Re: what characterset to use?

On Aug 22, 2:52 pm, sybra..._at_hccnet.nl wrote:
> On Wed, 22 Aug 2007 05:55:54 -0700, Ben <bal..._at_comcast.net> wrote:
> >10.2.0.2 Ent Ed, AIX5L
>
> >We are planning a new database and I'm having a little confusion on
> >what character set to use. We are not sure if in the future we may
> >need some double byte characters. For the most part we can suffice
> >with AMERICAN_AMERICA.WE8MSWIN1252 but it is possible that in the
> >future we need multibyte characters. I have been reading the
> >Globalization guide and the section in Tom Kyte's Expert Oracle
> >Database Architecture on this but I could be totally mis interrepting
> >something here. I haven't read chapter 6 on unicode in the
> >Globalization Guide (yet). I don't want to use multibyte data unless
> >it is necessary but I do want to have the option available.
>
> >1. Am I correct in thinking that if we use NLS_CHARACTERSET =
> >WE8MSWIN1252 and NLS_NCHAR_CHARACTERSET = AL16UTF16 we shouldn't have
> >any issues with losing multibyte characters?
>
> The basic guideline is you use a characterset which is native to the
> database server. As your database is on AIX5L, this is WE8ISO8859P15,
> NOT mswin1252. Oracle however is moving towards UTF, and I believe I
> did read a note ALL 11g databases are going to be UTF by default.
>
> >2. On my windows client I go to a command prompt and issue the
> >following c:\> echo %NLS_LANG%,
> >I get %NLS_LANG% returned back to me. I'm assuming that this means I
> >don't have the variable set. How does my client then treat the data
> >that I am getting from the database?
>
> The Oracle default for all O/S es is still US7ASCII. However, if you
> did install your client properly, you will have a *registry* string
> NLS_LANG set to MSWIN1252. This will work.

If I don't get a value returned for > echo %NLS_LANG% then I guess it isn't set, right? Exactly what part of the client install sets that value? I don't recall being asked or prompted for a character set setting? I checked my registry under
LOCAL_MACHINE-SOFTWARE-ORACLE and the NLS_LANG there is N/A. This is on a WinXP Pro client machine.

> >3. When I query v$nls_parameters does this show me what character set
> >my client session is using?
>
> It should but better query v$nls_session_parameters.
> V$ views have documented descriptions BTW: in the database (use DIC)
> in the documentation, and on Metalink.
>

Do you mean nls_session_parameters?

SQL> SELECT * FROM v$nls_session_parameters; SELECT * FROM v$nls_session_parameters

              *
ERROR at line 1:
ORA-00942: table or view does not exist

When I query nls_session_parameters there isn't a row returned for characterset.

> >4. When I query nls_database_parameters, does this show me what the
> >database has been setup as on the server side?
>
> see answer 3
> >5. Within sqlplus what does 'show parameter nls' tell me? I'm assuming
> >the init.ora nls settings.
>
> Exactly, you 'assume'.
> Your assumption is incorrect.
> It will show you the result from v$parameter. If you started your
> database using a spfile (which you should do anyway), the parameters
> from the spfile will show.
>

I guess I should have said spfile instead of init.ora, as we do use an spfile. I tend to refer to them as one in the same. Received on Thu Aug 23 2007 - 07:42:57 CDT