diff --git a/src/client/src/tscParseLineProtocol.c b/src/client/src/tscParseLineProtocol.c
index 43509d3533ebfa3143a7bb43c7e4953132e4474b..25438ef9404b8ec4e2d86383303d1e5312e06c49 100644
--- a/src/client/src/tscParseLineProtocol.c
+++ b/src/client/src/tscParseLineProtocol.c
@@ -371,6 +371,11 @@ static int32_t applySchemaAction(TAOS* taos, SSchemaAction* action, SSmlLinesInf
       buildColumnDescription(action->alterSTable.field, result+n, capacity-n, &outBytes);
       TAOS_RES* res = taos_query(taos, result); //TODO async doAsyncQuery
       code = taos_errno(res);
+      if (code == TSDB_CODE_MND_FIELD_ALREAY_EXIST) {
+        TAOS_RES* res2 = taos_query(taos, "RESET QUERY CACHE");
+        code = taos_errno(res2);
+        taos_free_result(res2);
+      }
       taos_free_result(res);
       break;
     }
@@ -380,6 +385,11 @@ static int32_t applySchemaAction(TAOS* taos, SSchemaAction* action, SSmlLinesInf
                              result+n, capacity-n, &outBytes);
       TAOS_RES* res = taos_query(taos, result); //TODO async doAsyncQuery
       code = taos_errno(res);
+      if (code == TSDB_CODE_MND_TAG_ALREAY_EXIST) {
+        TAOS_RES* res2 = taos_query(taos, "RESET QUERY CACHE");
+        code = taos_errno(res2);
+        taos_free_result(res2);
+      }
       taos_free_result(res);
       break;
     }
@@ -389,6 +399,11 @@ static int32_t applySchemaAction(TAOS* taos, SSchemaAction* action, SSmlLinesInf
                              capacity-n, &outBytes);
       TAOS_RES* res = taos_query(taos, result); //TODO async doAsyncQuery
       code = taos_errno(res);
+      if (code == TSDB_CODE_MND_INVALID_COLUMN_LENGTH) {
+        TAOS_RES* res2 = taos_query(taos, "RESET QUERY CACHE");
+        code = taos_errno(res2);
+        taos_free_result(res2);
+      }
       taos_free_result(res);
       break;
     }
@@ -398,6 +413,11 @@ static int32_t applySchemaAction(TAOS* taos, SSchemaAction* action, SSmlLinesInf
                              capacity-n, &outBytes);
       TAOS_RES* res = taos_query(taos, result); //TODO async doAsyncQuery
       code = taos_errno(res);
+      if (code == TSDB_CODE_MND_INVALID_TAG_LENGTH) {
+        TAOS_RES* res2 = taos_query(taos, "RESET QUERY CACHE");
+        code = taos_errno(res2);
+        taos_free_result(res2);
+      }
       taos_free_result(res);
       break;
     }
@@ -427,6 +447,11 @@ static int32_t applySchemaAction(TAOS* taos, SSchemaAction* action, SSmlLinesInf
       outBytes = snprintf(pos, freeBytes, ")");
       TAOS_RES* res = taos_query(taos, result);
       code = taos_errno(res);
+      if (code == TSDB_CODE_MND_TABLE_ALREADY_EXIST) {
+        TAOS_RES* res2 = taos_query(taos, "RESET QUERY CACHE");
+        code = taos_errno(res2);
+        taos_free_result(res2);
+      }
       taos_free_result(res);
       break;
     }
diff --git a/src/inc/taoserror.h b/src/inc/taoserror.h
index 368658377c1a92792e9a03c039a57ddcbc5bd127..b8ccada105f96f22ac43494e6f9ddd9c69b4310d 100644
--- a/src/inc/taoserror.h
+++ b/src/inc/taoserror.h
@@ -211,6 +211,9 @@ int32_t* taosGetErrno();
 #define TSDB_CODE_DND_TOO_MANY_VNODES           TAOS_DEF_ERROR_CODE(0, 0x0405)  //"Too many vnode directories")
 #define TSDB_CODE_DND_EXITING                   TAOS_DEF_ERROR_CODE(0, 0x0406)  //"Dnode is exiting"
 
+#define TSDB_CODE_MND_INVALID_TAG_LENGTH        TAOS_DEF_ERROR_CODE(0, 0x410)  //"invalid tag length")
+#define TSDB_CODE_MND_INVALID_COLUMN_LENGTH     TAOS_DEF_ERROR_CODE(0, 0x411)   //"invalid column length")
+
 // vnode
 #define TSDB_CODE_VND_ACTION_IN_PROGRESS        TAOS_DEF_ERROR_CODE(0, 0x0500)  //"Action in progress")
 #define TSDB_CODE_VND_MSG_NOT_PROCESSED         TAOS_DEF_ERROR_CODE(0, 0x0501)  //"Message not processed")
diff --git a/src/mnode/src/mnodeTable.c b/src/mnode/src/mnodeTable.c
index 0bc114ffdfe8d59f4941536b56bd95be96a03d0b..39a21a6747ef77999cd474cf04b5e6c3ae0417aa 100644
--- a/src/mnode/src/mnodeTable.c
+++ b/src/mnode/src/mnodeTable.c
@@ -1519,6 +1519,13 @@ static int32_t mnodeChangeSuperTableColumn(SMnodeMsg *pMsg) {
   SSchema *schema = (SSchema *) (pStable->schema + col);
   ASSERT(schema->type == TSDB_DATA_TYPE_BINARY || schema->type == TSDB_DATA_TYPE_NCHAR);
   schema->bytes = pAlter->schema[0].bytes;
+
+  if (pAlter->schema[0].bytes <= schema->bytes) {
+    mError("msg:%p, app:%p stable:%s, modify column len. column:%s, len from %d to %d", pMsg, pMsg->rpcMsg.ahandle,
+           pStable->info.tableId, name, schema->bytes, pAlter->schema[0].bytes);
+    return TSDB_CODE_MND_INVALID_COLUMN_LENGTH;
+  }
+
   pStable->sversion++;
   mInfo("msg:%p, app:%p stable %s, start to modify column %s len to %d", pMsg, pMsg->rpcMsg.ahandle, pStable->info.tableId,
          name, schema->bytes);
@@ -1548,6 +1555,12 @@ static int32_t mnodeChangeSuperTableTag(SMnodeMsg *pMsg) {
   // update
   SSchema *schema = (SSchema *) (pStable->schema + col + pStable->numOfColumns);
   ASSERT(schema->type == TSDB_DATA_TYPE_BINARY || schema->type == TSDB_DATA_TYPE_NCHAR);
+  if (pAlter->schema[0].bytes <= schema->bytes) {
+    mError("msg:%p, app:%p stable:%s, modify tag len. tag:%s, len from %d to %d", pMsg, pMsg->rpcMsg.ahandle,
+           pStable->info.tableId, name, schema->bytes, pAlter->schema[0].bytes);
+    return TSDB_CODE_MND_INVALID_TAG_LENGTH;
+  }
+
   schema->bytes = pAlter->schema[0].bytes;
   pStable->tversion++;
   mInfo("msg:%p, app:%p stable %s, start to modify tag len %s to %d", pMsg, pMsg->rpcMsg.ahandle, pStable->info.tableId,