1、主库生成RMAN备份注意:要运用backupascompressedbackupset,可以节省相当的空间run{allocatechannelc1devicetypedisk;backupascompressedbackupsetformat/u0
1、主库生成RMAN备份
注意:要运用backup as compressed backupset,可以节省相当的空间
run
{
allocate channel c1 device type disk;
backup as compressed backupset format ' /u01/rmanbak/nfs/bk_%U' database;
sql 'alter system archive log current';
release channel c1;
}
2、主库生成从库的控制文件
SQL> alter database create standby controlfile as '/tmp/control01.ctl';
Database altered.
3、主库生成的RMAN备份和控制文件放置到从库制定的位置
因为RMAN备份直接放置到了用从库建立了NFS上,香港服务器租用,所以无需额外的传输,但控制文件需要移动到备库的相应目录
[oracle@dgserver standby]$ mv /u01/rmanbak/nfs/control01.ctl control01.ctl
[oracle@dgserver standby]$ cp control01.ctl control03.ctl
[oracle@dgserver standby]$ cp control01.ctl control02.ctl
4、从库RMAN恢复
[oracle@dgserver standby]$ rman target /
Recovery Manager: Release 10.2.0.5.0 - Production on Sun May 5 09:38:16 2013
Copyright (c) 1982, 2007, Oracle. All rights reserved.
connected to target database: PRIMARY (DBID=1656746419, not open)
RMAN> run {
allocate channel c1 device type disk;
allocate channel c2 device type disk;
allocate channel c3 device type disk;
allocate channel c4 device type disk;
restore database;
switch datafile all;
release channel c1;
release channel c2;
release channel c3;
release channel c4;
}
2> 3> 4> 5> 6> 7> 8> 9> 10> 11> 12>
using target database control file instead of recovery catalog
allocated channel: c1
channel c1: sid=1479 devtype=DISK
allocated channel: c2
channel c2: sid=1478 devtype=DISK
allocated channel: c3
channel c3: sid=1477 devtype=DISK
allocated channel: c4
channel c4: sid=1476 devtype=DISK
Starting restore at 05-MAY-13
channel c1: starting datafile backupset restore
channel c1: specifying datafile(s) to restore from backup set
restoring datafile 00001 to /u01/oradata/standby/system.262.789583545
restoring datafile 00002 to /u01/oradata/standby/undotbs1.263.789583551
restoring datafile 00003 to /u01/oradata/standby/sysaux.264.789583551
restoring datafile 00004 to /u01/oradata/standby/undotbs2.266.789583557
restoring datafile 00005 to /u01/oradata/standby/users.267.789583559
restoring datafile 00006 to /u01/oradata/standby/inman_index.282.789655375
restoring datafile 00007 to /u01/oradata/standby/in_adcphcled_data.285.789655539
restoring datafile 00008 to /u01/oradata/standby/in_xian_index.286.789655615
restoring datafile 00009 to /u01/oradata/standby/in_xian_data.287.789655707
restoring datafile 00010 to /u01/oradata/standby/tbs_catalog.288.789655837
restoring datafile 00011 to /u01/oradata/standby/eport_index.291.789656023
restoring datafile 00012 to /u01/oradata/standby/in_man_index.292.789656085
restoring datafile 00013 to /u01/oradata/standby/in_suzhou_data.293.789656119
restoring datafile 00014 to /u01/oradata/standby/in_man_data.294.789656245
restoring datafile 00015 to /u01/oradata/standby/in_adcphc_index.295.789656363
restoring datafile 00016 to /u01/oradata/standby/auditadcphc.298.789656683
restoring datafile 00017 to /u01/oradata/standby/in_adcphc_data.299.789656797
restoring datafile 00018 to /u01/oradata/standby/eport_data.302.789657055
restoring datafile 00019 to /u01/oradata/standby/in_suzhou_index.303.789657231
restoring datafile 00020 to /u01/oradata/standby/in_suzhou_data.312.789659221
restoring datafile 00021 to /u01/oradata/standby/users.315.789661229
restoring datafile 00022 to /u01/oradata/standby/users.318.789661589
restoring datafile 00023 to /u01/oradata/standby/users.319.789661839
restoring datafile 00024 to +DATA/in_suzhou_data
restoring datafile 00025 to /u01/oradata/standby/in_suzhou_data
restoring datafile 00026 to /u01/oradata/standby/in_suzhou_data.9154.810742355
restoring datafile 00027 to /u01/oradata/standby/in_adcphc_data.9090.810742665
restoring datafile 00028 to /u01/oradata/standby/system_data
channel c1: reading from backup piece /u01/rmanbak/inc0_PRIMARY_sho8r312_1_1
ORA-19870: error reading backup piece /u01/rmanbak/inc0_PRIMARY_sho8r312_1_1
ORA-19505: failed to identify file "/u01/rmanbak/inc0_PRIMARY_sho8r312_1_1"
ORA-27037: unable to obtain file status
Linux-x86_64 Error: 2: No such file or directory
Additional information: 3
failover to previous backup
channel c1: starting datafile backupset restore
channel c1: specifying datafile(s) to restore from backup set
restoring datafile 00001 to /u01/oradata/standby/system.262.789583545
restoring datafile 00002 to /u01/oradata/standby/undotbs1.263.789583551
restoring datafile 00003 to /u01/oradata/standby/sysaux.264.789583551
restoring datafile 00004 to /u01/oradata/standby/undotbs2.266.789583557
restoring datafile 00005 to /u01/oradata/standby/users.267.789583559
restoring datafile 00006 to /u01/oradata/standby/inman_index.282.789655375
restoring datafile 00007 to /u01/oradata/standby/in_adcphcled_data.285.789655539
restoring datafile 00008 to /u01/oradata/standby/in_xian_index.286.789655615
restoring datafile 00009 to /u01/oradata/standby/in_xian_data.287.789655707
restoring datafile 00010 to /u01/oradata/standby/tbs_catalog.288.789655837
restoring datafile 00011 to /u01/oradata/standby/eport_index.291.789656023
restoring datafile 00012 to /u01/oradata/standby/in_man_index.292.789656085
restoring datafile 00013 to /u01/oradata/standby/in_suzhou_data.293.789656119
restoring datafile 00014 to /u01/oradata/standby/in_man_data.294.789656245
restoring datafile 00015 to /u01/oradata/standby/in_adcphc_index.295.789656363
restoring datafile 00016 to /u01/oradata/standby/auditadcphc.298.789656683
restoring datafile 00017 to /u01/oradata/standby/in_adcphc_data.299.789656797
restoring datafile 00018 to /u01/oradata/standby/eport_data.302.789657055
restoring datafile 00019 to /u01/oradata/standby/in_suzhou_index.303.789657231
restoring datafile 00020 to /u01/oradata/standby/in_suzhou_data.312.789659221
restoring datafile 00021 to /u01/oradata/standby/users.315.789661229
restoring datafile 00022 to /u01/oradata/standby/users.318.789661589
restoring datafile 00023 to /u01/oradata/standby/users.319.789661839
restoring datafile 00024 to +DATA/in_suzhou_data
restoring datafile 00025 to /u01/oradata/standby/in_suzhou_data
restoring datafile 00026 to /u01/oradata/standby/in_suzhou_data.9154.810742355
restoring datafile 00027 to /u01/oradata/standby/in_adcphc_data.9090.810742665
restoring datafile 00028 to /u01/oradata/standby/system_data
channel c1: reading from backup piece /u01/rmanbak/nfs/bk_ppo8iqa9_1_1
ORA-19870: error reading backup piece /u01/rmanbak/nfs/bk_ppo8iqa9_1_1
ORA-19504: failed to create file "+DATA/in_suzhou_data"
ORA-17502: ksfdcre:3 Failed to create file +DATA/in_suzhou_data
ORA-15001: diskgroup "DATA" does not exist or is not mounted
ORA-15077: could not locate ASM instance serving a required diskgroup
ORA-29701: unable to connect to Cluster Manager
failover to previous backup
channel c1: starting datafile backupset restore
channel c1: specifying datafile(s) to restore from backup set
restoring datafile 00001 to /u01/oradata/standby/system.262.789583545
restoring datafile 00013 to /u01/oradata/standby/in_suzhou_data.293.789656119
restoring datafile 00017 to /u01/oradata/standby/in_adcphc_data.299.789656797
restoring datafile 00019 to /u01/oradata/standby/in_suzhou_index.303.789657231
restoring datafile 00020 to /u01/oradata/standby/in_suzhou_data.312.789659221
restoring datafile 00024 to +DATA/in_suzhou_data
restoring datafile 00025 to /u01/oradata/standby/in_suzhou_data
restoring datafile 00027 to /u01/oradata/standby/in_adcphc_data.9090.810742665
restoring datafile 00028 to /u01/oradata/standby/system_data
channel c1: reading from backup piece /u01/rmanbak/inc0_PRIMARY_nho86012_1_1
ORA-19870: error reading backup piece /u01/rmanbak/inc0_PRIMARY_nho86012_1_1
ORA-19505: failed to identify file "/u01/rmanbak/inc0_PRIMARY_nho86012_1_1"
ORA-27037: unable to obtain file status
Linux-x86_64 Error: 2: No such file or directory
Additional information: 3
failover to previous backup
channel c1: starting datafile backupset restore
channel c1: specifying datafile(s) to restore from backup set
restoring datafile 00024 to +DATA/in_suzhou_data
channel c1: reading from backup piece /u01/rmanbak/nfs/`date +2013%mPRIMARY`_full_PRIMARY_1725_1_lto7pe31.bak
channel c2: starting datafile backupset restore
channel c2: specifying datafile(s) to restore from backup set
restoring datafile 00001 to /u01/oradata/standby/system.262.789583545
channel c2: reading from backup piece /u01/rmanbak/nfs/`date +2013%mPRIMARY`_full_PRIMARY_1727_1_lvo7pe31.bak
channel c3: starting datafile backupset restore
channel c3: specifying datafile(s) to restore from backup set
restoring datafile 00017 to /u01/oradata/standby/in_adcphc_data.299.789656797
restoring datafile 00020 to /u01/oradata/standby/in_suzhou_data.312.789659221
restoring datafile 00025 to /u01/oradata/standby/in_suzhou_data
channel c3: reading from backup piece /u01/rmanbak/nfs/`date +2013%mPRIMARY`_full_PRIMARY_1724_1_lso7pe31.bak
channel c4: starting datafile backupset restore
channel c4: specifying datafile(s) to restore from backup set
restoring datafile 00013 to /u01/oradata/standby/in_suzhou_data.293.789656119
restoring datafile 00019 to /u01/oradata/standby/in_suzhou_index.303.789657231
restoring datafile 00027 to /u01/oradata/standby/in_adcphc_data.9090.810742665
restoring datafile 00028 to /u01/oradata/standby/system_data
channel c4: reading from backup piece /u01/rmanbak/nfs/`date +2013%mPRIMARY`_full_PRIMARY_1726_1_luo7pe31.bak
ORA-19870: error reading backup piece /u01/rmanbak/nfs/`date +2013%mPRIMARY`_full_PRIMARY_1726_1_luo7pe31.bak
ORA-19505: failed to identify file "/u01/rmanbak/nfs/`date +2013%mPRIMARY`_full_PRIMARY_1726_1_luo7pe31.bak"
ORA-27037: unable to obtain file status
Linux-x86_64 Error: 2: No such file or directory
Additional information: 3
ORA-19870: error reading backup piece /u01/rmanbak/nfs/`date +2013%mPRIMARY`_full_PRIMARY_1725_1_lto7pe31.bak
ORA-19505: failed to identify file "/u01/rmanbak/nfs/`date +2013%mPRIMARY`_full_PRIMARY_1725_1_lto7pe31.bak"
ORA-27037: unable to obtain file status
Linux-x86_64 Error: 2: No such file or directory
Additional information: 3
ORA-19870: error reading backup piece /u01/rmanbak/nfs/`date +2013%mPRIMARY`_full_PRIMARY_1727_1_lvo7pe31.bak
ORA-19505: failed to identify file "/u01/rmanbak/nfs/`date +2013%mPRIMARY`_full_PRIMARY_1727_1_lvo7pe31.bak"
ORA-27037: unable to obtain file status
Linux-x86_64 Error: 2: No such file or directory
Additional information: 3
ORA-19870: error reading backup piece /u01/rmanbak/nfs/`date +2013%mPRIMARY`_full_PRIMARY_1724_1_lso7pe31.bak
ORA-19505: failed to identify file "/u01/rmanbak/nfs/`date +2013%mPRIMARY`_full_PRIMARY_1724_1_lso7pe31.bak"
ORA-27037: unable to obtain file status
Linux-x86_64 Error: 2: No such file or directory
Additional information: 3
failover to previous backup
creating datafile fno=28 name=/u01/oradata/standby/system_data
channel c1: starting datafile backupset restore
channel c1: specifying datafile(s) to restore from backup set
restoring datafile 00001 to /u01/oradata/standby/system.262.789583545
restoring datafile 00013 to /u01/oradata/standby/in_suzhou_data.293.789656119
restoring datafile 00017 to /u01/oradata/standby/in_adcphc_data.299.789656797
restoring datafile 00019 to /u01/oradata/standby/in_suzhou_index.303.789657231
restoring datafile 00020 to /u01/oradata/standby/in_suzhou_data.312.789659221
restoring datafile 00025 to /u01/oradata/standby/in_suzhou_data
restoring datafile 00027 to /u01/oradata/standby/in_adcphc_data.9090.810742665
channel c1: reading from backup piece /u01/rmanbak/inc0_PRIMARY_0ro5s5gv_1_1
channel c2: starting datafile backupset restore
channel c2: specifying datafile(s) to restore from backup set
restoring datafile 00024 to +DATA/in_suzhou_data
channel c2: reading from backup piece /u01/rmanbak/nfs/`date +2013%mPRIMARY`_full_PRIMARY_1619_1_ijo6sfbj.bak
ORA-19870: error reading backup piece /u01/rmanbak/inc0_PRIMARY_0ro5s5gv_1_1
ORA-19505: failed to identify file "/u01/rmanbak/inc0_PRIMARY_0ro5s5gv_1_1"
ORA-27037: unable to obtain file status
Linux-x86_64 Error: 2: No such file or directory
Additional information: 3
ORA-19870: error reading backup piece /u01/rmanbak/nfs/`date +2013%mPRIMARY`_full_PRIMARY_1619_1_ijo6sfbj.bak
ORA-19505: failed to identify file "/u01/rmanbak/nfs/`date +2013%mPRIMARY`_full_PRIMARY_1619_1_ijo6sfbj.bak"
ORA-27037: unable to obtain file status
Linux-x86_64 Error: 2: No such file or directory
Additional information: 3
failover to previous backup
creating datafile fno=1 name=/u01/oradata/standby/system.262.789583545
released channel: c1
released channel: c2
released channel: c3
released channel: c4
RMAN-00571: ===========================================================
RMAN-00569: =============== ERROR MESSAGE STACK FOLLOWS ===============
RMAN-00571: ===========================================================
RMAN-03002: failure of restore command at 05/05/2013 12:06:01
ORA-01180: can not create datafile 1
ORA-01110: data file 1: '/u01/oradata/standby/system.262.789583545'
RMAN>
------------------------------------------------------------------------
因为从库不存在 +DATA目录,需要RENAME,重新执行RESTORE
------------------------------------------------------------------------
RMAN>
RMAN> run {
allocate channel c1 device type disk;
allocate channel c2 device type disk;
allocate channel c3 device type disk;
allocate channel c4 device type disk;
set newname for datafile 24 to '/u01/oradata/standby/in_suzhou_data.dbf';
restore database;
switch datafile all;
release channel c1;
release channel c2;
release channel c3;
release channel c4;
}2> 3> 4> 5> 6> 7> 8> 9> 10> 11> 12> 13>
allocated channel: c1
channel c1: sid=1479 devtype=DISK
allocated channel: c2
channel c2: sid=1478 devtype=DISK
allocated channel: c3
channel c3: sid=1477 devtype=DISK
allocated channel: c4
channel c4: sid=1476 devtype=DISK
executing command: SET NEWNAME
Starting restore at 05-MAY-13
channel c1: starting datafile backupset restore
channel c1: specifying datafile(s) to restore from backup set
restoring datafile 00001 to /u01/oradata/standby/system.262.789583545
restoring datafile 00002 to /u01/oradata/standby/undotbs1.263.789583551
restoring datafile 00003 to /u01/oradata/standby/sysaux.264.789583551
restoring datafile 00004 to /u01/oradata/standby/undotbs2.266.789583557
restoring datafile 00005 to /u01/oradata/standby/users.267.789583559
restoring datafile 00006 to /u01/oradata/standby/inman_index.282.789655375
restoring datafile 00007 to /u01/oradata/standby/in_adcphcled_data.285.789655539
restoring datafile 00008 to /u01/oradata/standby/in_xian_index.286.789655615
restoring datafile 00009 to /u01/oradata/standby/in_xian_data.287.789655707
restoring datafile 00010 to /u01/oradata/standby/tbs_catalog.288.789655837
restoring datafile 00011 to /u01/oradata/standby/eport_index.291.789656023
restoring datafile 00012 to /u01/oradata/standby/in_man_index.292.789656085
restoring datafile 00013 to /u01/oradata/standby/in_suzhou_data.293.789656119
restoring datafile 00014 to /u01/oradata/standby/in_man_data.294.789656245
restoring datafile 00015 to /u01/oradata/standby/in_adcphc_index.295.789656363
restoring datafile 00016 to /u01/oradata/standby/auditadcphc.298.789656683
restoring datafile 00017 to /u01/oradata/standby/in_adcphc_data.299.789656797
restoring datafile 00018 to /u01/oradata/standby/eport_data.302.789657055
restoring datafile 00019 to /u01/oradata/standby/in_suzhou_index.303.789657231
restoring datafile 00020 to /u01/oradata/standby/in_suzhou_data.312.789659221
restoring datafile 00021 to /u01/oradata/standby/users.315.789661229
restoring datafile 00022 to /u01/oradata/standby/users.318.789661589
restoring datafile 00023 to /u01/oradata/standby/users.319.789661839
restoring datafile 00024 to /u01/oradata/standby/in_suzhou_data.dbf
restoring datafile 00025 to /u01/oradata/standby/in_suzhou_data
restoring datafile 00026 to /u01/oradata/standby/in_suzhou_data.9154.810742355
restoring datafile 00027 to /u01/oradata/standby/in_adcphc_data.9090.810742665
restoring datafile 00028 to /u01/oradata/standby/system_data
channel c1: reading from backup piece /u01/rmanbak/inc0_PRIMARY_sho8r312_1_1
ORA-19870: error reading backup piece /u01/rmanbak/inc0_PRIMARY_sho8r312_1_1
ORA-19505: failed to identify file "/u01/rmanbak/inc0_PRIMARY_sho8r312_1_1"
ORA-27037: unable to obtain file status
Linux-x86_64 Error: 2: No such file or directory
Additional information: 3
failover to previous backup
skipping datafile 2; already restored to file /u01/oradata/standby/undotbs1.263.789583551
skipping datafile 3; already restored to file /u01/oradata/standby/sysaux.264.789583551
skipping datafile 4; already restored to file /u01/oradata/standby/undotbs2.266.789583557
skipping datafile 5; already restored to file /u01/oradata/standby/users.267.789583559
skipping datafile 6; already restored to file /u01/oradata/standby/inman_index.282.789655375
skipping datafile 7; already restored to file /u01/oradata/standby/in_adcphcled_data.285.789655539
skipping datafile 8; already restored to file /u01/oradata/standby/in_xian_index.286.789655615
skipping datafile 9; already restored to file /u01/oradata/standby/in_xian_data.287.789655707
skipping datafile 10; already restored to file /u01/oradata/standby/tbs_catalog.288.789655837
skipping datafile 11; already restored to file /u01/oradata/standby/eport_index.291.789656023
skipping datafile 12; already restored to file /u01/oradata/standby/in_man_index.292.789656085
skipping datafile 14; already restored to file /u01/oradata/standby/in_man_data.294.789656245
skipping datafile 15; already restored to file /u01/oradata/standby/in_adcphc_index.295.789656363
skipping datafile 16; already restored to file /u01/oradata/standby/auditadcphc.298.789656683
skipping datafile 18; already restored to file /u01/oradata/standby/eport_data.302.789657055
skipping datafile 21; already restored to file /u01/oradata/standby/users.315.789661229
skipping datafile 22; already restored to file /u01/oradata/standby/users.318.789661589
skipping datafile 23; already restored to file /u01/oradata/standby/users.319.789661839
skipping datafile 26; already restored to file /u01/oradata/standby/in_suzhou_data.9154.810742355
channel c1: starting datafile backupset restore
channel c1: specifying datafile(s) to restore from backup set
restoring datafile 00001 to /u01/oradata/standby/system.262.789583545
restoring datafile 00013 to /u01/oradata/standby/in_suzhou_data.293.789656119
restoring datafile 00017 to /u01/oradata/standby/in_adcphc_data.299.789656797
restoring datafile 00019 to /u01/oradata/standby/in_suzhou_index.303.789657231
restoring datafile 00020 to /u01/oradata/standby/in_suzhou_data.312.789659221
restoring datafile 00024 to /u01/oradata/standby/in_suzhou_data.dbf
restoring datafile 00025 to /u01/oradata/standby/in_suzhou_data
restoring datafile 00027 to /u01/oradata/standby/in_adcphc_data.9090.810742665
restoring datafile 00028 to /u01/oradata/standby/system_data
channel c1: reading from backup piece /u01/rmanbak/nfs/bk_ppo8iqa9_1_1
channel c1: restored backup piece 1
piece handle=/u01/rmanbak/nfs/bk_ppo8iqa9_1_1 tag=TAG20130501T214233
channel c1: restore complete, elapsed time: 02:32:57
Finished restore at 05-MAY-13
datafile 24 switched to datafile copy
input datafile copy recid=29 stamp=814635208 filename=/u01/oradata/standby/in_suzhou_data.dbf
released channel: c1
released channel: c2
released channel: c3
released channel: c4
RMAN>
5、尝试应用日志
SQL> alter database recover managed standby database using current logfile disconnect from session;
alter database recover managed standby database using current logfile disconnect from session
*
ERROR at line 1:
ORA-38500: USING CURRENT LOGFILE option not available without stand
SQL> alter database add standby logfile group 10 ('/u01/oradata/standby/stand01.log') size 100m;
alter database add standby logfile group 11 ('/u01/oradata/standby/stand02.log') size 100m;
alter database add standby logfile group 12 ('/u01/oradata/standby/stand03.log') size 100m;
alter database add standby logfile group 13 ('/u01/oradata/standby/stand04.log') size 100m;
alter database add standby logfile group 14 ('/u01/oradata/standby/stand05.log') size 100m;
alter database add standby logfile group 15 ('/u01/oradata/standby/stand06.log') size 100m;
Database altered.
SQL>
Database altered.
SQL>
Database altered.
SQL>
Database altered.
SQL>
Database altered.
SQL>
Database altered.
SQL> SQL>
SQL> alter database recover managed standby database using current logfile disconnect from session;
Database altered.
SQL>
5、查看日志,已经正常应用了
root@dgserver standby]# cd /u01/app/oracle/admin/standby/bdump
[root@dgserver bdump]# tail -f *.log
Media Recovery Log /u01/archivelog/standby/arc_1_13753_789583539.dbf
Media Recovery Waiting for thread 2 sequence 17431
Fetching gap sequence in thread 2, gap sequence 17431-17530
FAL[client, MRP0]: Error 88 fetching archived redo log from PRIMARY
Sun May 05 20:09:26 CST 2013
Errors in file /u01/app/oracle/admin/standby/bdump/standby_mrp0_19416.trc:
ORA-00088: command cannot be executed by shared server
Sun May 05 20:09:27 CST 2013
RFS[2]: Archived Log: '/u01/archivelog/standby/arc_1_13769_789583539.dbf'
RFS[2]: Archived Log: '/u01/archivelog/standby/arc_1_13770_789583539.dbf'
Sun May 05 20:09:39 CST 2013
RFS[2]: Archived Log: '/u01/archivelog/standby/arc_1_13771_789583539.dbf'
Sun May 05 20:09:40 CST 2013
RFS[1]: Archived Log: '/u01/archivelog/standby/arc_2_17431_789583539.dbf'
RFS[1]: Archived Log: '/u01/archivelog/standby/arc_2_17432_789583539.dbf'
Sun May 05 20:09:49 CST 2013
RFS[2]: Archived Log: '/u01/archivelog/standby/arc_1_13772_789583539.dbf'
Sun May 05 20:09:55 CST 2013
RFS[1]: Archived Log: '/u01/archivelog/standby/arc_2_17433_789583539.dbf'
Sun May 05 20:09:56 CST 2013
Media Recovery Log /u01/archivelog/standby/arc_2_17431_789583539.dbf
本文出自 “麦地坞” 博客,请务必保留此出处
,香港虚拟主机,香港服务器
MySQLはGPLライセンスを使用します。 1)GPLライセンスにより、MySQLの無料使用、変更、分布が可能になりますが、変更された分布はGPLに準拠する必要があります。 2)商業ライセンスは、公的な変更を回避でき、機密性を必要とする商用アプリケーションに適しています。

Myisamの代わりにInnoDBを選択する場合の状況には、次のものが含まれます。1)トランザクションサポート、2)高い並行性環境、3)高いデータの一貫性。逆に、Myisamを選択する際の状況には、1)主に操作を読む、2)トランザクションサポートは必要ありません。 INNODBは、eコマースプラットフォームなどの高いデータの一貫性とトランザクション処理を必要とするアプリケーションに適していますが、Myisamはブログシステムなどの読み取り集約型およびトランザクションのないアプリケーションに適しています。

MySQLでは、外部キーの機能は、テーブル間の関係を確立し、データの一貫性と整合性を確保することです。外部キーは、参照整合性チェックとカスケード操作を通じてデータの有効性を維持します。パフォーマンスの最適化に注意し、それらを使用するときに一般的なエラーを避けてください。

MySQLには、B-Treeインデックス、ハッシュインデックス、フルテキストインデックス、空間インデックスの4つのメインインデックスタイプがあります。 1.B-Treeインデックスは、範囲クエリ、ソート、グループ化に適しており、従業員テーブルの名前列の作成に適しています。 2。HASHインデックスは、同等のクエリに適しており、メモリストレージエンジンのHASH_TABLEテーブルのID列の作成に適しています。 3。フルテキストインデックスは、記事テーブルのコンテンツ列の作成に適したテキスト検索に使用されます。 4.空間インデックスは、地理空間クエリに使用され、場所テーブルのGEOM列での作成に適しています。

tocreateanindexinmysql、usethecreateindexstatement.1)forasinglecolumn、 "createdexidx_lastnameonemployees(lastname);" 2)foracompositeindexを使用して、 "createindexidx_nameonemployees(lastname、firstname);" 3); "3)、" 3)を使用します

MySQLとSQLiteの主な違いは、設計コンセプトと使用法のシナリオです。1。MySQLは、大規模なアプリケーションとエンタープライズレベルのソリューションに適しており、高性能と高い並行性をサポートしています。 2。SQLiteは、モバイルアプリケーションとデスクトップソフトウェアに適しており、軽量で埋め込みやすいです。

MySQLのインデックスは、データの取得をスピードアップするために使用されるデータベーステーブル内の1つ以上の列の順序付けられた構造です。 1)インデックスは、スキャンされたデータの量を減らすことにより、クエリ速度を改善します。 2)B-Tree Indexは、バランスの取れたツリー構造を使用します。これは、範囲クエリとソートに適しています。 3)CreateIndexステートメントを使用して、createIndexidx_customer_idonorders(customer_id)などのインデックスを作成します。 4)Composite Indexesは、createIndexIDX_CUSTOMER_ORDERONORDERS(Customer_Id、Order_date)などのマルチコラムクエリを最適化できます。 5)説明を使用してクエリ計画を分析し、回避します

MySQLでトランザクションを使用すると、データの一貫性が保証されます。 1)StartTransactionを介してトランザクションを開始し、SQL操作を実行して、コミットまたはロールバックで送信します。 2)SavePointを使用してSave Pointを設定して、部分的なロールバックを許可します。 3)パフォーマンスの最適化の提案には、トランザクション時間の短縮、大規模なクエリの回避、分離レベルの使用が合理的に含まれます。


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