diff --git a/src/client/src/tscFunctionImpl.c b/src/client/src/tscFunctionImpl.c
index caaedca1f2..9995f94dbe 100644
--- a/src/client/src/tscFunctionImpl.c
+++ b/src/client/src/tscFunctionImpl.c
@@ -2965,14 +2965,28 @@ static void tag_project_function(SQLFunctionCtx *pCtx) {
   assert(pCtx->inputBytes == pCtx->outputBytes);
   
   for (int32_t i = 0; i < pCtx->size; ++i) {
-    tVariantDump(&pCtx->tag, pCtx->aOutputBuf, pCtx->outputType);
+    char* output = pCtx->aOutputBuf;
+  
+    if (pCtx->tag.nType == TSDB_DATA_TYPE_BINARY || pCtx->tag.nType == TSDB_DATA_TYPE_NCHAR) {
+      *(int16_t*) output = pCtx->tag.nLen;
+      output += VARSTR_HEADER_SIZE;
+    }
+    
+    tVariantDump(&pCtx->tag, output, pCtx->outputType);
     pCtx->aOutputBuf += pCtx->outputBytes;
   }
 }
 
 static void tag_project_function_f(SQLFunctionCtx *pCtx, int32_t index) {
   INC_INIT_VAL(pCtx, 1);
-  tVariantDump(&pCtx->tag, pCtx->aOutputBuf, pCtx->tag.nType);
+  
+  char* output = pCtx->aOutputBuf;
+  if (pCtx->tag.nType == TSDB_DATA_TYPE_BINARY || pCtx->tag.nType == TSDB_DATA_TYPE_NCHAR) {
+    *(int16_t*) output = pCtx->tag.nLen;
+    output += VARSTR_HEADER_SIZE;
+  }
+  
+  tVariantDump(&pCtx->tag, output, pCtx->tag.nType);
   pCtx->aOutputBuf += pCtx->outputBytes;
 }
 
@@ -3007,7 +3021,8 @@ static void tag_function_f(SQLFunctionCtx *pCtx, int32_t index) {
     *(int16_t*) output = pCtx->tag.nLen;
     output += VARSTR_HEADER_SIZE;
   }
-  tVariantDump(&pCtx->tag, pCtx->aOutputBuf, pCtx->tag.nType);
+  
+  tVariantDump(&pCtx->tag, output, pCtx->tag.nType);
 }
 
 static void copy_function(SQLFunctionCtx *pCtx) {
diff --git a/src/client/src/tscSQLParser.c b/src/client/src/tscSQLParser.c
index cf4aa3a50d..e23086c4e7 100644
--- a/src/client/src/tscSQLParser.c
+++ b/src/client/src/tscSQLParser.c
@@ -5132,7 +5132,7 @@ static int32_t doAddGroupbyColumnsOnDemand(SQueryInfo* pQueryInfo) {
     int16_t colIndex = pColIndex->colIndex;
     if (colIndex == TSDB_TBNAME_COLUMN_INDEX) {
       type = TSDB_DATA_TYPE_BINARY;
-      bytes = TSDB_TABLE_NAME_LEN;
+      bytes = TSDB_TABLE_NAME_LEN + VARSTR_HEADER_SIZE; // todo extract method
       name = TSQL_TBNAME_L;
     } else {
       if (TSDB_COL_IS_TAG(pColIndex->flag)) {
diff --git a/src/client/src/tscUtil.c b/src/client/src/tscUtil.c
index d07185b0ba..4844ab3db8 100644
--- a/src/client/src/tscUtil.c
+++ b/src/client/src/tscUtil.c
@@ -2134,7 +2134,7 @@ char* tscGetResultColumnChr(SSqlRes* pRes, SQueryInfo* pQueryInfo, int32_t colum
   if (type == TSDB_DATA_TYPE_NCHAR || type == TSDB_DATA_TYPE_BINARY) {
     int32_t realLen = varDataLen(pData);
     if (realLen < pInfo->pSqlExpr->resBytes - VARSTR_HEADER_SIZE) { // todo refactor
-      *(char*) (pData + realLen + sizeof(int16_t)) = 0;
+      *(char*) (pData + realLen + VARSTR_HEADER_SIZE) = 0;
     }
     
     return pData + VARSTR_HEADER_SIZE; // head is the length of binary/nchar data
diff --git a/src/mnode/src/mgmtUser.c b/src/mnode/src/mgmtUser.c
index 787459d667..b4dd58cb3b 100644
--- a/src/mnode/src/mgmtUser.c
+++ b/src/mnode/src/mgmtUser.c
@@ -20,6 +20,7 @@
 #include "tutil.h"
 #include "tglobal.h"
 #include "tgrant.h"
+#include "tdataformat.h"
 #include "dnode.h"
 #include "mgmtDef.h"
 #include "mgmtLog.h"
@@ -256,13 +257,13 @@ static int32_t mgmtGetUserMeta(STableMetaMsg *pMeta, SShowObj *pShow, void *pCon
   int32_t cols = 0;
   SSchema *pSchema = pMeta->schema;
 
-  pShow->bytes[cols] = TSDB_USER_LEN;
+  pShow->bytes[cols] = TSDB_USER_LEN + VARSTR_HEADER_SIZE;
   pSchema[cols].type = TSDB_DATA_TYPE_BINARY;
   strcpy(pSchema[cols].name, "name");
   pSchema[cols].bytes = htons(pShow->bytes[cols]);
   cols++;
 
-  pShow->bytes[cols] = 6;
+  pShow->bytes[cols] = 8 + VARSTR_HEADER_SIZE;
   pSchema[cols].type = TSDB_DATA_TYPE_BINARY;
   strcpy(pSchema[cols].name, "privilege");
   pSchema[cols].bytes = htons(pShow->bytes[cols]);
@@ -270,7 +271,7 @@ static int32_t mgmtGetUserMeta(STableMetaMsg *pMeta, SShowObj *pShow, void *pCon
 
   pShow->bytes[cols] = 8;
   pSchema[cols].type = TSDB_DATA_TYPE_TIMESTAMP;
-  strcpy(pSchema[cols].name, "create time");
+  strcpy(pSchema[cols].name, "create_time");
   pSchema[cols].bytes = htons(pShow->bytes[cols]);
   cols++;
 
@@ -303,16 +304,16 @@ static int32_t mgmtRetrieveUsers(SShowObj *pShow, char *data, int32_t rows, void
     cols = 0;
 
     pWrite = data + pShow->offset[cols] * rows + pShow->bytes[cols] * numOfRows;
-    strcpy(pWrite, pUser->user);
+    STR_WITH_MAXSIZE_TO_VARSTR(pWrite, pUser->user, TSDB_USER_LEN);
     cols++;
 
     pWrite = data + pShow->offset[cols] * rows + pShow->bytes[cols] * numOfRows;
     if (pUser->superAuth) {
-      strcpy(pWrite, "super");
+      STR_WITH_SIZE_TO_VARSTR(pWrite, "super", 5);
     } else if (pUser->writeAuth) {
-      strcpy(pWrite, "write");
+      STR_WITH_SIZE_TO_VARSTR(pWrite, "writable", 8);
     } else {
-      strcpy(pWrite, "read");
+      STR_WITH_SIZE_TO_VARSTR(pWrite, "readable", 8);
     }
     cols++;
 
diff --git a/src/mnode/src/mgmtVgroup.c b/src/mnode/src/mgmtVgroup.c
index d8007d000d..2162230606 100644
--- a/src/mnode/src/mgmtVgroup.c
+++ b/src/mnode/src/mgmtVgroup.c
@@ -23,6 +23,7 @@
 #include "ttime.h"
 #include "tbalance.h"
 #include "tglobal.h"
+#include "tdataformat.h"
 #include "mgmtDef.h"
 #include "mgmtLog.h"
 #include "mgmtDb.h"
@@ -374,9 +375,9 @@ int32_t mgmtGetVgroupMeta(STableMetaMsg *pMeta, SShowObj *pShow, void *pConn) {
   pSchema[cols].bytes = htons(pShow->bytes[cols]);
   cols++;
 
-  pShow->bytes[cols] = 9;
+  pShow->bytes[cols] = 9 + VARSTR_HEADER_SIZE;
   pSchema[cols].type = TSDB_DATA_TYPE_BINARY;
-  strcpy(pSchema[cols].name, "vgroup status");
+  strcpy(pSchema[cols].name, "vgroup_status");
   pSchema[cols].bytes = htons(pShow->bytes[cols]);
   cols++;
 
@@ -409,13 +410,13 @@ int32_t mgmtGetVgroupMeta(STableMetaMsg *pMeta, SShowObj *pShow, void *pConn) {
     pSchema[cols].bytes = htons(pShow->bytes[cols]);
     cols++;
 
-    pShow->bytes[cols] = 40;
+    pShow->bytes[cols] = 40 + VARSTR_HEADER_SIZE;
     pSchema[cols].type = TSDB_DATA_TYPE_BINARY;
-    strcpy(pSchema[cols].name, "end point");
+    strcpy(pSchema[cols].name, "end_point");
     pSchema[cols].bytes = htons(pShow->bytes[cols]);
     cols++;
 
-    pShow->bytes[cols] = 9;
+    pShow->bytes[cols] = 9 + VARSTR_HEADER_SIZE;
     pSchema[cols].type = TSDB_DATA_TYPE_BINARY;
     strcpy(pSchema[cols].name, "vstatus");
     pSchema[cols].bytes = htons(pShow->bytes[cols]);
@@ -475,7 +476,8 @@ int32_t mgmtRetrieveVgroups(SShowObj *pShow, char *data, int32_t rows, void *pCo
     cols++;
 
     pWrite = data + pShow->offset[cols] * rows + pShow->bytes[cols] * numOfRows;
-    strcpy(pWrite, pVgroup->status ? "updating" : "ready");
+    char* status = pVgroup->status? "updating" : "ready";
+    STR_TO_VARSTR(pWrite, status);
     cols++;
 
     for (int32_t i = 0; i < maxReplica; ++i) {
@@ -487,18 +489,20 @@ int32_t mgmtRetrieveVgroups(SShowObj *pShow, char *data, int32_t rows, void *pCo
 
       if (pDnode != NULL) {
         pWrite = data + pShow->offset[cols] * rows + pShow->bytes[cols] * numOfRows;
-        strncpy(pWrite, pDnode->dnodeEp, pShow->bytes[cols]-1);
+        STR_WITH_MAXSIZE_TO_VARSTR(pWrite, pDnode->dnodeEp, pShow->bytes[cols] - VARSTR_HEADER_SIZE);
         cols++;
 
         pWrite = data + pShow->offset[cols] * rows + pShow->bytes[cols] * numOfRows;
-        strcpy(pWrite, mgmtGetMnodeRoleStr(pVgroup->vnodeGid[i].role));
+        status = mgmtGetMnodeRoleStr(pVgroup->vnodeGid[i].role);
+        STR_TO_VARSTR(pWrite, status);
         cols++;
       } else {
         pWrite = data + pShow->offset[cols] * rows + pShow->bytes[cols] * numOfRows;
-        strcpy(pWrite, "null");
+        STR_WITH_SIZE_TO_VARSTR(pWrite, "NULL", 4);
         cols++;
+        
         pWrite = data + pShow->offset[cols] * rows + pShow->bytes[cols] * numOfRows;
-        strcpy(pWrite, "null");
+        STR_WITH_SIZE_TO_VARSTR(pWrite, "NULL", 4);
         cols++;
       }
     }
diff --git a/src/query/src/queryExecutor.c b/src/query/src/queryExecutor.c
index ed0da791dc..e8abe9d819 100644
--- a/src/query/src/queryExecutor.c
+++ b/src/query/src/queryExecutor.c
@@ -1427,7 +1427,7 @@ static int32_t setupQueryRuntimeEnv(SQueryRuntimeEnv *pRuntimeEnv, int16_t order
     int32_t index = pSqlFuncMsg->colInfo.colIndex;
     if (TSDB_COL_IS_TAG(pIndex->flag)) {
       if (pIndex->colId == TSDB_TBNAME_COLUMN_INDEX) {
-        pCtx->inputBytes = TSDB_TABLE_NAME_LEN;
+        pCtx->inputBytes = TSDB_TABLE_NAME_LEN + VARSTR_HEADER_SIZE;
         pCtx->inputType = TSDB_DATA_TYPE_BINARY;
       } else {
         pCtx->inputBytes = pQuery->tagColList[index].bytes;
@@ -5528,7 +5528,7 @@ static int32_t createSqlFunctionExprFromMsg(SQueryTableMsg *pQueryMsg, SExprInfo
       bytes = tDataTypeDesc[type].nSize;
     } else if (pExprs[i].base.colInfo.colId == TSDB_TBNAME_COLUMN_INDEX) {  // parse the normal column
       type  = TSDB_DATA_TYPE_BINARY;
-      bytes = TSDB_TABLE_NAME_LEN;
+      bytes = TSDB_TABLE_NAME_LEN + VARSTR_HEADER_SIZE;
     } else{
       int32_t j = getColumnIndexInSource(pQueryMsg, &pExprs[i].base, pTagCols);
       assert(j < pQueryMsg->numOfCols || j < pQueryMsg->numOfTags);