【问题与背景】
一、删除一个表？一个库？
drop table table_name;
drop table database_name;
二、删除一个用户下所有的数据？
最好先停掉库，shutdown immediate; && startup 这样能保证没有用户连接
或者 SELECT SID,SERIAL# FROM V$SESSION WHERE USERNAME=///'USERNAME///'; 查询到连接
SID SERIAL#
---------- ----------
24 25341
结束此用户的所有会话
SQL>ALTER SYSTEM KILL SESSION ///'24,25341///';
System altered.
再删除：DROP USER USERNAME CASCADE；
三、创建用户并授权 （本例给连接，修改，管理员）
create user username identified by passwd;
grant connect,resource,dba to username;
commit;
四、如何设置字符集？
查看客户端字符集环境：
select * from nls_instance_parameters；其来源于v$parameter
设置过程
SVRMGR> SHUTDOWN IMMEDIATE;
SVRMGR> STARTUP MOUNT;
SVRMGR> ALTER SYSTEM ENABLE RESTRICTED SESSION;
SVRMGR> ALTER SYSTEM SET JOB_QUEUE_PROCESSES=0;
SVRMGR> ALTER SYSTEM SET AQ_TM_PROCESSES=0;
SVRMGR> ALTER DATABASE OPEN;
SVRMGR> ALTER DATABASE CHARACTER SET zhs16gbk;
SVRMGR> SHUTDOWN IMMEDIATE;
SVRMGR> STARTUP;
如果报以下的错：
SQL> alter database character set zhs16gbk;
alter database character set zhs16gbk
*
ERROR at line 1:
ORA-12712: new character set must be a superset of old character set
处理方法：
SQL> ALTER DATABASE character set INTERNAL_USE zhs16gbk; # 使用INTERNAL_USE可以跳过超集的检查,ALTER DATABASE character set INTERNAL_USE
五、查询实例？所有库名？表名？
select * from v$database; show parameter db; // 查看当前的所有数据库:
show parameter optimizer; //显示设置信息
select table_name from user_tables; //当前用户的表
select table_name from all_tables; //所有用户的表
select table_name from dba_tables; //包括系统表
看字段名与数据类型:
desc talbename;
查看主键：
select * from user_constraints where constraint_type=///'P///' and TABLE_name=upper(///'TRD_USER///')
查看表空间的sql语句
col tablespace_name format a10;
select f.tablespace_name,a.total,u.used,f.free,round((u.used/a.total)*100) ///"% used///",
round((f.free/a.total)*100) ///"% Free///"
from
(select tablespace_name, sum(bytes/(1024*1024)) total
from dba_data_files group by tablespace_name) a,
(select tablespace_name, round(sum(bytes/(1024*1024))) used
from dba_extents group by tablespace_name) u,
(select tablespace_name, round(sum(bytes/(1024*1024))) free
from dba_free_space group by tablespace_name) f
WHERE a.tablespace_name = f.tablespace_name
and a.tablespace_name = u.tablespace_name;
六、增加表空间
为表空间增加数据文件：
alter tablespace users add datafile ///'/u01/oracle/oradata/trds/system01.dbf///' size 1000M;
增加表空间原有数据文件尺寸：
alter database datafile ///'/u01/oracle/oradata/trds/system01.dbf///' resize 1000M;
七、数据库临时表空间的数据文件的丢失
当数据库的临时表空间的数据文件丢失也会引起
ORA-01157的错误。因为数据库对临时表空间的数据文件不会发生检查点，所以这个时候数据库照样能够打开。这种情况下的解决方法是逻辑上删除临时表空间的数据文件，并且重新增加一个新的临时表空间的数据文件。
例如：
SELECT * FROM DBA_OBJECTS ORDER BY OBJECT_NAME；
select * from dba_objects order by object_name；
* ERROR at line 1:
ORA-01157: cannot identify/lock data file 5 - see DBWR trace file
ORA-01110: data file 5: ///'/Oracle/oradata/temp01.dbf///'
ALTER DATABASE TEMPFILE ///'/oracle/oradata/temp01.dbf///' DROP；
SELECT TABLESPACE_NAME,FILE_NAME FROM DBA_TEMP_FILES；
ALTER TABLESPACE TEMP ADD TEMPFILE ‘/Oracle/oradata/temp01.dbf‘ SIZE 100M；
八、查看ORACLE 用户连接数
select count(*) from v$session #连接数
Select count(*) from v$session where status=///'ACTIVE///' #并发连接数
查看oracle 数据库状态
select status from v$instance;
select open_mode from v$database;
九、PLS-213: package STANDARD not accessible报错解决方法
sqlplus /nolog
SQL> connect / as sysdba
SQL> $ORACLE_HOME/rdbms/admin/catalog.sql
SQL> $ORACLE_HOME/rdbms/admin/catproc.sql
SQL> $ORACLE_HOME/rdbms/admin/catexp.sql
十、运行lsnrctl start 出现
TNSLSNR for Linux: Version 8.1.7.0.0 - Production
System parameter file is /oracle/product/8.1.7/network/admin/listener.ora
Log messages written to /oracle/product/8.1.7/network/log/listener.log
Listening on: (DESCRIPTION=(ADDRESS=(PROTOCOL=ipc)(KEY=EXTPROC)))
Listening on: (DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=LinServer)(PORT=1521)))
Listening on: (DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=LinServer)(PORT=2481))(PROTOCOL_STACK=(PRESENTATION=GIOP)(SESSION=RAW)))
TNS-01201: Listener cannot find executable /oracle/product/8.1.7/bin/extproc for SID PLSExtProc
把binl里的extprocO 做一个叫extproc的link
十一、oemapp相关命令，如下：
oemapp dbastudio
oemapp console
oemapp txtm
十二、如何创建一个实例？
CREATE DATABASE trds
CONTROLFILE REUSE
LOGFILE ///'/data/oracle/trds/redo01.log///' SIZE 1M REUSE,
///'/data/oracle/trds/redo02.log///' SIZE 1M REUSE,
///'/data/oracle/trds/redo03.log///' SIZE 1M REUSE,
///'/data/oracle/trds/redo04.log///' SIZE 1M REUSE
DATAFILE ///'/data/oracle/trds/system01.dbf///' SIZE 10M REUSE
AUTOEXTEND ON
NEXT 10M MAXSIZE 200M
CHARACTER SET WE8ISO8859P1;
CREATE ROLLBACK SEGMENT rb_temp STORAGE (INITIAL 100 k NEXT 250 k);
ALTER ROLLBACK SEGMENT rb_temp ONLINE;
CREATE TABLESPACE rbs
DATAFILE ///'/data/oracle/trds/rbs01.dbf///' SIZE 5M REUSE AUTOEXTEND ON
NEXT 5M MAXSIZE 150M;
CREATE TABLESPACE users
DATAFILE ///'/data/oracle/trds/users01.dbf///' SIZE 3M REUSE AUTOEXTEND ON
NEXT 5M MAXSIZE 150M;
CREATE TABLESPACE temp
DATAFILE ///'/data/oracle/trds/temp01.dbf///' SIZE 2M REUSE AUTOEXTEND ON
NEXT 5M MAXSIZE 150M;
CREATE ROLLBACK SEGMENT rb1 STORAGE(INITIAL 50K NEXT 250K)
tablespace rbs;
CREATE ROLLBACK SEGMENT rb2 STORAGE(INITIAL 50K NEXT 250K)
tablespace rbs;
CREATE ROLLBACK SEGMENT rb3 STORAGE(INITIAL 50K NEXT 250K)
tablespace rbs;
CREATE ROLLBACK SEGMENT rb4 STORAGE(INITIAL 50K NEXT 250K)
tablespace rbs;
ALTER ROLLBACK SEGMENT rb1 ONLINE;
ALTER ROLLBACK SEGMENT rb2 ONLINE;
ALTER ROLLBACK SEGMENT rb3 ONLINE;
ALTER ROLLBACK SEGMENT rb4 ONLINE;
ALTER ROLLBACK SEGMENT rb_temp OFFLINE;
DROP ROLLBACK SEGMENT rb_temp ;
