Data Management—Relational Database Systems (RDBMS)

Abstract

Storage and management of data is a key aspect of data science. Data, simply speaking, is nothing but a collection of facts—a snapshot of the world—that can be stored and processed by computers. In order to process and manipulate data efficiently, it is very important that data is stored in an appropriate form. Data comes in many shapes and forms, and some of the most commonly known forms of data are numbers, text, images, and videos. Depending on the type of data, there exist multiple ways of storage and processing. In this chapter, we focus on one of the most commonly known and pervasive means of data storage—relational database management systems. We provide an introduction using which a reader can perform the essential operations. References for a deeper understanding are given at the end of the chapter.

Exercises

Ex. 3.1 Print list of all suppliers who do not keep stock for IPhone 5S Black.

Ex. 3.2 Find out the product that has the biggest inventory by value (i.e., the product that has the highest value in terms of total inventory).

Ex. 3.3 Print the supplier name who maintains the largest inventory of products.

Ex. 3.4 Due to the launch of a newer model, prices of IPhones have gone down and the inventory value has to be written down. Create a new column (new_price) where price is marked down by 20% for all black- and gold-colored phones, whereas it has to be marked down by 30% for the rest of the phones.

Ex. 3.5 Due to this recent markdown in prices (refer to Ex. 3.4), which supplier takes the largest hit in terms of inventory value?