diff --git a/src/client/src/TSDBJNIConnector.c b/src/client/src/TSDBJNIConnector.c
index 459b0f2b9877e46e8428c15f30c2d246726a51e9..a9a34286a85e910b85ce754100adae3cd574b74e 100644
--- a/src/client/src/TSDBJNIConnector.c
+++ b/src/client/src/TSDBJNIConnector.c
@@ -151,8 +151,8 @@ JNIEXPORT void JNICALL Java_com_taosdata_jdbc_TSDBJNIConnector_dumpMemoryLeakImp
 JNIEXPORT void JNICALL Java_com_taosdata_jdbc_TSDBJNIConnector_initImp(JNIEnv *env, jobject jobj, jstring jconfigDir) {
   if (jconfigDir != NULL) {
     const char *confDir = (*env)->GetStringUTFChars(env, jconfigDir, NULL);
-    if (confDir && strlen(configDir) != 0) {
-      strcpy(configDir, confDir);
+    if (confDir && strlen(confDir) != 0) {
+      tstrncpy(configDir, confDir, TSDB_FILENAME_LEN);
     }
     (*env)->ReleaseStringUTFChars(env, jconfigDir, confDir);
   }
@@ -385,7 +385,7 @@ JNIEXPORT jint JNICALL Java_com_taosdata_jdbc_TSDBJNIConnector_getAffectedRowsIm
   }
 
   jint ret = taos_affected_rows((SSqlObj *)res);
-  jniTrace("jobj:%p, conn:%p, sql:%p, affect rows:%d", jobj, tscon, (void *)con, res, ret);
+  jniTrace("jobj:%p, conn:%p, sql:%p, affect rows:%d", jobj, tscon, (SSqlObj*)res, ret);
 
   return ret;
 }
@@ -411,10 +411,10 @@ JNIEXPORT jint JNICALL Java_com_taosdata_jdbc_TSDBJNIConnector_getSchemaMetaData
   // jobject arrayListObj = (*env)->NewObject(env, g_arrayListClass, g_arrayListConstructFp, "");
 
   if (num_fields == 0) {
-    jniError("jobj:%p, conn:%p, resultset:%p, fields size is %d", jobj, tscon, res, num_fields);
+    jniError("jobj:%p, conn:%p, resultset:%p, fields size is %d", jobj, tscon, (void*)res, num_fields);
     return JNI_NUM_OF_FIELDS_0;
   } else {
-    jniTrace("jobj:%p, conn:%p, resultset:%p, fields size is %d", jobj, tscon, res, num_fields);
+    jniTrace("jobj:%p, conn:%p, resultset:%p, fields size is %d", jobj, tscon, (void*)res, num_fields);
     for (int i = 0; i < num_fields; ++i) {
       jobject metadataObj = (*env)->NewObject(env, g_metadataClass, g_metadataConstructFp);
       (*env)->SetIntField(env, metadataObj, g_metadataColtypeField, fields[i].type);
@@ -465,7 +465,7 @@ JNIEXPORT jint JNICALL Java_com_taosdata_jdbc_TSDBJNIConnector_fetchRowImp(JNIEn
   int         num_fields = taos_num_fields(result);
 
   if (num_fields == 0) {
-    jniError("jobj:%p, conn:%p, resultset:%p, fields size is %d", jobj, tscon, res, num_fields);
+    jniError("jobj:%p, conn:%p, resultset:%p, fields size is %d", jobj, tscon, (void*)res, num_fields);
     return JNI_NUM_OF_FIELDS_0;
   }
 
@@ -473,7 +473,7 @@ JNIEXPORT jint JNICALL Java_com_taosdata_jdbc_TSDBJNIConnector_fetchRowImp(JNIEn
   if (row == NULL) {
     int tserrno = taos_errno(result);
     if (tserrno == 0) {
-      jniTrace("jobj:%p, conn:%p, resultset:%p, fields size is %d, fetch row to the end", jobj, tscon, res, num_fields);
+      jniTrace("jobj:%p, conn:%p, resultset:%p, fields size is %d, fetch row to the end", jobj, tscon, (void*)res, num_fields);
       return JNI_FETCH_END;
     } else {
       jniTrace("jobj:%p, conn:%p, interruptted query", jobj, tscon);
@@ -571,9 +571,9 @@ JNIEXPORT jlong JNICALL Java_com_taosdata_jdbc_TSDBJNIConnector_subscribeImp(JNI
   sub = (jlong)tsub;
 
   if (sub == 0) {
-    jniTrace("jobj:%p, failed to subscribe: topic:%s", jobj, jtopic);
+    jniTrace("jobj:%p, failed to subscribe: topic:%s", jobj, topic);
   } else {
-    jniTrace("jobj:%p, successfully subscribe: topic: %s", jobj, jtopic);
+    jniTrace("jobj:%p, successfully subscribe: topic: %s", jobj, topic);
   }
 
   if (topic != NULL) (*env)->ReleaseStringUTFChars(env, jtopic, topic);
@@ -583,7 +583,7 @@ JNIEXPORT jlong JNICALL Java_com_taosdata_jdbc_TSDBJNIConnector_subscribeImp(JNI
 }
 
 JNIEXPORT jlong JNICALL Java_com_taosdata_jdbc_TSDBJNIConnector_consumeImp(JNIEnv *env, jobject jobj, jlong sub) {
-  jniTrace("jobj:%p, in TSDBJNIConnector_consumeImp, sub:%ld", jobj, sub);
+  jniTrace("jobj:%p, in TSDBJNIConnector_consumeImp, sub:%" PRId64, jobj, sub);
   jniGetGlobalMethod(env);
 
   TAOS_SUB *tsub = (TAOS_SUB *)sub;
diff --git a/src/client/src/tscAsync.c b/src/client/src/tscAsync.c
index f4fad427192f155b957ad339471ea2bd19bc0db1..770f3286340b58a8eb6b9481a2fb17e4c393c5ac 100644
--- a/src/client/src/tscAsync.c
+++ b/src/client/src/tscAsync.c
@@ -285,7 +285,7 @@ void taos_fetch_row_a(TAOS_RES *taosa, void (*fp)(void *, TAOS_RES *, TAOS_ROW),
     
     tscProcessSql(pSql);
   } else {
-    SSchedMsg schedMsg;
+    SSchedMsg schedMsg = { 0 };
     schedMsg.fp = tscProcessFetchRow;
     schedMsg.ahandle = pSql;
     schedMsg.thandle = pRes->tsrow;
@@ -387,7 +387,7 @@ void tscQueueAsyncError(void(*fp), void *param, int32_t code) {
   int32_t* c = malloc(sizeof(int32_t));
   *c = code;
   
-  SSchedMsg schedMsg;
+  SSchedMsg schedMsg = { 0 };
   schedMsg.fp = tscProcessAsyncError;
   schedMsg.ahandle = fp;
   schedMsg.thandle = param;
@@ -403,7 +403,7 @@ void tscQueueAsyncRes(SSqlObj *pSql) {
     tscError("%p add into queued async res, code:%s", pSql, tstrerror(pSql->res.code));
   }
 
-  SSchedMsg schedMsg;
+  SSchedMsg schedMsg = { 0 };
   schedMsg.fp = tscProcessAsyncRes;
   schedMsg.ahandle = pSql;
   schedMsg.thandle = (void *)1;
@@ -420,7 +420,7 @@ void tscProcessAsyncFree(SSchedMsg *pMsg) {
 void tscQueueAsyncFreeResult(SSqlObj *pSql) {
   tscTrace("%p sqlObj put in queue to async free", pSql);
 
-  SSchedMsg schedMsg;
+  SSchedMsg schedMsg = { 0 };
   schedMsg.fp = tscProcessAsyncFree;
   schedMsg.ahandle = pSql;
   schedMsg.thandle = (void *)1;
diff --git a/src/client/src/tscFunctionImpl.c b/src/client/src/tscFunctionImpl.c
index 457e187971605a94e34cff67376657ad5a880a1a..f0be65882c2667ae21ed26e1ae09fb0c39eb2e81 100644
--- a/src/client/src/tscFunctionImpl.c
+++ b/src/client/src/tscFunctionImpl.c
@@ -1853,26 +1853,14 @@ static void last_row_function(SQLFunctionCtx *pCtx) {
 static void last_row_finalizer(SQLFunctionCtx *pCtx) {
   // do nothing at the first stage
   SResultInfo *pResInfo = GET_RES_INFO(pCtx);
-  if (pCtx->currentStage == SECONDARY_STAGE_MERGE) {
-    if (pResInfo->hasResult != DATA_SET_FLAG) {
-      if (pCtx->outputType == TSDB_DATA_TYPE_BINARY || pCtx->outputType == TSDB_DATA_TYPE_NCHAR) {
-        setVardataNull(pCtx->aOutputBuf, pCtx->outputType);
-      } else {
-        setNull(pCtx->aOutputBuf, pCtx->outputType, pCtx->outputBytes);
-      }
-      
-      return;
-    }
-  } else {
-    if (pResInfo->hasResult != DATA_SET_FLAG) {
-      if (pCtx->outputType == TSDB_DATA_TYPE_BINARY || pCtx->outputType == TSDB_DATA_TYPE_NCHAR) {
-        setVardataNull(pCtx->aOutputBuf, pCtx->outputType);
-      } else {
-        setNull(pCtx->aOutputBuf, pCtx->outputType, pCtx->outputBytes);
-      }
-      
-      return;
+  if (pResInfo->hasResult != DATA_SET_FLAG) {
+    if (pCtx->outputType == TSDB_DATA_TYPE_BINARY || pCtx->outputType == TSDB_DATA_TYPE_NCHAR) {
+      setVardataNull(pCtx->aOutputBuf, pCtx->outputType);
+    } else {
+      setNull(pCtx->aOutputBuf, pCtx->outputType, pCtx->outputBytes);
     }
+    
+    return;
   }
   
   GET_RES_INFO(pCtx)->numOfRes = 1;
diff --git a/src/client/src/tscParseInsert.c b/src/client/src/tscParseInsert.c
index afd1a3e8c881b6f89224a9b7744dbb2b179e36fa..13fc298d6ea64b4917ccaee4f2b810cf75ee20cb 100644
--- a/src/client/src/tscParseInsert.c
+++ b/src/client/src/tscParseInsert.c
@@ -252,7 +252,7 @@ int32_t tsParseOneColumnData(SSchema *pSchema, SSQLToken *pToken, char *payload,
         numType = tscToInteger(pToken, &iv, &endptr);
         if (TK_ILLEGAL == numType) {
           return tscInvalidSQLErrMsg(msg, "invalid bigint data", pToken->z);
-        } else if (errno == ERANGE || iv > INT64_MAX || iv <= INT64_MIN) {
+        } else if (errno == ERANGE || iv == INT64_MIN) {
           return tscInvalidSQLErrMsg(msg, "bigint data overflow", pToken->z);
         }
 
@@ -594,7 +594,6 @@ int32_t tscAllocateMemIfNeed(STableDataBlocks *pDataBlock, int32_t rowSize, int3
   size_t    remain = pDataBlock->nAllocSize - pDataBlock->size;
   const int factor = 5;
   uint32_t nAllocSizeOld = pDataBlock->nAllocSize;
-  assert(pDataBlock->headerSize >= 0);
   
   // expand the allocated size
   if (remain < rowSize * factor) {
diff --git a/src/client/src/tscSQLParser.c b/src/client/src/tscSQLParser.c
index db12693c2925228b9947bd650a673c9b3de994e0..110137ba5e1ca3c05b9ac2eb92e7b773aca635c9 100644
--- a/src/client/src/tscSQLParser.c
+++ b/src/client/src/tscSQLParser.c
@@ -1445,7 +1445,7 @@ static int32_t setExprInfoForFunctions(SQueryInfo* pQueryInfo, SSchema* pSchema,
   }
 
   if (aliasName != NULL) {
-    strcpy(columnName, aliasName);
+    tstrncpy(columnName, aliasName, sizeof(columnName));
   } else {
     getRevisedName(columnName, functionID, sizeof(columnName) - 1, pSchema[pColIndex->columnIndex].name);
   }
@@ -2221,7 +2221,6 @@ int32_t setShowInfo(SSqlObj* pSql, struct SSqlInfo* pInfo) {
     // db prefix in tagCond, show table conds in payload
     SSQLToken* pDbPrefixToken = &pShowInfo->prefix;
     if (pDbPrefixToken->type != 0) {
-      assert(pDbPrefixToken->n >= 0);
 
       if (pDbPrefixToken->n >= TSDB_DB_NAME_LEN) {  // db name is too long
         return invalidSqlErrMsg(tscGetErrorMsgPayload(pCmd), msg3);
@@ -4765,7 +4764,7 @@ int32_t parseLimitClause(SQueryInfo* pQueryInfo, int32_t clauseIndex, SQuerySQL*
   pQueryInfo->clauseLimit = pQueryInfo->limit.limit;
   pQueryInfo->slimit = pQuerySql->slimit;
   
-  tscTrace("%p limit:%d, offset:%" PRId64 " slimit:%d, soffset:%" PRId64, pSql, pQueryInfo->limit.limit,
+  tscTrace("%p limit:%" PRId64 ", offset:%" PRId64 " slimit:%" PRId64 ", soffset:%" PRId64, pSql, pQueryInfo->limit.limit,
       pQueryInfo->limit.offset, pQueryInfo->slimit.limit, pQueryInfo->slimit.offset);
   
   if (pQueryInfo->slimit.offset < 0 || pQueryInfo->limit.offset < 0) {
@@ -5255,10 +5254,10 @@ static int32_t doAddGroupbyColumnsOnDemand(SQueryInfo* pQueryInfo) {
 
   for (int32_t i = 0; i < pQueryInfo->groupbyExpr.numOfGroupCols; ++i) {
     SColIndex* pColIndex = taosArrayGet(pQueryInfo->groupbyExpr.columnInfo, i);
-  
+    SSchema s;
     int16_t colIndex = pColIndex->colIndex;
     if (colIndex == TSDB_TBNAME_COLUMN_INDEX) {
-      SSchema s = tGetTableNameColumnSchema();
+      s = tGetTableNameColumnSchema();
       type  = s.type;
       bytes = s.bytes;
       name  = s.name;
diff --git a/src/client/src/tscSecondaryMerge.c b/src/client/src/tscSecondaryMerge.c
index 52a06277e360a583f8e56f27fed38db741815db0..a3e860d5aaae6605a13a602cd540ad4af7057207 100644
--- a/src/client/src/tscSecondaryMerge.c
+++ b/src/client/src/tscSecondaryMerge.c
@@ -230,6 +230,7 @@ void tscCreateLocalReducer(tExtMemBuffer **pMemBuffer, int32_t numOfBuffer, tOrd
       if (ds == NULL) {
         tscError("%p failed to create merge structure", pSql);
         pRes->code = TSDB_CODE_TSC_OUT_OF_MEMORY;
+        tfree(pReducer);
         return;
       }
       
@@ -266,6 +267,7 @@ void tscCreateLocalReducer(tExtMemBuffer **pMemBuffer, int32_t numOfBuffer, tOrd
   
   // no data actually, no need to merge result.
   if (idx == 0) {
+    tfree(pReducer);
     return;
   }
 
@@ -282,6 +284,7 @@ void tscCreateLocalReducer(tExtMemBuffer **pMemBuffer, int32_t numOfBuffer, tOrd
 
   pRes->code = tLoserTreeCreate(&pReducer->pLoserTree, pReducer->numOfBuffer, param, treeComparator);
   if (pReducer->pLoserTree == NULL || pRes->code != 0) {
+    tfree(pReducer);
     return;
   }
 
@@ -325,7 +328,7 @@ void tscCreateLocalReducer(tExtMemBuffer **pMemBuffer, int32_t numOfBuffer, tOrd
     tfree(pReducer->pResultBuf);
     tfree(pReducer->pFinalRes);
     tfree(pReducer->prevRowOfInput);
-
+    tfree(pReducer);
     pRes->code = TSDB_CODE_TSC_OUT_OF_MEMORY;
     return;
   }
@@ -685,6 +688,7 @@ int32_t tscLocalReducerEnvCreate(SSqlObj *pSql, tExtMemBuffer ***pMemBuffer, tOr
 
   if (createOrderDescriptor(pOrderDesc, pCmd, pModel) != TSDB_CODE_SUCCESS) {
     pRes->code = TSDB_CODE_TSC_OUT_OF_MEMORY;
+    tfree(pSchema);
     return pRes->code;
   }