Query related to MAX limit of VARCHAR2

Question

Hello,
I have run the below PL/SQL block and it gives out the o/p as follows:
DECLARE
  LEN1  NUMBER;
BEGIN
  SELECT LENGTH(RPAD('*', 32760, '*')) INTO LEN1 FROM DUAL;
  DBMS_OUTPUT.PUT_LINE('LEN1: '||LEN1);
END; Output--> LEN1: 4000
But why is it that when i run the same PL/SQL block by assigning the 32K character string to a variable it throws an error -
DECLARE
  LEN1  NUMBER;
  STR   VARCHAR2(32767);
BEGIN
  STR := RPAD('*', 32760, '*');
  SELECT LENGTH(STR) INTO LEN1 FROM DUAL;
  DBMS_OUTPUT.PUT_LINE('LEN1: '||LEN1);
END;  Output-->
ORA-01460: unimplemented or unreasonable conversion requested
ORA-06512: at line 8
I understand that VARCHAR2 has a limit of 4000 chars in SQL and 32767 chars in PL/SQL. If so, why not the second block atleast return 4000 going with this limitation?
Regards,
Sujana

Answer 1

Hi,
Maximum size for VARCHAR2 is 4000. So you cant add 32767 characters to a variable which you have defined with VARCHAR2 datatype.
Below will work
DECLARE
  LEN1  NUMBER;
  STR   VARCHAR2(32767);
BEGIN
  STR := RPAD('*', 4000, '*');
  SELECT LENGTH(STR) INTO LEN1 FROM DUAL;
  DBMS_OUTPUT.PUT_LINE('LEN1: '||LEN1);
END;Thanks,
Suri
Edited by: Suri on Aug 8, 2012 1:50 PM
Edited by: Suri on Aug 8, 2012 1:52 PM