DB2 data backup and recovery

This article discussesIBM DB2 With complete lab steps. This article tries to make readers understand the advantages and disadvantages of various database backup methods through specific experiments, and Master IBM DB2 Database backup and recovery technologies.
Unless otherwise specified, the following database backup and recovery test environments areWindows XP + IBM DB2 V9 Enterprise Edition, the same statement is also in AIX 5. 3 + IBM DB2 V8.2 . 5 .

I. Importance of Database Backup

In the era of increasingly developed information, data is particularly important. How can we ensure data integrity and security? How can we avoid data disasters? The importance of database backup as the most advantageous means of ensuring data security and integrity is self-evident.

The importance of database backup is mainly reflected in:

1Improve the system's high availability and disaster recovery; (What should I do if there is no database backup when the database system crashes !?)

2Restoring a database through database backup is the best solution that provides the minimum cost of data recovery when the database system crashes. (You cannot record the data for customers !?)

3Without data, there will be no things. database backup is a powerful means to prevent disasters before they happen. (without data, the fancy application is also the result of the image)

4For DBA The most important task is database backup.

II,DB2 Database Backup methods and categories

1Based on the impact of database backup on database usage
AOnline backup (also known as hot backup or online backup)
BOffline backup (also known as cold backup or offline backup)

Note: The biggest difference between online backup and offline backup is that the database can still be used by users while offline backup is not. When backing up a database offline, you must disconnect all applications connected to the database before proceeding.

2Based on the Data Backup range of the database
AFull backup
BIncremental Backup

Note: Full backup refers to backing up all data in the database, while Incremental Backup only backs up some data in the database. As to what data is backed up by Incremental backup, we will mention it later.
3And Incremental Backup
A, Incremental Backup (also called cumulative backup)
B, Delta Backup

Note: The two backup methods are strictly defined as follows,

Incremental backup is a backup of all changed data since the recent successful full backup.
DeltaBackup is the last successful full, incremental, or Delta Backup of the changed data after the backup.

Readers should carefully read the definitions of the above two Incremental backup methods, and pay attention to the nuances of the two backup methods. Here is an example.

Suppose there is a database, and some of its data is changing every day. We performed a full backup for the database on Monday evening and an incremental backup for the database on Tuesday evening.A (Note: The Incremental backup here refers to the cumulative backup, the same below), another Incremental backup was made on Wednesday evening. B On Thursday. Delta Backup.

Then, we can draw the following conclusions:
•The database backup on Monday contains all the data.
•Data that has not changed on Tuesday has not been backed up. data that has changed on Tuesday will be backed up and backed up to Incremental backup. A .
•The backup on Wednesday contains all the data that has changed since the full backup on Monday, including the data that has changed on Tuesday and Wednesday. Apparently, Incremental Backup A Incremental Backup B Include.
•Thursday is Delta Backup. Note that it only backs up data that has changed since the backup on Wednesday.

1 2 3 Next Page