Online incremental migration of DM database

In the actual production environment , We need to complete the database migration in a very short time , The traditional backup and restore method takes a long time , May not meet the migration needs . This requires Online incremental migration To migrate the database . principle ： Restore the target library through the backup set to rebuild the data file 、 Redo Log files , Update control files and other operations , And redo the archive log in the recovery phase to restore the target database to the latest state .

We have two database servers ： The source server （ Winning Qilin 7、DM8）, Target server （windows10、DM8）, Now you want to migrate the data of the source server database online incrementally to the target server , The source database must be archived .

The specific operation steps are as follows ：

1

View the mode of the source library

select name,arch_mode from v$database;

  

      If the archive is not opened , Then open the archive mode ：

alter database mountalter database add archivelog‘type=local,dest=/dm/arch,file_,space_limit=0’;alter database open

2

View the data file and other paths of the source library

select file_name,tablespace_name from dba_data_files;

3

Copy the database related files of the source server to the target database

     （1） Record source library's BEGIN_LSN/BEGIN_SEQ Information

Before starting copying , Call system procedure SP_BACKUP_COPY, Record the current system BEGIN_LSN/BEGIN_SEQ Information modification parameter file        

SP_BACKUP_COPY_BEGIN()

       （2） use xftp Software copy A Server database related files to B In the relevant directory of the server

（3） After copying , Call system procedure SP_BACKUP_COPY_END, Generate a backup set file    

SP_BACKUP_COPY_END('/dm8/backup/bak_copy')

（4） Copy the backup set file generated by the source server to the target server

4

Modify the parameter file and control file on the target server

 （1） Modify parameter file

Set the parameter file dm.ini in , It's about the path /dm8/data/DAMENG, Replace all with D:\dmdbms\data

（2） Modify the control file

① Convert binary files to text files , Then edit the content              

dmctlcvt TYPE=1 SRC=D:\dmdbms\data\dm.ctl DEST=D:\dmdbms\data\dmctl.txt

② take dmctl.txt The path is involved in the file /dm8/data/DAMENG, Replace all with D:\dmdbms\data

③ Put the text file dmctl.txt Convert to binary dm.ctl

5

Start the database of the target server to the configuration （mount） state

     （1） Start the Damon database configuration assistant , Select register database service

（2） Select parameter file

6

Restore the database on the target server

     （1） Close the database

（2） Execution restore ​​​​​​​

dmrmanrestore database 'D:\dmdbms\data\dm.ini' from backupset 'D:\dmdbms\backup';

（3） Copy the newly generated archive log file on the source server to the archive path of the target server

（4） Perform recovery

RECOVER DATABASE 'D:\dmdbms\data\dm.ini' WITH ARCHIVEDIR 'D:\dmdbms\arch';

RECOVER DATABASE 'D:\dmdbms\data\dm.ini' UPDATE DB_MAGIC;

（5） Start the database on the target server

matters needing attention ：

（1） The database must be archived ;

（2） When calling system procedures SP_BACKUP_COPY_BEGIN after , Can't go on create tablespace/drop tablespace Wait for the operation ;

（3）SP_BACKUP_COPY_BEGIN and SP_BACKUP_COPY_END Must be executed in the same session ;

（4） When executed UPDATEDB_MAGIC After the operation , You can no longer perform incremental recovery of archived logs , Only the database can be opened .