如果我们在做数据迁移或其它对数据库字符集有变更的动作前最好做一次全库的数据库检查，确认当字符集发生变化时，会不会有例外的情况存在。我们可以通过Oracle自带的工具csscan来完成检测工作。在官方站点提供从8i 到9i的各常用平台的download. 如果有需要可以到下面的连接中download.

csscan help=y

Character Set Scanner v1.1 : Release 9.2.0.1.0 - Production on Wed Mar 14 13:28:27 2007

Copyright (c) 1982, 2002, Oracle Corporation. All rights reserved.

You can let Scanner prompt you for parameters by entering the CSSCAN
command followed by your username/password:

Example: CSSCAN SYSTEM/MANAGER

Or, you can control how Scanner runs by entering the CSSCAN command
followed by various parameters. To specify parameters, you use keywords:

Example: CSSCAN SYSTEM/MANAGER FULL=y TOCHAR=utf8 ARRAY=102400 PROCESS=3

Keyword Default Prompt Description
---------- ------- ------ -------------------------------------------------
USERID yes username/password
FULL N yes scan entire database
USER yes user name of the table to scan
TABLE yes list of tables to scan
EXCLUDE list of tables to exclude from scan
TOCHAR yes new database character set name
FROMCHAR current database character set name
TONCHAR new NCHAR character set name
FROMNCHAR current NCHAR character set name
ARRAY 10240 yes size of array fetch buffer
PROCESS 1 yes number of scan process
MAXBLOCKS split table if larger than MAXBLOCKS
CAPTURE N capture convertible data
SUPPRESS suppress error log by N per table
FEEDBACK feedback progress every N rows
BOUNDARIES list of column size boundaries for summary report
LASTRPT N generate report of the last database scan
LOG scan base name of log files
PARFILE parameter file name
PRESERVE N preserve existing scan results
HELP N show help screen (this screen)
---------- ------- ------ -------------------------------------------------
Scanner terminated successfully.