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What is the best way to change NLS_CHARACTERSET?

Ajay AN
Ajay AN Member Posts: 6 Green Ribbon
edited Aug 3, 2022 2:16PM in General Database Discussions

We are using a Oracle database.

We wanted to change NLS_CHARACTERSET from "WE8MSWIN1252" to "AL32UTF8".

Can anybody suggest us a efficient plan?

Please share blogs or steps if any.


  • User_2DKLA
    User_2DKLA Member Posts: 63 Blue Ribbon
    edited Aug 4, 2022 7:50AM

    Consider using the Oracle Database Migration Assistant for Unicode, aka DMU (link).

    But start by reading the documentation (link) carefully before doing anything, so you may anticipate the possible difficulties.

    And make sure that you have a fallback plan (e.g. full backup, guaranteed restore point, etc.) in case things go wrong during (or after) the migration and you have to roll it back. This is a migration.


  • User_2DKLA
    User_2DKLA Member Posts: 63 Blue Ribbon

    Besides, the release is now out of support, which means Oracle will not provide with any fix for that release anymore (unless you have paid for the Market-Driven Support extension, which entitles you to receive corrections of Severity-1 and security issues until 31 Dec. 2022).

    This means that you'll probably have to upgrade to 19c very soon now, and therefore, you may want to delay the conversion to Unicode until after you've done that upgrade.