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
Objectives differentiate DDBMS and conventional DBMS; Describe Network topology for DDBMS; Describe the concepts of horizontal and vertical fragmentation; Descr
What are the requirements to ensure the objectives of file management principle is realized?
Explain the Fundamental concepts of object-orientation Software developers, data base administrators (DBAs) need to be familiar with fundamental concepts of object-orientation.
What do you understand by a view? What does WITH CHECK OPTION clause for a view do? - A view is a virtual table which comprises fields from one or more real tables. - It is
Describe log based recovery The most usably structure for recording data base modification is the LOG the log is a sequence of log records recording all the update activities i
Ask questApollo Hospitals (AH) is a popular medical service provider in Oman. AH wants to automate its business functions into an information system. The proposed information syst
Which is a valid SQL type? A valid SQL Should be in CHARACTER it is should be NUMERIC and FLOAT.
Describe the nested-loop join and block-nested loop join. Ans: The block nested- loop join algorithm is as described below: for every block B r of relation R do beg
What Is Recovery? During the life of a transaction, i.e., a after the start of a transaction but before the transaction commits, various changes may be made in a database state
Explain the structure of well formed formulae in relational calculus. Ans: a. An atom is a formula b. If P1 is a formula, after that so are ¬P1 and (P1) c. If P1 and P2 a
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