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 Two phase locking protocol A transaction is consider as to follow the two-phase locking protocol if all locking operations precede the first unlock operation in the tra
milestone assignment
Compare wait-die deadlock prevention scheme with wait-wound scheme Ans: Wait-Die Scheme a) Based upon a nonpreemptive technique. b) If Pi requests a resource present
Question A What is operational intelligence? Question B What is Business Intelligence? Explain the components of BI architecture Question C Differentiate between databas
Describe disk manager and their work? Disk Manager: Responsible for fetching data regulated through file Manager from disk storage within Main memory and deciding what data to
Super keys of a relation can have extra attributes. Candidate keys are minimal super key, i.e. such a key have no extraneous attribute. An attribute is known as extraneous if even
A distributed database is defined as "a collection of multiple logically interrelated database which are physically distributed over a computer network" (a) Give any three advan
What is an E-R model? Draw an E-R Diagram for the company database with following Descriptions? The company is organized within departments. Each department has a unique name a
For Colorado customers calculate the number of single products ordered. If a product is purchased on multiple orders, it should be counted only single time. The result should conta
What is view in SQL? How is it defined? Any relation that is not part of the logical model, but is made visible to a user as a virtual relation is known as a view. We descri
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