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!
Example:
RELATIONAL SCHEMA for PERSON:
PERSON (PERSON_ID: integer, NAME: string, AGE: integer, ADDRESS: String)
RELATION INSTANCE
In this instance, m = 3 and n = 4
PERSON_ID
NAME
AGE
ADDRESS
1
Sanjay Prasad
35
b-4,Modi Nagar
2
Sharad Gupta
30
Pocket 2, Mayur
Vihar.
3
Vibhu Datt
36
c-2, New Delhi
Therefore current relation state reflects only the valid tuples that show a particular state of the real world. Though, Null values can be assigned for the cases where the values are missing or unknown.
Determine the rule that a value of a foreign key should appear as a value of some particular table is called a Ans: Referential constraint. The rule that a value of a fo
Define the concept of generalization A generalization is relationship between specific kind of thing and general thing. It is also known as "is-a-kind-of" relationship. Inher
Define data model? A data model is a collection of conceptual tools for explaining data, data relationships, data semantics and consistency constraints.
Use of partial data by applications : In common, applications work with views rather than whole relations. Thus, it may be more appropriate to work with subsets of relations rather
Briefly describe concurrency execution? Lock - based protocols Locks There are several modes in which a data item may be locked in this section we restrict our attention
random file orgnization
distributed quey processing
Explain the concepts of relational data model? Relational Data Model - The relational model was first introduced through Prof. E.F. Codd of the IBM Research in the year 1970
What is called remapping of bad sectors? If the controller detects that a sector is injured when the disk is initially formatted, or when an attempt is made to write the secto
What are the kinds of Strings? -A binary string in MySQL is one that MySQL treats as case sensitive in comparisons. -A non binary string in MySQL is one that MySQL does'nt
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