Oracle DG之--构建Physical Standby 系统环境： 操作系统： RedHat EL4 Oracle: Oracle 10.2.0.1.0 650) this.width=650;" src="http://www.68idc.cn/help/uploads/allimg/151111/121R54538-0.jpg" title="dg2.png" alt="wKioL1R28C2B7wXmAACOWpabg-4498.jpg
Oracle DG之--构建Physical Standby
系统环境：
操作系统： RedHat EL4
Oracle: Oracle 10.2.0.1.0
从以上图中所示：主库为bj（db_unique_name)，备库为sh。
案例分析：
本案例采用RMAN Duplicate方式建立standby database。
一、配置主备库初始化参数
主库的初始化参数：initbj.ora
[oracle@ocmtest dbs]$ more initbj.ora *.audit_file_dest='/u01/app/oracle/admin/bj/adump' *.background_dump_dest='/u01/app/oracle/admin/bj/bdump' *.compatible='10.2.0.1.0' *.control_files='/u01/app/oracle/oradata/bj/control01.ctl','/u01/app/oracle/oradata/bj/control02.ctl','/u01/app/oracle/oradata/bj/control 03.ctl' *.core_dump_dest='/u01/app/oracle/admin/bj/cdump' *.db_block_size=8192 *.db_domain='' *.db_file_multiblock_read_count=16 *.db_name='bj' *.db_recovery_file_dest='/u01/app/oracle/flash_recovery_area' *.db_recovery_file_dest_size=2147483648 *.dispatchers='(PROTOCOL=TCP) (SERVICE=bjXDB)' *.job_queue_processes=10 *.open_cursors=300 *.pga_aggregate_target=68157440 *.processes=150 *.remote_login_passwordfile='EXCLUSIVE' *.sga_target=205520896 *.undo_management='AUTO' *.undo_tablespace='UNDOTBS1' *.user_dump_dest='/u01/app/oracle/admin/bj/udump'
以下为DG配置参数:
DB_UNIQUE_NAME=bj LOG_ARCHIVE_CONFIG='DG_CONFIG=(bj,sh)' LOG_ARCHIVE_DEST_1='LOCATION=/u01/disk1/arch/bj/ VALID_FOR=(ALL_LOGFILES,ALL_ROLES) DB_UNIQUE_NAME=bj' LOG_ARCHIVE_DEST_2='SERVICE=sh LGWR ASYNC VALID_FOR=(ONLINE_LOGFILES,PRIMARY_ROLE) DB_UNIQUE_NAME=sh' LOG_ARCHIVE_DEST_STATE_1=ENABLE LOG_ARCHIVE_DEST_STATE_2=ENABLE REMOTE_LOGIN_PASSWORDFILE=EXCLUSIVE LOG_ARCHIVE_MAX_PROCESSES=3 FAL_SERVER=sh FAL_CLIENT=bj DB_FILE_NAME_CONVERT='/u01/app/oracle/oradata/sh/','/u01/app/oracle/oradata/bj/' LOG_FILE_NAME_CONVERT='/u01/app/oracle/oradata/sh/','/u01/app/oracle/oradata/bj/' STANDBY_FILE_MANAGEMENT=AUTO
备库的初始化参数：initsh.ora
[oracle@ocmtest1 dbs]$ more initsh.ora *.audit_file_dest='/u01/app/oracle/admin/sh/adump' *.background_dump_dest='/u01/app/oracle/admin/sh/bdump' *.compatible='10.2.0.1.0' *.control_file_record_keep_time=7 *.control_files='/u01/app/oracle/oradata/sh/control01.ctl','/u01/app/oracle/oradata/sh/control02.ctl','/u01/app/oracle/oradata/sh/control 03.ctl' *.core_dump_dest='/u01/app/oracle/admin/sh/cdump' *.db_block_size=8192 *.db_domain='' *.db_file_multiblock_read_count=16 *.DB_FILE_NAME_CONVERT='/u01/app/oracle/oradata/bj/','/u01/app/oracle/oradata/sh/' *.db_name='bj' *.db_recovery_file_dest='/u01/app/oracle/flash_recovery_area' *.db_recovery_file_dest_size=2147483648 *.open_cursors=300 *.pga_aggregate_target=68157440 *.processes=150 *.REMOTE_LOGIN_PASSWORDFILE='EXCLUSIVE' *.sga_target=205520896 *.undo_management='AUTO' *.undo_tablespace='UNDOTBS1' *.user_dump_dest='/u01/app/oracle/admin/sh/udump'
以下为DG配置参数:
*.DB_UNIQUE_NAME='sh' *.FAL_CLIENT='sh' *.FAL_SERVER='bj' *.job_queue_processes=10 *.LOG_ARCHIVE_CONFIG='DG_CONFIG=(bj,sh)' *.LOG_ARCHIVE_DEST_1='LOCATION=/u01/disk1/arch/sh/ VALID_FOR=(ALL_LOGFILES,ALL_ROLES) DB_UNIQUE_NAME=sh' *.LOG_ARCHIVE_DEST_2='SERVICE=bj LGWR ASYNC VALID_FOR=(ONLINE_LOGFILES,PRIMARY_ROLE) DB_UNIQUE_NAME=bj' *.LOG_ARCHIVE_DEST_STATE_1='ENABLE' *.LOG_ARCHIVE_DEST_STATE_2='ENABLE' *.log_archive_format='arch_%t_%s_%r.log' *.LOG_ARCHIVE_MAX_PROCESSES=3 *.LOG_FILE_NAME_CONVERT='/u01/app/oracle/oradata/bj/','/u01/app/oracle/oradata/sh/' *.STANDBY_FILE_MANAGEMENT='AUTO'
二、在主库上建立standby 日志
对于默认的最大性能的保护方式，可以不用建立standby redo logfiles；但建立standby redo logfiles可以更好的保存redo log；standby redo日志组组数应等于或多于redo log，日志的大小应该一致。
SQL> alter database add standby logfile group 4 ('/u01/app/oracle/oradata/bj/redo04.log') size 50m;
SQL> alter database add standby logfile group 5 ('/u01/app/oracle/oradata/bj/redo05.log.rdo') size 50m;
SQL> alter database add standby logfile group 6 ('/u01/app/oracle/oradata/bj/redo06.log') size 50m;
三、在备库上建立相应目录：
[oracle@ocmtest1 dbs]$mkdir -p /u01/app/oracle/admin/sh/adump [oracle@ocmtest1 dbs]$mkdir -p /u01/app/oracle/admin/sh/udump [oracle@ocmtest1 dbs]$mkdir -p /u01/app/oracle/admin/sh/bdump [oracle@ocmtest1 dbs]$mkdir -p /u01/app/oracle/admin/sh/cdump [oracle@ocmtest1 dbs]$mkdir -p /u01/app/oracle/oradata/sh
四、在主库生成备库的controlfile和备份
1、数据库在mount 状态下
06:57:41 SQL> alter database create standby controlfile as '/home/oracle/std_control01.ctl';
2、 将生成的控制文件，拷贝到备库相同的目录下
[oracle@ocmtest1 ~]$ scp /home/oracle/std_control01.ctl 192.168.8.86:/home/oracle
对主库进行备份
[oracle@ocmtest bj]$ rman target /
Recovery Manager: Release 10.2.0.1.0 - Production on Wed Aug 31 10:55:55 2011
Copyright (c) 1982, 2005, Oracle. All rights reserved.
connected to target database (not started)
RMAN> run {
2> startup force mount;
3> backup database format='/u01/disk1/rman/bj/bj_%s.bak' plus archivelog;
4> alter database open;
5> }五、在备库上Duplicate Database（备库启动到弄mount）
1）在备库上建立/u01/disk1/rman/bj目录
拷贝主库的备份到备库/u01/disk1/rman/bj目录（拷贝到相同的目录下）
[oracle@ocmtest bj]$ scp /u01/disk1/rman/bj/bj_*.bak 192.168.8.86:/u01/disk1/rman/bj
2）配置Oracle network
因为，备库启动到no mount 状态，拒绝用户远程联机，所以采用静态注册，如下所示备库listenter
[oracle@ocmtest1 admin]$ cat listener.ora
# listener.ora Network Configuration File: /u01/app/oracle/product/10.2.0/db_1/network/admin/listener.ora
# Generated by Oracle configuration tools.
SID_LIST_LISTENER =
(SID_LIST =
(SID_DESC =
(SID_NAME = PLSExtProc)
(ORACLE_HOME = /u01/app/oracle/product/10.2.0/db_1)
(PROGRAM = extproc)
)
(SID_DESC =
(GLOBAL_DBNAME = bj)
(ORACLE_HOME = /u01/app/oracle/product/10.2.0/db_1)
(SID_NAME = bj)
)
)
LISTENER =
(DESCRIPTION_LIST =
(DESCRIPTION =
(ADDRESS = (PROTOCOL = TCP)(HOST = ocmtest1.51CTO提醒您，请勿滥发广告!)(PORT = 1521))
(ADDRESS = (PROTOCOL = IPC)(KEY = EXTPROC0))
)
)
如下所示：主库的tnsnames文件：
[oracle@ocmtest1 admin]$
[oracle@ocmtest admin]$ cat tnsnames.ora
# tnsnames.ora Network Configuration File: /u01/app/oracle/product/10.2.0/db_1/network/admin/tnsnames.ora
# Generated by Oracle configuration tools.
BJ =
(DESCRIPTION =
(ADDRESS_LIST =
(ADDRESS = (PROTOCOL = TCP)(HOST = 192.168.8.84)(PORT = 1521))
)
(CONNECT_DATA =
(SERVICE_NAME = bj)
)
)
SH =
(DESCRIPTION =
(ADDRESS_LIST =
(ADDRESS = (PROTOCOL = TCP)(HOST = 192.168.8.86)(PORT = 1521))
)
(CONNECT_DATA =
(SERVICE_NAME = sh)
(UR=A) ；添加此项连接到静态注册的备库
)
)
测试连接备库
[oracle@ocmtest bj]$ sqlplus sys/oracle@sh as sysdba
SQL*Plus: Release 10.2.0.1.0 - Production on Wed Aug 31 11:19:32 2011
Copyright (c) 1982, 2005, Oracle. All rights reserved.
Connected to:
Oracle Database 10g Enterprise Edition Release 10.2.0.1.0 - Production
With the Partitioning, OLAP and Data Mining options
SQL> exit
Disconnected from Oracle Database 10g Enterprise Edition Release 10.2.0.1.0 - Production
With the Partitioning, OLAP and Data Mining options
通过主库连接到备库，进行恢复（通过克隆方式建立备库）
[oracle@ocmtest bj]$ rman target /
Recovery Manager: Release 10.2.0.1.0 - Production on Wed Aug 31 11:19:36 2011
Copyright (c) 1982, 2005, Oracle. All rights reserved.
connected to target database: BJ (DBID=1015723911)
RMAN> connect auxiliary sys/oracle@sh;
connected to auxiliary database: BJ (not mounted)
RMAN> duplicate target database for standby;
Starting Duplicate Db at 31-AUG-11
using target database control file instead of recovery catalog
allocated channel: ORA_AUX_DISK_1
channel ORA_AUX_DISK_1: sid=155 devtype=DISK
contents of Memory Script:
{
restore clone standby controlfile;
sql clone 'alter database mount standby database';
}
executing Memory Script
Starting restore at 31-AUG-11
using channel ORA_AUX_DISK_1
channel ORA_AUX_DISK_1: restoring control file
channel ORA_AUX_DISK_1: copied control file copy
input filename=/home/oracle/stand.ctl
output filename=/u01/app/oracle/oradata/sh/control01.ctl
output filename=/u01/app/oracle/oradata/sh/control02.ctl
output filename=/u01/app/oracle/oradata/sh/control03.ctl
Finished restore at 31-AUG-11
sql statement: alter database mount standby database
released channel: ORA_AUX_DISK_1
contents of Memory Script:
{
set newname for tempfile 1 to
"/u01/app/oracle/oradata/sh/temp01.dbf";
switch clone tempfile all;
set newname for datafile 1 to
"/u01/app/oracle/oradata/sh/system01.dbf";
set newname for datafile 2 to
"/u01/app/oracle/oradata/sh/undotbs01.dbf";
set newname for datafile 3 to
"/u01/app/oracle/oradata/sh/sysaux01.dbf";
set newname for datafile 4 to
"/u01/app/oracle/oradata/sh/users01.dbf";
set newname for datafile 5 to
"/u01/app/oracle/oradata/sh/example01.dbf";
restore
check readonly
clone database
;
}
executing Memory Script
executing command: SET NEWNAME
renamed temporary file 1 to /u01/app/oracle/oradata/sh/temp01.dbf in control file
executing command: SET NEWNAME
executing command: SET NEWNAME
executing command: SET NEWNAME
executing command: SET NEWNAME
executing command: SET NEWNAME
Starting restore at 31-AUG-11
allocated channel: ORA_AUX_DISK_1
channel ORA_AUX_DISK_1: sid=155 devtype=DISK
channel ORA_AUX_DISK_1: starting datafile backupset restore
channel ORA_AUX_DISK_1: specifying datafile(s) to restore from backup set
restoring datafile 00001 to /u01/app/oracle/oradata/sh/system01.dbf
restoring datafile 00002 to /u01/app/oracle/oradata/sh/undotbs01.dbf
restoring datafile 00003 to /u01/app/oracle/oradata/sh/sysaux01.dbf
restoring datafile 00004 to /u01/app/oracle/oradata/sh/users01.dbf
restoring datafile 00005 to /u01/app/oracle/oradata/sh/example01.dbf
channel ORA_AUX_DISK_1: reading from backup piece /u01/disk1/rman/bj/bj_2.bak
channel ORA_AUX_DISK_1: restored backup piece 1
piece handle=/u01/disk1/rman/bj/bj_2.bak tag=TAG20110831T105953
channel ORA_AUX_DISK_1: restore complete, elapsed time: 00:00:48
Finished restore at 31-AUG-11
contents of Memory Script:
{
switch clone datafile all;
}
executing Memory Script
datafile 1 switched to datafile copy
input datafile copy recid=10 stamp=760621486 filename=/u01/app/oracle/oradata/sh/system01.dbf
datafile 2 switched to datafile copy
input datafile copy recid=11 stamp=760621487 filename=/u01/app/oracle/oradata/sh/undotbs01.dbf
datafile 3 switched to datafile copy
input datafile copy recid=12 stamp=760621487 filename=/u01/app/oracle/oradata/sh/sysaux01.dbf
datafile 4 switched to datafile copy
input datafile copy recid=13 stamp=760621487 filename=/u01/app/oracle/oradata/sh/users01.dbf
datafile 5 switched to datafile copy
input datafile copy recid=14 stamp=760621487 filename=/u01/app/oracle/oradata/sh/example01.dbf
Finished Duplicate Db at 31-AUG-11
---备库建立完毕，并启动到mount状态！
六、在备库上启动MRP进程
11:40:28 SQL> SELECT status from v$instance; STATUS ------------ MOUNTED 11:45:40 SQL> alter database recover managed standby database disconnect from session; Database altered. 告警日志： alter database recover managed standby database disconnect from session Wed Aug 31 11:46:00 2011 Attempt to start background Managed Standby Recovery process (sh) MRP0 started with pid=22, OS id=14159 Wed Aug 31 11:46:01 2011 MRP0: Background Managed Standby Recovery process started (sh) Managed Standby Recovery not using Real Time Apply Wed Aug 31 11:46:06 2011 Errors in file /u01/app/oracle/admin/sh/bdump/sh_mrp0_14159.trc: ORA-00313: open failed for members of log group 1 of thread 1 ORA-00312: online log 1 thread 1: '/u01/app/oracle/oradata/sh/redo01.log' ORA-27037: unable to obtain file status Linux Error: 2: No such file or directory Additional information: 3 Wed Aug 31 11:46:06 2011 Errors in file /u01/app/oracle/admin/sh/bdump/sh_mrp0_14159.trc: ORA-00313: open failed for members of log group 1 of thread 1 ORA-00312: online log 1 thread 1: '/u01/app/oracle/oradata/sh/redo01.log' ORA-27037: unable to obtain file status Linux Error: 2: No such file or directory Additional information: 3 Clearing online redo logfile 1 /u01/app/oracle/oradata/sh/redo01.log Clearing online log 1 of thread 1 sequence number 23 Wed Aug 31 11:46:06 2011 Errors in file /u01/app/oracle/admin/sh/bdump/sh_mrp0_14159.trc: ORA-00313: open failed for members of log group 1 of thread 1 ORA-00312: online log 1 thread 1: '/u01/app/oracle/oradata/sh/redo01.log' ORA-27037: unable to obtain file status Linux Error: 2: No such file or directory Additional information: 3 Wed Aug 31 11:46:07 2011 Completed: alter database recover managed standby database disconnect from session Wed Aug 31 11:46:08 2011 Clearing online redo logfile 1 complete Wed Aug 31 11:46:08 2011 Errors in file /u01/app/oracle/admin/sh/bdump/sh_mrp0_14159.trc: ORA-00313: open failed for members of log group 2 of thread 1 ORA-00312: online log 2 thread 1: '/u01/app/oracle/oradata/sh/redo02.log' ORA-27037: unable to obtain file status Linux Error: 2: No such file or directory Additional information: 3 Wed Aug 31 11:46:08 2011 Errors in file /u01/app/oracle/admin/sh/bdump/sh_mrp0_14159.trc: ORA-00313: open failed for members of log group 2 of thread 1 ORA-00312: online log 2 thread 1: '/u01/app/oracle/oradata/sh/redo02.log' ORA-27037: unable to obtain file status Linux Error: 2: No such file or directory Additional information: 3 Clearing online redo logfile 2 /u01/app/oracle/oradata/sh/redo02.log Clearing online log 2 of thread 1 sequence number 21 Wed Aug 31 11:46:08 2011 Errors in file /u01/app/oracle/admin/sh/bdump/sh_mrp0_14159.trc: ORA-00313: open failed for members of log group 2 of thread 1 ORA-00312: online log 2 thread 1: '/u01/app/oracle/oradata/sh/redo02.log' ORA-27037: unable to obtain file status Linux Error: 2: No such file or directory Additional information: 3 Clearing online redo logfile 2 complete Wed Aug 31 11:46:09 2011 Errors in file /u01/app/oracle/admin/sh/bdump/sh_mrp0_14159.trc: ORA-00313: open failed for members of log group 3 of thread 1 ORA-00312: online log 3 thread 1: '/u01/app/oracle/oradata/sh/redo03.log' ORA-27037: unable to obtain file status Linux Error: 2: No such file or directory Additional information: 3 Wed Aug 31 11:46:09 2011 Errors in file /u01/app/oracle/admin/sh/bdump/sh_mrp0_14159.trc: ORA-00313: open failed for members of log group 3 of thread 1 ORA-00312: online log 3 thread 1: '/u01/app/oracle/oradata/sh/redo03.log' ORA-27037: unable to obtain file status Linux Error: 2: No such file or directory Additional information: 3 Clearing online redo logfile 3 /u01/app/oracle/oradata/sh/redo03.log Clearing online log 3 of thread 1 sequence number 22 Wed Aug 31 11:46:09 2011 Errors in file /u01/app/oracle/admin/sh/bdump/sh_mrp0_14159.trc: ORA-00313: open failed for members of log group 3 of thread 1 ORA-00312: online log 3 thread 1: '/u01/app/oracle/oradata/sh/redo03.log' ORA-27037: unable to obtain file status Linux Error: 2: No such file or directory Additional information: 3 Clearing online redo logfile 3 complete Media Recovery Waiting for thread 1 sequence 23 Wed Aug 31 11:47:00 2011 Using STANDBY_ARCHIVE_DEST parameter default value as /u01/disk1/arch/sh/ Redo Shipping Client Connected as PUBLIC -- Connected User is Valid RFS[1]: Assigned to RFS process 14219 RFS[1]: Identified database type as 'physical standby' Wed Aug 31 11:47:00 2011 RFS LogMiner: Client disabled from further notification Wed Aug 31 11:47:01 2011 Redo Shipping Client Connected as PUBLIC -- Connected User is Valid RFS[2]: Assigned to RFS process 14221 RFS[2]: Identified database type as 'physical standby' Wed Aug 31 11:47:01 2011 RFS[1]: Archived Log: '/u01/disk1/arch/sh/arch_1_7_760458507.log' RFS[1]: Archived Log: '/u01/disk1/arch/sh/arch_1_8_760458507.log' Wed Aug 31 11:47:01 2011 RFS[2]: Archived Log: '/u01/disk1/arch/sh/arch_1_6_760458507.log' RFS[2]: Archived Log: '/u01/disk1/arch/sh/arch_1_10_760458507.log' Wed Aug 31 11:47:01 2011 RFS[1]: Archived Log: '/u01/disk1/arch/sh/arch_1_9_760458507.log' Wed Aug 31 11:47:02 2011 RFS[2]: Archived Log: '/u01/disk1/arch/sh/arch_1_11_760458507.log' Wed Aug 31 11:47:02 2011 RFS[1]: Archived Log: '/u01/disk1/arch/sh/arch_1_12_760458507.log' Wed Aug 31 11:47:02 2011 RFS[2]: Archived Log: '/u01/disk1/arch/sh/arch_1_13_760458507.log' Wed Aug 31 11:47:02 2011 RFS[1]: Archived Log: '/u01/disk1/arch/sh/arch_1_14_760458507.log' Wed Aug 31 11:47:02 2011 RFS[2]: Archived Log: '/u01/disk1/arch/sh/arch_1_15_760458507.log' Wed Aug 31 11:47:02 2011 RFS[1]: Archived Log: '/u01/disk1/arch/sh/arch_1_16_760458507.log' Wed Aug 31 11:47:03 2011 RFS[2]: Archived Log: '/u01/disk1/arch/sh/arch_1_17_760458507.log' Wed Aug 31 11:47:03 2011 RFS[1]: Archived Log: '/u01/disk1/arch/sh/arch_1_18_760458507.log' RFS[1]: Archived Log: '/u01/disk1/arch/sh/arch_1_19_760458507.log' Wed Aug 31 11:47:03 2011 RFS[2]: Archived Log: '/u01/disk1/arch/sh/arch_1_20_760458507.log' RFS[2]: Archived Log: '/u01/disk1/arch/sh/arch_1_22_760458507.log' Wed Aug 31 11:47:04 2011 RFS[1]: Archived Log: '/u01/disk1/arch/sh/arch_1_21_760458507.log' Wed Aug 31 11:47:04 2011 RFS[2]: Archived Log: '/u01/disk1/arch/sh/arch_1_24_760458507.log' RFS[2]: Archived Log: '/u01/disk1/arch/sh/arch_1_25_760458507.log' Wed Aug 31 11:47:05 2011 RFS[1]: Archived Log: '/u01/disk1/arch/sh/arch_1_23_760458507.log' Wed Aug 31 11:47:05 2011 RFS[2]: Archived Log: '/u01/disk1/arch/sh/arch_1_26_760458507.log' RFS[2]: Archived Log: '/u01/disk1/arch/sh/arch_1_27_760458507.log' Wed Aug 31 11:47:05 2011 RFS[1]: Archived Log: '/u01/disk1/arch/sh/arch_1_28_760458507.log' Wed Aug 31 11:47:05 2011 RFS[2]: Archived Log: '/u01/disk1/arch/sh/arch_1_29_760458507.log' Wed Aug 31 11:47:05 2011 Media Recovery Log /u01/disk1/arch/sh/arch_1_23_760458507.log Media Recovery Log /u01/disk1/arch/sh/arch_1_24_760458507.log Media Recovery Log /u01/disk1/arch/sh/arch_1_25_760458507.log Media Recovery Log /u01/disk1/arch/sh/arch_1_26_760458507.log Media Recovery Log /u01/disk1/arch/sh/arch_1_27_760458507.log Media Recovery Log /u01/disk1/arch/sh/arch_1_28_760458507.log Media Recovery Log /u01/disk1/arch/sh/arch_1_29_760458507.log Media Recovery Waiting for thread 1 sequence 30
七、在主库上切换日志测试数据同步
RMAN> sql'alter system switch logfile'; sql statement: alter system switch logfile 备库告警日志： RFS[1]: No standby redo logfiles created RFS[1]: Archived Log: '/u01/disk1/arch/sh/arch_1_30_760458507.log' Wed Aug 31 11:48:06 2011 Redo Shipping Client Connected as PUBLIC -- Connected User is Valid RFS[3]: Assigned to RFS process 14234 RFS[3]: Identified database type as 'physical standby' Primary database is in MAXIMUM PERFORMANCE mode Primary database is in MAXIMUM PERFORMANCE mode RFS[3]: No standby redo logfiles created Wed Aug 31 11:48:08 2011 Media Recovery Log /u01/disk1/arch/sh/arch_1_30_760458507.log Media Recovery Waiting for thread 1 sequence 31 (in transit) ---备库接收到归档日志，并对其做Media Recover。
八、查看数据库信息：
18:02:08 SYS@ bj >select name,database_role,protection_mode from v$database; NAME DATABASE_ROLE PROTECTION_MODE --------- ---------------- -------------------- BJ PRIMARY MAXIMUM PERFORMANCE 18:02:50 SYS@ sh >select name,database_role,protection_mode from v$database; NAME DATABASE_ROLE PROTECTION_MODE --------- ---------------- -------------------- BJ PHYSICAL STANDBY MAXIMUM PERFORMANCE
----@此案例采用Oracle 10g的环境，对于备库在recover状态下，只能启动到mount状态，如果启动到open环境，则会停止recover，失去了数据保护的功能；对于Oracle 11g，Oracle启用了新的特性，“Active Standby”，可以将备库启动到open状态，并且可以继续recover，从而增强了备库的应用范围和备库的功能。
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Mysql dunia nyata: Contoh dan kes penggunaanApr 14, 2025 am 12:15 AMAplikasi dunia nyata MySQL termasuk reka bentuk pangkalan data asas dan pengoptimuman pertanyaan kompleks. 1) Penggunaan Asas: Digunakan untuk menyimpan dan mengurus data pengguna, seperti memasukkan, menanyakan, mengemas kini dan memadam maklumat pengguna. 2) Penggunaan lanjutan: Mengendalikan logik perniagaan yang kompleks, seperti perintah dan pengurusan inventori platform e-dagang. 3) Pengoptimuman Prestasi: Meningkatkan prestasi dengan menggunakan indeks, jadual partisi dan cache pertanyaan.
Perintah SQL di MySQL: Contoh PraktikalApr 14, 2025 am 12:09 AMPerintah SQL di MySQL boleh dibahagikan kepada kategori seperti DDL, DML, DQL, dan DCL, dan digunakan untuk membuat, mengubah suai, memadam pangkalan data dan jadual, memasukkan, mengemas kini, memadam data, dan melakukan operasi pertanyaan yang kompleks. 1. Penggunaan asas termasuk jadual penciptaan createtable, memasukkan data memasukkan, dan pilih data pertanyaan. 2. Penggunaan lanjutan melibatkan gabungan untuk Jadual Bergabung, Subqueries dan Groupby untuk Agregasi Data. 3. Kesilapan umum seperti kesilapan sintaks, jenis data yang tidak sepadan dan masalah kebenaran boleh disahpepijat melalui pemeriksaan sintaks, penukaran jenis data dan pengurusan kebenaran. 4. Cadangan Pengoptimuman Prestasi termasuk menggunakan indeks, mengelakkan pengimbasan jadual penuh, mengoptimumkan operasi gabungan dan menggunakan transaksi untuk memastikan konsistensi data.
Bagaimanakah InnoDB mengendalikan pematuhan asid?Apr 14, 2025 am 12:03 AMInnoDB mencapai atomik melalui undolog, konsistensi dan pengasingan melalui mekanisme penguncian dan MVCC, dan kegigihan melalui redolog. 1) Atomicity: Gunakan Undolog untuk merekodkan data asal untuk memastikan urus niaga dapat dilancarkan kembali. 2) Konsistensi: Memastikan konsistensi data melalui penguncian peringkat baris dan MVCC. 3) Pengasingan: Menyokong pelbagai tahap pengasingan, dan RepeatableRead digunakan secara lalai. 4) Kegigihan: Gunakan redolog untuk merekodkan pengubahsuaian untuk memastikan data disimpan untuk masa yang lama.
Tempat Mysql: Pangkalan Data dan PengaturcaraanApr 13, 2025 am 12:18 AMKedudukan MySQL dalam pangkalan data dan pengaturcaraan sangat penting. Ia adalah sistem pengurusan pangkalan data sumber terbuka yang digunakan secara meluas dalam pelbagai senario aplikasi. 1) MySQL menyediakan fungsi penyimpanan data, organisasi dan pengambilan data yang cekap, sistem sokongan web, mudah alih dan perusahaan. 2) Ia menggunakan seni bina pelanggan-pelayan, menyokong pelbagai enjin penyimpanan dan pengoptimuman indeks. 3) Penggunaan asas termasuk membuat jadual dan memasukkan data, dan penggunaan lanjutan melibatkan pelbagai meja dan pertanyaan kompleks. 4) Soalan -soalan yang sering ditanya seperti kesilapan sintaks SQL dan isu -isu prestasi boleh disahpepijat melalui arahan jelas dan log pertanyaan perlahan. 5) Kaedah pengoptimuman prestasi termasuk penggunaan indeks rasional, pertanyaan yang dioptimumkan dan penggunaan cache. Amalan terbaik termasuk menggunakan urus niaga dan preparedStatemen
Mysql: Dari perniagaan kecil ke perusahaan besarApr 13, 2025 am 12:17 AMMySQL sesuai untuk perusahaan kecil dan besar. 1) Perniagaan kecil boleh menggunakan MySQL untuk pengurusan data asas, seperti menyimpan maklumat pelanggan. 2) Perusahaan besar boleh menggunakan MySQL untuk memproses data besar dan logik perniagaan yang kompleks untuk mengoptimumkan prestasi pertanyaan dan pemprosesan transaksi.
Apa yang dibaca oleh Phantom dan bagaimana InnoDB menghalang mereka (kunci seterusnya)?Apr 13, 2025 am 12:16 AMInnoDB secara berkesan menghalang pembacaan hantu melalui mekanisme utama. 1) Kekunci seterusnya menggabungkan kunci baris dan kunci jurang untuk mengunci rekod dan jurang mereka untuk mengelakkan rekod baru daripada dimasukkan. 2) Dalam aplikasi praktikal, dengan mengoptimumkan pertanyaan dan menyesuaikan tahap pengasingan, persaingan kunci dapat dikurangkan dan prestasi konkurensi dapat ditingkatkan.
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