What is a Relational Model?

The Relational Model is a clean and simple model that uses the concept of a relation using a table rather then a graph or shapes. The information is put into a grid like structure that consists of columns running up and down and rows that run from left to right, this is where information can be categorized and sorted.

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The columns contain information related to name, age, and so on. The rows contain all the data of a single instance of the table such as a person named Michelle.

In the Relational Model, every row must have a unique identification or key used to allocate the data that will follow it. Often, keys are used to join data from two or more relations based on matching identification.

Here is a small example of the grid like Relational Model:

The Relational Model can often also include concepts known commonly as foreign keys, foreign keys are primary keys in one relation that are kept in another relation to allow for the joining of data.

An example of foreign keys is storing your mother's and father's social security number in the row that represents you. Your parents' social security numbers are keys for the rows that represent them and are also foreign keys in the row that represents you. Now we can begin to understand how the Relational Model works.

How did we get the Relational Model?

Like most other things the Relational Model was born due to someone’s need. In 1969 Dr. Edgar F. Codd published the first use of the relational model though it was meant to be no more then a report for IBM, if swept across and through data analysis unlike any before it.

Codd's paper was primarily concerned with what later came to be called the structural part of the relational model; that is, it discusses relations per se (and briefly mentions keys), but it does not get into the relational operations at all (what later came to be called the manipulative part of the model).

Codd’s discovery, his creation was a breath of fresh air for those digging through data banks, trying to categorize and define data. When he invented this model he truly may have not foreseen what an incredible impact it would have on the world of data.

Known Issues with the Relational Model

Some believe there is a great deal of room for improvement where the Relational Model is concerned. It may be a surprise to find not everyone supported relational model. There have been claims that the rectangular tables do not allow for large amounts of data to be recorded.

With the example of apples and oranges, both are fruits and therefore related in that way but apples have different attributes then oranges, At times a user may only want to see one or the other, then again the may want to view both. Handling this type of data with the relational model can be very tricky.

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We are beginning to hear more and more about the need for a better model, a more adequate structure, still no one has been able to design something that can truly hold its own with the Relational Model.

True the model could use a bit of tweaking and leaves a little to be desired, yet, what would the perfect model be? What could we use that would apply to as many instances as the Relational model, and still surpass its usefulness?

Next Page: Relational Model Advantages