NLS_LENGTH_SEMANTICS=CHAR not effective?

Question

Hi,
I have two Oracle 10.2.0.3 databases - DB1 & DB2.
In both, following init.ora parameter is set :- NLS_LENGTH_SEMANTICS=CHAR
In DB1, for one query i received ORA-12899: value too large for column <tbsp1>.<tb1>.<col1> (actual: 17, maximum: 16)
In DB2, for the same query, didn't face any problems.
When i compared, the same table tb1 in both databases -
For DB2:
SQL> desc tb1;
Name Null? Type
col1 VARCHAR2(30 CHAR)
col2 VARCHAR2(50 CHAR)
=======================================
For DB1:
SQL> desc tb1;
Name Null? Type
col1 VARCHAR2(30)
col2 VARCHAR2(50)
If observed, column type for DB1 is VARCHAR2(30) and for DB2 its VARCHAR2(30 'CHAR').
To give you further details - Both the databases,DB1 & DB2 are on the same OS platform, have same init.ora parameters, every configuration is same, except both are installed on different servers.
Please help me for this problem which i am facing in DB1.
Edited by: user10552003 on Jan 27, 2011 4:42 PM

Answer 1

If you want to change the character length semantics for all the columns, you just need a bit of dynamic SQL. Something like
DECLARE
  l_sql VARCHAR2(1000);
BEGIN
  FOR cols IN (SELECT * FROM user_tab_cols WHERE data_type = 'VARCHAR2' and char_used = 'B')
  LOOP
    l_sql :=
      'ALTER TABLE ' || cols.table_name ||
      '  MODIFY( ' || cols.column_name || ' VARCHAR2(' || cols.data_length || ' CHAR) )';
    dbms_output.put_line( l_sql );
    execute immediate l_sql;
  END LOOP;
END;If you want to change the character semantics for tables in other schemas, you'll need to run this in each schema or change the code to use DBA_TAB_COLS. I'm also not doing any exception handling here to account for situations like object tables where this code won't work correctly.
Justin