Oracle 12c garbled, method of modifying character set

Installing Oracle 12c on Windows 7 64-bit does not have a set character set, using the operating system default character set: we8mswin1252, modify the character set to: ZHS16GBK. Because the process is irreversible, you first need to back up the database.

1. Fully prepared database

2. Querying the current character set

PARAMETER                                                    VALUE---------------------------------------------------------------------------------------- --------------------------------nls_characterset                                             we8mswin1252sql>

3. Close the database

SQL>shutdown  immediate; Database closed. Database dismounted. ORACLE instance shut down.

4. Start the database to Mount state

SQL>4982833152  bytesfixed size                  2934600  bytesvariable size             2734688440 bytes Database Buffers         2231369728  bytesredo buffers               13840384  bytes  Database mounted.

5. Limit session

SQL>alter  system enable restricted session; System altered.

6. Query the relevant parameters and modify to prevent the task from automatically start execution

SQL>  show parameter job_queue_processes;name                                 TYPE        VALUE---------------- -------------------------------------------------------------job_queue_processes                       integer      +

SQL>  show parameter aq_tm_processes;name                                 TYPE        VALUE-------------------- ---------------------------------------------------------aq_tm_processes                            integer     1 

SQL>  alterset job_queue_processes=0; System altered.

SQL>ALTERSET aq_tm_processes=0; System altered.

7. Open the Database

SQL>alterdatabaseopen  ; Database altered.

8. Modifying the character Set

Sql> Alter Database character SetAl32utf8;Alter Database character SetAl32utf8*ERROR at line1: ORA-12712: Newcharacter SetMust be a superset ofOldcharacter Set

When the error occurs, the new character set must be a superset of the old character set, and the original character set is a subset of the new character set, which can be queried on the Oracle Official document for the character set inclusion relationship. Following the use of Oracle internal command Internal_use, skip the superset check, which is not recommended by the production environment.

SQL>alterdatabasecharacterset  internal_use Al32utf8; Database altered.

9. Querying the current character set

SQL>Select*fromwhere parameter='nls_ CHARACTERSET'; PARAMETER                                                    VALUE--------------------------------------------------------------------- ---------------------------------------------------nls_characterset                                                      Al32utf8

10. Close the database

SQL>shutdown  immediatesql>shutdown  immediate  Database  closed. Database dismounted. ORACLE instance shut down.

11. Start the database to Mount state

SQL>4982833152  bytesfixed size                  2934600  bytesvariable size             2734688440 bytes Database Buffers         2231369728  bytesredo buffers               13840384  bytes  Database mounted.

12. Change the relevant parameters back to their original values

SQL>  alterset job_queue_processes=1000; System altered.

SQL>ALTERSET aq_tm_processes=1; System altered.

13. Open the Database

SQL>alterdatabaseopen  ; Database altered.

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Oracle 12c garbled, method of modifying character set

Oracle 12c garbled, method of modifying character set