Skip to Main Content

Database Software

Announcement

For appeals, questions and feedback about Oracle Forums, please email oracle-forums-moderators_us@oracle.com. Technical questions should be asked in the appropriate category. Thank you!

Interested in getting your voice heard by members of the Developer Marketing team at Oracle? Check out this post for AppDev or this post for AI focus group information.

CSSCAN in 11g Characterset migration from 'WE8ISO8859P15' to 'UTF8'

995359Mar 7 2013 — edited Mar 21 2013
Hi All,
I have the below doubts about Characterset ot changing from WE8ISO8859P15 to'UTF8
1)If I use CSSCAN utility, Will it convert application data also or only conver data dictionary.
2) How much time it will take to convert 25 GB database application data.

Kindly treat this as urgent.


Thanks
Hareesh Reddy

Edited by: 992356 on Mar 6, 2013 11:26 PM

Comments

Pierre Forstmann
Please note
1. this is a forum and not Oracle Support: you cannot ask for "urgent" answer.
2. character set migration has nothing to do with ASM: you should post to right forum 3052
3. CSSCAN does not convert data: it reports data that does not need conversion and data that needs specific conversion.
995359
Hi,
Thanks for your sugesstion and reply.
CSSCAN is a read only utility - it does not make any changes

http://docs.oracle.com/cd/E11882_01/server.112/e10729/ch12scanner.htm#i1005939

The CSALTER code will perform the actual conversion, assuming all of the prereqs are met - the time time taken will depend on the data present in the database that needs to be converted. The time can only be estimated by performing a test convert on test hardware that is similar or identical to production

HTH
Srini
995359
Thanks a lot srini for your reply.

One more doubt here. I would like to create new database with required character set and import old data into database. Will it show correly in new database.
It depends - on what the current characterset is and how data is stored in the current database - pl provide details on what issue you are trying to solve

HTH
Srini
995359
Hi Srini,

Please find the current set of db here. Existing DB is supporting Western Languages. Our requirement is need to store chinese character in DB.


PARAMETER VALUE
NLS_LANGUAGE AMERICAN
NLS_TERRITORY UNITED KINGDOM
NLS_CHARACTERSET WE8ISO8859P15
NLS_DATE_LANGUAGE AMERICAN
NLS_NCHAR_CHARACTERSET AL16UTF16
NLS_LENGTH_SEMANTICS BYTE
NLS_NCHAR_CONV_EXCP FALSE
NLS_RDBMS_VERSION 11.1.0.7.0
As per my analysis, I found two solutions for this problem.
1) by running CSSCAN utility need to covert DB but as I reffered there is a chance of loosing or truncating data.
2) Create new DB with required set up and importing existing DB data.

Kindly suggest best solution to solve this problem.

Thanks
Hareesh Reddy.
Please note that CSALTER will NOT convert user data. It will only convert CLOBs in the data dictionary (i.e. system columns). It will also change the character set declaration but it will not re-encode user data for the new character set. Only the DMU (http://www.oracle.com/technetwork/products/globalization/dmu/overview/index.html) and export/import can convert the database. The DMU does it in place, the export/import requires data to be moved out from the database and reinserted (or moved to another database).

Also, unless the database needs to support Oracle 8.x clients, do not migrate to the deprecated UTF8. Migrate to AL32UTF8.

-- Sergiusz
995359
Hi Wolicki,
Thanks for your reply and advice. Hope DMU tool is availabel in 11.2 version but we are using 11.1. Do I need to upgrade to 11.2 otherwise any other alternative is there.

Thanks
Hareesh Reddy
Zoltan Kecskemethy
Please [url http://docs.oracle.com/cd/E39404_01/doc/index.htm]read the fine manual.
[url http://docs.oracle.com/cd/E39404_01/doc/doc.12/e36716/ch2migrasteps.htm#BABDHEAC]DMU Overview of Requirements and Security Considerations
The release of Oracle Database must be 10.2.0.4, 10.2.0.5, 11.1.0.7, 11.2.0.1, or later. Check the latest version of the DMU release notes for any additional patches that must be installed in the database. The release notes also list further database releases that are supported with appropriate patches.
[url http://docs.oracle.com/cd/E39404_01/doc/doc.12/e39375/toc.htm]DMU Release notes
You can find all DMU supported database releases and platforms here: http://www.oracle.com/technetwork/products/globalization/dmu/learnmore/configurations-333837.html

Only 11.2.0.3 is supported on all platforms (except EBCDIC mainframes). Selected older releases are supported on selected platforms provided an appropriate patch is installed.


-- Sergiusz
995359
Hi ,
Currently we are using Unix AIX operating system which is having 64 bit configuration. Kindly let me how can I safely change character set without losing any data. Can you guide me which will support Chinese character in application. Please find current database setup details in the thread it self.

Thanks
Hareesh Reddy

Edited by: 992356 on Mar 11, 2013 10:47 AM
Srini Chavali-Oracle
You should use AL32UTF8 - http://docs.oracle.com/cd/E11882_01/server.112/e25494/create001.htm#ADMIN13343

HTH
Srini
Agreed. Always use AL32UTF8 unless you have a very good reason to use one of the legacy character sets.


-- Sergiusz
995359
Hi Srini/all
Thanks a lot for your guidence and help to resolve character set issue. I have run csalter utility and noticed that few of the application tables are impacted. Kindly let me know how can I handle Truncation, Lossy data.
Srini Chavali-Oracle
Pl see these MOS Docs

Csscan Output Explained [ID 444701.1]
Solving Convertible or Lossy data in Data Dictionary objects reported by Csscan when changing the NLS_CHARACTERSET [ID 258904.1]

HTH
Srini
orafad
Did you check the scan reports for what tables are impacted and what the lossy data are?

It is you who knows the application data best and should be able to find out how you can hande conversion exceptions.

Earlier in this thread you got several suggestions on the DMU tool. How did that turn out?


Read the doc for a description of e.g. Individual Exceptions and the two types of app data exceptions.
http://docs.oracle.com/cd/E11882_01/server.112/e10729/ch12scanner.htm#i1007101
1 - 16
Locked Post
New comments cannot be posted to this locked post.

Post Details

Locked on Apr 18 2013
Added on Mar 7 2013
16 comments
5,977 views