Solving Convertible or Lossy data in Data Dictionary objects reported by Csscan when changing the NLS_CHARACTERSET
(Doc ID 258904.1)
Last updated on APRIL 24, 2019
Oracle Database - Enterprise Edition - Version 184.108.40.206 to 220.127.116.11 [Release 8.0.3 to 11.2] Oracle Database - Standard Edition - Version 18.104.22.168 to 22.214.171.124 [Release 8.0.3 to 11.2] Oracle Database Cloud Schema Service - Version N/A and later Oracle Database Exadata Express Cloud Service - Version N/A and later Oracle Database Exadata Cloud Machine - Version N/A and later Information in this document applies to any platform.
You are planning to convert the database character set from one character set to another set (for example to AL32UTF8) .
And you used Csscan and found some "Convertible" or "Lossy" in Data Dictionary objects and plan on using using ALTER DATABASE CHARACTER SET or Csalter. This note tries to give a overview of the most commonly seen "Convertible" and "Lossy" in Data Dictionary objects and how to handle these when using ALTER DATABASE CHARACTER SET / Csalter.
Note that "Convertible" in Data Dictionary objects is NOT a problem when using export/import into a new / other database.
A list of notes in changing the NLS_CHARACTERSET is provided in <Note 225912.1> Changing the Database Character Set ( NLS_CHARACTERSET )
Please do note that: * Before changing the NLS_CHARACTERSET using Csalter or Alter Database..." it's mandatory to use Csscan. We strongly suggest to read <Note 444701.1> Csscan output explained * some actions in this note use the csscan "exclude" option, the list of table NEEDS to be between ( ) and on most Unix shells it need ' ' around the list of tables. Example: on windows use EXCLUDE=(owner.table,owner.table) , on unix platforms use EXCLUDE='(owner.table,owner.table)'. to avoid this one can use a parameter file for csscan, see <Note 444701.1> Csscan output explained , section " E) Do I need to always run a full database scan? / The Csscan EXCLUDE , USER or TABLE parameters do not appear to work." * some selects in this note use the rowid 's stored by csscan in "data_rowid" column of the csmig.csmv$errors table, if such a select give "ORA-01410: invalid ROWID" then this simply means that since the csscan some rows where removed in the object scanned. If this happens simply re-scan the table in question.
Any DBA who has "Convertible" or "Lossy" in Data Dictionary objects while using ALTER DATABASE CHARACTER SET or Csalter.
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