How to recover accidentally deleted data in oracle

As an enterprise-level database management system, Oracle is still the core data management system of many companies. However, despite Oracle's high reliability and stability, unexpected data loss often occurs in daily operations. This article will introduce how to use backup and recovery technology to make the accidentally deleted data come back to light after accidentally deleting data in the Oracle database.

1. The possibility of accidentally deleting data

Due to human errors, virus attacks, hardware failures and other reasons, inadvertently deleting data is very common in enterprise database management. . Once data is accidentally deleted, it may lead to corporate data loss and seriously affect the normal operation and smooth development of the company. However, many database administrators do not take scientific measures to recover data after accidentally deleting it, resulting in more serious consequences.

2. Oracle database backup

Before performing any operation on the Oracle database, it is very important to back up the database, so that even if there is a misoperation, etc., the backup can be used to restore the data. Oracle database provides many backup technologies, such as data file replication, RMAN backup, physical backup, logical backup, etc.

Physical backup and logical backup are the two most commonly used methods for Oracle database backup. Physical backup refers to the direct backup of database files, including data files, control files, archived log files, etc.; logical backup is based on SQL statements, including logical data export, data pump and other operations. The backed up data can be stored in disks, tapes or other storage devices, so that in the event of misoperation, the backup can be used for data recovery operations.

3. Recovery method of accidentally deleted data

When data is accidentally deleted, the database should be quickly restored and the precise range of accidentally deleted data should be found to ensure that the accidentally deleted data can be recovered. Effective recovery. Oracle also provides a wealth of data recovery technologies, including flashback technology, RMAN backup, etc.

1. Flashback technology

The flashback technology in Oracle database can roll back the entire database or restore specific tables and records. When data is accidentally deleted, you can enable the flashback function and use previously backed up data to restore it to ensure that the data will not be further affected.

Flashback technology provides many commands, such as FLASHBACK DATABASE, FLASHBACK TABLE, etc.; in addition, flashback technology can also be used in conjunction with database logs to quickly recover accidentally deleted data.

2. RMAN Backup

RMAN is the main tool for Oracle database backup and recovery. When data is accidentally deleted, RMAN backup can be used to restore the accidentally deleted data.

The steps are as follows:

1) Confirm the backup date and time.

2) Create a temporary table to save accidentally deleted data.

3) Restore relevant data from backup.

4) Copy the accidentally deleted data to the normal data table.

It is worth noting that when using RMAN backup to recover accidentally deleted data, you should pay attention to the compatibility between backup versions to prevent some data versions from being incompatible and causing recovery failure.

4. Methods to avoid accidental deletion of data

Prevention is better than cure. Administrators need to start from the perspective of database management to avoid accidental deletion of data as much as possible.

1. Separation of database permissions

Separating the various permissions of the Oracle database and assigning them to different users can effectively reduce the risk of accidentally deleting data.

2. Database monitoring

Install relevant database monitoring tools to detect abnormalities in the database, monitor changes in accidentally deleted data, and take corresponding countermeasures in a timely manner .

3. Data Recovery Plan

Administrators should develop a complete data recovery plan, including daily data backup plans, data recovery plans, etc., to ensure data security.

In short, the problem of accidentally deleting data in Oracle database is an inevitable challenge. However, using backup technology, recovery technology, and implementing scientific database management measures can make the recovery of accidentally deleted data faster and more accurate, and reduce corporate losses.

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