The function rank that we use in this query computes for each row a nu-
merical rank starting from the content of the window.
The analytical clause used in the previous example indicates that the rows
retrieved by the query are partitioned based on the value of the number of
credits (noc) and, then in each group the rows are ordered according to the
values of the gpa attribute.
In general, the computation of the analytical clause is done after the com-
putation of the from, where, group by, and having clauses.
Analytic functions are classified as shown in the table below
where STUDENTS.stno = GA.stno
An example of the use of an analytic function (which we discuss in detail
in Example 5.18.2) is the following query that computes a list of students, the
number of courses they took, and their grade point average.