Already have an account? Get multiple benefits of using own account!
Login in your account..!
Remember me
Don't have an account? Create your account in less than a minutes,
Forgot password? how can I recover my password now!
Enter right registered email to receive password!
Question:
This Question refers to the database schema given in the Appendix.
(a) The integrity of a database is enforced by integrity rules. Discuss what should happen on an attempt to delete the target of a foreign key reference (for example, to delete a lecturer in the LECTURER table who lectures at least one unit listed in the TIMETABLE table)? Your discussion should describe the three possible techniques which can be used to deal with the problem, and provide one example for each technique by using the above tables.
(b) Using the database schema, express the following queries in SQL:
(i) Create the TIMETABLE table including the primary and foreign key constraints in the code. Make any assumption you want to make.
(ii) Insert the first row in the TIMETABLE table and make any assumption.
(iii) Modify the code value to Workshop for the above record created assuming that the rest of the values have already been created.
(iv) Find the numbers of students who have achieved one or more final grade greater than 14.
(v) Find the student number, unit number and final grade for those students attending units run by the departments named ‘computing' or ‘accountancy'.
Explain the Relational Completeness Codd described the term relational completeness to consider to a language that is complete with respect to first-order predicate calculus ex
Define lock? Lock is the most common used to execute the requirement is to permit a transaction to access a data item only if it is currently holding a lock on that item.
What is Thread splitting A thread of control is a path by which a set of state diagrams on that a single object is active at a time. Objects are shared between threads
What is catalog in DBMS? Catalog - A relational DBMS maintains information about every table and index in which it contains. A catalog is a collection of special tables that st
WHAT IS DSS? WRITE ITS REQUIREMENTS.
recovey techniques based on deferred update and immediate update
Which are the two ways in which entities can participate in a relationship? Total and partial are the two ways in which entities can participate in a relationship
What is deadlock? How can it be avoided? How can it be resolved once it occurs? Deadlock happens when two transactions are each waiting on a resource that the other transaction
Normal 0 false false false EN-IN X-NONE X-NONE MicrosoftInternetExplorer4
write short note on mobile database
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!
whatsapp: +91-977-207-8620
Phone: +91-977-207-8620
Email: [email protected]
All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd