Oracle培训笔记 8.6 逻辑结构（二）

 

创建表空间语法

create [undo|temporary]tablespace 表空间名
datafile[tempfile] '文件名' size 文件大小 [autoextend on next 扩展大小 maxsize unlimited]
extent management local|dictionary //local 默认
autoallocate|uniform size 大小 //autoallocate默认
segment space management auto|manual //auto默认

1、持久表空间

drop tablespace tbs1 including contents and datafiles;
create tablespace tbs1
datafile
'E:\oracle\product\10.2.0\oradata\mydb\tbs101.dbf' size 5M,
'E:\oracle\product\10.2.0\oradata\mydb\tbs102.dbf' size 5M;

select * from dba_tablespaces;
select * from dba_data_files;

drop table t01;
create table t01  tablespace tbs1 as select * from dba_objects;
create table t02(id number)  tablespace tbl1 storage(buffer_pool keep);

select * from dba_segments where segment_name='T01';
header_file： 存储在的文件编号
header_block: 段头所在的块号 11
bytes： 表大小
blocks：使用块数
extents：使用区数
buffer_pool: 段数据内存存储 keep_pool

select * from dba_extents  where segment_name='T01';
extent_id: 区编号，从0开始
file_id: 所在文件编号
block_id: 给段分配的区的起始块号
bytes：区的大小
blocks：区的块数

块使用分析
tbs1： 1~8块，数据文件头使用
       从第9块开始分配给表，第一个区从第9块到16块，11块是块头，9和10号块

查询数据存储位置      
select rowid from t01 where rownum<2; 
AAACgVAAFAAAAAMAAA

rowid解释
AAACgV: 数据对象编号 2*64*64 32*64 21 8192+2048+21
AAF：相对文件编号: 5
AAAAAM：块编号: 12
AAA：行编号: 0

A~Z 0~25
a~z 26~51
0~9 52~61
+/ 62,63

数据对象编号解释
select * from dba_objects where object_name='T01'
object_id: 10261, 对象id，不变
data_object_id: 10261，数据对象编号，可变，表移动时变

alter system dump datafile 5 block 9;
alter system dump datafile 5 block min 9 block max 10;

会话信息和进程信息查询
v$session: 记录会话信息

select * from v$session;
取当前会话sid
sid: session id
select * from v$mystat where rownum<2
取当前会话对应服务器进程地址
select paddr from v$session where sid=150;

v$process：记录进程信息    
select spid from v$process where addr='6CE4C01C';

查询当前会话对应服务器进程 id
select spid from v$process where addr=(select paddr from v$session where sid=(select distinct sid from v$mystat))

监控CPU使用，跟踪会话
sqlplus system/1
declare
i number;
begin
loop
i:=i+1;
end loop;
end;

使用工具ProcessExplorer查CPU使用情况，找到进程id

根据进程id找到session
select sid,serial#,program,machine,sql_id from v$session where paddr=(select addr from v$process where spid=3412)
根据sql_id查看执行语句
select * from v$sql where sql_id='700dz3jf0nvrs';

杀掉session
alter system kill session '144,64';

查询表空间的剩余空间
select *  from dba_free_space;

select * from dba_extents

select tablespace_name,sum(bytes) from dba_extents group by tablespace_name
select tablespace_name,sum(bytes) from dba_data_files group by tablespace_name

查询表空间使用情况
select f.tablespace_name,sum(f.bytes) total,sum(e.bytes) used
from dba_data_files f left join dba_extents e
on f.tablespace_name=e.tablespace_name
group by f.tablespace_name

2、undo表空间
create undo tablespace undo01
datafile 'E:\oracle\product\10.2.0\oradata\mydb\undo01.dbf'
size 100M;

SQL> show parameter undo

NAME                                 TYPE        VALUE
------------------------------------ ----------- ---------------
undo_management                      string      AUTO
undo_retention                       integer     900
undo_tablespace                      string      UNDOTBS1

alter system set undo_tablespace=undo01;
alter tablespace undo01 retention guarantee;
select * from dba_tablespaces

alter system set undo_tablespace=UNDOTBS1;
drop tablespace undo01 including contents and datafiles;

3、临时表空间
作用：order by，union ,distinct ,group by, 临时表
create temporary tablespace temp01
tempfile 'E:\oracle\product\10.2.0\oradata\mydb\temp001.dbf'
size 10M autoextend on next 1M;

select * from dba_temp_files

练习：
创建用户指定临时表空间
create user u1 identified by u1
default tablespace users temporary tablespace temp01
quota unlimited on users;

grant dba to u1;

登录
sqlplus u1/u1
create table t as select * from dba_objects;
insert into t select * from t;

select * from t order by ....;

观察临时表空间使用
select * from v$sort_usage

临时表空间组
drop tablespace temp01 including contents and datafiles;
drop tablespace temp02 including contents and datafiles;

create temporary tablespace temp01
tempfile 'E:\oracle\product\10.2.0\oradata\mydb\temp001.dbf'
size 10M autoextend on next 1M
tablespace group tempg;

create temporary tablespace temp02
tempfile 'E:\oracle\product\10.2.0\oradata\mydb\temp002.dbf'
size 10M autoextend on next 1M
tablespace group tempg;

select * from dba_tablespace_groups

练习
修改用户u1的临时表空间，指定到临时表空间组
alter user u1 temporary tablespace tempg;

登录排序

session1:
sqlplus u1/u1
select * from t order by ....;

session2:
sqlplus u1/u1
select * from t order by ....;

观察临时表空间使用
select * from v$sort_usage

4、表空间维护
修改：
增加文件
alter tablespace 表空间名 add datafile|tempfile '';

修改文件属性
alter database  datafile 'a.dbf' autoextend on next 1M;
alter database  datafile 'a.dbf' resize 10M;

删除
drop tablespace xxxx including contents and datafiles;

5、OMF-oracle manage file
SQL> show parameter file_dest

NAME                                 TYPE        VALUE
------------------------------------ ----------- ------------------------------
db_create_file_dest                  string

alter system set db_create_file_dest = 'E:\oracle\product\10.2.0\oradata\mydb';

create tablespace xxx;
drop tablespace xxx;

select * from dba_tablespaces;
select * from dba_data_files;