存储管理

Posted 2020-10-02 夜月色下

查询预定义表空间：

SQL> select TABLESPACE_NAME,CONTENTS from dba_tablespaces;

SQL> select FILE_NAME, TABLESPACE_NAME from dba_data_files;

创建新表空间：

SQL> create tablespace tbs01 datafile \'/u01/app/oracle/oradata/orcl/tbs01.dbf\' SIZE 10M AUTOEXTEND ON NEXT 10M MAXSIZE 100M;

在指定的表空间中创建表：

SQL> create table t1 tablespace tbs01 as select * from dba_objects where 1=0;

SQL> select bytes, blocks, extents, tablespace_name from dba_segments where segment_name=\'T1\';

SQL> insert into t1 select * from dba_objects;

SQL> select bytes, blocks, extents, tablespace_name from dba_segments where segment_name=\'T1\';

SQL> select extent_id, bytes, blocks from dba_extents where segment_name=\'T1\';

SQL> insert into t1 select * from t1;

SQL> insert into t1 select * from t1;

SQL> insert into t1 select * from t1;

SQL> select bytes, blocks, extents, tablespace_name from dba_segments where segment_name=\'T1\';

SQL> select extent_id, bytes, blocks from dba_extents where segment_name=\'T1\';

SQL> insert into t1 select * from t1; 空间不足，报错

SQL> rollback;

SQL> select bytes, blocks, extents, tablespace_name from dba_segments where segment_name=\'T1\'; 空间不释放

SQL> alter table t1 move; 释放空间

只读表空间：

SQL> alter tablespace tbs01 read only;

SQL> delete t1; 禁止dml

SQL> insert into t1 select * from t1; 禁止dml

SQL> update t1 set x=1; 失败

 

SQL> create table t2 (x int) tablespace tbs01; 失败

SQL> alter table t1 add (x int); 成功

SQL> drop table t1; 成功

dml和ddl的区别

 

改变表空间大小：

resize，直接调整数据文件大小（推荐）

autoextend，自动扩展

add datafile添加数据文件 后期添加的话会自动负载均衡

 

删除表空间：

SQL> drop tablespace tbs01 including contents and datafiles;