Discuss the relevant knowledge of Oracle database backup and deletion in detail

With the continuous deepening of enterprise informatization, data backup and data deletion have become important tasks of enterprise data management. As a representative of relational databases, Oracle database backup and deletion are also issues that enterprises must face. This article will discuss the relevant knowledge of Oracle database backup and deletion in detail.

1. Oracle database backup

1. Why do you need to back up?

A normally operating Oracle database stores important business data of an enterprise. Once the data is accidentally lost or maliciously attacked, it will cause serious losses and impacts. Enterprises need to perform data backup to avoid data loss. At the same time, Oracle database backup can also be used for database recovery, data migration, troubleshooting, etc.

2. Backup strategy

Backup strategy is the core of data backup. Different strategies will have an impact on backup efficiency and reliability. According to the backup frequency, backup can be divided into three types: full backup, incremental backup and differential backup. Among them, full backup backs up the entire database, incremental backup backs up data that has been added since the last full backup, and differential backup backs up data that has been modified since a certain backup. Different strategies can be selected based on business needs and data changes. It is generally recommended to use incremental backup and differential backup strategies to improve backup efficiency and save storage space.

3. Backup Tool

Oracle database backup can be performed using Oracle's official tool RMAN (Recovery Manager). RMAN provides comprehensive backup and recovery functions, supporting multiple backup and recovery methods such as full backup, incremental backup, differential backup, incremental recovery, and point recovery. At the same time, RMAN can also use additional options to meet the various needs of backup and recovery tasks, such as backup compression, backup set management, backup set interval recovery, etc. In addition to the official tool RMAN, there are many third-party backup tools, such as NetBackup, Commvault, EMC, etc., which can also be used for Oracle database backup.

4. Backup storage

Backup storage is an important link in the backup process, which determines the reliability and recovery efficiency of backup data. There are two options for backup storage: disk storage and tape storage. Disk storage backup speed is fast and reliable, but the cost is high; tape storage backup speed is slow and the cost is relatively low, but it takes longer to restore.

5. Backup verification

After the backup is completed, backup verification needs to be performed to ensure the reliability and integrity of the backup data. The method of verifying backups can be manual verification or automatic verification. Manual verification requires manual operations and is relatively time-consuming; automatic verification can be implemented through commands such as Perform Validation, which greatly improves the efficiency of backup verification.

2. Oracle database deletion

1. Why does it need to be deleted?

The data stored in the Oracle database not only includes useful business data, but also a lot of temporary data, unnecessary data and expired data. This data will occupy a large amount of storage space and reduce the performance and availability of the database. Therefore, data deletion and cleaning need to be performed regularly to improve database operating efficiency and reliability.

2. Deletion strategy

The data deletion strategy is also very important. Different strategies will have an impact on deletion efficiency and data integrity. There are two methods of soft deletion and hard deletion. Soft deletion means that the data to be deleted is marked for deletion but is not actually deleted. The data can be restored through recovery operations. Hard deletion refers to deleting the data to be deleted directly from the physical storage medium and cannot be restored, so it needs to be operated with caution. You can choose different deletion strategies based on business needs and data changes.

3. Deletion tool

SQL commands can be used to delete Oracle database. The delete statement can be used to delete specified rows of data in the table; the truncate statement can be used to delete all data in the entire table; the drop statement can be used to delete the entire table. In addition, Oracle database also provides purge command and flashback command to delete data from the underlying physical file and restore data.

4. Deletion verification

After the deletion is completed, deletion verification is required to ensure the reliability and integrity of the deleted data. Deletion verification can use manual verification or automatic verification to verify the integrity, correctness and legality of the deleted data.

Summary

The backup and deletion of Oracle database is an important part of enterprise data management. Backup can avoid data loss and ensure the security of business data; deletion can improve the operating efficiency of the database and free up storage space. At the same time, backup and deletion strategies are also the key to successful backup and deletion. Enterprises need to formulate reasonable backup and deletion strategies based on actual conditions, and choose appropriate backup and deletion tools to ensure the efficiency and reliability of backup and deletion, and provide a strong guarantee for enterprise information management.

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