BUSINESS-RELATED DATABASE APPLICATION

Design and Implement, using Access, a Business-Related Database Application

Design and Implement, using Access, a Business-Related Database Application

Security Database integrity

Database integrity is a central underlying issue in the implementation of database technology. Trust in the Correctness of the data that is held by the database system is a prerequisite for using the data in business, research and decision making applications. Data base Integrity refers to the trustworthiness of system resources over their entire life cycle (Bernstein & Hadzilacos, 1987: 47).

In a database system, a method to ensure data integrity is fundamental to providing database reliability and security. In particular, as data is communicated or distributed over networks, a method to validate information as authentic is required. The value of a database is dependent upon a user's ability to trust the completeness and soundness of the information contained in the data. Three basic types of database integrity constraints are (Bernstein & Hadzilacos, 1987: 48):

Entity integrity

Domain

Referential integrity

Integrity means that the data will be safe and will not be subject to changes wither they were initial or accidental. There are many, many causes that change data over time such as human error, system malfunction etc. Integrity keeps the data intact and in its original form.

Disk Storage Systems

“Disks can fail when a single bit or few bits will flip. This problem can often be detected and corrected at the hardware level by using error correcting codes in the embedded system of the drive”. It can also happen at the software level.

RAID Disk Technology

The one way to prevent data corruption or data lost due to a hard drive is to have in place a RAID. The design of RAID technology has allowed improvement in storage performance, reliability and recovery. The levels of RAID organization divide the disks into reliability groups with each group having extra check disks containing redundant information (Pratt & Adamski, 2010: 15). When a disk fails, the assumption is that within a short time the failed disk can be replaced and the information can be reconstructed on the new disk using the redundant information.

RAID

level 1 mirrors each disk with a full image copy. Every write to a disk is also a write to a check disk. Although the check disk can be used to improve read performance, this is a costly option

level 2 bit-interleaves the data across the disks in a group and adds enough check disks to correct a ...