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
Advantages And Drawbacks Of Ddbms There are various reasons for building distributed database systems, with sharing of data, reliability and availability, and speedup of query
Fourth Normal Form (4NF) When attributes in a relation have multi-valued dependency, further Normalization to 4NF and 5NF are needed. Let us first find out what multi-valued d
What do you understand by transitive dependencies? Define with an example any two problems that can take place in the database if transitive dependencies are available in the datab
What are the typical phases of query processing
Index And Tree Structure Let us talk about the data structure that is used for creating indexes. Can we use Binary Search Tree (BST) as Indexes? Let us initial reconsider
What is magnetic disks?explain it? Magnetic disk provides the bulk of secondary storage of modern computer system. The disk capacity is growing at over 50% per year. But the st
What is Message switching Message switching transmits data units which can be arbitrarily long. Packet switching has a utmost packet size, if any message longer than that, it s
Explain Candidate Key and Super Key A super key is a set of one or more than attributes that, taken collectively, permits us to identify uniquely a tuple in the relation. Wher
Explain degree of relation? Degree of a Relation - The degree or arity of a relation is the number of attributes n of its relation schema.
Problem: a) Briefly describe what you understand by Client-Server environment b) The File Server is a simple form of Client-Server. Describe the principles of the File Serve
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