  SFuncDef* pDef = calloc(1, sizeof(SFuncDef));
+  if (NULL == pDef) {
+    return NULL;
+  }
+  strcpy(pDef->name, name);
+  pDef->maxNumOfParams = maxNumOfParams;
+  return pDef;
+}
+
+FuncDef setOneParamSignature(FuncDef def, int64_t resDataType, int64_t paramDataType) {
+  // todo
+}
+
+FuncDef setTwoParamsSignature(FuncDef def, int64_t resDataType, int64_t p1DataType, int64_t p2DataType) {
+  // todo
+}
+
+FuncDef setFollowParamSignature(FuncDef def, int64_t paramDataType) {
+  // todo
+}
+
+FuncDef setFollowParamsSignature(FuncDef def, int64_t p1DataType, int64_t p2DataType, int32_t followNo) {
+  // todo
+}
+
+FuncDef setExecFuncs(FuncDef def, FExecGetEnv getEnv, FExecInit init, FExecProcess process, FExecFinalize finalize) {
+  SFuncDef* pDef = (SFuncDef*)def;
+  pDef->execFuncs.getEnv = getEnv;
+  pDef->execFuncs.init = init;
+  pDef->execFuncs.process = process;
+  pDef->execFuncs.finalize = finalize;
+  return def;
+}
+
+int32_t registerFunc(FuncDef func) {
+
+}
diff --git a/source/libs/function/src/taggfunction.c b/source/libs/function/src/taggfunction.c
index 3af4a8fe57..3b3edf1501 100644
--- a/source/libs/function/src/taggfunction.c
+++ b/source/libs/function/src/taggfunction.c
@@ -4835,3 +4835,9 @@ SAggFunctionInfo aggFunc[35] = {{
                               statisRequired,
                           }
                           };
+
+FuncDef defineCount() {
+  FuncDef def = createFuncDef("count", 1);
+  // todo define signature
+  return setExecFuncs(def, NULL, function_setup, count_function, doFinalizer);
+}
diff --git a/source/libs/planner/src/logicPlan.c b/source/libs/planner/src/logicPlan.c
index ae058c1f85..a5ced983c7 100644
--- a/source/libs/planner/src/logicPlan.c
+++ b/source/libs/planner/src/logicPlan.c
@@ -212,7 +212,7 @@ static SQueryPlanNode* doAddTableColumnNode(const SQueryStmtInfo* pQueryInfo, SQ
       pExpr[i] = p;
     }
 
-    pNode = createQueryNode(QNODE_PROJECT, "Projection", &pNode, 1, pExpr, numOfCols, NULL);
+    // pNode = createQueryNode(QNODE_PROJECT, "Projection", &pNode, 1, pExpr, numOfCols, NULL);
     tfree(pExpr);
   }
 
diff --git a/source/libs/planner/src/physicalPlanJson.c b/source/libs/planner/src/physicalPlanJson.c
index db1b1c84d1..d92ea9fd33 100644
--- a/source/libs/planner/src/physicalPlanJson.c
+++ b/source/libs/planner/src/physicalPlanJson.c
@@ -117,6 +117,26 @@ static bool fromPnode(const cJSON* json, const char* name, FFromJson func, void*
   return func(jObj, *obj);
 }
 
+static bool fromPnodeArray(const cJSON* json, const char* name, FFromJson func, SArray** array) {
+  const cJSON* jArray = cJSON_GetObjectItem(json, name);
+  int32_t size = (NULL == jArray ? 0 : cJSON_GetArraySize(jArray));
+  if (size > 0) {
+    *array = taosArrayInit(size, POINTER_BYTES);
+    if (NULL == *array) {
+      return false;
+    }
+  }
+  for (int32_t i = 0; i < size; ++i) {
+    cJSON* jItem = cJSON_GetArrayItem(jArray, i);
+    void* item = calloc(1, getPnodeTypeSize(jItem));
+    if (NULL == item || !func(jItem, item)) {
+      return false;
+    }
+    taosArrayPush(*array, &item);
+  }
+  return true;
+}
+
 static bool addTarray(cJSON* json, const char* name, FToJson func, const SArray* array, bool isPoint) {
   size_t size = (NULL == array) ? 0 : taosArrayGetSize(array);
   if (size > 0) {
@@ -387,8 +407,8 @@ static const char* jkFunctionChild = "Child";
 static bool functionToJson(const void* obj, cJSON* jFunc) {
   const tExprNode* exprInfo = (const tExprNode*)obj;
   bool res = cJSON_AddStringToObject(jFunc, jkFunctionName, exprInfo->_function.functionName);
-  if (res) {
-    res = addRawArray(jFunc, jkFunctionChild, exprNodeToJson, exprInfo->_function.pChild, sizeof(tExprNode*), exprInfo->_function.num);
+  if (res && NULL != exprInfo->_function.pChild) {
+      res = addRawArray(jFunc, jkFunctionChild, exprNodeToJson, *(exprInfo->_function.pChild), sizeof(tExprNode*), exprInfo->_function.num);
   }
   return res;
 }
@@ -396,6 +416,10 @@ static bool functionToJson(const void* obj, cJSON* jFunc) {
 static bool functionFromJson(const cJSON* json, void* obj) {
   tExprNode* exprInfo = (tExprNode*)obj;
   copyString(json, jkFunctionName, exprInfo->_function.functionName);
+  exprInfo->_function.pChild = calloc(1, sizeof(tExprNode*));
+  if (NULL == exprInfo->_function.pChild) {
+    return false;
+  }
   return fromRawArrayWithAlloc(json, jkFunctionChild, exprNodeFromJson, (void**)exprInfo->_function.pChild, sizeof(tExprNode*), &exprInfo->_function.num);
 }
 
@@ -851,7 +875,7 @@ static bool specificPhyNodeFromJson(const cJSON* json, void* obj) {
     case OP_SystemTableScan:
       return scanNodeFromJson(json, obj);
     case OP_Aggregate:
-      break; // todo
+      return aggNodeFromJson(json, obj);
     case OP_Project:
       return true;
     // case OP_Groupby:
@@ -922,7 +946,7 @@ static bool phyNodeFromJson(const cJSON* json, void* obj) {
     res = fromObject(json, jkPnodeSchema, dataBlockSchemaFromJson, &node->targetSchema, true);
   }
   if (res) {
-    res = fromArray(json, jkPnodeChildren, phyNodeFromJson, &node->pChildren, sizeof(SSlotSchema));
+    res = fromPnodeArray(json, jkPnodeChildren, phyNodeFromJson, &node->pChildren);
   }
   if (res) {
     res = fromObject(json, node->info.name, specificPhyNodeFromJson, node, true);
diff --git a/source/nodes/CMakeLists.txt b/source/nodes/CMakeLists.txt
new file mode 100644
index 0000000000..b30534f3f2
--- /dev/null
+++ b/source/nodes/CMakeLists.txt
@@ -0,0 +1,15 @@
+aux_source_directory(src NODES_SRC)
+add_library(nodes STATIC ${NODES_SRC})
+target_include_directories(
+    nodes
+    PUBLIC "${CMAKE_SOURCE_DIR}/include/nodes"
+    PRIVATE "${CMAKE_CURRENT_SOURCE_DIR}/inc"
+)
+target_link_libraries(
+    nodes
+    PRIVATE os util
+)
+
+if(${BUILD_TEST})
+    ADD_SUBDIRECTORY(test)
+endif(${BUILD_TEST})
\ No newline at end of file
diff --git a/source/nodes/src/nodesClone.c b/source/nodes/src/nodesClone.c
new file mode 100644
index 0000000000..04f6df5623
--- /dev/null
+++ b/source/nodes/src/nodesClone.c
@@ -0,0 +1,20 @@
+/*
+ * Copyright (c) 2019 TAOS Data, Inc. <jhtao@taosdata.com>
+ *
+ * This program is free software: you can use, redistribute, and/or modify
+ * it under the terms of the GNU Affero General Public License, version 3
+ * or later ("AGPL"), as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "nodes.h"
+
+void cloneNode(const SNode* pNode) {
+
+}
diff --git a/source/nodes/src/nodesCode.c b/source/nodes/src/nodesCode.c
new file mode 100644
index 0000000000..7fe919ffe8
--- /dev/null
+++ b/source/nodes/src/nodesCode.c
@@ -0,0 +1,24 @@
+/*
+ * Copyright (c) 2019 TAOS Data, Inc. <jhtao@taosdata.com>
+ *
+ * This program is free software: you can use, redistribute, and/or modify
+ * it under the terms of the GNU Affero General Public License, version 3
+ * or later ("AGPL"), as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "nodes.h"
+
+int32_t nodeToString(const SNode* pNode, char** pStr, int32_t* pLen) {
+
+}
+
+int32_t stringToNode(const char* pStr, SNode** pNode) {
+
+}
diff --git a/source/nodes/src/nodesEqual.c b/source/nodes/src/nodesEqual.c
new file mode 100644
index 0000000000..bef025fbea
--- /dev/null
+++ b/source/nodes/src/nodesEqual.c
@@ -0,0 +1,141 @@
+/*
+ * Copyright (c) 2019 TAOS Data, Inc. <jhtao@taosdata.com>
+ *
+ * This program is free software: you can use, redistribute, and/or modify
+ * it under the terms of the GNU Affero General Public License, version 3
+ * or later ("AGPL"), as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "nodes.h"
+
+#define COMPARE_SCALAR_FIELD(fldname) \
+	do { \
+		if (a->fldname != b->fldname) \
+			return false; \
+	} while (0)
+
+#define COMPARE_STRING(a, b)	\
+	(((a) != NULL && (b) != NULL) ? (strcmp(a, b) == 0) : (a) == (b))
+
+#define COMPARE_STRING_FIELD(fldname) \
+	do { \
+		if (!COMPARE_STRING(a->fldname, b->fldname)) \
+			return false; \
+	} while (0)
+
+#define COMPARE_NODE_FIELD(fldname) \
+	do { \
+		if (!nodeEqual(a->fldname, b->fldname)) \
+			return false; \
+	} while (0)
+
+#define COMPARE_ARRAY_FIELD(fldname) \
+	do { \
+		if (!nodeArrayEqual(a->fldname, b->fldname)) \
+			return false; \
+	} while (0)
+
+static bool nodeArrayEqual(const SArray* a, const SArray* b) {
+  if (a == b) {
+    return true;
+  }
+
+  if (NULL == a || NULL == b) {
+    return false;
+  }
+
+  if (taosArrayGetSize(a) != taosArrayGetSize(b)) {
+    return false;
+  }
+
+  size_t size = taosArrayGetSize(a);
+  for (size_t i = 0; i < size; ++i) {
+    if (!nodeEqual((SNode*)taosArrayGetP(a, i), (SNode*)taosArrayGetP(b, i))) {
+      return false;
+    }
+  }
+  return true;
+}
+
+static bool columnNodeEqual(const SColumnNode* a, const SColumnNode* b) {
+  COMPARE_STRING_FIELD(dbName);
+  COMPARE_STRING_FIELD(tableName);
+  COMPARE_STRING_FIELD(colName);
+  return true;
+}
+
+static bool valueNodeEqual(const SValueNode* a, const SValueNode* b) {
+  COMPARE_STRING_FIELD(literal);
+  return true;
+}
+
+static bool operatorNodeEqual(const SOperatorNode* a, const SOperatorNode* b) {
+  COMPARE_SCALAR_FIELD(opType);
+  COMPARE_NODE_FIELD(pLeft);
+  COMPARE_NODE_FIELD(pRight);
+  return true;
+}
+
+static bool logicConditionNodeEqual(const SLogicConditionNode* a, const SLogicConditionNode* b) {
+  COMPARE_SCALAR_FIELD(condType);
+  COMPARE_ARRAY_FIELD(pParameterList);
+  return true;
+}
+
+static bool isNullConditionNodeEqual(const SIsNullCondNode* a, const SIsNullCondNode* b) {
+  COMPARE_NODE_FIELD(pExpr);
+  COMPARE_SCALAR_FIELD(isNot);
+  return true;
+}
+
+static bool functionNodeEqual(const SFunctionNode* a, const SFunctionNode* b) {
+  COMPARE_SCALAR_FIELD(funcId);
+  COMPARE_ARRAY_FIELD(pParameterList);
+  return true;
+}
+
+bool nodeEqual(const SNode* a, const SNode* b) {
+  if (a == b) {
+    return true;
+  }
+
+  if (NULL == a || NULL == b) {
+    return false;
+  }
+
+  if (nodeType(a) != nodeType(b)) {
+    return false;
+  }
+
+  switch (nodeType(a)) {
+    case QUERY_NODE_COLUMN:
+      return columnNodeEqual((const SColumnNode*)a, (const SColumnNode*)b);
+    case QUERY_NODE_VALUE:
+      return valueNodeEqual((const SValueNode*)a, (const SValueNode*)b);
+    case QUERY_NODE_OPERATOR:
+      return operatorNodeEqual((const SOperatorNode*)a, (const SOperatorNode*)b);
+    case QUERY_NODE_LOGIC_CONDITION:
+      return logicConditionNodeEqual((const SLogicConditionNode*)a, (const SLogicConditionNode*)b);
+    case QUERY_NODE_IS_NULL_CONDITION:
+      return isNullConditionNodeEqual((const SIsNullCondNode*)a, (const SIsNullCondNode*)b);
+    case QUERY_NODE_FUNCTION:
+      return functionNodeEqual((const SFunctionNode*)a, (const SFunctionNode*)b);
+    case QUERY_NODE_REAL_TABLE:
+    case QUERY_NODE_TEMP_TABLE:
+    case QUERY_NODE_JOIN_TABLE:
+    case QUERY_NODE_GROUPING_SET:
+    case QUERY_NODE_ORDER_BY_EXPR:
+      return false; // todo
+    default:
+      break;
+  }
+
+  return false;
+}
diff --git a/source/nodes/src/nodesTraverse.c b/source/nodes/src/nodesTraverse.c
new file mode 100644
index 0000000000..eac8288099
--- /dev/null
+++ b/source/nodes/src/nodesTraverse.c
@@ -0,0 +1,83 @@
+/*
+ * Copyright (c) 2019 TAOS Data, Inc. <jhtao@taosdata.com>
+ *
+ * This program is free software: you can use, redistribute, and/or modify
+ * it under the terms of the GNU Affero General Public License, version 3
+ * or later ("AGPL"), as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "nodes.h"
+
+typedef bool (*FQueryNodeWalker)(SNode* pNode, void* pContext);
+
+bool nodeArrayWalker(SArray* pArray, FQueryNodeWalker walker, void* pContext) {
+    size_t size = taosArrayGetSize(pArray);
+    for (size_t i = 0; i < size; ++i) {
+      if (!nodeTreeWalker((SNode*)taosArrayGetP(pArray, i), walker, pContext)) {
+        return false;
+      }
+    }
+    return true;
+}
+
+bool nodeTreeWalker(SNode* pNode, FQueryNodeWalker walker, void* pContext) {
+  if (NULL == pNode) {
+    return true;
+  }
+
+  if (!walker(pNode, pContext)) {
+    return false;
+  }
+
+  switch (nodeType(pNode)) {
+    case QUERY_NODE_COLUMN:
+    case QUERY_NODE_VALUE:
+      // these node types with no subnodes
+      return true;
+    case QUERY_NODE_OPERATOR: {
+      SOperatorNode* pOpNode = (SOperatorNode*)pNode;
+      if (!nodeTreeWalker(pOpNode->pLeft, walker, pContext)) {
+        return false;
+      }
+      return nodeTreeWalker(pOpNode->pRight, walker, pContext);
+    }
+    case QUERY_NODE_LOGIC_CONDITION:
+      return nodeArrayWalker(((SLogicConditionNode*)pNode)->pParameterList, walker, pContext);
+    case QUERY_NODE_IS_NULL_CONDITION:
+      return nodeTreeWalker(((SIsNullCondNode*)pNode)->pExpr, walker, pContext);
+    case QUERY_NODE_FUNCTION:
+      return nodeArrayWalker(((SFunctionNode*)pNode)->pParameterList, walker, pContext);
+    case QUERY_NODE_REAL_TABLE:
+    case QUERY_NODE_TEMP_TABLE:
+      return true; // todo
+    case QUERY_NODE_JOIN_TABLE: {
+      SJoinTableNode* pJoinTableNode = (SJoinTableNode*)pNode;
+      if (!nodeTreeWalker(pJoinTableNode->pLeft, walker, pContext)) {
+        return false;
+      }
+      if (!nodeTreeWalker(pJoinTableNode->pRight, walker, pContext)) {
+        return false;
+      }
+      return nodeTreeWalker(pJoinTableNode->pOnCond, walker, pContext);
+    }
+    case QUERY_NODE_GROUPING_SET:
+      return nodeArrayWalker(((SGroupingSetNode*)pNode)->pParameterList, walker, pContext);
+    case QUERY_NODE_ORDER_BY_EXPR:
+      return nodeTreeWalker(((SOrderByExprNode*)pNode)->pExpr, walker, pContext);
+    default:
+      break;
+  }
+
+  return false;
+}
+
+bool stmtWalker(SNode* pNode, FQueryNodeWalker walker, void* pContext) {
+
+}
diff --git a/source/nodes/src/nodesUtil.c b/source/nodes/src/nodesUtil.c
new file mode 100644
index 0000000000..fe5883d809
--- /dev/null
+++ b/source/nodes/src/nodesUtil.c
@@ -0,0 +1,24 @@
+/*
+ * Copyright (c) 2019 TAOS Data, Inc. <jhtao@taosdata.com>
+ *
+ * This program is free software: you can use, redistribute, and/or modify
+ * it under the terms of the GNU Affero General Public License, version 3
+ * or later ("AGPL"), as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "nodes.h"
+
+bool isTimeorderQuery(const SNode* pQuery) {
+
+}
+
+bool isTimelineQuery(const SNode* pQuery) {
+
+}
diff --git a/source/nodes/test/CMakeLists.txt b/source/nodes/test/CMakeLists.txt
new file mode 100644
index 0000000000..80725a79fb
--- /dev/null
+++ b/source/nodes/test/CMakeLists.txt
@@ -0,0 +1,19 @@
+
+MESSAGE(STATUS "build nodes unit test")
+
+# GoogleTest requires at least C++11
+SET(CMAKE_CXX_STANDARD 11)
+AUX_SOURCE_DIRECTORY(${CMAKE_CURRENT_SOURCE_DIR} SOURCE_LIST)
+
+ADD_EXECUTABLE(nodesTest ${SOURCE_LIST})
+
+TARGET_INCLUDE_DIRECTORIES(
+        nodesTest
+        PUBLIC "${CMAKE_SOURCE_DIR}/include/nodes/"
+        PRIVATE "${CMAKE_SOURCE_DIR}/source/nodes/inc"
+)
+
+TARGET_LINK_LIBRARIES(
+        nodesTest
+        PUBLIC os util common nodes gtest
+)
diff --git a/source/nodes/test/nodesTest.cpp b/source/nodes/test/nodesTest.cpp
new file mode 100644
index 0000000000..7df3cd8b4c
--- /dev/null
+++ b/source/nodes/test/nodesTest.cpp
@@ -0,0 +1,25 @@
+/*
+ * Copyright (c) 2019 TAOS Data, Inc. <jhtao@taosdata.com>
+ *
+ * This program is free software: you can use, redistribute, and/or modify
+ * it under the terms of the GNU Affero General Public License, version 3
+ * or later ("AGPL"), as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <gtest/gtest.h>
+
+TEST(NodesTest, traverseTest) {
+  // todo
+}
+
+int main(int argc, char* argv[]) {
+	testing::InitGoogleTest(&argc, argv);
+	return RUN_ALL_TESTS();
+}
diff --git a/tests/test/c/create_table.c b/tests/test/c/create_table.c
index 6df31c7b8b..d387bf483b 100644
--- a/tests/test/c/create_table.c
+++ b/tests/test/c/create_table.c
@@ -28,9 +28,14 @@ int32_t numOfThreads = 1;
 int64_t numOfTables = 200000;
 int32_t createTable = 1;
 int32_t insertData = 0;
-int32_t batchNum = 100;
+int32_t batchNumOfTbl = 100;
+int32_t batchNumOfRow = 1;
 int32_t numOfVgroups = 2;
 int32_t showTablesFlag = 0;
+int32_t queryFlag = 0;
+
+int64_t startTimestamp = 1640966400000; // 2020-01-01 00:00:00.000
+
 
 typedef struct {
   int64_t   tableBeginIndex;
@@ -167,7 +172,7 @@ void showTables() {
 
 void *threadFunc(void *param) {
   SThreadInfo *pInfo = (SThreadInfo *)param;
-  char        *qstr = malloc(2000 * 1000);
+  char        *qstr = malloc(batchNumOfTbl * batchNumOfRow * 128);
   int32_t      code = 0;
 
   TAOS *con = taos_connect(NULL, "root", "taosdata", NULL, 0);
@@ -192,7 +197,7 @@ void *threadFunc(void *param) {
       // batch = MIN(batch, batchNum);
 
       int32_t len = sprintf(qstr, "create table");
-      for (int32_t i = 0; i < batchNum;) {
+      for (int32_t i = 0; i < batchNumOfTbl;) {
         len += sprintf(qstr + len, " %s_t%" PRId64 " using %s tags(%" PRId64 ")", stbName, t, stbName, t);
         t++;
         i++;
@@ -205,7 +210,7 @@ void *threadFunc(void *param) {
       TAOS_RES *pRes = taos_query(con, qstr);
       code = taos_errno(pRes);
       if ((code != 0) && (code != TSDB_CODE_RPC_AUTH_REQUIRED)) {
-        pError("failed to create table t%" PRId64 ", code: %d, reason:%s", t, code, tstrerror(code));
+        pError("failed to create table t%" PRId64 ", reason:%s", t, tstrerror(code));
       }
       taos_free_result(pRes);
       int64_t endTs = taosGetTimestampUs();
@@ -227,31 +232,49 @@ void *threadFunc(void *param) {
   if (insertData) {
     int64_t curMs = 0;
     int64_t beginMs = taosGetTimestampMs();
+    pInfo->startMs = beginMs;
+    int64_t t = pInfo->tableBeginIndex;
+    for (; t <= pInfo->tableEndIndex;) {
+      // int64_t batch = (pInfo->tableEndIndex - t);
+      // batch = MIN(batch, batchNum);
 
-    pInfo->startMs = taosGetTimestampMs();
-    for (int64_t t = pInfo->tableBeginIndex; t < pInfo->tableEndIndex; ++t) {
-      int64_t batch = (pInfo->tableEndIndex - t);
-      batch = MIN(batch, batchNum);
-
-      int32_t len = sprintf(qstr, "insert into");
-      for (int32_t i = 0; i < batch; ++i) {
-        len += sprintf(qstr + len, " t%" PRId64 " values(now, %" PRId64 ")", t + i, t + i);
-      }
+      int32_t len = sprintf(qstr, "insert into ");
+	  
+      for (int32_t i = 0; i < batchNumOfTbl;) {
+		int64_t ts = startTimestamp;	  	
+        len += sprintf(qstr + len, "%s_t%" PRId64 " values ", stbName, t);
+        for (int32_t j = 0; j < batchNumOfRow; j++) {
+		  len += sprintf(qstr + len, "(%" PRId64 ", 6666) ", ts++);
+        }
+		
+        t++;
+        i++;
+        if (t > pInfo->tableEndIndex) {
+          break;
+        }
+      }	  
 
+      int64_t   startTs = taosGetTimestampUs();
       TAOS_RES *pRes = taos_query(con, qstr);
       code = taos_errno(pRes);
-      if (code != 0) {
-        pError("failed to insert table t%" PRId64 ", reason:%s", t, tstrerror(code));
+      if ((code != 0) && (code != TSDB_CODE_RPC_AUTH_REQUIRED)) {
+        pError("failed to insert %s_t%" PRId64 ", reason:%s", stbName, t, tstrerror(code));
       }
       taos_free_result(pRes);
+      int64_t endTs = taosGetTimestampUs();
+      int64_t delay = endTs - startTs;
+      // printf("==== %"PRId64" -  %"PRId64", %"PRId64"\n", startTs, endTs, delay);
+      if (delay > pInfo->maxDelay) pInfo->maxDelay = delay;
+      if (delay < pInfo->minDelay) pInfo->minDelay = delay;
 
       curMs = taosGetTimestampMs();
       if (curMs - beginMs > 10000) {
+        beginMs = curMs;
+        // printf("==== tableBeginIndex: %"PRId64", t: %"PRId64"\n", pInfo->tableBeginIndex, t);
         printInsertProgress(pInfo, t);
       }
-      t += (batch - 1);
     }
-    printInsertProgress(pInfo, pInfo->tableEndIndex);
+    printInsertProgress(pInfo, t);
   }
 
   taos_close(con);
@@ -280,9 +303,13 @@ void printHelp() {
   printf("%s%s\n", indent, "-i");
   printf("%s%s%s%d\n", indent, indent, "insertData, default is ", insertData);
   printf("%s%s\n", indent, "-b");
-  printf("%s%s%s%d\n", indent, indent, "batchNum, default is ", batchNum);
+  printf("%s%s%s%d\n", indent, indent, "batchNumOfTbl, default is ", batchNumOfTbl);
   printf("%s%s\n", indent, "-w");
   printf("%s%s%s%d\n", indent, indent, "showTablesFlag, default is ", showTablesFlag);
+  printf("%s%s\n", indent, "-q");
+  printf("%s%s%s%d\n", indent, indent, "queryFlag, default is ", queryFlag);
+  printf("%s%s\n", indent, "-l");
+  printf("%s%s%s%d\n", indent, indent, "batchNumOfRow, default is ", batchNumOfRow);
 
   exit(EXIT_SUCCESS);
 }
@@ -309,10 +336,15 @@ void parseArgument(int32_t argc, char *argv[]) {
     } else if (strcmp(argv[i], "-i") == 0) {
       insertData = atoi(argv[++i]);
     } else if (strcmp(argv[i], "-b") == 0) {
-      batchNum = atoi(argv[++i]);
+      batchNumOfTbl = atoi(argv[++i]);
+    } else if (strcmp(argv[i], "-l") == 0) {
+      batchNumOfRow = atoi(argv[++i]);
     } else if (strcmp(argv[i], "-w") == 0) {
       showTablesFlag = atoi(argv[++i]);
+    } else if (strcmp(argv[i], "-q") == 0) {
+      queryFlag = atoi(argv[++i]);
     } else {
+	  pPrint("%s unknow para: %s %s", GREEN, argv[++i], NC);
     }
   }
 
@@ -324,8 +356,10 @@ void parseArgument(int32_t argc, char *argv[]) {
   pPrint("%s numOfVgroups:%d %s", GREEN, numOfVgroups, NC);
   pPrint("%s createTable:%d %s", GREEN, createTable, NC);
   pPrint("%s insertData:%d %s", GREEN, insertData, NC);
-  pPrint("%s batchNum:%d %s", GREEN, batchNum, NC);
+  pPrint("%s batchNumOfTbl:%d %s", GREEN, batchNumOfTbl, NC);
+  pPrint("%s batchNumOfRow:%d %s", GREEN, batchNumOfRow, NC);
   pPrint("%s showTablesFlag:%d %s", GREEN, showTablesFlag, NC);
+  pPrint("%s queryFlag:%d %s", GREEN, queryFlag, NC);
 
   pPrint("%s start create table performace test %s", GREEN, NC);
 }
@@ -338,8 +372,15 @@ int32_t main(int32_t argc, char *argv[]) {
     return 0;
   }
 
-  createDbAndStb();
+  if (queryFlag) {
+    //selectRowsFromTable();
+    return 0;
+  }
 
+  if (createTable) {
+    createDbAndStb();
+  }
+  
   pPrint("%d threads are spawned to create %" PRId64 " tables", numOfThreads, numOfTables);
 
   pthread_attr_t thattr;
@@ -396,9 +437,11 @@ int32_t main(int32_t argc, char *argv[]) {
     insertDataSpeed += pInfo[i].insertDataSpeed;
   }
 
-  pPrint("%s total %" PRId64 " tables, %.1f tables/second, threads:%d, maxDelay: %" PRId64 "us, minDelay: %" PRId64
+  if (createTable) {
+    pPrint("%s total %" PRId64 " tables, %.1f tables/second, threads:%d, maxDelay: %" PRId64 "us, minDelay: %" PRId64
          "us %s",
          GREEN, numOfTables, createTableSpeed, numOfThreads, maxDelay, minDelay, NC);
+  }
 
   if (insertData) {
     pPrint("%s total %" PRId64 " tables, %.1f rows/second, threads:%d %s", GREEN, numOfTables, insertDataSpeed,