“Which of the following is not a data type?” is an easy question to answer because it is simply a statement. It has no complex grammar or any other constraints at all. However, when you consider that a “data type” can be implemented in many different programming languages, it is easy to see why this question is so difficult to answer.
There are two approaches that you can take when trying to answer the question, “what is a (n)?” in terms of your requirements. One approach is to go one step further and ask what would NOT be a (n) in the database. The second approach is to adopt an operational or engineering approach to what is a (n) and instead define a concept that describes relationships among (n) and (s) where n is a subset of the size of s.
Let’s define a new system, now using a database. The database system needs to be able to satisfy the requirements of the user. The requirements may include which of the following is not a (n) in the user’s view – the records that do not contain data for the user. Or, the user may have a specific key that does not exist in the database, and that she would like to add. The new record will be added to the end of the list of records in the system. In this example, the second view of the new system would be considered a view of the updated version of the record.
When the question, “which of the following is not a (n)?” is asked, it is easy to answer, “the new system does not include a (n) in its view.” However, what if a second view of the record exists in the system – one that does contain data for the user. This view would not be considered a view that does not contain data, but rather a view that provides information about the current version of the record without actually updating the record in the system.
Therefore, when the question, “What is a database approach?” is asked, the answer can only be, “The new system contains data for all of the users who access it, regardless of whether they have modified the record since the last time it was viewed.” In other words, in this example the database approach would be considered a view, not a static data type.
Thus, the question “what is a database approach?” has two correct answers. One is a view of the record, the other is a view of the updated status of that record. If we choose to use a view of the record which merely displays the record as it exists at the moment it is accessed, we are not asking the right question, and we are assuming the wrong answer.
The second correct answer, which is what is a database approach in this example is, “A system development application would use a relational database such as MySQL to manage a table that contains records that change over time such as which employees have moved in the last five years or which products have been added or removed.” This is how the right question to ask comes in. We are assuming that the system developer chooses to implement a data-driven system where changes occur instantaneously and where these changes are reflected in real time. If we choose to define a database approach using a data model such as an object-oriented programming language such as Java, the question becomes, “Does the data model to describe the data that the application needs to operate successfully?” If the answer is yes, then the SQL is not a database system.
The third correct answer is, “A (n) is a subset of a (m) which is a subset of (a) and so on.” This is how the SQL must be implemented when used in a data management system. In other words, if the user accesses the table, the results are going to be stored in a format that the application understands. If the application cannot interpret the data, then the result is an SQL statement.