Textbook ordering system, Database Management System

Assignment Help:

Question:

Consider the following database relations for a textbook ordering system used by a college bookshop:

Book (b-copy#, bname, ISBN#, author, price, subject)
Order (s#, b-copy#, order-date, payment)
Student (s#, sname, address, phone, course)

Assuming that:

?The attribute subject contained in the Book relation indicates the subject area a particular book belongs to. Examples of these subjects include 'programming', 'databases', 'operating systems', etc.

? The Student relation contains 1500 records;

? The Order relation contains 3500 records.

? The Book relation contains 4500 records. Each book copy has a unique number b-copy#. There are only 150 copies of "databases" books.

Provide the following:

(i) Express the following query in SQL:

"find all student names who have ordered any database book".

(ii) Choose two possible methods to evaluate the query, and use the relational algebra to formulate clearly all the steps required in the evaluation.

(iii) For each method, produce a query tree depicting all the steps.

(iv) For each method, calculate the number of tuples for all the intermediate relations (namely, size of the intermediate relations) required for each step.


Related Discussions:- Textbook ordering system

What is called mirroring, What is called mirroring? The simplest approa...

What is called mirroring? The simplest approach to introducing redundancy is to duplicate each disk. This method is called mirroring or shadowing.

Define the schema at the intermediate level of abstraction, Define Accordin...

Define According to the levels of abstraction, the schema at the intermediate level is called  Ans: As per to the levels of abstraction, the schema at the intermediate level is

Describe the four main ways of optimising disk block access, Describe the f...

Describe the four main ways of optimising disk block access. Ans: a. Disk  b. Non-volatile writes buffers c. File organization (Clustering) d. Log-based file system

Explain weak and strong entity sets, Explain weak and strong entity sets? ...

Explain weak and strong entity sets? Weak and Strong entity sets: A physically powerful entity set has a primary key. All tuples in the group are distinguishable through that k

Nested relational model, what is Nested relational model? Explain with exam...

what is Nested relational model? Explain with examples.

What is the use of with clause in sql, What is the use of with clause in SQ...

What is the use of with clause in SQL? The with clause gives a way of defining a temporary view whose explanation is available only to the query in which the with clause occurs

Data aggregation, Q.   Explain  data aggregatio n and discuss differen...

Q.   Explain  data aggregatio n and discuss different design constraints. Sol. Aggregation   One limitation of the E-R model is that it cannot express relationships amon

What are audit trails, What are audit trails? An audit trail is a log o...

What are audit trails? An audit trail is a log of all alters to the database along with information like which user performed the change and when the alter was performed.

Entity relationship model, Let us first look into some of the important fea...

Let us first look into some of the important features of ER model. Entity relationship model is a high-level conceptual data model. It permits us to define the data invo

What is primary index, Primary Index In primary index, there is a one-t...

Primary Index In primary index, there is a one-to-one relationship among the entries in the index table and the records in the major table. Primary index can be of two types:

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd