private static boolean isRename(EnvironmentContext environmentContext) {
    if (environmentContext.isSetProperties()) {
      String operation = environmentContext.getProperties().get(HiveMetaHook.ALTER_TABLE_OPERATION_TYPE);
      return operation != null && AlterTableType.RENAME == AlterTableType.valueOf(operation);
    }
    return false;
  }
Updates the existing table metadata with the new metadata.

@param fullyQlfdTblName
         name of the existing table
@param newTbl
         new name of the table. could be the old name
@param transactional
         Need to generate and save a table snapshot into the metastore?
@throws HiveException
ql/src/java/org/apache/hadoop/hive/ql/metadata/Hive.java