Nls_length_sematic affect on variables

Question

Hi
A simple question
Does NLS_LENGTH_SEMANTICS affect the size of VARCHAR2 variables ?
Thanks

Answer 1

Hmmmm, just a wild guess: maybe the characterset matters?
Here's what I got when running your tests:
Connected to Oracle9i Enterprise Edition Release 9.2.0.8.0
SQL> set serverout on
SQL> select * from nls_database_parameters where parameter = 'NLS_CHARACTERSET';
PARAMETER                      VALUE
NLS_CHARACTERSET               WE8ISO8859P15
SQL>
SQL> begin
  2   execute immediate 'alter session set nls_length_semantics=byte';
  3   execute immediate 'declare
  4                        v varchar2(1) := unistr(''€'');
  5                      begin
  6                        dbms_output.put_line(lengthb(v));
  7                        dbms_output.put_line(lengthb(unistr(''€'')));
  8                      end;';
  9  end;
10  /
1
2
PL/SQL procedure successfully completed
SQL>
SQL> begin
  2   execute immediate 'alter session set nls_length_semantics=char';
  3   execute immediate 'declare
  4                        v varchar2(1) := unistr(''€'');
  5                      begin
  6                        dbms_output.put_line(lengthb(v));
  7                        dbms_output.put_line(lengthb(unistr(''€'')));
  8                      end;';
  9  end;
10  /
1
2
PL/SQL procedure successfully completed
SQL> Same results for 10.2.0.4.
And you were probably doing your tests on 11.2, ofcourse ;)