今天来学习一下达梦数据库如何进行物理备份和恢复。对于物理备份，需要进行数据库一些设置，如归档。
mount实例：
[dmdba@mogdb enmotech]$ dmserver mount /opt/dm/dmdbms/data/enmotech/dm.ini
file dm.key not found, use default license!
version info: develop
Use normal os_malloc instead of HugeTLB
Use normal os_malloc instead of HugeTLB
DM Database Server x64 V8 1-1-126-20.09.04-126608-ENT startup...
Database mode = 0, oguid = 0
License will expire on 2021-09-09
file lsn: 85619148
ndct db load finished
ndct fill fast pool finished
nsvr_startup end.
aud sys init success.
aud rt sys init success.
systables desc init success.
ndct_db_load_info success.
SYSTEM IS READY.
–配置归档
SQL> alter database archivelog;
executed successfully
used time: 7.019(ms). Execute id is 0.
SQL> ALTER DATABASE ADD ARCHIVELOG 'DEST=/opt/dm/dmarch,TYPE = local,FILE_SIZE=200,SPACE_LIMIT=2048';
executed successfully
used time: 4.581(ms). Execute id is 0.
SQL> alter database open;
executed successfully
used time: 00:00:01.789. Execute id is 0.
SQL> select version();
select version();
[-2207]:Error in line: 1
Member access [VERSION] unresolved.
used time: 1.037(ms). Execute id is 0.
SQL> select * from v$version;
LINEID BANNER
---------- -------------------------
1 DM Database Server 64 V8
2 DB Version: 0x7000b
used time: 1.129(ms). Execute id is 4.
SQL>
++++ 通过disql 进行数据库全备份
SQL> backup database full backupset '/opt/dm/dmbak/db_full_20210826_bak_01' parallel 2;
executed successfully
used time: 00:00:36.553. Execute id is 4.
SQL>
其中log日志会有类似记录：
2021-08-26 05:03:02.883 [INFO] database P0000017453 T0000000000000017541 backup database full backupset '/opt/dm/dmbak/db_full_20210826_bak_01' parallel 2;
2021-08-26 05:03:02.883 [INFO] database P0000017453 T0000000000000017541 BACKUP DATABASE [enmottch]
2021-08-26 05:03:02.883 [INFO] database P0000017453 T0000000000000017541 CMD START......
2021-08-26 05:03:39.428 [INFO] database P0000017453 T0000000000000017541 CMD END.CODE:[0]
接下来我们进行一次增量备份：
SQL> create table test_incr as select * from dba_objects;
executed successfully
used time: 71.209(ms). Execute id is 5.
SQL> insert into test_incr select * from test_incr;
affect rows 1705
used time: 11.900(ms). Execute id is 6.
SQL> /
affect rows 3410
used time: 15.428(ms). Execute id is 7.
SQL> /
affect rows 6820
used time: 35.236(ms). Execute id is 8.
SQL> /
affect rows 13640
used time: 51.031(ms). Execute id is 9.
SQL> /
affect rows 27280
used time: 96.810(ms). Execute id is 10.
SQL> commit;
executed successfully
used time: 2.096(ms). Execute id is 11.
SQL> backup database increment with backupdir '/opt/dm/dmbak/db_increment_bak';
backup database increment with backupdir '/opt/dm/dmbak/db_increment_bak';
[-8036]:No base backup or no base backup matched.
used time: 00:00:01.844. Execute id is 0.
SQL> backup database increment with backupdir '/opt/dm/dmbak/db_full_20210826_bak_01' backupset '/opt/dm/dmbak/db_increment20210826_bak_01';
executed successfully
used time: 00:00:22.118. Execute id is 13.
SQL>
可以看到如果要进行增量备份，必须指定基础全备，否则会报错No base backup的Error。 同样针对增量备份的信息也会在日志中进行简单记录：
2021-08-26 05:05:55.948 [ERROR] database P0000017453 T0000000000000017541 CMD END.CODE:[-8036],DESC:[No base backup or no base backup matched]
2021-08-26 05:07:50.845 [INFO] database P0000017453 T0000000000000017541 backup database increment with backupdir '/opt/dm/dmbak/db_full_20210826_bak_01' backupset '/opt/dm/dmbak/db_increment20210826_bak_01';
2021-08-26 05:07:50.846 [INFO] database P0000017453 T0000000000000017541 BACKUP DATABASE [enmottch]
2021-08-26 05:07:50.846 [INFO] database P0000017453 T0000000000000017541 CMD START......
2021-08-26 05:08:12.149 [INFO] database P0000017453 T0000000000000017467 ckpt2_log_adjust: ckpt_lsn(85675335), ckpt_fil(0), ckpt_off(2350671360), cur_lsn(85675335), l_next_seq(738460), g_next_seq(738460), cur_free(2350671872), total_space(9437171712), free_space(9437171200), n_ep(1)
2021-08-26 05:08:12.961 [INFO] database P0000017453 T0000000000000017541 CMD END.CODE:[0]
此外还可以进行基于表空间的备份；当然也支持增量；同时也支持加密，压缩等：
SQL> backup tablespace enmotech full backupset '/opt/dm/dmbak/ts_enmotech_full20210826_bak_01';
executed successfully
used time: 00:00:01.810. Execute id is 14.
SQL>
除此之外还有一一点让我感觉非常有趣的地方是，还可以对表进行备份：
SQL> backup table benchmarksql.test0826 backupset '/opt/dm/dmbak/tab_test0826_bak';
executed successfully
used time: 924.811(ms). Execute id is 15.
SQL>
既然这样的话，那么肯定也支持restore table了。 我们来看看备份文件长什么样。
[dmdba@mogdb dm]$ cd dmbak/
[dmdba@mogdb dmbak]$ ls -ltr
total 0
drwxr-xr-x. 4 dmdba dinstall 143 Aug 26 05:03 db_full_20210826_bak_01
drwxr-xr-x. 2 dmdba dinstall 126 Aug 26 05:08 db_increment20210826_bak_01
drwxr-xr-x. 2 dmdba dinstall 93 Aug 26 05:12 ts_enmotech_full20210826_bak_01
drwxr-xr-x. 2 dmdba dinstall 63 Aug 26 05:15 tab_test0826_bak
[dmdba@mogdb dmbak]$ cd tab_test0826_bak
[dmdba@mogdb tab_test0826_bak]$ ls -ltr
total 96
-rw-r--r--. 1 dmdba dinstall 29184 Aug 26 05:15 tab_test0826_bak.bak
-rw-r--r--. 1 dmdba dinstall 62976 Aug 26 05:15 tab_test0826_bak.meta
可以看到这里实际上产生了2个备份文件。通过strings meta文件发现里面是元数据信息：
[dmdba@mogdb tab_test0826_bak]$ strings tab_test0826_bak.meta
]"]6
V7.1.7.126-Build(2020.09.04-126608)ENT
/opt/dm/dmdbms/data/enmotech
TAB_BTREE_20210826_051522_323393
tab_test0826_bak
enmottch
#<L=W
#DaMeng Database Server Configuration file
#this is comments
#file location of dm.ctl
CTL_PATH = /opt/dm/dmdbms/data/enmotech/dm.ctl #ctl file path
CTL_BAK_PATH = /opt/dm/dmdbms/data/enmotech/ctl_bak #dm.ctl backup path
CTL_BAK_NUM = 10 #backup number of dm.ctl, allowed to keep one more backup file besides specified number.
SYSTEM_PATH = /opt/dm/dmdbms/data/enmotech #system path
......
tab_test0826_bak.bak
(D~K
`0L%~
`0L%~
ts_enmotech_full20210826_bak_01.meta
ENABLE_ADJUST_NLI_COST = 1 #Whether adjust
TEST0826
BENCHMARKSQL
MAIN
BENCHMARKSQL'
CREATE SCHEMA "%s" AUTHORIZATION "%s" ;V
CREATE TABLE "TEST0826"
"A" INT,
"B" VARCHAR2(20)) STORAGE(ON "MAIN", NOBRANCH) ;
另外一个bak文件应该就是存放实际数据了。
[dmdba@mogdb tab_test0826_bak]$ strings tab_test0826_bak.bak
]"]6
V7.1.7.126-Build(2020.09.04-126608)ENT
Parameter[%s] has setup, repeat setting is not allowed
Parameter [%s]'s value[%s] Inval
www.enmotech.com
[dmdba@mogdb tab_test0826_bak]$
接下来进行一下相关恢复的测试：
SQL> select * from benchmarksql.test0826;
LINEID A B
---------- ----------- ----------------
1 10 www.enmotech.com
used time: 1.044(ms). Execute id is 16.
SQL> drop table benchmarksql.test0826;
executed successfully
used time: 62.535(ms). Execute id is 17.
SQL> backup table benchmarksql.test0826 backupset '/opt/dm/dmbak/tab_test0826_bak';
executed successfully
used time: 924.811(ms). Execute id is 15.
SQL> select * from benchmarksql.test0826;
LINEID A B
---------- ----------- ----------------
1 10 www.enmotech.com
used time: 1.044(ms). Execute id is 16.
SQL> drop table benchmarksql.test0826;
executed successfully
used time: 62.535(ms). Execute id is 17.
SQL> restore table benchmarksql.test0826 from backupset '/opt/dm/dmbak/tab_test0826_bak';
restore table benchmarksql.test0826 from backupset '/opt/dm/dmbak/tab_test0826_bak';
[-2106]:Error in line: 1
Invalid table or view name [TEST0826].
used time: 0.750(ms). Execute id is 0.
SQL>
SQL> CREATE TABLE benchmarksql.test0826("A" INT, "B" VARCHAR2(20)) STORAGE(ON "MAIN", NOBRANCH) ;
executed successfully
used time: 8.810(ms). Execute id is 18.
SQL> restore table benchmarksql.test0826 from backupset '/opt/dm/dmbak/tab_test0826_bak';
executed successfully
used time: 53.326(ms). Execute id is 19.
SQL>
SQL>
SQL> truncate table benchmarksql.test0826;
executed successfully
used time: 6.999(ms). Execute id is 20.
SQL> restore table benchmarksql.test0826 from backupset '/opt/dm/dmbak/tab_test0826_bak';
executed successfully
used time: 46.922(ms). Execute id is 21.
SQL> select * from benchmarksql.test0826;
LINEID A B
---------- ----------- ----------------
1 10 www.enmotech.com
used time: 1.592(ms). Execute id is 22.
从测试来看，对于drop table的情况，是无法直接恢复的，需要先创建表空间，通过strings 备份文件即可获得表结构；对于truncate table的情况，可以直接restore恢复。
从这个操作来看，更像是一个逻辑层的insert into或者类似oracle sqlldr 数据加载的恢复操作方式。
对于数据备份的restore 还原操作；disql 工具只能支持对于表的操作，不支持数据库级别/表空间级别或者schema级别。
如果要进行数据库级别，tablespace等级别的还原和恢复操作，那么需要使用dmrman 工具。接下里玩一玩！
[dmdba@mogdb ~]$ dmrman
dmrman V8
RMAN> CONFIGURE help
[-8301]:line [1],col [10] and nearby [help] exists error[-2007]:Syntax error
RMAN> CONFIGURE;
THE DMRMAN DEFAULT SETTING:
DEFAULT DEVICE:
MEDIA : DISK
DEFAULT TRACE :
FILE :
LEVEL : 1
DEFAULT BACKUP DIRECTORY:
TOTAL COUNT :0
DEFAULT ARCHIVE DIRECTORY:
TOTAL COUNT :0
time used: 1.433(ms)
RMAN> CONFIGURE TRACE 2
[-8301]:line [1],col [10] and nearby [TRACE] exists error[-2007]:Syntax error
RMAN> CONFIGURE DEFAULT TRACE LEVEL 2;
configure default trace successfully!
time used: 0.091(ms)
RMAN> CONFIGURE DEFAULT TRACE FILE '/opt/dm/dmbak/trace';
configure default trace successfully!
time used: 0.507(ms)
RMAN> CONFIGURE DEFAULT BACKUPDIR '/opt/dm/dmbak/';
configure default backupdir update successfully!
DEFAULT BACKUP DIRECTORY:
TOTAL COUNT :1
/opt/dm/dmbak
time used: 0.627(ms)
RMAN> CONFIGURE DEFAULT ARCHIVEDIR '/opt/dm/dmarch';
configure default archivedir update successfully!
DEFAULT ARCHIVE DIRECTORY:
TOTAL COUNT :1
/opt/dm/dmarch
time used: 1.116(ms)
RMAN>
RMAN> backup database '/opt/dm/dmdbms/data/enmotech/dm.ini' ;
backup database '/opt/dm/dmdbms/data/enmotech/dm.ini';
file dm.key not found, use default license!
[-137]:DM server is running or exist other process which is operating the same database
RMAN>
由于dmrman是脱机备份工具，因此数据库必须是关闭状态，否则会报错；这里我先把库停掉。
[dmdba@mogdb log]$ DmServicedmdb stop
Stopping DmServicedmdb: [ OK ]
[dmdba@mogdb log]$
[dmdba@mogdb ~]$ dmrman
dmrman V8
RMAN> backup database '/opt/dm/dmdbms/data/enmotech/dm.ini' ;
backup database '/opt/dm/dmdbms/data/enmotech/dm.ini';
file dm.key not found, use default license!
Database mode = 0, oguid = 0
EP[0]'s cur_lsn[85675643]
BACKUP DATABASE [enmottch],execute......
CMD CHECK LSN......
BACKUP DATABASE [enmottch],collect dbf......
CMD CHECK ......
DBF BACKUP SUBS......
total 1 packages processed...
total 16 packages processed...
total 148 packages processed...
total 276 packages processed...
total 282 packages processed...
DBF BACKUP MAIN......
BACKUPSET [/opt/dm/dmdbms/data/enmotech/bak/DB_enmottch_FULL_20210826_054644_098866] END, CODE [0]......
META GENERATING......
total 284 packages processed...
total 284 packages processed...
total 284 packages processed!
CMD END.CODE:[0]
backup successfully!
time used: 00:00:21.388
RMAN>
RMAN> backup database '/opt/dm/dmdbms/data/enmotech/dm.ini' increment with backupdir '/opt/dm/dmbak' BACKUPSET '/opt/dm/dmbak/db_increment_bak_02';
backup database '/opt/dm/dmdbms/data/enmotech/dm.ini' increment with backupdir '/opt/dm/dmbak' BACKUPSET '/opt/dm/dmbak/db_increment_bak_02';
Database mode = 0, oguid = 0
EP[0]'s cur_lsn[85675643]
BACKUP DATABASE [enmottch],execute......
CMD CHECK LSN......
BACKUP DATABASE [enmottch],collect dbf......
CMD CHECK ......
DBF BACKUP SUBS......
total 1 packages processed...
total 16 packages processed...
total 90 packages processed...
total 148 packages processed...
total 276 packages processed...
total 282 packages processed...
DBF BACKUP MAIN......
BACKUPSET [/opt/dm/dmbak/db_increment_bak_02] END, CODE [0]......
META GENERATING......
total 284 packages processed...
total 284 packages processed...
total 284 packages processed!
CMD END.CODE:[0]
backup successfully!
time used: 00:00:13.537
在脱机情况下才能通过dmrman进行备份，如果做全备份，数据库还必须是正常停机，如果是异常情况下，那么还需要先进行修复到一致状态才能进行备份。 这让人难以理解？
如果只能在脱机情况下进行备份，那么要这个有何用？查询了一下dm的官方文档，发现确实是这样说的：
创建完全备份
执行数据库备份要求数据库处于脱机状态。若是正常退出的数据库，则脱机备份前不需要配置归档；若是故障退出的数据库，则备份前，需先进行归档修复。以正常退出的数据库为例，一个完整的创建脱机数据库备份的步骤如下：
保证数据库处于脱机状态；
启动DMRMAN命令行工具；
DMRMAN中输入以下命令：
RMAN>BACKUP DATABASE ‘/opt/dmdbms/data/DAMENG/dm.ini’ FULL BACKUPSET ‘/home/dm_bak/db_full_bak_01’;
命令中的FULL参数表示执行的备份为完全备份，也可以不指定该参数，DMRMAN默认执行的备份类型为完全备份。
创建增量备份
增量备份指基于指定的库的某个备份（完全备份或者增量备份），备份自该备份以来所有发生修改了的数据页。脱机增量备份要求两次备份之间数据库必须有操作，否则备份会报错。
创建归档备份
执行归档备份要求数据库处于脱机状态。与联机归档备份一样，脱机归档备份需要配置归档。
达梦官方文档链接：https://eco.dameng.com/docs/zh-cn/pm/backup-restore-combat.html
查看文档发现dmrman还支持一些show和check，repair等命令，在恢复时可以用到：
RMAN> check backupset '/opt/dm/dmdbms/data/enmotech/bak/DB_enmottch_FULL_20210826_054644_098866';
check backupset '/opt/dm/dmdbms/data/enmotech/bak/DB_enmottch_FULL_20210826_054644_098866';
CMD END.CODE:[0]
check backupset successfully.
time used: 89.174(ms)
RMAN> check backupset '/opt/dm/dmbak/db_increment_bak_02';
check backupset '/opt/dm/dmbak/db_increment_bak_02';
CMD END.CODE:[0]
check backupset successfully.
time used: 25.830(ms)
RMAN> show backupset '/opt/dm/dmdbms/data/enmotech/bak/DB_enmottch_FULL_20210826_054644_098866';
show backupset '/opt/dm/dmdbms/data/enmotech/bak/DB_enmottch_FULL_20210826_054644_098866';
<backupset [DEVICE TYPE:DISK, BACKUP_PATH: /opt/dm/dmdbms/data/enmotech/bak/DB_enmottch_FULL_20210826_054644_098866] info start ..........>
<DB INFO>
system path: /opt/dm/dmdbms/data/enmotech
pmnt_magic: 272050232
src_db_magic: 148545590
db_magic: 148545590
dsc node: 1
sys mode: 0
page check: 0
rlog encrypt: 0
external cipher[id/name]: 0/
external hash[id/name]: 0/
length in char: 0
use new hash: 1
page size: 8KB
extent size: 16
case sensitive: 1
log page size: 512B
unicode_flag/charset: 0
data version: 0x7000B
sys version: V8
enable policy: 0
archive flag: 1
blank_pad_mode: 0
crc_check: TRUE
page_enc_slice_size: 0
<META INFO>
backupset sig: BA
backupset version: 0x400A
database name: enmottch
backup name: DB_FULL_20210826_054644_098866
backupset description:
n_magic: 0x392E7BA0
parent n_magic: 0xFFFFFFFF
meta file size : 82432
compressed level: 0
encrypt type: 0
parallel num: 1
backup range: database
mpp_timestamp: 1629982003
with_huge: FALSE
backupset_type: NORMAL
mpp_flag: FALSE
backup level: offline
backup type: full
without log: FALSE
end_lsn: 85675643
max_trxid: 85675402
base begin_lsn: -1
base end_lsn: -1
base n_magic: 0xFFFFFFFF
base name:
base backupset:
backup time: 2021-08-26 05:47:05
min exec ver: 0x08010101
min dct ver: 4
pkg size: 0x02000000
<EP INFO>
EP[0]:
begin_pkg_seq: 738489
begin_lsn: 85675643
end_pkg_seq: 738489
end_lsn: 85675643
<FILE INFO>
backupset directory: /opt/dm/dmdbms/data/enmotech/bak/DB_enmottch_FULL_20210826_054644_098866
backupset name: DB_enmottch_FULL_20210826_054644_098866
backup data file num: 5
backup piece num: 1
backup huge file num: 0
<backup_piece_list>
$file_seq |$size(KB) |$pos_desc |$content_type
0 |4456417 |DB_enmottch_FULL_20210826_054644_098866.bak |DATA
<data_file_list>
$file_seq |$group_id |$group_name |$file_id |$file_path |$mirror_path |$file_len |$copy_num |$size_flag
1 |0 |SYSTEM |0 |/opt/dm/dmdbms/data/enmotech/SYSTEM.DBF| |25165824 |0 |0
2 |1 |ROLL |0 |/opt/dm/dmdbms/data/enmotech/ROLL.DBF| |485490688 |0 |0
3 |4 |MAIN |0 |/opt/dm/dmdbms/data/enmotech/MAIN.DBF| |4426039296 |0 |0
4 |5 |ENMOTECH |0 |/opt/dm/dmdbms/data/enmotech/enmotech01.dbf| |4273995776 |0 |0
5 |5 |ENMOTECH |1 |/opt/dm/dmdbms/data/enmotech/enmotech02.dbf| |202375168 |0 |0
<arch_file_list>
$file_seq |$dsc_seq |$file_len |$begin_seqno |$begin_lsn |$end_seqno |$end_lsn
<huge_file_list>
$group_id |$schema_id|$table_id |column_id |$file_id |$file_len |$path
<backupset [DEVICE TYPE:DISK, BACKUP_PATH: /opt/dm/dmdbms/data/enmotech/bak/DB_enmottch_FULL_20210826_054644_098866] info end .>
show backupsets successfully.
time used: 16.419(ms)
RMAN>
—创建测试表空间，验证备份恢复功能
SQL> create tablespace test_recover datafile '/opt/dm/dmdbms/data/enmotech/test_recover.dbf' size 128;
executed successfully
used time: 27.254(ms). Execute id is 6.
SQL> create table test_rec tablespace test_recover as select * from dba_objects where rownum=1;
executed successfully
used time: 30.473(ms). Execute id is 7.
SQL> select * from test_rec;
LINEID OWNER OBJECT_NAME SUBOBJECT_NAME OBJECT_ID DATA_OBJECT_ID OBJECT_TYPE CREATED
---------- ------------ ------------ -------------- --------- -------------- ----------- ----------------------------------------------------------------------------------------------------
LAST_DDL_TIME
----------------------------------------------------------------------------------------------------
TIMESTAMP STATUS TEMPORARY GENERATED SECONDARY NAMESPACE EDITION_NAME
---------------------------------------------------------------------------------------------------- ------ --------- --------- --------- --------- ------------
1 BENCHMARKSQL BENCHMARKSQL NULL 150995945 NULL SCH 2021-08-26 17:45:42.091959
NULL
NULL VALID N NULL NULL NULL NULL
used time: 1.075(ms). Execute id is 8.
SQL> backup tablespace test_recover full backupset '/opt/dm/dmbak/ts_test_recover_20210826_bak_01';
executed successfully
used time: 820.217(ms). Execute id is 9.
SQL> drop tablespace test_recover;
drop tablespace test_recover;
[-3412]:Try to drop used tablespace.
used time: 5.893(ms). Execute id is 0.
SQL> alter tablespace TEST_RECOVER offline;
executed successfully
used time: 101.733(ms). Execute id is 13.
SQL> select name,STATUS$,TOTAL_SIZE from v$tablespace;
LINEID NAME STATUS$ TOTAL_SIZE
---------- ------------ ----------- --------------------
1 SYSTEM 0 3072
2 ROLL 0 59264
3 TEMP 0 131072
4 MAIN 0 540288
5 ENMOTECH 0 546432
6 TEST_RECOVER 1 16384
6 rows got
used time: 1.737(ms). Execute id is 15.
SQL> host
[dmdba@mogdb log]$ rm -rf /opt/dm/dmdbms/data/enmotech/test_recover.dbf
[dmdba@mogdb log]$ exit
exit
SQL> shutdown immediate
2 ;
executed successfully
used time: 0.415(ms). Execute id is 0.
SQL>
停掉数据库之后，我们开始用dmrman来进行恢复被删除的表空间文件：
[dmdba@mogdb ~]$ dmrman
dmrman V8
RMAN> restore database '/opt/dm/dmdbms/data/enmotech/dm.ini' tablespace test_recover from backupset '/opt/dm/dmbak/ts_test_recover_20210826_bak_01';
restore database '/opt/dm/dmdbms/data/enmotech/dm.ini' tablespace test_recover from backupset '/opt/dm/dmbak/ts_test_recover_20210826_bak_01';
RESTORE TABLESPACE[test_recover] IN DB[/opt/dm/dmdbms/data/enmotech/dm.ini] CHECK......
Database mode = 0, oguid = 0
EP[0]'s cur_lsn[85676271]
RESTORE TABLESPACE[test_recover] IN DB[/opt/dm/dmdbms/data/enmotech/dm.ini],dbf collect......
RESTORE TABLESPACE[test_recover] IN DB[/opt/dm/dmdbms/data/enmotech/dm.ini],ts status and dbf refresh ......
RESTORE BACKUPSET [/opt/dm/dmbak/ts_test_recover_20210826_bak_01] START......
total 1 packages processed...
total 3 packages processed...
RESTORE TABLESPACE[test_recover] IN DB[/opt/dm/dmdbms/data/enmotech/dm.ini],UPDATE ctl file......
total 3 packages processed...
total 3 packages processed!
CMD END.CODE:[0]
restore successfully.
time used: 332.263(ms)
RMAN> recover database '/opt/dm/dmdbms/data/enmotech/dm.ini' tablespace test_recover;
recover database '/opt/dm/dmdbms/data/enmotech/dm.ini' tablespace test_recover;
Database mode = 0, oguid = 0
[WARN]tablespace TEST_RECOVER is corrupted(state: 2), restore or drop please.
EP[0]'s cur_lsn[85676271]
RECOVER TABLESPACE[test_recover] IN DB[/opt/dm/dmdbms/data/enmotech/dm.ini] CHECK......
EP[0]'s cur_lsn[85676271]
EP:0 total 4 pkgs applied, percent: 11%
EP:0 total 8 pkgs applied, percent: 23%
EP:0 total 12 pkgs applied, percent: 35%
EP:0 total 16 pkgs applied, percent: 47%
EP:0 total 20 pkgs applied, percent: 58%
EP:0 total 24 pkgs applied, percent: 70%
EP:0 total 28 pkgs applied, percent: 82%
EP:0 total 32 pkgs applied, percent: 94%
EP:0 total 34 pkgs applied, percent: 100%
Recover from archive log finished, time used:0.020s.
CMD END.CODE:[0]
recover successfully.
time used: 526.667(ms)
RMAN>
接下来我们启动数据库看看。
[dmdba@mogdb log]$ DmServicedmdb start
Starting DmServicedmdb: [ OK ]
[dmdba@mogdb log]$ ls -ltr /opt/dm/dmdbms/data/enmotech/test_recover*
-rw-r--r--. 1 dmdba dinstall 134217728 Aug 26 06:15 /opt/dm/dmdbms/data/enmotech/test_recover.dbf
[dmdba@mogdb log]$ disql
disql V8
username:
password:
Server[LOCALHOST:5236]:mode is normal, state is open
login used time : 5.687(ms)
SQL> select name,STATUS$,TOTAL_SIZE from v$tablespace;
LINEID NAME STATUS$ TOTAL_SIZE
---------- ------------ ----------- --------------------
1 SYSTEM 0 3072
2 ROLL 0 59264
3 TEMP 0 131072
4 MAIN 0 540288
5 ENMOTECH 0 546432
6 TEST_RECOVER 0 16384
6 rows got
used time: 6.705(ms). Execute id is 4.
SQL> select OWNER,object_name,object_id from test_rec;
LINEID OWNER OBJECT_NAME OBJECT_ID
---------- ------------ ------------ ---------
1 BENCHMARKSQL BENCHMARKSQL 150995945
used time: 2.602(ms). Execute id is 5.
SQL>
表空间被自动online了。
最开始翻了一个文档，说是要启动dmap服务；我这里确实没启动；先启动服务。
[dmdba@mogdb root]$ DmServicedmdb stop
Stopping DmServicedmdb: [ OK ]
[dmdba@mogdb root]$ DmServicedmdb start
Starting DmServicedmdb: [ OK ]
[dmdba@mogdb root]$ DmAPService start
Starting DmAPService: [ OK ]
[dmdba@mogdb root]$
[dmdba@mogdb log]$ ps -ef|grep amap
dmdba 19626 16924 0 06:49 pts/1 00:00:00 grep --color=auto amap
[dmdba@mogdb log]$ ps -ef|grep dmap
dmdba 19552 1 0 06:44 pts/1 00:00:00 /opt/dmdbms/bin/dmap
dmdba 19628 16924 0 06:49 pts/1 00:00:00 grep --color=auto dmap
[dmdba@mogdb log]$
再次测试dmrman能否进行联机恢复：
SQL> backup tablespace test_recover full backupset '/opt/dm/dmbak/ts_test_recover_20210826_bak_02';
executed successfully
used time: 818.856(ms). Execute id is 106.
SQL> alter tablespace TEST_RECOVER offline;
executed successfully
used time: 98.804(ms). Execute id is 107.
SQL> host
[dmdba@mogdb log]$ rm -rf /opt/dm/dmdbms/data/enmotech/test_recover.dbf
[dmdba@mogdb log]$
[dmdba@mogdb ~]$ dmrman use_ap=1
dmrman V8
RMAN> restore database '/opt/dm/dmdbms/data/enmotech/dm.ini' tablespace test_recover from backupset '/opt/dm/dmbak/ts_test_recover_20210826_bak_02';
restore database '/opt/dm/dmdbms/data/enmotech/dm.ini' tablespace test_recover from backupset '/opt/dm/dmbak/ts_test_recover_20210826_bak_02';
file dm.key not found, use default license!
[-137]:DM server is running or exist other process which is operating the same database
RMAN>
尽管启动了dmap服务，可以看到，仍然是不行的。可以通过disql来进行全备份。但是就恢复而言，通过dmrman进行，只能脱机操作。
最后简单总结一下物理备份恢复：
1、通过参数bak_use_ap来控制是否需要通过dmap进行来进行辅助，便于进行联机热备；联机备份只能通过disql进行。
2、disql 备份支持数据库级别，表空间级别，用户级别以及 table级别；
3、disql的恢复操作，只能支持表级别；不支持全库或者表空间级别；
4、dmrman备份恢复工具是脱机备份恢复工具；这跟Oracle RMAN差距较大；
5、达梦数据库仅支持表的联机还原，数据库、表空间和归档日志的还原必须通过脱机工具DMRMAN执行。
如果数据库运行中，其中一个文件或者表空间有问题，需要进行备份恢复，那么达梦似乎就无法应对这情况了，只能把实例停掉。。。
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