oracle回滚段该如何实现？

[littledonkey]

如何配置呢

[littledonkey]

kai!

[siuzjh]

--修改现有回滚段，使之失效，下线
alter rollback segment rb1 offline;
alter rollback segment rb2 offline;
alter rollback segment rb3 offline;
alter rollback segment rb4 offline;
alter rollback segment rb5 offline;
alter rollback segment rb6 offline;
alter rollback segment rb7 offline;
alter rollback segment rb8 offline;
alter rollback segment rb9 offline;
alter rollback segment rb10 offline;
alter rollback segment rb11 offline;
alter rollback segment rb12 offline;
alter rollback segment rb13 offline;
alter rollback segment rb14 offline;
alter rollback segment rb15 offline;
alter rollback segment rb16 offline;

--删除原有回滚段
drop rollback segment rb1;
drop rollback segment rb2;
drop rollback segment rb3;
drop rollback segment rb4;
drop rollback segment rb5;
drop rollback segment rb6;
drop rollback segment rb7;
drop rollback segment rb8;
drop rollback segment rb9;
drop rollback segment rb10;
drop rollback segment rb11;
drop rollback segment rb12;
drop rollback segment rb13;
drop rollback segment rb14;
drop rollback segment rb15;
drop rollback segment rb16;

以下表空间的名称应尽量有定的含义；下面只是举例说明所有名称任意取得；
--建数据表空间1
--出口
create tablespace USER_DATA1 datafile
'/oradata1/user1_1.ora' size 512M,
'/oradata1/user1_2.ora' size 512M,
'/oradata1/user1_3.ora' size 512M,
'/oradata1/user1_4.ora' size 512M,
AUTOEXTEND ON NEXT 5M MAXSIZE UNLIMITED
default storage (initial 128K next 2M pctincrease 0);
--initial 128K，因为，用户建在表空间上，而表建在用户里，为用户所拥有，
--用户继承数据表空间的存储参数，表继承用户的存储参数
--如果initial设的过大，如：5M，则每建一个空表就要占用5M的空间，即使一条记录也没有
--AUTOEXTEND ON NEXT 5M MAXSIZE UNLIMITED，设置数据文件自动扩展，每一次扩展增加5M，最大空间不受限

--建数据表空间2
--进口
create tablespace USER_DATA2 datafile
'/oradata2/user2_1.ora' size 512M,
'/oradata2/user2_2.ora' size 512M,
'/oradata2/user2_3.ora' size 512M,
'/oradata2/user2_4.ora' size 512M,
AUTOEXTEND ON NEXT 5M MAXSIZE UNLIMITED
default storage (initial 128K next 2M pctincrease 0);


--建数据表空间3
--报刊
create tablespace USER_DATA3 datafile
'/oradata3/user3_1.ora' size 512M,
'/oradata3/user3_2.ora' size 512M,
'/oradata3/user3_3.ora' size 512M,
'/oradata3/user3_4.ora' size 512M,
AUTOEXTEND ON NEXT 5M MAXSIZE UNLIMITED
default storage (initial 128K next 2M pctincrease 0);


--建数据表空间4
--帐务和管理等
create tablespace USER_DATA4 datafile
'/oradata4/user4_1.ora' size 512M,
'/oradata4/user4_2.ora' size 512M,
'/oradata4/user4_3.ora' size 512M,
'/oradata4/user4_4.ora' size 512M,
AUTOEXTEND ON NEXT 5M MAXSIZE UNLIMITED
default storage (initial 128K next 2M pctincrease 0);

--建索引表空间1
--建索引表空间2
--建索引表空间3
--建索引表空间4
与上述创建过程类似

--建回滚表空间1
--设置初始值40M（initial 40M），则每在这个表空间中建一个回滚段，
--此回滚段自动继承此回滚表空间的存储参数，也即默认文件为40M
create tablespace ROLLBACK_DATA1 datafile
'/oradata1/roll1_1.ora' size 512M，
'/oradata1/roll1_2.ora' size 512M
AUTOEXTEND ON NEXT 5M MAXSIZE UNLIMITED
default storage (initial 40M next 5M pctincrease 0);

--建回滚表空间2
create tablespace ROLLBACK_DATA2 datafile
'/oradata2/roll2_1.ora' size 512M,
'/oradata/roll2_2.ora' size 512M
AUTOEXTEND ON NEXT 5M MAXSIZE UNLIMITED
default storage (initial 40M next 5M pctincrease 0);

--建临时表空间1
create tablespace TEMPORARY_DATA1 datafile
'/oradata3/temp1_1.ora' size 512M
default storage (initial 10M next 3M pctincrease 0);

--建临时表空间2
create tablespace TEMPORARY_DATA2 datafile
'/oradata4/temp2_1.ora' size 512M
default storage (initial 10M next 3M pctincrease 0);

--使其真正成为临时的
alter tablespace TEMPORARY_DATA1 temporary;
alter tablespace TEMPORARY_DATA2 temporary;

--建立新的回滚段，每个都一样大，不同大小的回滚段没有什么意义，系统是随机选择的。（但可以在编程时指定使用回滚段）
--建多少个，根据并发访问用户的多少，
--如果每天有300-1000个人员使用Oracle系统开发的管理软件，应该100个以上

create public rollback segment rb01 tablespace rollback_data1;
create public rollback segment rb02 tablespace rollback_data1;
create public rollback segment rb03 tablespace rollback_data1;
create public rollback segment rb04 tablespace rollback_data1;
create public rollback segment rb05 tablespace rollback_data1;
create public rollback segment rb06 tablespace rollback_data1;
create public rollback segment rb07 tablespace rollback_data1;
create public rollback segment rb08 tablespace rollback_data1;
create public rollback segment rb09 tablespace rollback_data1;
create public rollback segment rb10 tablespace rollback_data1;
。。。。。。。。。。。。。。。。。。。。。。。。。
--前50个建在回滚表空间1中，后50个在回滚表空间2
create public rollback segment rb11 tablespace rollback_data2;
create public rollback segment rb12 tablespace rollback_data2;
create public rollback segment rb13 tablespace rollback_data2;
create public rollback segment rb14 tablespace rollback_data2;
create public rollback segment rb15 tablespace rollback_data2;
create public rollback segment rb16 tablespace rollback_data2;
create public rollback segment rb17 tablespace rollback_data2;
create public rollback segment rb18 tablespace rollback_data2;
create public rollback segment rb19 tablespace rollback_data2;
create public rollback segment rb20 tablespace rollback_data2;
。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。

--使回滚段online，即有效
alter rollback segment rb01 online;
alter rollback segment rb02 online;
alter rollback segment rb03 online;
alter rollback segment rb04 online;
alter rollback segment rb05 online;
alter rollback segment rb06 online;
alter rollback segment rb07 online;
alter rollback segment rb08 online;
alter rollback segment rb09 online;
alter rollback segment rb10 online;
alter rollback segment rb11 online;
alter rollback segment rb12 online;
alter rollback segment rb13 online;
alter rollback segment rb14 online;
alter rollback segment rb15 online;
alter rollback segment rb16 online;
alter rollback segment rb17 online;
alter rollback segment rb18 online;
alter rollback segment rb19 online;
alter rollback segment rb20 online;
。。。。。。。。。。。。。。。。。。。。。。。。。。。。。

--查看现有回滚段及其状态
col segment format a30
SELECT SEGMENT_NAME,OWNER,TABLESPACE_NAME,SEGMENT_ID,FILE_ID,STATUS FROM DBA_ROLLBACK_SEGS;

--查看数据文件及其所在表空间、大小、状态
col file_name format a40
col tablespace_name format a20
select file_name,file_id,tablespace_name,bytes,status from dba_data_files;



至此，表空间重新规划完毕，这里讲的比较通俗，还有好多参数值得设置，能够把Oracle设置到最优的境界，

[littledonkey]

靠，好强！