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:
Define the Third Normal Form: The third normal form (3NF) is a normal form employed in database normalization. 3NF was initially defined by E.F. Codd in 1971. Codd's definitio
Explain ER Relationship model? An entity-relationship model (ERM): An entity-relationship model (ERM) is an abstract theoretical illustration of structured data. Entity-relatio
Design Documentation The Design Document shall be an extension of Requirements Analysis Design. "The Design Document will comprise a revised and much more detailed descrip
discuss the purpose of the concurrency control?
Determine the Other System Design Issue How to realise subsystems; through hardware or software? How is object model mapped on chosen hardware software? Mapping
What are the disadvantages of relational data ? Disadvantages • Performance - If the number of tables among that relationships to be established are large and the tables t
Describe an data dictionary? A data dictionary is a data structure which keeps meta data about the structure of the database ie. the schema of the database.
Benefits of Hashed file Organisation 1. Insertion or search on hash-key is quick. 2. Best if equality search is required on hash-key. Drawbacks of Hashed file
How to create a table from existing table? Create table as e.g, To create a new table ‘N_emp' with employee names and their identification numbers only from employee ta
Give an example of Operations from the functions of a bank. For creation of a saving account, you can write: bank::: create -savings-account (customer)->account. For oper
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