What are the strategy of backup and recovery in data warehouses?

Backup and recovery define the process of backing up records in the method of a loss and setting up systems that enable that data recovery because of data loss. Backing up data needed copying and archiving computer information, so that it is applicable in case of data deletion or corruption.

The goal of the backup is to make a copy of data that can be renewed in the event of a primary data failure. Primary data failures can be the outcome of hardware or software failure, data corruption, or a human-caused event, including a malicious attack (virus or malware), or accidental removal of information. Backup copies enable data to be resaved from a previous point in time to support the business recovery from an unintended event.

There are various types of backup which are as follows −

  • Complete backup − The entire database is backed up simultaneously. This includes all data files, control files, and journal files.

  • Cold backup − t is a backup that is taken while the database is completely shut-down.

  • Hot backup − It is a backup that is not cold and is considered to be hot. The term hot is used because the database engine is up and running. A backup of the database is made when it is open and potentially in use. The DBMS will need to have special facilities to ensure that data in the backup is consistent.

Recovery is the phase of reconstructing a database after some element of a database has been lost. The recovery structure of a new database is inherited from the structure database when the new database is made. The model for a database can be changed after the database has been created. There are the following factors are considered while defining the backup and recovery strategy which are as follows −

  • Data to be backed up − The data is identified which must be backed up regularly. It indicates the size of a regular backup.

  • Batch window of the warehouse − Back up of the data is available even when the system is online, but these are expensive. The maximum allowable time, which is needed by the warehouse is determined. The part of that batch window is allocated to the regular warehouse to report generation and other similar batch jobs.

  • Acceptable costs for backup and recovery − Different backup mechanisms imply different costs. The enterprise can have budgetary constants that limit its backup and recovery options.