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!
Define entity integrity and referential integrity. How does SQL allow specification of these?
Ans: Entity Integrity Rule- If the attribute A of relation R is a prime attribute of R after that A cannot accept null values.
Referential Integrity Rule- In referential integrity, it is made sure that a value that appears in one relation for a given set of attributes as well appears for a particular set of attributes in another relation.
In SQL, referential integrity and entity integrity rules are implemented as constraints on the relation known as reference Key constraint and primary Key constraint correspondingly.
These constraints can be fixed with relation at the time of creation of the relations or after the creation of the relations by altering the definition of the relations. For instance:
Explain Clustering file organization (i) Determine if a record of file is physically ordered on a nonkey field - that does not comprise a different value for each record - that
what is the need of a log in dbms
Example: //REVOKE ALL ON EMP FROM MCA12; (All permissions will be cancelled) You can also cancel only some of the permissions. Drop: A user-
The definition of the classes and operation can often be adjusted to increase the amount of inheritance". Justify the above statement. Adjustment of Inheritance The def
At its most essential level the DBMS architecture can be divide into two parts: the back end and the front end. The back end is responsible for managing the physical database an
explain normalisation
Which method is used to key transformation ? A hash method is used to key transformation.
(A) For the relation; CarSales (RegNo, BuyerName, Address, SalesPerson, Make, Model, Commission) The following functional dependences hold, RegNo _ID à Make, Model Reg
The result of the UNION operation between R1 and R2 is a relation that includes? The result of the operation between R1 and R2 includes all the tuples of R1 and R2 which have c
What is the difference between serial and sequential files? How searching is applied on both? Ans: A serial file is one where the records have been stored in the order where
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