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
a) Suppose we updated the catalog tables in real time, that is, after every update, insert, or delete SQL statement were executed-rather than only running RUNSTATS once every few
Explain the disadvantages of using DBMS There could be a few disadvantages of using DBMS. As DBMS requires computers, we have to invest a good amount in acquiring the hardwa
Define the categories of SQL Statements? 1) Statements that don't return a result set. This statement class includes INSERT, DELETE, and UPDATE. 2)Statements that return
What is catalog in DBMS? Catalog - A relational DBMS maintains information about every table and index in which it contains. A catalog is a collection of special tables that st
Serialisable Schedules: If the processes of two transactions conflict with each other, how to verify that no concurrency related problems have happened? For this, serialisability t
(a) What is a Sub-Query? (b) What is the difference between a scalar sub-query and a tabular sub-query? (c) Write an equivalent SQL statement to get the Name of Product wh
Explain outer join? Outer Join - If there are any values in one table which do not have corresponding value(s) in the other, in an equi-join which will not be chosen. Such ro
Express the subsequent query in SQL assumes which the data is stored within EMPLOYEE table with relevant fields (i) Display name, job, salary, and hire date of employee who are
The State of Newyork certifies firefighters throughout state keep track all of them, as well as the state’s of fire departments. Each fire department has unique department number
Consider the relations EMP(ENO,ENAME,AGE,BASIC_SALARY) WORK_IN(ENO,DNO) DEPT(DNO,DNAME,CITY) Express the following queries in SQL (i) Find names of employees who work in a dep
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