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!
Before we talk about the relational model in more detail, let us first define some very basic terms used in this model.
Tuple
Every row in a table shows a record and is called a tuple. A table containing 'n' attributes in a record is called n-tuple.
Attribute
The name of every column in a table is used to interpret its meaning and is known as an attribute. Every table is called a relation.
For instance, Figure shows a relation PERSON. The columns NAME, PERSON_ID, AGE and ADDRESS are the attributes of PERSON and every row in the table represents a separate tuple (record).
Relation Name: PERSON
PERSON_ID
NAME
AGE
ADDRESS
TELEPHONE
1
Sanjay Prasad
35
b-4,Modi Nagar
011-25347527
2
Sharad Gupta
30
Pocket 2, Mayur Vihar.
023-12245678
3
Vibhu Datt
36
c-2, New Delhi
033-1601138
Figure: An extended PERSON relation
Single-Valued Dependencies A database is a collection of related information and it is therefore inevitable that some items of information in the database would depend on some
Can i get help with weka software
What is the main difference between read-only and update methods? A read-only method does not affect the values of a variable in an object, whereas an update method may alter t
Problem : AirwaysCentre, an international airline booking company currently uses a relational database system for their operations, which includes the following relations: P
Lack of standards and experience: The lack of standards has considerably limited the potential of distributed DBMSs. As well, there are no tools or methodologies to help users cha
Attributes that are directly kept in the data base. For example, 'Birth date' attribute of a person. Derived Attributes that are not stored directly but can be derived
Find out the names and company names of all employees sorted in ascending order of company name and descending order of employee names of by which company. SELECT EMPLOYEE_NAME,
What will be create when a primary key if combined with a foreign key? A primary key if combined with a foreign key it creates Parent-Child relationship between the tables that
Define garbage collection. Garbage may be formed also as a side effect of crashes. Periodically, it is essential to find all the garbage pages and to add them to the list of fr
For problems 1-4, give all candidate keys for the tables with FDs specified. Composite candidate keys must be put in parentheses, and candidate keys must be separated with commas
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