Oracle 11g rac + Dataguard 环境调整 redo log 大小
目录
- Oracle 11g rac + Dataguard 环境调整 redo log 大小
- 一、问题的产生
- 1、查看日志文件、日志组信息
- 2、日志切换较快出现的问题
- 二、 确认 DG 同步是否正常
- 1、检查数据库角色
- 2、查看进程信息
- 3、检查归档是否一致
- 4、查看 GAP 是否有延迟
- 三、在主库上重建 redo log file
- 1、查看 redo 日志组及大小
- 2、在主库删除 standby log
- 3、在主库替换 redo log
- 4、主库添加 standby log
- 四、在备库上重建 standby log
- 步骤1：查看 redo 日志组及大小
- 步骤2：备库取消日志应用
- 步骤3：修改日志管理模式为手动
- 步骤4：删除备库 standby log
- 步骤5：备库新建 standby log
- 步骤6：主库切日志，将临时`standby logfile`切到`UNASSIGNED`状态，然后删除：
- 步骤7：打开实时应用日志和自动日志管理
- 步骤8：重新启动备库，查看数据同步情况
一、问题的产生
客户的生产库为 Oracle 11g rac双节点集群，并且配置有Dataguard，近期业务出现卡顿，检查发现日志文件异常，系统一共配置6组redo log（1号线程与2号线程各3组，每个日志文件的大小为100MB）与8组standby log（1号线程与2号线程各4组）。
1、查看日志文件、日志组信息
（1）日志文件信息
SQL> select * from v$logfile;
GROUP# STATUS TYPE MEMBER IS_
-----------------------------------------------------------------------------------
1 ONLINE +DATA/hisdb/onlinelog/redo01.log NO
2 ONLINE +DATA/hisdb/onlinelog/redo02.log NO
4 ONLINE +DATA/hisdb/onlinelog/redo04.log NO
5 ONLINE +DATA/hisdb/onlinelog/redo05.log NO
6 ONLINE +DATA/hisdb/onlinelog/redo06.log NO
3 ONLINE +DATA/hisdb/onlinelog/redo03.log NO
7 STANDBY +DATA/hisdb/onlinelog/group_7.446.1121009477 NO
8 STANDBY +DATA/hisdb/onlinelog/group_8.447.1121009483 NO
9 STANDBY +DATA/hisdb/onlinelog/group_9.448.1121009489 NO
10 STANDBY +DATA/hisdb/onlinelog/group_10.449.1121009493 NO
11 STANDBY +DATA/hisdb/onlinelog/group_11.450.1121009499 NO
12 STANDBY +DATA/hisdb/onlinelog/group_12.451.1121009507 NO
13 STANDBY +DATA/hisdb/onlinelog/group_13.452.1121009507 NO
14 STANDBY +DATA/hisdb/onlinelog/group_14.453.1121009507 NO
14 rows selected.
（2）日志组信息
SQL> select group#,thread#,sequence#,round(bytes/1024/1024,2) size_mb,members,archived,status,first_change#,first_time from v$log;
GROUP# THREAD# SEQUENCE# SIZE_MB MEMBERS ARC STATUS FIRST_CHANGE# FIRST_TIME
------------- ---------------------- ---------- ---------- ---------- ---------- --- ----------
1 2 114460 100 1 YES ACTIVE 9057709636 03-JAN-25
2 2 114461 100 1 YES ACTIVE 9057751045 03-JAN-25
3 2 114462 100 1 NO CURRENT 9057800557 03-JAN-25
4 1 324121 100 1 YES ACTIVE 9057794541 03-JAN-25
5 1 324122 100 1 NO CURRENT 9057807196 03-JAN-25
6 1 324120 100 1 YES ACTIVE 9057790272 03-JAN-25
6 rows selected.
（3）standby log信息
SQL> select group#,thread#,round(bytes/1024/1024,2) size_mb,status from v$standby_log;
GROUP# THREAD# SIZE_MB STATUS
---------- ---------- ---------- ----------
7 1 100 UNASSIGNED
8 1 100 UNASSIGNED
9 1 100 UNASSIGNED
10 1 100 UNASSIGNED
11 2 100 UNASSIGNED
12 2 100 UNASSIGNED
13 2 100 UNASSIGNED
14 2 100 UNASSIGNED
8 rows selected.
2、日志切换较快出现的问题
频繁的日志切换会增加CPU和I/O负载，因为每次切换都需要更新控制文件和数据字典，并且产生新的归档。
日志组循环写满以后，LGWR进程要覆盖先前的日志文件，如果未完成归档会导致无法切换，出现等待，数据库将陷于停顿状态，直到要覆盖的日志文件完成归档。
在生产环境中，设置一个相对合理的redo log大小是十分重要的，可以提升数据库的整体性能，减轻系统I/O负担，数据库恢复时间合理。
理想性状态下，平均一个小时切换2-4次较为合理。
使用以下脚本可以查看日志每小时切换次数，平均每小时2-4次合适，也就是15-30分钟切一次日志。
set linesize 120
set pagesize 100
column day format a15 heading 'Day'
column d_0 format a3 heading '00'
column d_1 format a3 heading '01'
column d_2 format a3 heading '02'
column d_3 format a3 heading '03'
column d_4 format a3 heading '04'
column d_5 format a3 heading '05'
column d_6 format a3 heading '06'
column d_7 format a3 heading '07'
column d_8 format a3 heading '08'
column d_9 format a3 heading '09'
column d_10 format a3 heading '10'
column d_11 format a3 heading '11'
column d_12 format a3 heading '12'
column d_13 format a3 heading '13'
column d_14 format a3 heading '14'
column d_15 format a3 heading '15'
column d_16 format a3 heading '16'
column d_17 format a3 heading '17'
column d_18 format a3 heading '18'
column d_19 format a3 heading '19'
column d_20 format a3 heading '20'
column d_21 format a3 heading '21'
column d_22 format a3 heading '22'
column d_23 format a3 heading '23'
select
substr(to_char(FIRST_TIME,'YYYY/MM/DD,DY'),1,15) day,
decode(sum(decode(substr(to_char(FIRST_TIME,'HH24'),1,2),'00',1,0)),0,'-',sum(decode(substr(to_char(FIRST_TIME,'HH24'),1,2),'00',1,0))) d_0,
decode(sum(decode(substr(to_char(FIRST_TIME,'HH24'),1,2),'01',1,0)),0,'-',sum(decode(substr(to_char(FIRST_TIME,'HH24'),1,2),'01',1,0))) d_1,
decode(sum(decode(substr(to_char(FIRST_TIME,'HH24'),1,2),'02',1,0)),0,'-',sum(decode(substr(to_char(FIRST_TIME,'HH24'),1,2),'02',1,0))) d_2,
decode(sum(decode(substr(to_char(FIRST_TIME,'HH24'),1,2),'03',1,0)),0,'-',sum(decode(substr(to_char(FIRST_TIME,'HH24'),1,2),'03',1,0))) d_3,
decode(sum(decode(substr(to_char(FIRST_TIME,'HH24'),1,2),'04',1,0)),0,'-',sum(decode(substr(to_char(FIRST_TIME,'HH24'),1,2),'04',1,0))) d_4,
decode(sum(decode(substr(to_char(FIRST_TIME,'HH24'),1,2),'05',1,0)),0,'-',sum(decode(substr(to_char(FIRST_TIME,'HH24'),1,2),'05',1,0))) d_5,
decode(sum(decode(substr(to_char(FIRST_TIME,'HH24'),1,2),'06',1,0)),0,'-',sum(decode(substr(to_char(FIRST_TIME,'HH24'),1,2),'06',1,0))) d_6,
decode(sum(decode(substr(to_char(FIRST_TIME,'HH24'),1,2),'07',1,0)),0,'-',sum(decode(substr(to_char(FIRST_TIME,'HH24'),1,2),'07',1,0))) d_7,
decode(sum(decode(substr(to_char(FIRST_TIME,'HH24'),1,2),'08',1,0)),0,'-',sum(decode(substr(to_char(FIRST_TIME,'HH24'),1,2),'08',1,0))) d_8,
decode(sum(decode(substr(to_char(FIRST_TIME,'HH24'),1,2),'09',1,0)),0,'-',sum(decode(substr(to_char(FIRST_TIME,'HH24'),1,2),'09',1,0))) d_9,
decode(sum(decode(substr(to_char(FIRST_TIME,'HH24'),1,2),'10',1,0)),0,'-',sum(decode(substr(to_char(FIRST_TIME,'HH24'),1,2),'10',1,0))) d_10,
decode(sum(decode(substr(to_char(FIRST_TIME,'HH24'),1,2),'11',1,0)),0,'-',sum(decode(substr(to_char(FIRST_TIME,'HH24'),1,2),'11',1,0))) d_11,
decode(sum(decode(substr(to_char(FIRST_TIME,'HH24'),1,2),'12',1,0)),0,'-',sum(decode(substr(to_char(FIRST_TIME,'HH24'),1,2),'12',1,0))) d_12,
decode(sum(decode(substr(to_char(FIRST_TIME,'HH24'),1,2),'13',1,0)),0,'-',sum(decode(substr(to_char(FIRST_TIME,'HH24'),1,2),'13',1,0))) d_13,
decode(sum(decode(substr(to_char(FIRST_TIME,'HH24'),1,2),'14',1,0)),0,'-',sum(decode(substr(to_char(FIRST_TIME,'HH24'),1,2),'14',1,0))) d_14,
decode(sum(decode(substr(to_char(FIRST_TIME,'HH24'),1,2),'15',1,0)),0,'-',sum(decode(substr(to_char(FIRST_TIME,'HH24'),1,2),'15',1,0))) d_15,
decode(sum(decode(substr(to_char(FIRST_TIME,'HH24'),1,2),'16',1,0)),0,'-',sum(decode(substr(to_char(FIRST_TIME,'HH24'),1,2),'16',1,0))) d_16,
decode(sum(decode(substr(to_char(FIRST_TIME,'HH24'),1,2),'17',1,0)),0,'-',sum(decode(substr(to_char(FIRST_TIME,'HH24'),1,2),'17',1,0))) d_17,
decode(sum(decode(substr(to_char(FIRST_TIME,'HH24'),1,2),'18',1,0)),0,'-',sum(decode(substr(to_char(FIRST_TIME,'HH24'),1,2),'18',1,0))) d_18,
decode(sum(decode(substr(to_char(FIRST_TIME,'HH24'),1,2),'19',1,0)),0,'-',sum(decode(substr(to_char(FIRST_TIME,'HH24'),1,2),'19',1,0))) d_19,
decode(sum(decode(substr(to_char(FIRST_TIME,'HH24'),1,2),'20',1,0)),0,'-',sum(decode(substr(to_char(FIRST_TIME,'HH24'),1,2),'20',1,0))) d_20,
decode(sum(decode(substr(to_char(FIRST_TIME,'HH24'),1,2),'21',1,0)),0,'-',sum(decode(substr(to_char(FIRST_TIME,'HH24'),1,2),'21',1,0))) d_21,
decode(sum(decode(substr(to_char(FIRST_TIME,'HH24'),1,2),'22',1,0)),0,'-',sum(decode(substr(to_char(FIRST_TIME,'HH24'),1,2),'22',1,0))) d_22,
decode(sum(decode(substr(to_char(FIRST_TIME,'HH24'),1,2),'23',1,0)),0,'-',sum(decode(substr(to_char(FIRST_TIME,'HH24'),1,2),'23',1,0))) d_23
from
gv$log_history where first_time> sysdate-60
group by
substr(to_char(FIRST_TIME,'YYYY/MM/DD,DY'),1,15)
order by
substr(to_char(FIRST_TIME,'YYYY/MM/DD,DY'),1,15) desc;
-- 运行结果如下：
Day 00 01 02 03 04 05 06 07 08 09 10 11 12 13 14 15 16 17 18 19 20 21 22 23
------- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- ---
2025/01/02,THU - - - - - - 1 - - - - - - - 5 - - - - - - - 1 -
2025/01/01,WED - - - - 1 - - - - - - - - - - - - 2 - 1 1 1 - -
2024/12/31,TUE - - - - - - - - - - - - - - - - 1 - - - - - - -
2024/12/30,MON - - - - - - - - - - - - - - - - - - - - - 4 2 -
经过分析日志的切换频率，拟把日志文件大小扩容为1024MB，操作步骤如下：
二、 确认 DG 同步是否正常
1、检查数据库角色
--主库
SQL> select db_unique_name, open_mode, switchover_status, database_role from v$database;
DB_UNIQUE_NAME OPEN_MODE SWITCHOVER_STATUS DATABASE_ROLE
---------------------------------------------- -------------------- --------------------
HISDB READ WRITE SESSIONS ACTIVE PRIMARY
--备库
SQL> select db_unique_name, open_mode, switchover_status, database_role from v$database;
DB_UNIQUE_NAME OPEN_MODE SWITCHOVER_STATUS DATABASE_ROLE
---------------------------------------------- -------------------- --------------------
DGHISDB READ ONLY WITH APPLY NOT ALLOWED PHYSICAL STANDBY
2、查看进程信息
（1）在主库查看LNS进程，此进程负责将主数据库的重做日志条目传输到备用数据库。
SQL> select process, status, sequence# from v$managed_standby;
PROCESS STATUS SEQUENCE#
--------- ------------ ----------
ARCH CLOSING 324114
ARCH CLOSING 317879
ARCH CLOSING 324115
ARCH CLOSING 324116
LNS WRITING 324117
（2）在备库查看MRP0进程，此进程负责将接收到的归档日志应用到备用数据库上，以维持与主数据库的同步。MRP进程是DG中的关键组件，它确保备用数据库的数据与主数据库保持一致。
SQL> select process, status, sequence# from v$managed_standby;
PROCESS STATUS SEQUENCE#
--------- ------------ ----------
ARCH CLOSING 324117
ARCH CLOSING 114458
ARCH CONNECTED 0
ARCH CLOSING 324116
RFS IDLE 324118
RFS IDLE 0
RFS IDLE 0
RFS IDLE 0
MRP0 APPLYING_LOG 324118
RFS IDLE 0
RFS IDLE 0
RFS IDLE 114459
RFS IDLE 0
13 rows selected.
3、检查归档是否一致
-- 主库
SQL> select max(sequence#),thread# from v$archived_log where RESETLOGS_CHANGE# = (SELECT RESETLOGS_CHANGE# FROM V$DATABASE_INCARNATION WHERE STATUS = 'CURRENT') GROUP BY THREAD#;
MAX(SEQUENCE#) THREAD#
-------------- ----------
324117 1
114458 2
-- 备库
SQL> select max(sequence#),thread# from v$archived_log where RESETLOGS_CHANGE# = (SELECT RESETLOGS_CHANGE# FROM V$DATABASE_INCARNATION WHERE STATUS = 'CURRENT') GROUP BY THREAD#;
MAX(SEQUENCE#) THREAD#
-------------- ----------
324117 1
114458 2
4、查看 GAP 是否有延迟
GAP产生的原因是，一般是备库已经长时间未与主库同步，等发现的时候，主库的归档日志已经删除，备库无法再次与主库同步，这时候GAP就产生了。
-- 主库
SQL> select * from v$archive_gap;
no rows selected
SQL> select STATUS, GAP_STATUS from V$ARCHIVE_DEST_STATUS where DEST_ID = 2;
STATUS GAP_STATUS
--------- ------------------------
VALID NO GAP
-- 备库
SQL> select * from v$archive_gap;
no rows selected
SQL> select STATUS, GAP_STATUS from V$ARCHIVE_DEST_STATUS where DEST_ID = 2;
STATUS GAP_STATUS
--------- ------------------------
VALID RESOLVABLE GAP
三、在主库上重建 redo log file
1、查看 redo 日志组及大小
（1）查看日志文件
SQL> select * from v$logfile;
GROUP# STATUS TYPE MEMBER IS_
-----------------------------------------------------------------------------------
1 ONLINE +DATA/hisdb/onlinelog/redo01.log NO
2 ONLINE +DATA/hisdb/onlinelog/redo02.log NO
4 ONLINE +DATA/hisdb/onlinelog/redo04.log NO
5 ONLINE +DATA/hisdb/onlinelog/redo05.log NO
6 ONLINE +DATA/hisdb/onlinelog/redo06.log NO
3 ONLINE +DATA/hisdb/onlinelog/redo03.log NO
7 STANDBY +DATA/hisdb/onlinelog/group_7.446.1121009477 NO
8 STANDBY +DATA/hisdb/onlinelog/group_8.447.1121009483 NO
9 STANDBY +DATA/hisdb/onlinelog/group_9.448.1121009489 NO
10 STANDBY +DATA/hisdb/onlinelog/group_10.449.1121009493 NO
11 STANDBY +DATA/hisdb/onlinelog/group_11.450.1121009499 NO
12 STANDBY +DATA/hisdb/onlinelog/group_12.451.1121009507 NO
13 STANDBY +DATA/hisdb/onlinelog/group_13.452.1121009507 NO
14 STANDBY +DATA/hisdb/onlinelog/group_14.453.1121009507 NO
14 rows selected.
（2）查看redo log信息
SQL> select group#,thread#,sequence#,round(bytes/1024/1024,2) size_mb,members,archived,status,first_change#,first_time from v$log;
GROUP# THREAD# SEQUENCE# SIZE_MB MEMBERS ARC STATUS FIRST_CHANGE# FIRST_TIME
------------- ---------------------- ---------- ---------- ---------- ---------- --- ----------
1 2 114460 100 1 YES ACTIVE 9057709636 03-JAN-25
2 2 114461 100 1 YES ACTIVE 9057751045 03-JAN-25
3 2 114462 100 1 NO CURRENT 9057800557 03-JAN-25
4 1 324121 100 1 YES ACTIVE 9057794541 03-JAN-25
5 1 324122 100 1 NO CURRENT 9057807196 03-JAN-25
6 1 324120 100 1 YES ACTIVE 9057790272 03-JAN-25
6 rows selected.
（3）查看standby log信息
SQL> select group#,thread#,round(bytes/1024/1024,2) size_mb,status from v$standby_log;
GROUP# THREAD# SIZE_MB STATUS
---------- ---------- ---------- ----------
7 1 100 UNASSIGNED
8 1 100 UNASSIGNED
9 1 100 UNASSIGNED
10 1 100 UNASSIGNED
11 2 100 UNASSIGNED
12 2 100 UNASSIGNED
13 2 100 UNASSIGNED
14 2 100 UNASSIGNED
8 rows selected.
2、在主库删除 standby log
删除旧的 standby log（group: 7-14）：
alter database drop logfile group 7;
alter database drop logfile group 8;
alter database drop logfile group 9;
alter database drop logfile group 10;
alter database drop logfile group 11;
alter database drop logfile group 12;
alter database drop logfile group 13;
alter database drop logfile group 14;
3、在主库替换 redo log
步骤1：添加两组临时日志文件：
节点1：
alter database add logfile thread 1 group 14 '+DATA' size 1024M;
alter database add logfile thread 1 group 15 '+DATA' size 1024M;
节点2：
alter database add logfile thread 2 group 16 '+DATA' size 1024M;
alter database add logfile thread 2 group 17 '+DATA' size 1024M;
SQL> select group#,thread#,sequence#,round(bytes/1024/1024,2) size_mb,members,archived,status,first_change#,first_time from v$log;
GROUP# THREAD# SEQUENCE# SIZE_MB MEMBERS ARC STATUS FIRST_CHANGE# FIRST_TIME
---------- ---------- ---------- ---------- ---------- --- ---------------- ------------- ------------
1 2 114484 100 1 YES ACTIVE 9058578050 03-JAN-25
2 2 114485 100 1 YES ACTIVE 9058584300 03-JAN-25
3 2 114483 100 1 YES ACTIVE 9058554867 03-JAN-25
4 1 324142 100 1 YES ACTIVE 9058579106 03-JAN-25
5 1 324140 100 1 YES INACTIVE 9058515833 03-JAN-25
6 1 324141 100 1 YES ACTIVE 9058538032 03-JAN-25
14 1 324143 1024 1 NO CURRENT 9058623959 03-JAN-25
15 1 0 1024 1 YES UNUSED 0
16 2 114486 1024 1 NO CURRENT 9058621526 03-JAN-25
17 2 0 1024 1 YES UNUSED 0
10 rows selected.
步骤2：切日志，让旧的日志文件（group: 1-6）组为INACTIVE：
alter system switch logfile;
alter system checkpoint;
select group#,thread#,sequence#,round(bytes/1024/1024,2) size_mb,members,archived,status,first_change#,first_time from v$log;
SQL> select group#,thread#,sequence#,round(bytes/1024/1024,2) size_mb,members,archived,status,first_change#,first_time from v$log;
GROUP# THREAD# SEQUENCE# SIZE_MB MEMBERS ARC STATUS FIRST_CHANGE# FIRST_TIME
---------- ---------- ---------- ---------- ---------- --- ---------------- ------------- ------------
1 2 114484 100 1 YES INACTIVE 9058578050 03-JAN-25
2 2 114485 100 1 YES INACTIVE 9058584300 03-JAN-25
3 2 114483 100 1 YES INACTIVE 9058554867 03-JAN-25
4 1 324142 100 1 YES INACTIVE 9058579106 03-JAN-25
5 1 324140 100 1 YES INACTIVE 9058515833 03-JAN-25
6 1 324141 100 1 YES INACTIVE 9058538032 03-JAN-25
14 1 324143 1024 1 YES INACTIVE 9058623959 03-JAN-25
15 1 324144 1024 1 NO CURRENT 9058634615 03-JAN-25
16 2 114486 1024 1 NO CURRENT 9058621526 03-JAN-25
17 2 0 1024 1 YES UNUSED 0
10 rows selected.
步骤3：删除1-6组日志文件：
alter database drop logfile group 1;
alter database drop logfile group 2;
alter database drop logfile group 3;
alter database drop logfile group 4;
alter database drop logfile group 5;
alter database drop logfile group 6;
SQL> select group#,thread#,sequence#,round(bytes/1024/1024,2) size_mb,members,archived,status,first_change#,first_time from v$log;
GROUP# THREAD# SEQUENCE# SIZE_MB MEMBERS ARC STATUS FIRST_CHANGE# FIRST_TIME
---------- ---------- ---------- ---------- ---------- --- ---------------- ------------- ------------
14 1 324143 1024 1 YES INACTIVE 9058623959 03-JAN-25
15 1 324144 1024 1 NO CURRENT 9058634615 03-JAN-25
16 2 114486 1024 1 NO CURRENT 9058621526 03-JAN-25
17 2 0 1024 1 YES UNUSED 0
步骤4：添加新的日志文件：
/*
SQL> select * from v$logfile;
GROUP# STATUS TYPE MEMBER IS_
-----------------------------------------------------------------------------------
1 ONLINE +DATA/hisdb/onlinelog/redo01.log NO
2 ONLINE +DATA/hisdb/onlinelog/redo02.log NO
4 ONLINE +DATA/hisdb/onlinelog/redo04.log NO
5 ONLINE +DATA/hisdb/onlinelog/redo05.log NO
6 ONLINE +DATA/hisdb/onlinelog/redo06.log NO
3 ONLINE +DATA/hisdb/onlinelog/redo03.log NO
7 STANDBY +DATA/hisdb/onlinelog/group_7.446.1121009477 NO
8 STANDBY +DATA/hisdb/onlinelog/group_8.447.1121009483 NO
9 STANDBY +DATA/hisdb/onlinelog/group_9.448.1121009489 NO
10 STANDBY +DATA/hisdb/onlinelog/group_10.449.1121009493 NO
11 STANDBY +DATA/hisdb/onlinelog/group_11.450.1121009499 NO
12 STANDBY +DATA/hisdb/onlinelog/group_12.451.1121009507 NO
13 STANDBY +DATA/hisdb/onlinelog/group_13.452.1121009507 NO
14 STANDBY +DATA/hisdb/onlinelog/group_14.453.1121009507 NO
14 rows selected.
*/
alter database add logfile thread 2 group 1 '+DATA/hisdb/onlinelog/redo1.log' size 1024M;
alter database add logfile thread 2 group 2 '+DATA/hisdb/onlinelog/redo2.log' size 1024M;
alter database add logfile thread 2 group 3 '+DATA/hisdb/onlinelog/redo3.log' size 1024M;
alter database add logfile thread 1 group 4 '+DATA/hisdb/onlinelog/redo4.log' size 1024M;
alter database add logfile thread 1 group 5 '+DATA/hisdb/onlinelog/redo5.log' size 1024M;
alter database add logfile thread 1 group 6 '+DATA/hisdb/onlinelog/redo6.log' size 1024M;
SQL> select group#,thread#,sequence#,round(bytes/1024/1024,2) size_mb,members,archived,status,first_change#,first_time from v$log;
GROUP# THREAD# SEQUENCE# SIZE_MB MEMBERS ARC STATUS FIRST_CHANGE# FIRST_TIME
---------- ---------- ---------- ---------- ---------- --- ---------------- ------------- ------------
1 2 0 1024 1 YES UNUSED 0
2 2 0 1024 1 YES UNUSED 0
3 2 0 1024 1 YES UNUSED 0
4 1 0 1024 1 YES UNUSED 0
5 1 0 1024 1 YES UNUSED 0
6 1 0 1024 1 YES UNUSED 0
14 1 324143 1024 1 YES INACTIVE 9058623959 03-JAN-25
15 1 324144 1024 1 NO CURRENT 9058634615 03-JAN-25
16 2 114486 1024 1 NO CURRENT 9058621526 03-JAN-25
17 2 0 1024 1 YES UNUSED 0
10 rows selected.
步骤5：切日志，删除临时添加的日志文件：
alter system switch logfile;
alter system checkpoint;
SQL> select group#,thread#,sequence#,round(bytes/1024/1024,2) size_mb,members,archived,status,first_change#,first_time from v$log;
GROUP# THREAD# SEQUENCE# SIZE_MB MEMBERS ARC STATUS FIRST_CHANGE# FIRST_TIME
---------- ---------- ---------- ---------- ---------- --- ---------------- ------------- ------------
1 2 114487 1024 1 NO CURRENT 9058754188 03-JAN-25
2 2 0 1024 1 YES UNUSED 0
3 2 0 1024 1 YES UNUSED 0
4 1 324145 1024 1 YES INACTIVE 9058753823 03-JAN-25
5 1 324146 1024 1 NO CURRENT 9058759093 03-JAN-25
6 1 0 1024 1 YES UNUSED 0
14 1 324143 1024 1 YES INACTIVE 9058623959 03-JAN-25
15 1 324144 1024 1 YES INACTIVE 9058634615 03-JAN-25
16 2 114486 1024 1 YES INACTIVE 9058621526 03-JAN-25
17 2 0 1024 1 YES UNUSED 0
10 rows selected.
alter database drop logfile group 14;
alter database drop logfile group 15;
alter database drop logfile group 16;
alter database drop logfile group 17;
SQL> select group#,thread#,sequence#,round(bytes/1024/1024,2) size_mb,members,archived,status,first_change#,first_time from v$log;
GROUP# THREAD# SEQUENCE# SIZE_MB MEMBERS ARC STATUS FIRST_CHANGE# FIRST_TIME
---------- ---------- ---------- ---------- ---------- --- ---------------- ------------- ------------
1 2 114487 1024 1 NO CURRENT 9058754188 03-JAN-25
2 2 0 1024 1 YES UNUSED 0
3 2 0 1024 1 YES UNUSED 0
4 1 324145 1024 1 YES INACTIVE 9058753823 03-JAN-25
5 1 324146 1024 1 NO CURRENT 9058759093 03-JAN-25
6 1 0 1024 1 YES UNUSED 0
6 rows selected.
4、主库添加 standby log
Alter database add standby logfile thread 1 group 7 '+DATA/hisdb/onlinelog/standby07.log' size 1024m;
Alter database add standby logfile thread 1 group 8 '+DATA/hisdb/onlinelog/standby08.log' size 1024m;
Alter database add standby logfile thread 1 group 9 '+DATA/hisdb/onlinelog/standby09.log' size 1024m;
Alter database add standby logfile thread 1 group 10 '+DATA/hisdb/onlinelog/standby10.log' size 1024m;
Alter database add standby logfile thread 2 group 11 '+DATA/hisdb/onlinelog/standby11.log' size 1024m;
Alter database add standby logfile thread 2 group 12 '+DATA/hisdb/onlinelog/standby12.log' size 1024m;
Alter database add standby logfile thread 2 group 13 '+DATA/hisdb/onlinelog/standby13.log' size 1024m;
Alter database add standby logfile thread 2 group 14 '+DATA/hisdb/onlinelog/standby14.log' size 1024m;
四、在备库上重建 standby log
步骤1：查看 redo 日志组及大小
查看日志文件信息
SQL> select * from v$logfile;
GROUP# STATUS TYPE MEMBER IS_
------------------------------------------------------------------------
1 ONLINE /oradata/dghisdb/onlinelog/redo01.log NO
2 ONLINE /oradata/dghisdb/onlinelog/redo02.log NO
4 ONLINE /oradata/dghisdb/onlinelog/redo04.log NO
5 ONLINE /oradata/dghisdb/onlinelog/redo05.log NO
6 ONLINE /oradata/dghisdb/onlinelog/redo06.log NO
3 ONLINE /oradata/dghisdb/onlinelog/redo03.log NO
7 STANDBY /oradata/dghisdb/onlinelog/group_7.446.1121009477 NO
8 STANDBY /oradata/dghisdb/onlinelog/group_8.447.1121009483 NO
9 STANDBY /oradata/dghisdb/onlinelog/group_9.448.1121009489 NO
10 STANDBY /oradata/dghisdb/onlinelog/group_10.449.1121009493 NO
11 STANDBY /oradata/dghisdb/onlinelog/group_11.450.1121009499 NO
12 STANDBY /oradata/dghisdb/onlinelog/group_12.451.1121009507 NO
13 STANDBY /oradata/dghisdb/onlinelog/group_13.452.1121009507 NO
14 STANDBY /oradata/dghisdb/onlinelog/group_14.453.1121009507 NO
14 rows selected.
SQL> select group#,thread#,round(bytes/1024/1024,2) size_mb,status from v$standby_log;
GROUP# THREAD# SIZE_MB STATUS
---------- ---------- ---------- ----------
7 1 100 UNASSIGNED
8 1 100 UNASSIGNED
9 1 100 UNASSIGNED
10 1 100 UNASSIGNED
11 2 100 UNASSIGNED
12 2 100 UNASSIGNED
13 2 100 UNASSIGNED
14 2 100 UNASSIGNED
8 rows selected.
步骤2：备库取消日志应用
alter database recover managed standby database cancel;
步骤3：修改日志管理模式为手动
SQL> alter system set standby_file_management='manual';
SQL> show parameter standby_file_management
NAME TYPE VALUE
------------------------------------ ----------- ------------------------------
standby_file_management string manual
步骤4：删除备库 standby log
（1）添加两组临时standby log file：
alter database add standby logfile group 15 '/oradata/dghisdb/onlinelog/stlog15.log' size 1024m reuse;
alter database add standby logfile group 16 '/oradata/dghisdb/onlinelog/stlog16.log' size 1024m reuse;
（2）在主库切日志，将active状态切到临时文件上，将所有旧的standby log的status刷到UNASSIGNED：
SQL> alter system switch logfile;
--备库查看
SQL> select group#,thread#,round(bytes/1024/1024,2) size_mb,status from v$standby_log;
（3）删除旧的standby log file：
alter database drop logfile group 7;
alter database drop logfile group 8;
alter database drop logfile group 9;
alter database drop logfile group 10;
alter database drop logfile group 11;
alter database drop logfile group 12;
alter database drop logfile group 13;
alter database drop logfile group 14;
步骤5：备库新建 standby log
重新添加standby log，大小为1024m，group: 7-14：
alter database add standby logfile group 7 '/oradata/dghisdb/onlinelog/standby07.log' size 1024m reuse;
alter database add standby logfile group 8 '/oradata/dghisdb/onlinelog/standby08.log' size 1024m reuse;
alter database add standby logfile group 9 '/oradata/dghisdb/onlinelog/standby09.log' size 1024m reuse;
alter database add standby logfile group 10 '/oradata/dghisdb/onlinelog/standby10.log' size 1024m reuse;
alter database add standby logfile group 11 '/oradata/dghisdb/onlinelog/standby11.log' size 1024m reuse;
alter database add standby logfile group 12 '/oradata/dghisdb/onlinelog/standby12.log' size 1024m reuse;
alter database add standby logfile group 13 '/oradata/dghisdb/onlinelog/standby13.log' size 1024m reuse;
alter database add standby logfile group 14 '/oradata/dghisdb/onlinelog/standby14.log' size 1024m reuse;
步骤6：主库切日志，将临时standby logfile切到UNASSIGNED状态，然后删除：
alter database drop logfile group 15;
alter database drop logfile group 16;
说明：关于备库的 redo log 处理
通常情况下，备库为只读模式，不对数据库进行修改，不会启用redo log files。
另外，由于 DG 备库处于只读模式，因此，不对备库的 redo log 做任何操作。
步骤7：打开实时应用日志和自动日志管理
完成以上操作后，dg 环境的redo logfile和standby logfile就算更新完成了，接下来只需要恢复数据同步即可。
alter database recover managed standby database using current logfile disconnect;
alter system set standby_file_management='AUTO';
步骤8：重新启动备库，查看数据同步情况
SQL> select process ,status , sequence# from v$managed_standby;
PROCESS STATUS SEQUENCE#
--------- ------------ ----------
ARCH CLOSING 324152
ARCH CONNECTED 0
ARCH CONNECTED 0
ARCH CLOSING 114489
RFS IDLE 0
RFS IDLE 0
RFS IDLE 114490
RFS IDLE 0
RFS IDLE 324153
RFS IDLE 0
MRP0 APPLYING_LOG 324153
11 rows selected.
SQL> select group#,thread#,sequence#,archived,status from v$standby_log;
GROUP# THREAD# SEQUENCE# ARC STATUS
---------- ---------- ---------- --- ----------
7 2 114490 YES ACTIVE
8 2 0 NO UNASSIGNED
9 1 324153 YES ACTIVE
10 1 0 NO UNASSIGNED
11 0 0 YES UNASSIGNED
12 0 0 YES UNASSIGNED
13 0 0 YES UNASSIGNED
14 0 0 YES UNASSIGNED
8 rows selected.
