What is a data view in SAS?

A data view in SAS is best described as a virtual data set that retrieves data from an underlying data set. This means that a data view does not store data itself but rather provides a way to access and manipulate data dynamically from the original data set whenever the view is accessed. Because it is virtual, it does not take up storage space like a physical copy of the data would, and any changes made to the original data set are reflected in the data view automatically.

This functionality of data views is particularly useful for managing large datasets, allowing for efficient data manipulation without the need to create and maintain multiple physical copies of the data. By using a data view, users can filter, select, or join data easily while still maintaining a direct link to the original datasets.

Choosing other options would misrepresent the nature of data views. For instance, a physical copy of a data set implies that data is stored permanently, which is contrary to the concept of a data view. Additionally, while methods to summarize data visually are important in data analysis, they do not pertain directly to the definition and function of a data view in SAS.