9 Replies Latest reply: Sep 8, 2010 7:30 AM by "Gunther Vermeir, Oracle-Oracle" RSS

    NLS_LANG client set to AL32UTF8  and abnormal select performance issue

    399831
      Hi,
      I use a simple select statement via sqlplus and noticed when changing the NLS_LANG from WE8ISO8859P15 to AL32UTF8 the query runtime is 10x longer.


      DB: Oracle Database 10g Enterprise Edition Release 10.2.0.4.0 - 64bit Production
      NLS_CHARACTERSET: AL32UTF8


      The table has 500.000 rows and some varchar2(32), number(10) and date columns.

      The select statement has no where conditions and looks like:

      select a, b, c, a_date, b_date, c_date from x

      The NLS_LANG for the OCI client is the only change before I connect the instance via sqlplus to perform the query.

      The runtime is abnormal and I have no idea since the client and server charset are both AL32UTF8 and normally no conversion should happen.

      Many thanks in advance for a clue.

      Best regards,
      Andreas