Data exploration is an important part of every data science project; without these insights into data, we will mostly make blind and inaccurate estimations that will not meet our intentions and needs. We learned about statistics made with T-SQL in three parts, going from the easiest to the most difficult.
In the first section of the chapter, we described almost all aggregate functions used for descriptive statistics. By using functions such as COUNT or SUM, we became familiar with their particular purposes and the roles they are playing in data science, and we also observed their common behavior. The GROUP BY and GROUP BY GROUPING SETS clauses of SELECT statements were also described in detail.
In the second section of the chapter, we introduced ranking functions and their functionality. With the help of ranking functions, we also learned about framing and windowing, helping...