Download Session 7 Solution

Session 7 Solution
additional information
What are DML and DDL? Why are they necessary?
DML: Is data manipulation Language, it is used mainly for following user operations:




ADD
DELETE
MODIFY
READ (SELECT)
DDL: is data description Language and is used for data description, data type, length of data, who
created it etc..
Construct a query using SQL (see page 75) that will give names of all customers from Customer file
SELECT customer name
FROM CUSTOMER;
Ex: if the query was give the names of all customers that live in CHICAGO, query will be:
SELECT cust_name
FROM CUSTOMER
WHERE city = ‘CHICAGO’;
Q1. What is a Database, Data, DBMS and file? Describe some application that use databases.
Clearly explain how database is used in those applications.
Data is raw facts, like student name, student address, GPA
Information: data that has been processed, like average GPA, maximum test score etc.
DBMS is collection of integrated data that can be shared by many people
File: is a collection of records
Database: A collection of related data
Q2. What is data warehouse ?
A data warehouse is logical collection of information gathered from many different sources like
Government
Competitors
Internal documents
Q3. Defining Queries for a Video Rental Store. Consider your local video rental store. It
certainly has an operational database to support its online transaction processing (OLTP). The
operational database supports such things as the adding of new customers, the renting of videos
(obviously), the ordering of videos, and a host of other activities. Now, assume that the video
rental store also uses that same database for online analytical processing (OLAP) in the form of
creating queries to extract meaningful information. Develop CUSTOMER & MOVIE tables
with attributes. If you were the manager of the video rental store, what kinds of queries would
you build?
CUSTOMER table should have attributes related to customers. For example,
CUSTOMER (customer_name, Cust_address, date_mambership, customer_credit_card)
Movie table should have attributes related to monvies.
MOVIE (movie_name, no_of_copies, date_released, total_copies_available)
as a manager, you may be interested in knowing the following
.
 List of repeat customers
 Customers with consistent late charges.
 Videos that haven’t rented in a given period of time.
 “New release” movies that have experienced a decline in rentals (it may be time to move
them off the premier shelves).
 Movies with several copies that do not consistently have multiple copies rented out (it
may be time to sell some of them).
The information in data warehouse is used to create business opportunities. It is used in executive
decision making and creating business intelligence/
Q4. Visit the Internet and define what is BI? How can data be manipulated to create BI?
Business intelligence (BI) refers to technologies, applications and practices for the collection,
integration, analysis, and presentation of business information and sometimes to the information
itself. The purpose of business intelligence--a term that dates at least back to 1958--is to support
better business decision making. source
http://en.wikipedia.org/wiki/Business_intelligence
Data in warehouse can be manipulated using statistical, mathematical and inference tools to extract
patterns, relations and behaviors to create BI which can be used for business purposes.
For example, A BI analysis may show during Super bowl, pamper sales go up!!!! While husbands (or
wives) are watching super bowl, their spouses go for shopping. It may make sense to
Have extra diapers in the store during super bowl. Or a BI may show that people living near schools with
income between 20,000 to 50,000
have two or more kids buy our product. A company may look for such demographics in other part of the
city to expand their business..