Ora-01012:not logged on exception
Cause of the problem: the application may have a bug that did not release the connection in time.
Workaround: The root of the problem is to modify the processes value, or prohibit some unusual access.
Problem-Solving ideas:
1, such as the number of database access connections decreased users re-login;
2, Sqlplus "/as SYSDBA" after landing,
Shutdown abort;
3, Ps-ef|grep Ora_dbw0_$oracle_sid
Kill-9 pid;
4. Kill off some unimportant session.
One, PL/SQL Developer Text field display garbled
Reason: Because the database number format and the PL/SQL Developer encoding format is not unified.
Second, view and modify the Oracle database character set:
Select Userenv (' language ') from dual;
Query Result:
Simplified Chinese_china. Al32utf8
--Modifying the Oracle Database Character set: (In SQL Plus)
Sql> Conn/as sysdba;
sql> shutdown immediate;
Database closed.
Database dismounted.
Oracle instance shut down.
sql> startup Mount;
Oracle instance started.
Total system global Area 135337420 bytes
Fixed size 452044 bytes
Variable size 109051904 bytes
Database buffers 25165824 bytes
Redo Buffers 667648 bytes
Database mounted.
Sql> alter system enable restricted session;
System altered.
Sql> alter system set job_queue_processes=0;
System altered.
Sql> alter system set aq_tm_processes=0;
System altered.
sql> ALTER DATABASE open;
Database altered.
Sql> ALTER DATABASE character set Internal_use Ja16sjis;
sql> shutdown immediate;
Sql> startup;
Third, modify the format of PL/SQL developer encoding:
Create a system environment variable named "Nls_lang" in Windows and set its value to "simplified Chinese_china. ZHS16GBK ",
Then restart the PL/SQL developer, so that the retrieved Chinese content will not be garbled. If you want to convert to the UTF8 character set, you can assign "Nls_lang" to "American_america." UTF8, and then restart the PL/SQL developer. Other character set settings ibid.
Oracle Character Set settings