This ability to put dissimilar lists together swiftly and powerfully makes this variety of database a favorite for reporters. The example below shows the relational path between two files having campaign contributors and political candidates, respectively. Often the form checks spelling, bars numbers or other characters in fields set for alphabetic letters, and so on. Lists, of course, are the very essence of databases. This way, slow moving goods can be put-up for discount or shifted to stores where sales are strong.
Junk mail needs databases to survive.
The logic of list extraction allows air conditioning ads to be sent to the sweltering souls of Phoenix, not arctic Alaska. Essential to modern databases is the ability to add variables and cases. In this example, Access readily accepts a new product category without major problems. Old databases had to be laboriously recoded to accept changes. Access is a complex tool.