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!
An entity type usually has an attribute whose values are distinct for every individual entity in the collection. Such an attribute is known as a key attribute and its values can be used to recognize each entity uniquely.
Strong entity set: The entity types having a key attribute are known as strong entity types or regular entity types.
Attributes
Let us first answer the question:
What is an attribute?
An attribute is a property used to define the specific feature of the entity. So to define an entity entirely, a set of attributes is used.
For example, a student entity may be defined by the student's name, address, age, course, etc.
An entity will have a value for every of its attributes. For example for a specific student the following values can be assigned:
RollNo: 1234
Name: Supriya
Age: 18
Address: B-4, Mayapuri, Delhi. Course: B.Sc. (H)
Cardinality of Relationship One-to-One Only one entity of the first set is linked to only one entity of the second set. E.g. A teacher teaches a student. Only one teacher
let us consider a table having 2200 records and the fixed size of the table to be considered as 25.then how many numbers of table is requredto perform horizontal fragmentation
Can we delete data element, which is being used by table fields. No we cant delete data element.
Create 1 experiment to demonstrate an aspect of query optimisation by using access-path structures (indexes), decomposition, or denormalisation. Once satisfied with your experiment
Suppose R is a relation with attributes A1, A2,..., An. As a function of n, tell how many superkeys R has, if: 1.1 The only key is A1. 1.2 The only key is A1 and A2. 1.3 The o
Explain the two types of participation constraint. Total: The participation of an entity set E in a relationship set R is said to be total if each entity in E participates i
Isolation or Independence : The isolation property shows that the updates of a transaction should not be visible till they are committed. Isolation assurance that the progresses of
Example -Find the employee name, salary, department number and average salary of his/her department, for those employees whose salary is more than the average salary of that depart
A relation has: Relational Schema Relation instance Relational Schema: A relational schema shows the relation's name, its attributes and the domain of every a
Define Direct file organization? The direct file organization is employed to enhance the performance in accessing the records than sequential file organization. In direct file
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