构建Dataguard逻辑备库指南

  一直想做一个logical standby,每次都是以失败告终，在屡败屡战之后，终于迎来了胜利！据说可以使用网格控制器点几下，简单的把物理备库转换成逻辑备库，下次有工夫的时候可以测试下！相信一切问题都是时间问题，一切烦恼都是自寻烦恼！下面来描述下如何将physical standby转换成logical standby,在开始之前，请先配好dataguard 的physical standby

physical standby配置请参考：
http://ylw6006.blog.51cto.com/470441/661105
dataguard各参数含义请参考：
http://space.itpub.net/519536/viewspace-578352
http://hi.baidu.com/edeed/blog/item/f54c6e06b92bc77703088174.html
 

环境介绍：
主库：
IP地址: 192.168.227.20/24
OS版本：Rhel5.4 32位
SID名称： orcl
db_name:  orcl
db_unique_name: primary

物理备库：(转换前)
IP地址: 192.168.227.30/24
OS版本：Rhel5.4 32位
SID名称： orcl
db_name:  orcl
db_unique_name: standby

逻辑备库：(转换后)
IP地址: 192.168.227.20/24
OS版本：Rhel5.4 32位
SID名称： orcl
db_name:  logdb
db_unique_name: logdb

一：在物理备库上确认归档日志apply正常

SQL> SELECT ARCH.THREAD# "Thread", ARCH.SEQUENCE# "Last Sequence Received",           APPL.SEQUENCE# "Last Sequence Applied"          FROM          (SELECT THREAD# ,SEQUENCE# FROM V$ARCHIVED_LOG          WHERE (THREAD#,FIRST_TIME )           IN          (SELECT THREAD#,MAX(FIRST_TIME) FROM V$ARCHIVED_LOG GROUP BY THREAD#)) ARCH,           (SELECT THREAD# ,SEQUENCE# FROM V$LOG_HISTORY WHERE (THREAD#,FIRST_TIME )           IN          (SELECT THREAD#,MAX(FIRST_TIME) FROM V$LOG_HISTORY GROUP BY THREAD#)) APPL      WHERE ARCH.THREAD# = APPL.THREAD# ORDER BY 1     Thread Last Sequence Received Last Sequence Applied ---------- ---------------------- ---------------------          1                     10                    10

二:在备库上停止接收和应用归档日志

SQL> alter database recover managed standby database cancel; Database altered.

三:配置主库  

SQL> show parameter log_archive_config; NAME                                 TYPE        VALUE ------------------------------------ ----------- ------------------------------ log_archive_config                   string      DG_CONFIG=(primary,logdb) SQL> show parameter dest_1; NAME                                 TYPE        VALUE ------------------------------------ ----------- ------------------------------ db_create_online_log_dest_1          string log_archive_dest_1                   string      LOCATION=/u01/arch/orcl valid_                                                  for=(all_logfiles,all_roles) d                                                  b_unique_name=primary              SQL> show parameter dest_2; //service=standby，这里standby指的是tns串 NAME                                 TYPE        VALUE ------------------------------------ ----------- ------------------------------ db_create_online_log_dest_2          string log_archive_dest_2                   string      service=standby lgwr async val                                                  id_for=(online_logfiles,primar                                                  y_role) db_unique_name=logdb SQL> !mkdir -p /u01/arch/standby/orcl SQL> alter system set log_archive_dest_3='LOCATION=/u01/arch/standby/orcl  VALID_FOR=(STANDBY_LOGFILES,STANDBY_ROLE)'; System altered.   在主库生成LogMiner字典,切换日志 SQL> execute dbms_logstdby.build; PL/SQL procedure successfully completed.

四：配置备库
将物理备库转换成逻辑备库，在这之前请确保物理备库使用spfile启动

SQL> alter database recover to logical standby logdb; Database altered.  SQL> shutdown immediate SQL> startup mount SQL> show parameter log_archive_config;  //dg_config后面的参数指的是db_unique_name NAME                                 TYPE        VALUE ------------------------------------ ----------- ------------------------------ log_archive_config                   string      DG_CONFIG=(primary,logdb) SQL> alter system set db_unique_name='logdb' scope=spfile; System altered SQL> alter system set log_archive_dest_1='LOCATION=/u01/arch/orcl valid_for=(online_logfiles,all_roles) db_unique_name=logdb' scope=spfile; System altered  SQL> !mkdir -p /u01/arch/standby/orcl SQL> alter system set log_archive_dest_3='LOCATION=/u01/arch/standby/orcl  VALID_FOR=(STANDBY_LOGFILES,STANDBY_ROLE)'; System altered. SQL> shutdown immediate 修改tnsnames.ora文件，主库上也需要修改 [oracle@orcl u01]$ tnsping standby TNS Ping Utility for Linux: Version 10.2.0.1.0 - Production on 28-SEP-2011 11:01:31 Copyright (c) 1997, 2005, Oracle.  All rights reserved. Used parameter files: Used TNSNAMES adapter to resolve the alias  ) ERVICE_NAME = logdb.herostart.com) 192.168.227.30)(PORT = 1521))  OK (20 msec)   将备库打开，置为应用sql模式 SQL> conn /as sysdba Connected to an idle instance. SQL> startup mount SQL> ALTER DATABASE OPEN RESETLOGS; Database altered. SQL> alter database start logical standby apply immediate; alter database start logical standby apply immediate * ERROR at line 1: ORA-16239: IMMEDIATE option not available without standby redo logs SQL> alter database add standby logfile group 4 '/u01/app/oracle/oradata/orcl/standby04.dbf' size 50M; Database altered. SQL> alter database add standby logfile group 5 '/u01/app/oracle/oradata/orcl/standby05.dbf' size 50M; Database altered. SQL> alter database add standby logfile group 6 '/u01/app/oracle/oradata/orcl/standby06.dbf' size 50M; Database altered. SQL> alter database start logical standby apply immediate; Database altered SQL> select name, database_role from v$database; NAME      DATABASE_ROLE --------- ---------------- LOGDB     LOGICAL STANDBY

五：测试

主库更新： SQL> select sysdate from dual; SYSDATE ------------------- 2011-09-28:14:07:04 SQL> update hr.employees set salary=200 where employee_id=100; 1 row updated. 备库查询： SQL> select salary from hr.employees where employee_id=100;     SALARY ----------        100 SQL> select sysdate from dual; SYSDATE ------------------- 2011-09-28:14:08:38 主库提交，切换日志 SQL> commit; Commit complete. SQL> alter system switch logfile; System altered. 备库再次查询 SQL> select salary from hr.employees where employee_id=100;     SALARY ----------        200

六：验证

SQL> SELECT SEQUENCE#, FIRST_TIME, NEXT_TIME, DICT_BEGIN, DICT_END FROM DBA_LOGSTDBY_LOG ORDER BY SEQUENCE#;  SEQUENCE# FIRST_TIME          NEXT_TIME           DIC DIC ---------- ------------------- ------------------- --- ---         24 2011-09-28:13:19:50 2011-09-28:13:46:09 NO  NO         25 2011-09-28:13:46:09 2011-09-28:14:09:11 NO  NO SQL>  select file_name,applied from DBA_LOGSTDBY_LOG ; FILE_NAME                                     APPLIED --------------------------------------------- -------- /u01/arch/standby/orcl/1_24_760125331.arc     YES /u01/arch/standby/orcl/1_25_760125331.arc     YES       SQL> SELECT EVENT_TIME, STATUS, EVENT FROM DBA_LOGSTDBY_EVENTS ORDER BY EVENT_TIME, COMMIT_SCN; EVENT_TIME           STATUS               EVENT -------------------- -------------------- -------------------------------- 2011-09-28:11:09:32  ORA-16111: log minin                      g and apply setting                      up 2011-09-28:11:28:04  ORA-16128: User init                      iated stop apply suc                      cessfully completed   2011-09-28:11:28:04  ORA-16112: log minin                      g and apply stopping   EVENT_TIME           STATUS               EVENT -------------------- -------------------- --------------------------------   2011-09-28:11:28:14  ORA-16111: log minin                      g and apply setting                      up     2011-09-28:11:53:23  ORA-16226: DDL skipp ALTER DATABASE OPEN                      ed due to lack of su                      pport 2011-09-28:12:49:31  ORA-16128: User init                      iated stop apply suc EVENT_TIME           STATUS               EVENT -------------------- -------------------- --------------------------------                      cessfully completed 2011-09-28:12:50:11  ORA-16111: log minin                      g and apply setting                      up 2011-09-28:13:23:59  ORA-16226: DDL skipp ALTER DATABASE OPEN                      ed due to lack of su                      pport 8 rows selected. [oracle@orcl orcl]$ tail -f /u01/app/oracle/admin/orcl/bdump/alert_orcl.log    Primary database is in MAXIMUM PERFORMANCE mode Wed Sep 28 14:09:13 2011 LOGMINER: Log Auto Delete - deleting: /u01/arch/orcl/1_22_760125331.arc Deleted file /u01/arch/orcl/1_22_760125331.arc Wed Sep 28 14:09:13 2011 LOGMINER: Log Auto Delete - deleting: /u01/arch/orcl/1_23_760125331.arc Deleted file /u01/arch/orcl/1_23_760125331.arc Wed Sep 28 14:09:13 2011 RFS[3]: Successfully opened standby log 4: '/u01/app/oracle/oradata/orcl/standby04.dbf' Wed Sep 28 14:09:15 2011 LOGMINER: Begin mining logfile: /u01/app/oracle/oradata/orcl/standby04.dbf Wed Sep 28 14:09:15 2011 RFS LogMiner: Registered logfile [/u01/arch/standby/orcl/1_25_760125331.arc] to LogMiner session id [1]   [oracle@orcl ~]$ ll /u01/arch/standby/orcl/* -rw-r----- 1 oracle oinstall  772608 Sep 28 13:46 /u01/arch/standby/orcl/1_24_760125331.arc -rw-r----- 1 oracle oinstall 1597952 Sep 28 14:09 /u01/arch/standby/orcl/1_25_760125331.arc   SQL> SELECT NAME, VALUE FROM V$LOGSTDBY_STATS; NAME                                                         VALUE ------------------------------------------------------------ ---------- number of preparers                                          1 number of appliers                                           5 maximum SGA for LCR cache                                    30 parallel servers in use                                      9 maximum events recorded                                      100 preserve commit order                                        TRUE transaction consistency                                      FULL record skip errors                                           Y record skip DDL                                              Y record applied DDL                                           N record unsupported operations                                N NAME                                                         VALUE ------------------------------------------------------------ ---------- coordinator state                                            IDLE transactions ready                                           364 transactions applied                                         364 coordinator uptime                                           10071 realtime logmining                                           Y apply delay                                                  0 Log Miner session ID                                         1 txns delivered to client                                     3466 DML txns delivered                                           1498 DDL txns delivered                                           11 CTAS txns delivered                                          0 NAME                                                         VALUE ------------------------------------------------------------ ---------- Recursive txns delivered                                     1957 Rolled back txns seen                                        6 LCRs delivered to client                                     11908 bytes of redo processed                                      11022032 bytes paged out                                              0 seconds spent in pageout                                     0 bytes checkpointed                                           0 seconds spent in checkpoint                                  0 bytes rolled back                                            0 seconds spent in rollback                                    0 seconds system is idle                                       2509 33 rows selected. SQL> SELECT APPLIED_SCN, LATEST_SCN, MINING_SCN, RESTART_SCN FROM V$LOGSTDBY_PROGRESS; APPLIED_SCN LATEST_SCN MINING_SCN RESTART_SCN ----------- ---------- ---------- -----------      550947     550963     550948      550948

七：排错

先前一直出现如下错误 SQL> SELECT TYPE, STATUS_CODE, STATUS FROM V$LOGSTDBY_PROCESS; TYPE                           STATUS_CODE        STATUS ------------------------------ ----------------------------------- COORDINATOR                    1291              ORA-01291: missing logfile  SQL> SELECT * FROM V$LOGSTDBY_STATE; PRIMARY_DBID SESSION_ID   REALTIME_APPLY          STATE ------------ -------------------------------------------------------   1287906064   1          Y              WAITING FOR DICTIONARY LOGS     后来发现是因为日志文件未从主库传送到备库，手动传送并注册后正常，传送不成功的原因是主库的log_archive_dest_2参数设置不正确导致 SQL> ALTER DATABASE REGISTER LOGICAL LOGFILE '/u01/arch/orcl/1_11_760125331.arc'; Database altered. SQL> ALTER DATABASE REGISTER LOGICAL LOGFILE '/u01/arch/orcl/1_12_760125331.arc'; Database altered. SQL> ALTER DATABASE REGISTER LOGICAL LOGFILE '/u01/arch/orcl/1_13_760125331.arc'; Database altered. SQL> ALTER DATABASE REGISTER LOGICAL LOGFILE '/u01/arch/orcl/1_14_760125331.arc'; Database altered. SQL> select session_id,state from v$logstdby_state; SESSION_ID STATE ---------- -------------------          1 LOADING DICTIONARY   值得一提的是逻辑备库会自动删除已经应用的日志   [oracle@orcl u01]$ tail -f /u01/app/oracle/admin/orcl/bdump/alert_orcl.log Deleted file /u01/arch/orcl/1_13_760125331.arc Wed Sep 28 11:53:54 2011 LOGMINER: End mining logfile: /u01/arch/orcl/1_15_760125331.arc Wed Sep 28 11:53:54 2011 LOGMINER: Begin mining logfile: /u01/arch/orcl/1_16_760125331.arc Wed Sep 28 11:53:55 2011 LOGMINER: End mining logfile: /u01/arch/orcl/1_16_760125331.arc Wed Sep 28 11:53:55 2011 LOGMINER: Log Auto Delete - deleting: /u01/arch/orcl/1_14_760125331.arc Deleted file /u01/arch/orcl/1_14_760125331.arc SQL> select file_name,applied from DBA_LOGSTDBY_LOG ; FILE_NAME                        APPLIED -------------------------------- -------- /u01/arch/orcl/1_15_760125331.arc CURRENT /u01/arch/orcl/1_16_760125331.arc CURRENT

八：备注

以下数据类型不被逻辑备库支持： NCLOB LONG LONG RAW BFILE ROWID UROWID 检查不被逻辑备库支持的表： SQL> SELECT DISTINCT OWNER,TABLE_NAME FROM DBA_LOGSTDBY_UNSUPPORTED ORDER BY OWNER,TABLE_NAME; 以下操作不被逻辑备库支持： ALTER DATABASE ALTER SESSION ALTER SNAPSHOT ALTER SNAPSHOT LOG ALTER SYSTEM SWITCH LOG CREATE CONTROL FILE CREATE DATABASE CREATE DATABASE LINK CREATE PFILE FROM SPFILE CREATE SCHEMA AUTHORIZATION CREATE SNAPSHOT CREATE SNAPSHOT LOG CREATE SPFILE FROM PFILE CREATE TABLE AS SELECT FROM A CLUSTER TABLE DROP DATABASE LINK DROP SNAPSHOT DROP SNAPSHOT LOG EXPLAIN LOCK TABLE RENAME SET CONSTRAINTS SET ROLE SET TRANSACTION 高级队列的管理和物化视图的刷新不被支持（DBMS_AQADM，DBMS_MVIEW_REFRESH） Logical Standby要求每张表应该有Primary key或者Unique index，如果必须有没有唯一性标示的表，那么可以激活Primary库的supplemental logging属性，但是这样将会在redo log中记录该表中每一条记录的所有字段作为标示，会大大增加redo log的记录量。   检查没有唯一性标示的表： SQL> SELECT OWNER, TABLE_NAME,BAD_COLUMN FROM DBA_LOGSTDBY_NOT_UNIQUE WHERE TABLE_NAME NOT IN (SELECT TABLE_NAME FROM DBA_LOGSTDBY_UNSUPPORTED);   如果可以确认表中有唯一标示的字段，但是又不想真正创建主键或者索引来增加更新的开销，那么可以创建disabled RELY类型的约束，比如： SQL> ALTER TABLE mytab ADD PRIMARY KEY (id, name) RELY DISABLE;   检查supplemental logging是否已经被激活。 SQL> SELECT SUPPLEMENTAL_LOG_DATA_PK, SUPPLEMENTAL_LOG_DATA_UI FROM V$DATABASE; 用以下方法激活Primary库的supplemental logging属性： SQL> ALTER DATABASE ADD SUPPLEMENTAL LOG DATA (PRIMARY KEY, UNIQUE INDEX) COLUMNS; 激活supplemental logging属性以后，作一次日志切换，保证当前日志中不包含非追加日志数据（nonsupplemental log）。 SQL> ALTER SYSTEM ARCHIVE LOG CURRENT;   创建一个新的表空间，用于LogMiner，否则Logical Standby需要的对象将默认创建在SYSTEM表空间中。 SQL> CREATE TABLESPACE logmnrts DATAFILE '/disk1/oracle/dbs/logmnrts.dbf' SIZE25MAUTOEXTEND ON MAXSIZE UNLIMITED; SQL> EXECUTE DBMS_LOGMNR_D.SET_TABLESPACE('logmnrts'); 无论是物理备库还是逻辑备库，都应该先启动备库，再启动主库；先关闭主库，后关闭备库！

参考文档：
http://avdeo.com/2010/05/04/converting-physical-standby-to-logical-oracle-dataguard-10g/

本文出自 “斩月” 博客，谢绝转载！