diff --git a/src/client/inc/tsclient.h b/src/client/inc/tsclient.h
index 054b2894c5cff77b63f57b16b069aaf60e150ecc..9657912716fe019b8d92abd4fc4232cf3a133301 100644
--- a/src/client/inc/tsclient.h
+++ b/src/client/inc/tsclient.h
@@ -468,7 +468,6 @@ int32_t tscToSQLCmd(SSqlObj* pSql, struct SSqlInfo* pInfo);
 extern void *     pVnodeConn;
 extern void *     pTscMgmtConn;
 extern void *     tscCacheHandle;
-extern int32_t    globalCode;
 extern int        slaveIndex;
 extern void *     tscTmr;
 extern void *     tscQhandle;
diff --git a/src/client/src/tscAsync.c b/src/client/src/tscAsync.c
index 99104ed68cae4526ba2ef6b1c9a4c52c56885e4d..36cd42332b0d84b09798138080da33a856f26a21 100644
--- a/src/client/src/tscAsync.c
+++ b/src/client/src/tscAsync.c
@@ -200,7 +200,6 @@ void taos_fetch_rows_a(TAOS_RES *taosa, void (*fp)(void *, TAOS_RES *, int), voi
   SSqlObj *pSql = (SSqlObj *)taosa;
   if (pSql == NULL || pSql->signature != pSql) {
     tscError("sql object is NULL");
-//    globalCode = TSDB_CODE_DISCONNECTED;
     tscQueueAsyncError(fp, param, TSDB_CODE_DISCONNECTED);
     return;
   }
@@ -232,7 +231,6 @@ void taos_fetch_row_a(TAOS_RES *taosa, void (*fp)(void *, TAOS_RES *, TAOS_ROW),
   SSqlObj *pSql = (SSqlObj *)taosa;
   if (pSql == NULL || pSql->signature != pSql) {
     tscError("sql object is NULL");
-//    globalCode = TSDB_CODE_DISCONNECTED;
     tscQueueAsyncError(fp, param, TSDB_CODE_DISCONNECTED);
     return;
   }
diff --git a/src/client/src/tscPrepare.c b/src/client/src/tscPrepare.c
index 8b065fcf51e3115792a6312ea74e4e0a130206a9..caa14d082bc144be7614fa3290908ca3108fa58f 100644
--- a/src/client/src/tscPrepare.c
+++ b/src/client/src/tscPrepare.c
@@ -467,14 +467,14 @@ static int insertStmtExecute(STscStmt* stmt) {
 TAOS_STMT* taos_stmt_init(TAOS* taos) {
   STscObj* pObj = (STscObj*)taos;
   if (pObj == NULL || pObj->signature != pObj) {
-    globalCode = TSDB_CODE_DISCONNECTED;
+    terrno = TSDB_CODE_DISCONNECTED;
     tscError("connection disconnected");
     return NULL;
   }
 
   STscStmt* pStmt = calloc(1, sizeof(STscStmt));
   if (pStmt == NULL) {
-    globalCode = TSDB_CODE_CLI_OUT_OF_MEMORY;
+    terrno = TSDB_CODE_CLI_OUT_OF_MEMORY;
     tscError("failed to allocate memory for statement");
     return NULL;
   }
@@ -482,7 +482,7 @@ TAOS_STMT* taos_stmt_init(TAOS* taos) {
   SSqlObj* pSql = calloc(1, sizeof(SSqlObj));
   if (pSql == NULL) {
     free(pStmt);
-    globalCode = TSDB_CODE_CLI_OUT_OF_MEMORY;
+    terrno = TSDB_CODE_CLI_OUT_OF_MEMORY;
     tscError("failed to allocate memory for statement");
     return NULL;
   }
diff --git a/src/client/src/tscSql.c b/src/client/src/tscSql.c
index bbfd8645bd81c4668dee2ee2a411615c9dcb0ad5..f6c1fee633308260da4c8c9ce8c5e327c67338fb 100644
--- a/src/client/src/tscSql.c
+++ b/src/client/src/tscSql.c
@@ -57,17 +57,17 @@ STscObj *taosConnectImpl(const char *ip, const char *user, const char *pass, con
   taos_init();
   
   if (!validUserName(user)) {
-    globalCode = TSDB_CODE_INVALID_ACCT;
+    terrno = TSDB_CODE_INVALID_ACCT;
     return NULL;
   }
 
   if (!validPassword(pass)) {
-    globalCode = TSDB_CODE_INVALID_PASS;
+    terrno = TSDB_CODE_INVALID_PASS;
     return NULL;
   }
 
   if (tscInitRpc(user, pass) != 0) {
-    globalCode = TSDB_CODE_NETWORK_UNAVAIL;
+    terrno = TSDB_CODE_NETWORK_UNAVAIL;
     return NULL;
   }
 
@@ -92,7 +92,7 @@ STscObj *taosConnectImpl(const char *ip, const char *user, const char *pass, con
   
   STscObj *pObj = (STscObj *)calloc(1, sizeof(STscObj));
   if (NULL == pObj) {
-    globalCode = TSDB_CODE_CLI_OUT_OF_MEMORY;
+    terrno = TSDB_CODE_CLI_OUT_OF_MEMORY;
     return NULL;
   }
 
@@ -107,7 +107,7 @@ STscObj *taosConnectImpl(const char *ip, const char *user, const char *pass, con
     /* db name is too long */
     if (len > TSDB_DB_NAME_LEN) {
       free(pObj);
-      globalCode = TSDB_CODE_INVALID_DB;
+      terrno = TSDB_CODE_INVALID_DB;
       return NULL;
     }
 
@@ -122,7 +122,7 @@ STscObj *taosConnectImpl(const char *ip, const char *user, const char *pass, con
 
   SSqlObj *pSql = (SSqlObj *)calloc(1, sizeof(SSqlObj));
   if (NULL == pSql) {
-    globalCode = TSDB_CODE_CLI_OUT_OF_MEMORY;
+    terrno = TSDB_CODE_CLI_OUT_OF_MEMORY;
     free(pObj);
     return NULL;
   }
@@ -140,7 +140,7 @@ STscObj *taosConnectImpl(const char *ip, const char *user, const char *pass, con
 
   pSql->cmd.command = TSDB_SQL_CONNECT;
   if (TSDB_CODE_SUCCESS != tscAllocPayload(&pSql->cmd, TSDB_DEFAULT_PAYLOAD_SIZE)) {
-    globalCode = TSDB_CODE_CLI_OUT_OF_MEMORY;
+    terrno = TSDB_CODE_CLI_OUT_OF_MEMORY;
     free(pSql);
     free(pObj);
     return NULL;
@@ -303,7 +303,7 @@ int taos_query(TAOS *taos, const char *sqlstr) {
 TAOS_RES *taos_use_result(TAOS *taos) {
   STscObj *pObj = (STscObj *)taos;
   if (pObj == NULL || pObj->signature != pObj) {
-    globalCode = TSDB_CODE_DISCONNECTED;
+    terrno = TSDB_CODE_DISCONNECTED;
     return NULL;
   }
 
@@ -662,7 +662,7 @@ static void waitForRetrieveRsp(void *param, TAOS_RES *tres, int numOfRows) {
 TAOS_ROW taos_fetch_row(TAOS_RES *res) {
   SSqlObj *pSql = (SSqlObj *)res;
   if (pSql == NULL || pSql->signature != pSql) {
-    globalCode = TSDB_CODE_DISCONNECTED;
+    terrno = TSDB_CODE_DISCONNECTED;
     return NULL;
   }
   
@@ -694,7 +694,7 @@ int taos_fetch_block(TAOS_RES *res, TAOS_ROW *rows) {
   int nRows = 0;
 
   if (pSql == NULL || pSql->signature != pSql) {
-    globalCode = TSDB_CODE_DISCONNECTED;
+    terrno = TSDB_CODE_DISCONNECTED;
     *rows = NULL;
     return 0;
   }
@@ -733,7 +733,7 @@ int taos_select_db(TAOS *taos, const char *db) {
 
   STscObj *pObj = (STscObj *)taos;
   if (pObj == NULL || pObj->signature != pObj) {
-    globalCode = TSDB_CODE_DISCONNECTED;
+    terrno = TSDB_CODE_DISCONNECTED;
     return TSDB_CODE_DISCONNECTED;
   }
 
@@ -1011,7 +1011,7 @@ int taos_print_row(char *str, TAOS_ROW row, TAOS_FIELD *fields, int num_fields)
 int taos_validate_sql(TAOS *taos, const char *sql) {
   STscObj *pObj = (STscObj *)taos;
   if (pObj == NULL || pObj->signature != pObj) {
-    globalCode = TSDB_CODE_DISCONNECTED;
+    terrno = TSDB_CODE_DISCONNECTED;
     return TSDB_CODE_DISCONNECTED;
   }
 
@@ -1143,7 +1143,7 @@ int taos_load_table_info(TAOS *taos, const char *tableNameList) {
 
   STscObj *pObj = (STscObj *)taos;
   if (pObj == NULL || pObj->signature != pObj) {
-    globalCode = TSDB_CODE_DISCONNECTED;
+    terrno = TSDB_CODE_DISCONNECTED;
     return TSDB_CODE_DISCONNECTED;
   }
 
diff --git a/src/client/src/tscSub.c b/src/client/src/tscSub.c
index 9d172d4ea5279c648b636df0d8895c1a20bda7cd..fd457a12dd26ac8bba28890db971b311f04b12a3 100644
--- a/src/client/src/tscSub.c
+++ b/src/client/src/tscSub.c
@@ -99,14 +99,14 @@ void tscUpdateSubscriptionProgress(void* sub, int64_t uid, TSKEY ts) {
 static SSub* tscCreateSubscription(STscObj* pObj, const char* topic, const char* sql) {
   SSub* pSub = calloc(1, sizeof(SSub));
   if (pSub == NULL) {
-    globalCode = TSDB_CODE_CLI_OUT_OF_MEMORY;
+    terrno = TSDB_CODE_CLI_OUT_OF_MEMORY;
     tscError("failed to allocate memory for subscription");
     return NULL;
   }
 
   SSqlObj* pSql = calloc(1, sizeof(SSqlObj));
   if (pSql == NULL) {
-    globalCode = TSDB_CODE_CLI_OUT_OF_MEMORY;
+    terrno = TSDB_CODE_CLI_OUT_OF_MEMORY;
     tscError("failed to allocate SSqlObj for subscription");
     goto failed;
   }
@@ -309,7 +309,7 @@ void tscSaveSubscriptionProgress(void* sub) {
 TAOS_SUB *taos_subscribe(TAOS *taos, int restart, const char* topic, const char *sql, TAOS_SUBSCRIBE_CALLBACK fp, void *param, int interval) {
   STscObj* pObj = (STscObj*)taos;
   if (pObj == NULL || pObj->signature != pObj) {
-    globalCode = TSDB_CODE_DISCONNECTED;
+    terrno = TSDB_CODE_DISCONNECTED;
     tscError("connection disconnected");
     return NULL;
   }
diff --git a/src/client/src/tscSystem.c b/src/client/src/tscSystem.c
index ead8c09dec3062b74745318b29c6eb3af11b96f8..ea4cf12f9de399b7ff934ff189fa600930bb6374 100644
--- a/src/client/src/tscSystem.c
+++ b/src/client/src/tscSystem.c
@@ -33,7 +33,6 @@ void *  pVMeterConn;
 void *  pTscMgmtConn;
 void *  pSlaveConn;
 void *  tscCacheHandle;
-int32_t globalCode = 0;
 int     slaveIndex;
 void *  tscTmr;
 void *  tscQhandle;
diff --git a/src/client/src/tscUtil.c b/src/client/src/tscUtil.c
index 9b1771164d8b1cf4556d7de1013576f90cf578b5..0294120ccb718633af35de4472ec303f61faca9e 100644
--- a/src/client/src/tscUtil.c
+++ b/src/client/src/tscUtil.c
@@ -819,7 +819,7 @@ void tscCloseTscObj(STscObj* pObj) {
   pObj->signature = NULL;
   SSqlObj* pSql = pObj->pSql;
   if (pSql) {
-    globalCode = pSql->res.code;
+    terrno = pSql->res.code;
   }
   
   taosTmrStopA(&(pObj->pTimer));
@@ -2153,7 +2153,7 @@ int16_t tscGetJoinTagColIndexByUid(STagCond* pTagCond, uint64_t uid) {
 
 bool tscIsUpdateQuery(STscObj* pObj) {
   if (pObj == NULL || pObj->signature != pObj) {
-    globalCode = TSDB_CODE_DISCONNECTED;
+    terrno = TSDB_CODE_DISCONNECTED;
     return TSDB_CODE_DISCONNECTED;
   }
 
diff --git a/src/query/tests/astTest.cpp b/src/query/tests/astTest.cpp
index ac10cd2429ea5a7634fe226d4bc9f80f17e44e28..3b1f36e90f9fc4001fcf11d5dbcf105985787205 100644
--- a/src/query/tests/astTest.cpp
+++ b/src/query/tests/astTest.cpp
@@ -9,6 +9,9 @@
 #include "tsdb.h"
 #include "tskiplist.h"
 
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wwrite-strings"
+
 typedef struct ResultObj {
   int32_t numOfResult;
   char *  resultName[64];
diff --git a/src/query/tests/tsBufTest.cpp b/src/query/tests/tsBufTest.cpp
index 2392bd00b53c52126585d5bf1e795fe8db15f106..ff58e2a97446da04f96cc23fe224632fa7f7ad49 100644
--- a/src/query/tests/tsBufTest.cpp
+++ b/src/query/tests/tsBufTest.cpp
@@ -158,7 +158,7 @@ void loadDataTest() {
     for (int32_t i = 0; i < numOfTags; ++i) {
       int64_t* list = createTsList(num, start, step);
       tsBufAppend(pTSBuf, j, i, (const char*)list, num * sizeof(int64_t));
-      printf("%d - %lld\n", i, list[0]);
+      printf("%d - %" PRIu64 "\n", i, list[0]);
 
       free(list);
       start += step * num;
@@ -195,7 +195,7 @@ void loadDataTest() {
   tsBufResetPos(pNewBuf);
 
   int64_t s = taosGetTimestampUs();
-  printf("start:%lld\n", s);
+  printf("start:%" PRIu64 "\n", s);
 
   int32_t x = 0;
   while (tsBufNextPos(pNewBuf)) {
@@ -204,11 +204,11 @@ void loadDataTest() {
       break;
     }
 
-    //    printf("%d-%lld-%lld\n", elem.vnode, elem.tag, elem.ts);
+    //    printf("%d-%" PRIu64 "-%" PRIu64 "\n", elem.vnode, elem.tag, elem.ts);
   }
 
   int64_t e = taosGetTimestampUs();
-  printf("end:%lld, elapsed:%lld, total obj:%d\n", e, e - s, x);
+  printf("end:%" PRIu64 ", elapsed:%" PRIu64 ", total obj:%d\n", e, e - s, x);
 }
 
 void randomIncTsTest() {}
@@ -229,14 +229,14 @@ void TSTraverse() {
     for (int32_t i = 0; i < numOfTags; ++i) {
       int64_t* list = createTsList(num, start, step);
       tsBufAppend(pTSBuf, j, i, (const char*)list, num * sizeof(int64_t));
-      printf("%d - %d - %lld, %lld\n", j, i, list[0], list[num - 1]);
+      printf("%d - %d - %" PRIu64 ", %" PRIu64 "\n", j, i, list[0], list[num - 1]);
 
       free(list);
       start += step * num;
 
       list = createTsList(num, start, step);
       tsBufAppend(pTSBuf, j, i, (const char*)list, num * sizeof(int64_t));
-      printf("%d - %d - %lld, %lld\n", j, i, list[0], list[num - 1]);
+      printf("%d - %d - %" PRIu64 ", %" PRIu64 "\n", j, i, list[0], list[num - 1]);
       free(list);
 
       start += step * num;
@@ -250,7 +250,7 @@ void TSTraverse() {
   ////////////////////////////////////////////////////////////////////////////////////////
   // reverse traverse
   int64_t s = taosGetTimestampUs();
-  printf("start:%lld\n", s);
+  printf("start:%" PRIu64 "\n", s);
 
   pTSBuf->cur.order = TSQL_SO_DESC;
 
@@ -258,7 +258,7 @@ void TSTraverse() {
   int32_t x = 0;
   while (tsBufNextPos(pTSBuf)) {
     STSElem elem = tsBufGetElem(pTSBuf);
-    //    printf("%d-%lld-%lld\n", elem.vnode, elem.tag, elem.ts);
+    //    printf("%d-%" PRIu64 "-%" PRIu64 "\n", elem.vnode, elem.tag, elem.ts);
   }
 
   // specify the data block with vnode and tags value
@@ -273,7 +273,7 @@ void TSTraverse() {
   int32_t totalOutput = 10;
   while (1) {
     STSElem elem = tsBufGetElem(pTSBuf);
-    printf("%d-%lld-%lld\n", elem.vnode, elem.tag, elem.ts);
+    printf("%d-%" PRIu64 "-%" PRIu64 "\n", elem.vnode, elem.tag, elem.ts);
 
     if (!tsBufNextPos(pTSBuf)) {
       break;
@@ -303,7 +303,7 @@ void TSTraverse() {
   // complete forwards traverse
   while (tsBufNextPos(pTSBuf)) {
     STSElem elem = tsBufGetElem(pTSBuf);
-    //    printf("%d-%lld-%lld\n", elem.vnode, elem.tag, elem.ts);
+    //    printf("%d-%" PRIu64 "-%" PRIu64 "\n", elem.vnode, elem.tag, elem.ts);
   }
 
   // specify the data block with vnode and tags value
@@ -318,7 +318,7 @@ void TSTraverse() {
   totalOutput = 10;
   while (1) {
     STSElem elem = tsBufGetElem(pTSBuf);
-    printf("%d-%lld-%lld\n", elem.vnode, elem.tag, elem.ts);
+    printf("%d-%" PRIu64 "-%" PRIu64 "\n", elem.vnode, elem.tag, elem.ts);
 
     if (!tsBufNextPos(pTSBuf)) {
       break;
@@ -429,7 +429,7 @@ void mergeIdenticalVnodeBufferTest() {
     STSElem elem = tsBufGetElem(pTSBuf1);
     EXPECT_EQ(elem.vnode, 12);
 
-    printf("%d-%lld-%lld\n", elem.vnode, elem.tag, elem.ts);
+    printf("%d-%" PRIu64 "-%" PRIu64 "\n", elem.vnode, elem.tag, elem.ts);
   }
 
   tsBufDestory(pTSBuf1);
diff --git a/src/query/tests/unitTest.cpp b/src/query/tests/unitTest.cpp
index c7520c90f9fbdb818d85d8f3b321c49820441f2d..df28a3e4d11168b915781ec9f13bda768be36e6b 100644
--- a/src/query/tests/unitTest.cpp
+++ b/src/query/tests/unitTest.cpp
@@ -11,6 +11,9 @@
 #include "tvariant.h"
 #include "ttokendef.h"
 
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wwrite-strings"
+
 namespace {
 int32_t testValidateName(char* name) {
   SSQLToken token = {0};
diff --git a/src/util/inc/tcache.h b/src/util/inc/tcache.h
index 36635fff30f32f3ad3a993e2e0c5139f35eec1a6..a29e720e67904b5ffbc32a575ccb86dd0ccdbabb 100644
--- a/src/util/inc/tcache.h
+++ b/src/util/inc/tcache.h
@@ -98,7 +98,7 @@ SCacheObj *taosCacheInit(void *tmrCtrl, int64_t refreshTimeInSeconds);
  * @param keepTime      survival time in second
  * @return              cached element
  */
-void *taosCachePut(SCacheObj *pCacheObj, char *key, void *pData, size_t dataSize, int keepTimeInSeconds);
+void *taosCachePut(SCacheObj *pCacheObj, const char *key, const void *pData, size_t dataSize, int keepTimeInSeconds);
 
 /**
  * get data from cache
diff --git a/src/util/src/tcache.c b/src/util/src/tcache.c
index 5f04765f010416eb06c0016764af08c4e88496bf..8bfec97032478251b0c83078c1559ecdb6a27e4d 100644
--- a/src/util/src/tcache.c
+++ b/src/util/src/tcache.c
@@ -233,8 +233,8 @@ static FORCE_INLINE void taosCacheMoveToTrash(SCacheObj *pCacheObj, SCacheDataNo
  * @param dataSize
  * @return
  */
-static SCacheDataNode *taosUpdateCacheImpl(SCacheObj *pCacheObj, SCacheDataNode *pNode, char *key, int32_t keyLen,
-                                           void *pData, uint32_t dataSize, uint64_t duration) {
+static SCacheDataNode *taosUpdateCacheImpl(SCacheObj *pCacheObj, SCacheDataNode *pNode, const char *key, int32_t keyLen,
+                                           const void *pData, uint32_t dataSize, uint64_t duration) {
   SCacheDataNode *pNewNode = NULL;
   
   // only a node is not referenced by any other object, in-place update it
@@ -288,7 +288,7 @@ static SCacheDataNode *taosUpdateCacheImpl(SCacheObj *pCacheObj, SCacheDataNode
  * @param pNode
  * @return
  */
-static FORCE_INLINE SCacheDataNode *taosAddToCacheImpl(SCacheObj *pCacheObj, char *key, size_t keyLen, const void *pData,
+static FORCE_INLINE SCacheDataNode *taosAddToCacheImpl(SCacheObj *pCacheObj, const char *key, size_t keyLen, const void *pData,
                                                        size_t dataSize, uint64_t duration) {
   SCacheDataNode *pNode = taosCreateHashNode(key, keyLen, pData, dataSize, duration);
   if (pNode == NULL) {
@@ -401,7 +401,7 @@ SCacheObj *taosCacheInit(void *tmrCtrl, int64_t refreshTime) {
   return pCacheObj;
 }
 
-void *taosCachePut(SCacheObj *pCacheObj, char *key, void *pData, size_t dataSize, int duration) {
+void *taosCachePut(SCacheObj *pCacheObj, const char *key, const void *pData, size_t dataSize, int duration) {
   SCacheDataNode *pNode;
   
   if (pCacheObj == NULL || pCacheObj->pHashTable == NULL) {
diff --git a/src/util/tests/cacheTest.cpp b/src/util/tests/cacheTest.cpp
index 1902fef4b64d0b796a85d9f58e1f422fe0df59e8..13fb7d7afbdcd669bf107f5869ff7842b34ceee0 100644
--- a/src/util/tests/cacheTest.cpp
+++ b/src/util/tests/cacheTest.cpp
@@ -22,15 +22,15 @@ TEST(testCase, client_cache_test) {
   void* tscTmr = taosTmrInit (tsMaxMgmtConnections*2, 200, 6000, "TSC");
   SCacheObj* tscCacheHandle = taosCacheInit(tscTmr, REFRESH_TIME_IN_SEC);
 
-  char* key1 = "test1";
-  char* data1 = "test11";
+  const char* key1 = "test1";
+  char data1[] = "test11";
 
   char* cachedObj = (char*) taosCachePut(tscCacheHandle, key1, data1, strlen(data1), 1);
   sleep(REFRESH_TIME_IN_SEC+1);
 
   printf("obj is still valid: %s\n", cachedObj);
 
-  char* data2 = "test22";
+  char data2[] = "test22";
   taosCacheRelease(tscCacheHandle, (void**) &cachedObj, false);
 
   /* the object is cleared by cache clean operation */
@@ -43,8 +43,8 @@ TEST(testCase, client_cache_test) {
 
   getchar();
 
-  char* key3 = "test2";
-  char* data3 = "kkkkkkk";
+  const char* key3 = "test2";
+  const char* data3 = "kkkkkkk";
 
   char* cachedObj2 = (char*) taosCachePut(tscCacheHandle, key3, data3, strlen(data3), 1);
   printf("%s\n", cachedObj2);
@@ -55,11 +55,11 @@ TEST(testCase, client_cache_test) {
   char* d = (char*) taosCacheAcquireByName(tscCacheHandle, key3);
 //    assert(d == NULL);
 
-  char* key5 = "test5";
-  char* data5 = "data5kkkkk";
+  char key5[] = "test5";
+  char data5[] = "data5kkkkk";
   cachedObj2 = (char*) taosCachePut(tscCacheHandle, key5, data5, strlen(data5), 20);
 
-  char* data6= "new Data after updated";
+  const char* data6= "new Data after updated";
   taosCacheRelease(tscCacheHandle, (void**) &cachedObj2, false);
 
   cachedObj2 = (char*) taosCachePut(tscCacheHandle, key5, data6, strlen(data6), 20);
@@ -67,7 +67,7 @@ TEST(testCase, client_cache_test) {
 
   taosCacheRelease(tscCacheHandle, (void**) &cachedObj2, true);
 
-  char* data7 = "add call update procedure";
+  const char* data7 = "add call update procedure";
   cachedObj2 = (char*) taosCachePut(tscCacheHandle, key5, data7, strlen(data7), 20);
   printf("%s\n=======================================\n\n", cachedObj2);
 
@@ -76,8 +76,8 @@ TEST(testCase, client_cache_test) {
   taosCacheRelease(tscCacheHandle, (void**) &cachedObj2, true);
   taosCacheRelease(tscCacheHandle, (void**) &cc, false);
 
-  char* data8 = "ttft";
-  char* key6 = "key6";
+  const char* data8 = "ttft";
+  const char* key6 = "key6";
 
   char* ft = (char*) taosCachePut(tscCacheHandle, key6, data8, strlen(data8), 20);
   taosCacheRelease(tscCacheHandle, (void**) &ft, false);
@@ -86,7 +86,7 @@ TEST(testCase, client_cache_test) {
    * 140ns
    */
   uint64_t startTime = taosGetTimestampUs();
-  printf("Cache Performance Test\nstart time:%lld\n", startTime);
+  printf("Cache Performance Test\nstart time:%" PRIu64 "\n", startTime);
   for(int32_t i=0; i<1000; ++i) {
     char* dd = (char*) taosCacheAcquireByName(tscCacheHandle, key6);
     if (dd != NULL) {
@@ -101,7 +101,7 @@ TEST(testCase, client_cache_test) {
   uint64_t endTime = taosGetTimestampUs();
   int64_t el = endTime - startTime;
 
-  printf("End of Test, %lld\nTotal Elapsed Time:%lld us.avg:%f us\n", endTime, el, el/1000.0);
+  printf("End of Test, %" PRIu64 "\nTotal Elapsed Time:%" PRIu64 " us.avg:%f us\n", endTime, el, el/1000.0);
 
   taosCacheCleanup(tscCacheHandle);
 }
@@ -125,7 +125,7 @@ TEST(testCase, cache_resize_test) {
   }
   uint64_t endTime = taosGetTimestampUs();
 
-  printf("add %d object cost:%lld us, avg:%f us\n", num, endTime - startTime, (endTime-startTime)/(double)num);
+  printf("add %d object cost:%" PRIu64 " us, avg:%f us\n", num, endTime - startTime, (endTime-startTime)/(double)num);
 
   startTime = taosGetTimestampUs();
   for(int32_t i = 0; i < num; ++i) {
@@ -134,7 +134,7 @@ TEST(testCase, cache_resize_test) {
     assert(k != 0);
   }
   endTime = taosGetTimestampUs();
-  printf("retrieve %d object cost:%lld us,avg:%f\n", num, endTime - startTime, (endTime - startTime)/(double)num);
+  printf("retrieve %d object cost:%" PRIu64 " us,avg:%f\n", num, endTime - startTime, (endTime - startTime)/(double)num);
 
   taosCacheCleanup(pCache);
   taosMsleep(20000);
diff --git a/src/util/tests/skiplistTest.cpp b/src/util/tests/skiplistTest.cpp
index c009231874de94530ffa18d15f745531c4daa94c..9e690c3924062e67aea47974d0e2d08d78fa46b7 100644
--- a/src/util/tests/skiplistTest.cpp
+++ b/src/util/tests/skiplistTest.cpp
@@ -175,7 +175,7 @@ void stringKeySkiplistTest() {
   }
 
   int64_t e = taosGetTimestampUs();
-  printf("elapsed time:%lld us to insert %d data, avg:%f us\n", (e - s), total, (double)(e - s) / total);
+  printf("elapsed time:%" PRIu64 " us to insert %d data, avg:%f us\n", (e - s), total, (double)(e - s) / total);
 
   printf("level two------------------\n");
   tSkipListPrint(pSkipList, 1);
@@ -237,13 +237,13 @@ void skiplistPerformanceTest() {
       int64_t cur = taosGetTimestampMs();
 
       int64_t elapsed = cur - prev;
-      printf("add %d, elapsed time: %lld ms, avg elapsed:%f ms, total:%d\n", 100000, elapsed, elapsed / 100000.0, i);
+      printf("add %d, elapsed time: %" PRIu64 " ms, avg elapsed:%f ms, total:%d\n", 100000, elapsed, elapsed / 100000.0, i);
       prev = cur;
     }
   }
 
   int64_t e = taosGetTimestampMs();
-  printf("total:%lld ms, avg:%f\n", e - s, (e - s) / (double)size);
+  printf("total:%" PRIu64 " ms, avg:%f\n", e - s, (e - s) / (double)size);
   printf("max level of skiplist:%d, actually level:%d\n ", pSkipList->maxLevel, pSkipList->level);
 
   assert(tSkipListGetSize(pSkipList) == size);
diff --git a/src/vnode/tsdb/src/tsdbRead.c b/src/vnode/tsdb/src/tsdbRead.c
index cf75f21a4581e6660464ee9a5a713afed57f1856..30d0e949507b997fa1cbee4cfcac338fe3c16f7e 100644
--- a/src/vnode/tsdb/src/tsdbRead.c
+++ b/src/vnode/tsdb/src/tsdbRead.c
@@ -1053,7 +1053,7 @@ typedef struct SSyntaxTreeFilterSupporter {
  * convert the result pointer to STabObj instead of tSkipListNode
  * @param pRes
  */
-static void tansformQueryResult(SArray* pRes) {
+static UNUSED_FUNC void tansformQueryResult(SArray* pRes) {
   if (pRes == NULL || taosArrayGetSize(pRes) == 0) {
     return;
   }
@@ -1305,10 +1305,10 @@ bool tSkipListNodeFilterCallback(const void* pNode, void* param) {
 }
 
 static int32_t doQueryTableList(STable* pSTable, SArray* pRes, const char* pCond) {
-  STColumn* stcol = schemaColAt(pSTable->tagSchema, 0);
+//  STColumn* stcol = schemaColAt(pSTable->tagSchema, 0);
   
   tExprNode* pExpr = NULL;
-  tSQLBinaryExprFromString(&pExpr, stcol, schemaNCols(pSTable->tagSchema), (char*) pCond, strlen(pCond));
+//  tSQLBinaryExprFromString(&pExpr, stcol, schemaNCols(pSTable->tagSchema), (char*) pCond, strlen(pCond));
   
   // failed to build expression, no result, return immediately
   if (pExpr == NULL) {
@@ -1319,18 +1319,18 @@ static int32_t doQueryTableList(STable* pSTable, SArray* pRes, const char* pCond
   }
   
   // query according to the binary expression
-  SSyntaxTreeFilterSupporter s = {.pTagSchema = stcol, .numOfTags = schemaNCols(pSTable->tagSchema)};
-  
-  SBinaryFilterSupp supp = {
-      .fp = (__result_filter_fn_t)tSkipListNodeFilterCallback,
-      .setupInfoFn = (__do_filter_suppl_fn_t)filterPrepare,
-      .pExtInfo = &s
-  };
-  
-  tSQLBinaryExprTraverse(pExpr, pSTable->pIndex, pRes, &supp);
-  tExprTreeDestroy(&pExpr, tSQLListTraverseDestroyInfo);
-  
-  tansformQueryResult(pRes);
+//  SSyntaxTreeFilterSupporter s = {.pTagSchema = stcol, .numOfTags = schemaNCols(pSTable->tagSchema)};
+//
+//  SBinaryFilterSupp supp = {
+//      .fp = (__result_filter_fn_t)tSkipListNodeFilterCallback,
+//      .setupInfoFn = (__do_filter_suppl_fn_t)filterPrepare,
+//      .pExtInfo = &s
+//  };
+//
+//  tSQLBinaryExprTraverse(pExpr, pSTable->pIndex, pRes, &supp);
+//  tExprTreeDestroy(&pExpr, tSQLListTraverseDestroyInfo);
+//
+//  tansformQueryResult(pRes);
   
   return TSDB_CODE_SUCCESS;
 }
diff --git a/tests/examples/c/demo.c b/tests/examples/c/demo.c
index ddca1ac05d97617cdf718e5f0a2e5ed9e8c035a7..853a949162e10ae64677734d77ad7ffeec2eb3bb 100644
--- a/tests/examples/c/demo.c
+++ b/tests/examples/c/demo.c
@@ -24,44 +24,20 @@
 
 void taosMsleep(int mseconds);
 
-static int32_t doQuery(TAOS* taos, const char* sql) {
-  int32_t code = taos_query(taos, sql);
-  if (code != 0) {
-    printf("failed to execute query, reason:%s\n", taos_errstr(taos));
-    return -1;
-  }
-  
-  TAOS_RES* res = taos_use_result(taos);
-  TAOS_ROW row = NULL;
-  char buf[512] = {0};
-  
-  int32_t numOfFields = taos_num_fields(res);
-  TAOS_FIELD* pFields = taos_fetch_fields(res);
-  
-  while((row = taos_fetch_row(res)) != NULL) {
-    taos_print_row(buf, row, pFields, numOfFields);
-    printf("%s\n", buf);
-    memset(buf, 0, 512);
-  }
-  
-  taos_free_result(res);
-}
-
 int main(int argc, char *argv[]) {
   TAOS *    taos;
   char      qstr[1024];
   TAOS_RES *result;
-
+  
   // connect to server
   if (argc < 2) {
     printf("please input server-ip \n");
     return 0;
   }
-
-  taos_options(TSDB_OPTION_CONFIGDIR, "~/sec/cfg");
+  
   // init TAOS
   taos_init();
-
+  
   taos = taos_connect(argv[1], "root", "taosdata", NULL, 0);
   if (taos == NULL) {
     printf("failed to connect to server, reason:%s\n", taos_errstr(taos));
@@ -69,20 +45,6 @@ int main(int argc, char *argv[]) {
   }
   printf("success to connect to server\n");
   
-  doQuery(taos, "create database if not exists test");
-  doQuery(taos, "use test");
-  doQuery(taos, "create table if not exists tm0 (ts timestamp, k int);");
-  doQuery(taos, "insert into tm0 values(now, 1)(now+1s, 2)(now+2s, 3)(now+3s, 4);");
-  doQuery(taos, "select * from tm0;");
-//  doQuery(taos, "insert into tm01 values(now, 1)(now+1s, 2)(now+2s, 3)(now+3s, 4);");
-//  doQuery(taos, "insert into tm0 values(now, 1)(now+1s, 2)(now+2s, 3)(now+3s, 4);");
-//  doQuery(taos, "insert into tm0 values(now, 1)(now+1s, 2)(now+2s, 3)(now+3s, 4);");
-//  doQuery(taos, "insert into tm0 values(now, 1)(now+1s, 2)(now+2s, 3)(now+3s, 4);");
-  
-  taos_close(taos);
-  
-  getchar();
-  return 0;
   
   taos_query(taos, "drop database demo");
   if (taos_query(taos, "create database demo") != 0) {
@@ -90,19 +52,19 @@ int main(int argc, char *argv[]) {
     exit(1);
   }
   printf("success to create database\n");
-
+  
   taos_query(taos, "use demo");
-
+  
   // create table
   if (taos_query(taos, "create table m1 (ts timestamp, speed int)") != 0) {
     printf("failed to create table, reason:%s\n", taos_errstr(taos));
     exit(1);
   }
   printf("success to create table\n");
-
+  
   // sleep for one second to make sure table is created on data node
   // taosMsleep(1000);
-
+  
   // insert 10 records
   int i = 0;
   for (i = 0; i < 10; ++i) {
@@ -113,28 +75,35 @@ int main(int argc, char *argv[]) {
     //sleep(1);
   }
   printf("success to insert rows, total %d rows\n", i);
-
+  
   // query the records
   sprintf(qstr, "SELECT * FROM m1");
   if (taos_query(taos, qstr) != 0) {
     printf("failed to select, reason:%s\n", taos_errstr(taos));
     exit(1);
   }
-
+  
   result = taos_use_result(taos);
-
+  
   if (result == NULL) {
     printf("failed to get result, reason:%s\n", taos_errstr(taos));
     exit(1);
   }
-
-//  TAOS_ROW    row;
+  
+  TAOS_ROW    row;
   int         rows = 0;
   int         num_fields = taos_field_count(taos);
   TAOS_FIELD *fields = taos_fetch_fields(result);
   char        temp[256];
   
-
+  printf("select * from table, result:\n");
+  // fetch the records row by row
+  while ((row = taos_fetch_row(result))) {
+    rows++;
+    taos_print_row(temp, row, fields, num_fields);
+    printf("%s\n", temp);
+  }
+  
   taos_free_result(result);
   printf("====demo end====\n\n");
   return getchar();