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oracle表空间Managing Tablespace & Data Files

2012-07-24

oracle表空间Managing Tablespace & Data Files[sql]一、Objectives Define the purpose of tablespaces and data files(定义的表空间和数据文件的目的) Create tablespaces www.2cto.com M...


oracle表空间Managing Tablespace & Data Files
[sql]
一、Objectives
Define the purpose of tablespaces and data files(定义的表空间和数据文件的目的)
Create tablespaces www.2cto.com
Manage tablespaces
Create and manage tablespaces using Oracle Managed Files(OMF)
Obtain tablespace information (获取表空间信息)
二、Tablespaces & Data Files
Oracle stores data logically in tablespaces and physically in data files
Tablespaces
--Can belong to only on database at a time
--
Data files
三、Storage Hierarchy summary存储层次结构总结
logical
Database->Tablespace->segment->extent->oracle data block
Database->Schema
Physical
Datafile->OS block
一个Tablespace 对应多个Data file
一个ORacle data block 对应多个 OS black 是os block的倍数
四、Types of Tablespaces
1、SYSTEM tablespace
--Create with the database
--Contains the data dicationary
--Contains the SYSTEM undo segment
2、Non-System tablespace
--Separate segments
--Eases space administration 简化空间管理
--Controls amount of space allocated to a user
www.2cto.com
另外三种划分(permanent,undo,temporary)
五、查看表空间相关信息
1、查看表空间
select * from v$tablespace;
2、查看表空间包含数据
select file_name,tablespace_name from dba_data_files;
六、Create Tablespaces
create tablespace paul datafile
'/u01/app/oracle/product/10.2.0/oradata/oamis/paul01.dbf' size 20m;
七、两种方式
dictionary-mangage tablespace 中央集中式
a locally managed 独立式 (9版本都采用这种方式,但还是兼容以前的方式)
9i以后如果system 表空间是 locally managed 管理,那新建的都是
将Dictionary-mangage方式转换为locally managed
DBMS_SPACE_ADMIN.TABLESPCAE_MIGRATE_TO_LOCAL('system')(共有7步工作)
八、Undo Tablespace(用于回滚操作)
1、Used to store undo segments
2、Cannot contain any other objects
3、Extents are locally managed
4、Can only use the DataFile and Extent management clauses
www.2cto.com
create undo tablespace undo1
datafile '/u01/app/oracle/oradata/undo01.dbf' size 40M;
九、Temporary Tablespace(最好单独指定)
1、used for sort operation
2、can be shared by multiple user
3、cannot contain any permanent objects(不能包含永久信息)
4、Locally managed extents recommended (推荐使用locally 方式)
5、
Create temporary tablespace temp
tempfile '/u01/app/oracle/oradata/temp01.dbf' size 20M
extent management local uniform size 4M
1、创建数据库的时候指定Temporary tablespace
2、创建临时表空间,然后修改
①、创建
create temporary tablespace mytemp1
tempfile '/u01/app/oracle/product/10.2.0/oradata/oamis/mytemp01.dbf' size 100M
extent management local;
②、修改
alter database default temporary tablespace mytemp1;
Temporary Tablespace Restriction
1、Dropped until after a new default is made available 不能删除
2、Taken offline 不能离线
3、Altered to a permanent tablespace 不能改变为永久表空间
十、Read-only Tablespace
1、Causes a checkpoint (导致了一个检查点)
2、Data available only for read operation
3、Object can be dropped from tablespace
(System Tablespace 不可能read-only,drop 的时候只是drop 数据字典的东西)
4、测试上面三点 www.2cto.com
①、创建表空间
create tablespace shanxi datafile
'/u01/app/oracle/product/10.2.0/oradata/oamis/shanxi.dbf' size 20m
extent management local uniform size 128k;
②、创建用户,默认表空间是shanxi
create user fc identified by fc default tablespace shanxi
③、赋予权限
grant connect,resource to fc;
④、登录
conn fc/fc@oamis;
⑤、创建表并添加记录 提交
create table t (id integer,name char(10));
insert into t values(1,'yuncheng');
commit;
⑥、修改表空间只读
alter tablespace shanxi read only;
⑦、测试结果
不能增删改 只能drop
⑧、恢复表空间write
alter table shanxi read write;
十一、Taking a Tablespace Offline(使表空间离线)
表空间状态(read ,write,offline ,online)
1、Not avaliable for data access
2、Tablespace that cannot be taken offline
①、system tablespace www.2cto.com
②、Tablespaces whit active undo segment ()
③、Default temporary tablespace (temporary tablespace 不是默认的可以离线)
2、测试表空间离线
①、创建表 添加数据
create table t2 (id integer,name char(10));
insert into t2 values(1,'aaa');
insert into t2 values(2,'bbb');
commit;
insert into t2 values(3,'ccc');
②、将表空间shanxi离线(sys用户)
alter tablespace shanxi offline;(表空间离线)
这个时候查询不行了
alter tablespace shanxi online; (表空间在线)
这个时候可以了
十二、Changing Storage Settingg(改变存储设置)
1、可以分为三个层次进行设置(数据库级,表空间级,segament级)
2、Storage setting for locally managed tablespaces cannot be altered;
十三、Resizing a TableSpace(调整表空间的大小)
A tablespace can be resized by:
1、Changing the size of a data file(改变数据文件的大小)
①、Automatically using autoextend (自动改变,一个步调,一个极限)
三种方式实现: create database ,create tablespace,alter tablespace ...add datafile
Example:
Create Tablespace user_data
datafile='/u01/oradata/userdata01.dbf' size=200M
autoextend on next 10m maxsize 500M; (可以应用于create database 或者 create tablespace) www.2cto.com
修改表空间(增加一个)
alter tablespace shanxi add datafile
'/u01/app/oracle/product/10.2.0/oradata/oamis/shanxi2.dbf' size 20m
autoextend on next 10M maxsize 100M;
修改表空间(修改原来的)
alter database datafile '/u01/app/oracle/product/10.2.0/oradata/oamis/shanxi.dbf'
autoextend on next 10m maxsize 100M;
查询tablespace是否自动增长
select file_name,tablespace_name,autoextensible from dba_data_files;
②、Manually using Alter Database (手工改变方式)
(从小的往大变,如果从大的往小变则根据数据库文件实际的大小来定)
Alter database datafile '/u01/app/oracle/product/10.2.0/oradata/oamis/shanxi.dbf' resize 20M;
2、Add a data file using Alter Tablespace (添加一个新的)
(这种方式好,例如一个100G跟10个10g,10个的这个会并发,速度快)
alter tablespace shanxi add datafile '/u01/app/oracle/product/10.2.0/oradata/oamis/shanxi3.dbf' size 5M;
3、查询表空间的使用情况(这个查询需要点时间)
主要是 DBA_DATA_FILES和dba_free_space
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;
www.2cto.com
临时表空间在DBA_TEMP_FILES中查找
十四、Methods for moving data file(移动数据文件)
1、Alter Tablespace
前提
①、Tablespace must be offline
②、Targer data file must exist
步骤
①、alter tablespace shanxi offline;
②、离线状态下dba_data_files 中bytes是空的
③、将shanxi3.dbf更改到上一级
alter tablespace shanxi rename datafile '/u01/app/oracle/product/10.2.0/oradata/oamis/shanxi3.dbf'
to '/u01/app/oracle/product/10.2.0/oradata/shanxi3.dbf';
④、在通过dba_data_files查询发现路径变化了
2、Alter Database
前提:
①、database must be mounted
②、targer data file must exist;
步骤
①、关闭数据库
shutdown immediate;
②、移动数据文件或拷贝
mv shanxi3.dbf oamis/
③、打开数据库到mount状态
startup mount;
④、执行下面命令
alter database rename file '/u01/app/oracle/product/10.2.0/oradata/shanxi3.dbf' to
'/u01/app/oracle/product/10.2.0/oradata/oamis/shanxi3.dbf';
⑤、修改数据库为打开状态
alter database open;
⑥、查询dba_data_files文件看路径
十五、Dropping Tablespace
You cannot drop a tablespace if it:
-Is the System tablespace
-Has active segment
including contents drops the segments
including contexts and datafile deletes data files
cascade constraints drops all referential integrity constraints
命令:
drop tablespace userdata including contents and datafiles
www.2cto.com
删除表空间shanxi及文件
drop tablespace shanxi including contents and datafiles;
十六、Get Tablespace information
1、Tablespace information
--dba_tablespaces
--v$tablespace
2、Data file information
dba_data_files
v$datafile
3、Temp file information
dba_temp_files
v$tempfile
作者 liyangfd
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