Advanced Replication同步复制实验(基于Trigger&基于Materialized View)

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1. 高级复制和流复制介绍

1.1 高级复制(Advanced Replication)

高级复制也称为对称复制，分为多主体站点复制(Multiple Master Rplication)、物化视图站点复制(Materialized View Replication)和前两种的混合复制。高级复制主要是用在对称的、等同的数据库(仅限Oracle数据库之间)表之间的(单向或双向)的复制，以满足分布式应用的需求。多主体站点复制基于Oracle的触发器(Trigger)捕获DML和DDL操作，并将这些操作封装在Remote Procedure Calls(RPCs)里，并借助Deferred Transaction Queue来传递RPCs并在目标数据库利用Internal Trigger执行传递过来的RPCs从而实现了数据的同步，如果仅仅是高级复制环境中的只读物化视图环境，那么会直接利用解析物化视图日志的方式来实现数据的同步，而不用DTQ来传递RPCs，基于这一特点，高级复制对网络的稳定性和传输速度要求较高，配置也稍显麻烦。另外一点要特别注意，就是物化视图复制方式不支持DDL的变更同步。

1.2 流复制(Stream)

流复制是Oracle 10g新推出的同步技术，基于logminer（数据库必须运行在Archive Log模式），通过Oracle Advanced Queue来实现数据的同步复制，可以实现表，用户，数据库级别的同步，而高级复制支持的对象仅为表，索引，同义词，触发器，视图，过程，函数，程序包，程序包体等。Stream相对高级复制而言配置简单,通过oracle gateway还可用于异构平台和异构数据库的数据同步，这是高级复制做不到的。

2. 基于触发器的用户表复制

环境：11.2.0.3+oel 5.7

主体站：host:zlm 192.168.1.55 sid:zlm11g/global name:zlm11g/net service name:zlm11g

复制站：host:adrep 192.168.1.65 sid:strmtarget/global name:target/net service name:target

以下操作如不指定目标端，即表示在源端操作

2.1 建立高级复制管理用户表空间，用户，并赋予权限

--source

SQL> conn sys/oracle@zlm11g as sysdba

SQL> create tablespace reptbs datafile '/u01/app/oracle/oradata/zlm11g/rep_tbs.dbf' size 20m reuse autoextend on maxsize unlimited;

SQL> create user repadmin identified by oracle default tablespace reptbs temporary tablespace temp quota unlimited on reptbs;

SQL> exec dbms_repcat_admin.grant_admin_any_schema('repadmin');

SQL> exec dbms_defer_sys.register_propagator('repadmin')

--target

SQL> conn system/oracle@target

SQL> create tablespace reptbs datafile '/u01/app/oracle/oradata/strmtarget/rep_tbs.dbf' size 20m reuse autoextend on maxsize unlimited;

SQL> create user repadmin identified by oracle default tablespace reptbs temporary tablespace temp quota unlimited on reptbs;

SQL> exec dbms_repcat_admin.grant_admin_any_schema('repadmin');

SQL> exec dbms_defer_sys.register_propagator('repadmin')

2.2 创建复制SCHEMA及复制表

--source

SQL> conn system/oracle@zlm11g

SQL> create user repuser identified by repuser default tablespace reptbs temporary tablespace temp quota unlimited on reptbs;

SQL> grant resource,connect to repuser;

SQL> conn repuser/repuser@zlm11g;

SQL> create table rptest(id number primary key,name varchar2(20));

--target

SQL> conn system/oracle@target

SQL> create user repuser identified by repuser default tablespace reptbs temporary tablespace temp quota unlimited on reptbs;

SQL> grant resource,connect to repuser;

SQL> conn repuser/repuser@target

SQL> create table rptest(id number primary key,name varchar2(20));

2.3 创建dblink

--source

SQL> conn repadmin/oracle@zlm11g

SQL> alter system set job_queue_process=10 --11g默认是1000,也可以不用设置

SQL> alter system set global_names = true; --11g默认是false，需要设置

SQL> create database link target connect to repadmin identified by oracle using 'target';

SQL> col db_link for a15

SQL> select owner,db_link from dba_db_links;

OWNER DB_LINK

------------------------------ ---------------

STRMADMIN TARGET

REPADMIN TARGET

SQL> select name from v$database@target;

NAME

---------

STRMTARG --目标端的db_name

--target

SQL> conn repadmin/oracle@target

SQL> alter system set job_queue_process=10

SQL> alter system set global_names = true;

SQL> create database link zlm11g connect to repadmin identified by oracle using 'zlm11g';

SQL> col db_link for a15

SQL> select owner,db_link from dba_db_links;

OWNER DB_LINK

------------------------------ ---------------

STRMADMIN STRMTARGET

REPADMIN ZLM11G

2.4 创建复制组

SQL> conn repadmin/oracle@zlm11g

SQL> exec dbms_repcat.create_master_repgroup('rep_gp');

SQL> select gname,master,status from dba_repgroup where gname='REP_GP';

GNAME MASTER STATUS

--------------- --------------- ---------

REP_GP Y QUIESCED

2.5 添加复制对象(此处是表)

SQL> exec dbms_repcat.create_master_repobject(sname=>'repuser',oname=>'rptest',type=>'table',use_existing_object=>true,gname=>'rep_gp',copy_rows=>false);

SQL> select sname,oname,status,gname from dba_repobject where gname='REP_GP';

SNAME ONAME STATUS GNAME

------------------------------ ------------------------------ ---------- ------------------------------

REPUSER RPTEST VALID REP_GP

2.6 对复制对象启动复制支持

SQL> exec dbms_repcat.generate_replication_support('repuser','rptest','table');

SQL> select sname,oname,status,gname from dba_repobject where gname='REP_GP';

SNAME ONAME STATUS GNAME

------------------------------ ------------------------------ ---------- ------------------------------

REPUSER RPTEST VALID REP_GP

REPUSER RPTEST$RP VALID REP_GP

启用复制支持以后会多出ONAME=’%ONAME$RP’的两行内容，并且目标端也的dba_repobject也会生成相应内容，源端执行复制之前的内容是空的

2.7 添加复制主体节点

SQL> exec dbms_repcat.add_master_database(gname=>'rep_gp',master=>'target',

use_existing_objects=>true,copy_rows=>false,propagation_mode=>'synchronous');

SQL> col gname format a15

SQL> col dblink format a15

SQL> col masterdef for a15

SQL> col master format a15

SQL> select gname,dblink,masterdef,master from dba_repsites where gname='REP_GP';

GNAME DBLINK MASTERDEF MASTER

--------------- --------------- --------------- ---------------

REP_GP ZLM11G Y Y

REP_GP TARGET N Y

2.8 登录主体复制节点(目标端)查看复制站点信息和复制对象信息

SQL> conn repadmin/oracle@target

SQL> select gname,dblink,masterdef,master from dba_repsites where gname='REP_GP';

GNAME DBLINK MASTERDEF MASTER

--------------- --------------- --------------- ---------------

REP_GP TARGET N Y

REP_GP ZLM11G Y Y

SQL> select sname,oname,status,gname from dba_repobject where gname='REP_GP';

SNAME ONAME STATUS GNAME

------------------------------ ------------------------------ ---------- ---------------

REPUSER RPTEST VALID REP_GP

REPUSER RPTEST$RP VALID REP_GP

2.9 主体定义站启动复制

SQL> exec dbms_repcat.resume_master_activity('rep_gp');

2.10 测试复制同步(DML)

2.10.1 主体定义站测试用户修改测试表

SQL> conn repuser/repuser@zlm11g

Connected.

SQL> insert into rptest values(1,'aaron8219');

1 row created.

SQL> commit;

Commit complete.

2.10.2 主体站登录测试用户验证测试表同步

SQL> conn repuser/repuser@target

Connected.

SQL> select * from rptest;

ID NAME

---------- --------------------

1 aaron8219

可以看到，表数据可以已经同步

这里还碰到了一个小插曲，就是原先没有先在主体站(target端)先创建dblink，等创建完复制组，复制对象，启用复制支持，创建复制站后，发现不能同步，再去补创建dblink后，删除复制组，复制对象后依然不见效，复制定义主站对表进行操作时，皆会报如下错误：

SQL> insert into rptest values(3,'zhao');

insert into rptest values(3,'zhao')

ERROR at line 1:

ORA-24277: invalid database link "REPUSER"."RPTEST$RP"."REP_INSERT"

ORA-02063: preceding line from TARGET

SQL> delete from rptest;

delete from rptest

ERROR at line 1:

ORA-24277: invalid database link "REPUSER"."RPTEST$RP"."REP_DELETE"

ORA-02063: preceding line from TARGET

[oracle@zlm ~]$ oerr ora 24277

24277, 00000, "invalid database link %s "

// *Cause: The database link did not exist.

// *Action: Make sure the database link name is correct.

查看了一下，关于这个报错，是因为dblink名字不对，可能和之前没有立即在target端创建到主体定义站的dblink，之后才创建有关。删除dblink后重新再两端创建dblink，再把复制组，复制对象过程重新再走一遍，问题解决。

2.11 测试复制同步(DDL)

2.11.1 修改表结构

如果要做ddl同步，需要把复制组先挂起，做ddl后重新生成复制支持，然后把组resume

SQL> conn repadmin/oracle@zlm11g

SQL> exec dbms_repcat.suspend_master_activity('rep_gp');

SQL> exec dbms_repcat.alter_master_repobject(sname => 'repuser',oname => 'rptest',type => 'table',ddl_text =>'alter table repuser.rptest add(city varchar(10))');

SQL> exec dbms_repcat.generate_replication_support(sname => 'repuser',oname => 'rptest',type => 'table',min_communication => true,generate_80_compatible => false);

SQL> select gname,master,status from dba_repgroup where gname='REP_GP';

SQL> select sname,oname,status,gname from dba_repobject where gname='REP_GP';

2.11.2 验证结果

SQL> conn repuser/repuser@zlm11g

Connected.

SQL> set lin 30 pages 200

SQL> desc rptest

Name Null? Type

----------------- -------- ------------

ID NOT NULL NUMBER

NAME VARCHAR2(20)

CITY VARCHAR2(10)

SQL> conn repuser/repuser@target

Connected.

SQL> set lin 30 pages 200

SQL> desc rptest

Name Null? Type

----------------- -------- ------------

ID NOT NULL NUMBER

NAME VARCHAR2(20)

CITY VARCHAR2(10)

可以看到，修改表结构的DDL操作也已经同步过来了

SQL> show user

USER is "REPUSER"

SQL> insert into rptest values(2,'zlm','shanghai');

insert into rptest values(2,'zlm','shanghai')

ERROR at line 1:

ORA-23326: object group

"PUBLIC"."REP_GP" is quiesced

SQL> !

[oracle@zlm ~]$ oerr ora 23326

23326, 00000, "object group \"%s\".\"%s\" is quiesced"

// *Cause: Either suspend_master_activity has been called before the object

// group has resumed normal operation or a (deferred) rpc operation

// was attempted while the object group was quiesced.

// *Action: If suspend_master_activity has been called and a

// resume_master_activity request is pending, wait until it

// completes, and then reinvoke suspend_master_activity.

// Otherwise, resume database activity with the resume_master_activity

// call.

[oracle@zlm ~]$ exit

exit

SQL> conn repadmin/oracle@zlm11g

Connected.

SQL> exec dbms_repcat.resume_master_activity('rep_gp');

PL/SQL procedure successfully completed.

SQL> select gname,master,status from dba_repgroup where gname='REP_GP';

GNAME MASTER STATUS

--------------- --------------- ---------

REP_GP Y NORMAL

SQL> conn repuser/repuser@zlm11g

Connected.

SQL> insert into rptest values(2,'zlm','shanghai');

1 row created.

SQL> commit;

Commit complete.

SQL> conn repuser/repuser@target

SQL> set lin 120 pages 200

SQL> select * from rptest;

ID NAME CITY

---------- -------------------- ----------

2 zlm shanghai

1 aaron8219

2.12 清除操作

如果实验中遇到不能同步，可以删除以下对象后重新做一遍(通常只需删除复制组，对象会一并删除)

删除用户

SQL> drop user repadmin cascade;

SQL> drop user repuser cascade;

删除复制对象

SQL> exec dbms_repcat.drop_master_repobject(sname=>'repuser',oname =>'rptest',

type=>'table');

删除复制组

SQL> exec dbms_repcat.drop_master_repgroup(gname=>'rep_gp',all_sites=>true);

检查错误的管理请求

SQL> select * from dba_repcatlog where status ='ERROR';

3. 基于物化视图的复制

3.1 源端赋予复制用户权限

SQL> conn system/oracle@zlm11g

SQL> grant comment any table to repuser;

SQL> grant lock any table to repuser;

SQL> grant execute any procedure to repuser;

SQL> grant create any table to repuser;

SQL> grant create materialized view to repuser;

3.2 源端创建测试表

SQL> conn repuser/repuser@zlm11g

SQL> create table mvtest(id number(5) primary key);

SQL> begin

for i in 1..5 loop

insert into mvtest values(i);

end loop;

end;

3.3 源端创建物化视图日志

SQL> create materialized view log on mvtest with primary key including new values;

3.4 目标端赋予复制用户权限

SQL> conn system/oracle@target

SQL> grant create database link to repuser;

SQL> grant create materialized view to repuser;

SQL> grant execute any procedure to repuser;

3.5 目标端创建物化视图

3.5.1 创建DBlink

SQL> conn repuser/repuser@target

SQL> alter system set global_names = true;

SQL> create database link zlm11g connect to repuser identified by repuser using 'zlm11g';

SQL> select db_link,owner from all_db_links;

DB_LINK OWNER

--------------- ------------------------------

ZLM11G REPUSER

3.5.2 创建测试表

SQL> create table mvtest as select * from repuser.mvtest@zlm11g where 1=2;

SQL> desc mvtest;

Name Null? Type

----------------------- -------- ----------------

ID NOT NULL NUMBER(5)

SQL> select * from mvtest;

no rows selected

3.5.3 创建物化视图

SQL> create materialized view mvtest

on prebuilt table

refresh force with primary key

on demand

as select * from repuser.mvtest@zlm11g;

3.6 全量刷新

SQL> exec dbms_mview.refresh('mvtest','complete');

3.7 验证目标端数据

SQL> conn repuser/repuser@target

SQL> select * from mvtest;

----------

SQL> conn repuser/repuser@zlm11g

SQL> insert into mvtest values(6);

1 row created.

SQL> commit;

Commit complete.

SQL> conn repuser/repuser@target

SQL> select * from mvtest;

----------

源端新插入的一条记录并没有同步过来，目标端再执行一次全量刷新

SQL> conn repuser/repuser@target

SQL> exec dbms_mview.refresh('mvtest','complete');

SQL> select * from mvtest;

----------

又一次同步了mvtest表的数据，以上是最简单的基于手动的刷新物化视图，另外还可以配置job，让物化视图定期刷新。注意，物化视图复制并不支持DDL的复制

查看源端复制用户基表中的物化视图日志

SQL> select * from repuser.mlog$_mvtest;

查看目标物化视图的刷新情况

SQL> select mview_name,owner from user_mviews;

SQL> select * from user_jobs;

SQL> select * from dba_jobs_running;

查看物化视图所在的基表最后被成功刷新的时间

SQL> select master,log_table,current_snapshots from dba_snapshot_logs;

4 总结

高级复制(Advanced Replication)可以说是Oracle最早的HA技术了，最早出现于Oracle 7e，之后的8i,9i继续沿用，一直到10g，出现了流技术(Stream)，高级复制技术才逐渐开始被取代，虽然一直到11g，还是可以使用AR技术，但其弊端是显而易见的，由于它的复制机制是基于Oracle的内部对象触发器(Trigger)，他会严格控制事务的一致性，对于开发人员而言，也许是不错的特性，但是对于DBA来说，可谓是麻烦重重，一旦事务之间互相请求的资源被别的事务所占用，往往会造成等待，更严重的就是产生死锁，造成数据库hang住。虽然如此，高级复制技术的物化视图，还是有一定的利用价值的，因为它并不通过内部触发器来控制对象的复制，这样就可以把容易消耗资源的查询分散到物化视图上，通过查询实时更新的物化视图来获取需要的报表数据，这对于提高数据库性能是由一定积极作用的。

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By aaron8219 Chinaunix Blog：http://blog.chinaunix.net/uid/24612962.html

原创内容，转载请注明链接，谢谢！

http://blog.csdn.net/aaron8219/article/details/11707137