Cost is another consideration. If it breaks, you replace it rather than repair it. 2.12 Operations and Management Classifications of information systems. A Relational DataBase is the most common structure. A database is a structured grouping of data.
Dirty data can t rely on the data.
A DataBase Management System is software that provides a means of accessing data. The ability to add, delete and alter data is what makes databases useful. A typical Personal Computer has about 10-30 GigaBytes of memory. A typical Data Warehouse system can require 10-20 TeraBytes of memory. Some debit charges may be transmitted immediately to the bank depending upon how the merchant is tied into the system.