How to change the user name in Oracle

In practice, you sometimes need to modify the user name, and the common practice is the exp imp method. If the data volume is large, the exp imp method will waste a lot of time, the following describes how to modify the user name by modifying the Oracle base table.

-- Directly modify the underlying table USER $ to change the USER name (this method is passed in Oracle9i)

SQL> UPDATE USER $ SET NAME = 'TT' WHERE USER # = 91;

1 row updated.

SQL> COMMIT;

Submitted.

SQL> ALTER SYSTEM CHECKPOINT;

The system has been changed.

SQL> ALTER USER TT IDENTIFIED BY VALUES '294ce6e71_dd890 ';

Alter user tt identified by values '294ce6e71_dd890'

*

ERROR is located in row 1st:

ORA-01918: User 'TT' does not exist

Force Oracle to read actual data, rather than read the cache

SQL> ALTER SYSTEM FLUSH SHARED_POOL;

The system has been changed.

SQL> ALTER USER TT IDENTIFIED BY VALUES '294ce6e71_dd890 ';

The user has changed.

Test connection

SQL> CONN TT/TT

Connected.

SQL> SELECT * FROM TAB;

TNAME TABTYPE CLUSTERID

-----------------------------------------------

TEST_TT TABLE

SQL> CONN/AS SYSDBA

Connected.

SQL> SHOW USER

USER is "SYS"

SQL> SHUTDOWN IMMEDIATE

The database has been closed.

The database has been detached.

The ORACLE routine has been disabled.

SQL> STARTUP

The ORACLE routine has been started.

......

The database has been loaded.

The database has been opened.

It can be seen that TEST is not recovered.

SQL> SELECT USER #, NAME, PASSWORD FROM USER $ WHERE USER # = 91;

USER # NAME PASSWORD

--------------------------------------------------------

91 TT 294ce6e7425dd890

SQL> CONN TT/TT

Connected.

View data objects

SQL> SELECT * FROM TAB;

TNAME TABTYPE CLUSTERID

-----------------------------------------------

TEST_TT TABLE

SQL> SELECT * FROM TEST_TT;

A

-

A

The object permission is still valid.

SQL> SELECT * FROM TEST1.TEST1 _ TT;

A

-

A

The system permission is still valid.

SQL> CREATE TABLE KK AS SELECT * FROM TEST1.TEST1 _ TT;

The table has been created.

SQL> SELECT * FROM TAB;

TNAME TABTYPE CLUSTERID

-----------------------------------------------

KK TABLE

TEST_TT TABLE

SQL> CONN/AS SYSDBA

Connected.

SQL> SHOW USER

USER is "SYS"

-- No problem with DROP USER

SQL> DROP USER TT CASCADE;

User discarded

SQL> DROP USER TEST1 CASCADE;

User discarded