Data backup is extremely important for data preservation. If there is no one or two additional backups of important core production data, once an accident occurs and document data is lost, then these data may never be found. Today we will talk about the concepts and differences between cold backup and hot backup of data backup.
Concept of cold backup
Cold backup occurs when the database has been closed normally, and when it is closed normally, it will provide us with a complete database. A saying that you copy vital files to another location during cold backup. For backup Oracle information, the fastest and safest way to cold backups. The advantages of cold backup are:
1. It is a very fast backup method (just copy the file)
2. Easy to archive (just copy)
3. Easy to restore to a certain time point (just copy the file back)
4. It can be combined with archive methods to restore the database “best state”.
5. Low maintenance and high safety.
Concept of hot backup
Hot backup is a method of backing up the database using archivelog mode when the database is running. So, if you have a cold backup from last night and today’s hot backup file, you can use these data to restore more information when problems occur. Hot backup requires the database to operate in Archivelog mode and requires a large amount of archive space. Once the database is running in archivelog state, it can be backed up. The hot backup command file consists of three parts:
1. Backup of data files one tablespace and one tablespace.
(1) Set the table space to backup status
(2) Back up the table space data file
(3) The reply table space is in normal state
2. Backup archive log files
(1) Temporarily stop the archive process
(2) The files in the archive rede log target directory under log
(3) Restart the archive process
(4) Backup archived redo log files
3. The advantages of using the alter database bachup controlfile command to backup and control files are:
1. You can backup at the tablespace or database file level, with a short backup time.
2. The database is still available during backup.
3. It can reach the second level of recovery (restore to a certain point in time).
4. Recovery of almost all database entities
5. Recovery is fast and in most cases love databases are still working while recovery.
Shanghai Lanchang Information Technology can provide data backup, cold backup and hot backup services according to user needs. For more information, please contact Lanchang customer service.
