Error when altering table not in default database

[sky88088]

Hi all,        I encounter error when I was trying to alter a table not in 
default database.
        The command I type is        alter table db1.table_A drop partition 
(id=1);                Error info is        FAILED: ParseException line 2:12 
cannot recognize input near 'db1' '.' 'table_A' in alter table statement        
            Is this a bug of hive? Any suggestions about how to solve it?
 Best Regards,ypg