diff --git a/src/client/inc/tsclient.h b/src/client/inc/tsclient.h
index d60c6756d68ad2bc5d6cba0a0ea3e97beb5cdd25..6b6b8a23c60539d52985b1f4a58a9267036d6335 100644
--- a/src/client/inc/tsclient.h
+++ b/src/client/inc/tsclient.h
@@ -184,6 +184,7 @@ typedef struct {
   uint32_t     allocSize;
   char *       payload;
   int32_t      payloadLen;
+  void *       pBuf;               // table meta buffer
 
   SHashObj    *pTableMetaMap;  // local buffer to keep the queried table meta, before validating the AST
   SQueryInfo  *pQueryInfo;
@@ -273,7 +274,6 @@ typedef struct SSqlObj {
   void *           pStream;
   void *           pSubscription;
   char *           sqlstr;
-  void *           pBuf;         // tableMeta buffer
   char             parseRetry;
   char             retry;
   char             maxRetry;
diff --git a/src/client/src/tscSQLParser.c b/src/client/src/tscSQLParser.c
index 13fd9a8092642a2b727f61e56e35572ee3ebdb0e..18d17e9016555970eec8aa2091f10e97069d8fa8 100644
--- a/src/client/src/tscSQLParser.c
+++ b/src/client/src/tscSQLParser.c
@@ -7697,8 +7697,8 @@ int32_t loadAllTableMeta(SSqlObj* pSql, struct SSqlInfo* pInfo) {
   char     name[TSDB_TABLE_FNAME_LEN] = {0};
 
   assert(maxSize < 80 * TSDB_MAX_COLUMNS);
-  if (!pSql->pBuf) {
-    if (NULL == (pSql->pBuf = tcalloc(1, 80 * TSDB_MAX_COLUMNS))) {
+  if (!pSql->cmd.pBuf) {
+    if (NULL == (pSql->cmd.pBuf = tcalloc(1, 80 * TSDB_MAX_COLUMNS))) {
       return TSDB_CODE_TSC_OUT_OF_MEMORY;
     }
   }
@@ -7718,7 +7718,7 @@ int32_t loadAllTableMeta(SSqlObj* pSql, struct SSqlInfo* pInfo) {
 
     if (pTableMeta->id.uid > 0) {
       if (pTableMeta->tableType == TSDB_CHILD_TABLE) {
-        code = tscCreateTableMetaFromSTableMeta(pTableMeta, name, pSql->pBuf);
+        code = tscCreateTableMetaFromSTableMeta(pTableMeta, name, pSql->cmd.pBuf);
 
         // create the child table meta from super table failed, try load it from mnode
         if (code != TSDB_CODE_SUCCESS) {
diff --git a/src/client/src/tscServer.c b/src/client/src/tscServer.c
index 223c03b108ae26491e92184cb644f8e8466d2f0f..2f469a382853e4415222fdf7533a70e68d157e72 100644
--- a/src/client/src/tscServer.c
+++ b/src/client/src/tscServer.c
@@ -2596,8 +2596,8 @@ int32_t tscGetTableMetaImpl(SSqlObj* pSql, STableMetaInfo *pTableMetaInfo, bool
 
   // TODO resize the tableMeta
   assert(size < 80 * TSDB_MAX_COLUMNS);
-  if (!pSql->pBuf) {
-    if (NULL == (pSql->pBuf = tcalloc(1, 80 * TSDB_MAX_COLUMNS))) {
+  if (!pSql->cmd.pBuf) {
+    if (NULL == (pSql->cmd.pBuf = tcalloc(1, 80 * TSDB_MAX_COLUMNS))) {
       return TSDB_CODE_TSC_OUT_OF_MEMORY;
     }
   }
@@ -2606,7 +2606,7 @@ int32_t tscGetTableMetaImpl(SSqlObj* pSql, STableMetaInfo *pTableMetaInfo, bool
   if (pMeta->id.uid > 0) {
     // in case of child table, here only get the
     if (pMeta->tableType == TSDB_CHILD_TABLE) {
-      int32_t code = tscCreateTableMetaFromSTableMeta(pTableMetaInfo->pTableMeta, name, pSql->pBuf);
+      int32_t code = tscCreateTableMetaFromSTableMeta(pTableMetaInfo->pTableMeta, name, pSql->cmd.pBuf);
       if (code != TSDB_CODE_SUCCESS) {
         return getTableMetaFromMnode(pSql, pTableMetaInfo, autocreate);
       }
diff --git a/src/client/src/tscUtil.c b/src/client/src/tscUtil.c
index 2e0d5c7d8a7bda6e3dc79441a99ddac64bb5a1f3..bf997f3cbb7df27265fe741f5c957301bf644f11 100644
--- a/src/client/src/tscUtil.c
+++ b/src/client/src/tscUtil.c
@@ -1450,7 +1450,6 @@ void tscFreeSqlObj(SSqlObj* pSql) {
   pSql->signature = NULL;
   pSql->fp = NULL;
   tfree(pSql->sqlstr);
-  tfree(pSql->pBuf);
 
   tfree(pSql->pSubs);
   pSql->subState.numOfSub = 0;
@@ -1461,8 +1460,9 @@ void tscFreeSqlObj(SSqlObj* pSql) {
 
   memset(pCmd->payload, 0, (size_t)pCmd->allocSize);
   tfree(pCmd->payload);
+  tfree(pCmd->pBuf);
   pCmd->allocSize = 0;
-  
+
   tsem_destroy(&pSql->rspSem);
   memset(pSql, 0, sizeof(*pSql));
   free(pSql);
diff --git a/src/common/src/ttypes.c b/src/common/src/ttypes.c
index 34dda32401b604450b3179cf0f344f53b6e2cb51..24789d01ad79e4ea448616f51edc748b1ac03975 100644
--- a/src/common/src/ttypes.c
+++ b/src/common/src/ttypes.c
@@ -515,7 +515,7 @@ static void *nullValues[] = {
     &nullTinyIntu, &nullSmallIntu, &nullIntu,     &nullBigIntu,
 };
 
-void *getNullValue(int32_t type) {
+const void *getNullValue(int32_t type) {
   assert(type >= TSDB_DATA_TYPE_BOOL && type <= TSDB_DATA_TYPE_UBIGINT);
   return nullValues[type - 1];
 }
diff --git a/src/cq/src/cqMain.c b/src/cq/src/cqMain.c
index cd762f311075e7d315cf3ad9811056a909be50dc..b45234901b3f6d9c012ecb053e828df0cfb8a0eb 100644
--- a/src/cq/src/cqMain.c
+++ b/src/cq/src/cqMain.c
@@ -492,7 +492,7 @@ static void cqProcessStreamRes(void *param, TAOS_RES *tres, TAOS_ROW row) {
     STColumn *c = pSchema->columns + i;
     void* val = row[i];
     if (val == NULL) {
-      val = getNullValue(c->type);
+      val = (void *)getNullValue(c->type);
     } else if (c->type == TSDB_DATA_TYPE_BINARY) {
       val = ((char*)val) - sizeof(VarDataLenT);
     } else if (c->type == TSDB_DATA_TYPE_NCHAR) {
diff --git a/src/inc/taosdef.h b/src/inc/taosdef.h
index f5be879878f5384dc6805fa4c2be6de77f243a90..0caf204baf37431809f3752143cbd5afdb189376 100644
--- a/src/inc/taosdef.h
+++ b/src/inc/taosdef.h
@@ -329,8 +329,9 @@ do { \
 #define TSDB_MAX_JOIN_TABLE_NUM         10
 #define TSDB_MAX_UNION_CLAUSE           5
 
-#define TSDB_MAX_BINARY_LEN            (16384-TSDB_KEYSIZE) // keep 16384
-#define TSDB_MAX_NCHAR_LEN             (16384-TSDB_KEYSIZE) // keep 16384
+#define TSDB_MAX_FIELD_LEN              16384
+#define TSDB_MAX_BINARY_LEN            (TSDB_MAX_FIELD_LEN-TSDB_KEYSIZE) // keep 16384
+#define TSDB_MAX_NCHAR_LEN             (TSDB_MAX_FIELD_LEN-TSDB_KEYSIZE) // keep 16384
 #define PRIMARYKEY_TIMESTAMP_COL_INDEX  0
 
 #define TSDB_MAX_RPC_THREADS            5
diff --git a/src/inc/ttype.h b/src/inc/ttype.h
index 2581589563fc9e7ec6a6aaea222ad9971535eeab..d0266d6a5c4cd11bb3f53bf5df4557e2125e21b3 100644
--- a/src/inc/ttype.h
+++ b/src/inc/ttype.h
@@ -178,7 +178,7 @@ bool isValidDataType(int32_t type);
 void  setVardataNull(char* val, int32_t type);
 void  setNull(char *val, int32_t type, int32_t bytes);
 void  setNullN(char *val, int32_t type, int32_t bytes, int32_t numOfElems);
-void *getNullValue(int32_t type);
+const void *getNullValue(int32_t type);
 
 void assignVal(char *val, const char *src, int32_t len, int32_t type);
 void tsDataSwap(void *pLeft, void *pRight, int32_t type, int32_t size, void* buf);
diff --git a/src/tsdb/src/tsdbMeta.c b/src/tsdb/src/tsdbMeta.c
index 621be04e216683681f276ff6181a34ffc3613ba4..b599e38e3af18e6448599c1b7424508cd51cec4b 100644
--- a/src/tsdb/src/tsdbMeta.c
+++ b/src/tsdb/src/tsdbMeta.c
@@ -787,7 +787,7 @@ static char *getTagIndexKey(const void *pData) {
   void *    res = tdGetKVRowValOfCol(pTable->tagVal, pCol->colId);
   if (res == NULL) {
     // treat the column as NULL if we cannot find it
-    res = getNullValue(pCol->type);
+    res = (void *)getNullValue(pCol->type);
   }
   return res;
 }