What is the difference when I use the listener (@), to run a query ??

Hi

What is the difference when I use the listener ), to run a query ??,

The case is the following:

I need to make a select to view ASM, I make next connection and I have rows:

sqlplus USER / passwd DataBase

But, if I use the next string; I don't have rows.

sqlplus USER / passwd

the conections is the same user.

The script is....:

SELECT 'DATA' dum1,
       free_mb / DECODE (TYPE, 'NORMAL', 2, 'HIGH', 3, 'EXTER N', 1)
          SPACE_AVAIL,
       (total_mb - free_mb) SPACE_USED
  FROM v $ asm_diskgroup_stat
WHERE name = 'DG_OTHER_SCHEMA'
       AND (state = 'MOUNTED' OR state = 'CONNECTED');

Somebody know about this