In order to prevent data loss, you should create backup copies of the database on an external storage device. Having these copies allows you to recover the database beginning from the moment of the initial data backup. There are differences between online and offline backups: online backups are created without having to shut down the database. During the security process, the database records the undertaken changes in a separate area and adds them to the relevant file at the end of the process. If you shut it down during the backup, this is an offline backup. This data backup technique has the advantage of being relatively easy to perform, but it also means that the applications or websites won’t be available during the course of the backup process. If possible, it makes more sense to perform an offline backup during the night when there is less data traffic.
Regarding the breakdown of online and offline backups: they can be split into the following three types depending on the way the data is transferred:
- Full backup: Just as the name suggests, this type of data backup transfers all the stored data. This means that lots of room is required for frequent backups. In cases where one particular data set is lost and needs to be restored, only the corresponding full backup is needed.
- Differential backup: When it comes to a differential backup, a full backup first needs to be created. It then differs from a full backup in that only the files that have been changed or added since the last backup are saved. So unlike full backups, storage space is spared. With each differential backup modified and new files are copied until the next full backup. A successful full recovery of lost data therefore requires two things with this method: the last full backup, and the desired respective differential backup.
- Incremental backup: For an incremental backup, only the files that have been modified or added since the last backup are copied following a complete backup. Unlike the differential methods, an incremental backup refers to the previous backup (both full backup and incremental backup). Files are only saved once, which frees up some storage space. In order to recover the desired files, all the backups are needed; from most recent full backup to the desired state.
As you can see there are a few options for backing up database systems such as SQL databases or Microsoft Access. The most suitable backup method depends on the needs of the user or business. Skipping backups in order to save storage memory should never be done. External storage devices like hard drives should be kept in a separate area where they are protected from theft and fire damage. The saved data should additionally be encrypted so that if it’s stolen, it can’t be used by any third parties.