RE: Database character set conversion.

From: Crisler, Jon <>
Date: Fri, 14 Aug 2009 17:54:40 -0400
Message-ID: <56211FD5795F8346A0719FEBC0DB067504C3029E_at_mds3aex08.USIEXCHANGE.COM>

The other thing to consider is that you probably want to move to AL32UTF8 characterset. Metalink doc id 260192.1 is what I normally use to perform the characterset change.  

[] On Behalf Of Mercadante, Thomas F (LABOR)
Sent: Wednesday, August 12, 2009 12:02 PM To:
Subject: RE: Database character set conversion.  


Dave is correct is his statements.  

But let me say that generally (and I mean generally), most applications that do not use the extended character sets can exist in a database that supports extended character sets. There is some discussion about additional use of disk space when using the extended character set. But I don't think you will see any differences if you move your application there.

The CSSCAN utility will tell you everything you need to know about your specific database.  

And as always, test, test, test and for a change of pace, test it again.


[] On Behalf Of David Mann Sent: Wednesday, August 12, 2009 11:20 AM To:
Subject: Re: Database character set conversion.  

Fred Tilly wrote:

>We have two applications that use one database, and the database is
>with character set WE8ISO8859P1. One of the applications needs to
>multiple languages so the vendor wants us to convert ot a 16 bit
character set.
>However the other application in the database has not been tested
against a
>16bit database, and there are a lot of tables with fields defined as
>varchar2(4000) and clobs.
>Has anyone actually done such a conversion and is there anything we
should be
>looking out for.

My first stop for character set conversions is usually the CSSCAN utility. You can run it against your database and indicate the character set you would like to convert to and it will check all fields for any conversion anomalies and report them.  

Here is a pointer to the documentation for 10g: er.htm#sthref1571  

As far as application issues, an analysis of your technology stack would be in order. For projects such as this I usually lean on my developers to analyze their client apps and access methods for character set compatibility. If all else fails you can convert a test system and have QA give the data a once over.  


Dave Mann - Database Stuff -

Received on Fri Aug 14 2009 - 16:54:40 CDT

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