There are two types
of SAS data sets:
A SAS data file both
describes and physically stores your data values. A SAS view, on the
other hand, does not actually store values. Instead, it is a query
that creates a logical SAS data set that you can use as if it were
a single SAS data set. It enables you to look at data stored in one
or more SAS data sets or in other vendors' software files. SAS views
enable you to create logical SAS data sets without using the storage
space required by SAS data files.
A SAS data set consists of the following:
The descriptor information
describes the contents of the SAS data set to SAS. The data values
are data that has been collected or calculated. They are organized
into rows, called observations, and columns, called variables. An
observation is a collection of data values that usually relate to
a single object. A variable is the set of data values that describe
a given characteristic. The following figure represents a SAS data
set.
Usually,
an observation is the data that is associated with an entity such
as an inventory item, a regional sales office, a client, or a patient
in a medical clinic. Variables are characteristics of these entities,
such as sale price, number in stock, and originating vendor. When
data values are incomplete, SAS uses a missing value to represent
a missing variable within an observation.