Archival vs Backup | File archiving and Database archiving, Hot backups and Cold backups
Archiving and backing up are two main topics related to databases. Backups are used as a database disaster-recovery solution. Archives are used to store a specific version of a table data or a file, or separate/move a set of data, which is not actively used, from the database. In database (RDBMS) field backing up is widely used than archiving. But in large file systems (FS), archiving is widely used than backing up, because archiving can be used as a good file version control solution.
As mentioned before, archiving has several types. File archiving and database archiving. File archiving is not a disaster recovery solution, but it is a file version control system. Database archiving is moving part of data, which is not actively used, from actively used data. This archived data are still important for future references. Archived data are not moved to a separate media or system. If the system is a database, after data archiving those archived data remain in the same database. (In ORACLE databases, there is a mode called ARCHIVELOG mode. In this mode, ORACLE server archives all the database changes as archive log files.)
Backups are used as data recovery solution. That means; it is useful to recover database when the database is corrupted or when the database server is destroyed. Actually, these backups are copies of the original data. There are several types of backups. Hot backups and cold backups are two main types. Hot backups are taken when the database is being used, and cold backups are taken when the database is not being used. A good backup method should have faster restoration capability and the data loss should be minimized (zero data loss). Backups must be copy to separate disks or tapes to use in disasters.
What is the difference between Archiving and Backups?
1. Archiving is not a disaster recovery solution. But backups are for effective database recovery from human errors, data block corruptions, hardware failures and natural disasters.
2. Restore and recoveries are not needed to use archived data. But restoring and recovering is essential to use backup data.
3. File system archiving can be used as a version controlling method, as well. But backups can’t be used as a version controller.
4. Archived data are necessary for reporting situations and backups are not used for reporting.
5. Archiving will keep all the available data. But in backups, users will decide the necessary backups and delete the obsolete or unwanted backups.