The default buffer sizes depend on the oracle version. In the above case the limit was 2000 bytes.

You can increase the buffer size up to 1,000,000.

Pl/SQL:  DBMS_OUTPUT.ENABLE(100000)

SQL*Plus: set serveroutput on size 1000000

 

From Oracle 10g, it is possible to make the buffer size unlimited:

PL/SQL: DBMS_OUTPUT.ENABLE (buffer_size => NULL);

SQL*Plus: set serveroutput on size unlimited

 

 set serveroutput on setting is now equivalent to set serveroutput on size unlimited

Example:

Problem:

set serveroutput on

BEGIN
     FOR i IN 1 .. ((1000000/32767)+1) LOOP
        DBMS_OUTPUT.PUT_LINE( RPAD('x',32767,'x') );
     END LOOP;
  END;
  /

 

ORA-20000: ORU-10027: buffer overflow, limit of 20000 bytes

ORA-06512: at "SYS.DBMS_OUTPUT", line 32

ORA-06512: at "SYS.DBMS_OUTPUT", line 97

ORA-06512: at "SYS.DBMS_OUTPUT", line 112

ORA-06512: at line 3

Solution:

SQL*Plus:

set serveroutput on

or

set serverout on size unlimited

BEGIN

     FOR i IN 1 .. ((10000000/32767)+1) LOOP

        DBMS_OUTPUT.PUT_LINE( RPAD('X',32760,'X') );

     END LOOP;

  END;

  /

 

PL/SQL:

set serveroutput on

 

BEGIN

 DBMS_OUTPUT.ENABLE (buffer_size => NULL);

     FOR i IN 1 .. ((10000000/32767)+1) LOOP

        DBMS_OUTPUT.PUT_LINE( RPAD('X',32760,'X') );

     END LOOP;

  END;

  /

 If the solution does not work please check your oracle version and the client support this features or not.