Prevention, Detection and Repair of Database Corruption Part-1

Corruption can be defined as an inconsistency in the data block structures or memory structures as a result of disparate problems. Corruption can be the result of human error (including software, firmware, and hardware bugs) or the environment (component failure).

Lets first define Prevention, Detection, and Repair.

Prevention :

Prevention can be defined as a set of steps that can be taken to anticipate and stop corruption from happening in a production environment. In general, the most common cause of corruption is user error. While we cannot completely prevent corruption, the risk of corrupting the production environments can be greatly reduced by improving the operational infrastructure.

Examples of prevention by improving operational infrastructure include the following:
· Having redundant hardware such as mirrored disks.
· Defining and enforcing strict security procedures.
· Strict change control with proper testing practices.

Detection :

Detection can be defined as a method to determine the existence of a problem. In the context, detection can be defined as the ways to discover the presence of a corruption in the database. In particular, detecting a corruption must encompass detecting anomalies in the hardware, disks, memory, database and application data.

The following are some examples of detecting corruption:
· Monitoring the System logs
· Monitoring the Oracle trace files
· Monitoring any application logs
· Monitor audit trails for any security violations

Repair :

Repair can be defined as a method of restoring the system to a healthy state. In the context, repair can be defined as the steps taken to bring a database back to a consistent state. Interestingly, the way Oracle software defines a consistent state may differ from what the business needs are. For example, in some environments, some data loss is acceptable. The method of repair will vary due to the extent of the corruption and the business needs. For this reason, the scope will focus on quickly repairing damage to Oracle database objects.

More in next comments:

Types of Corruption
Redo log Corruption
Data file Corruption
Lots more....



Note: All the documentations are being gather from different sites/blogs/groups/etc. for helping the newbies in Database field. This blog is only and only meant to help the newbies. Suggestion/Advices are highly appreciated.