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!
It defines that no primary key value can be null. This is as the primary key is used to recognize individual tuple in the relation. So we will not be able to recognize the records uniquely containing null values for the primary key attributes. This constraint is specified on single individual relation.
Example: Let R be the Table
A#
B
C
Null
B1
C1
A2
B2
C2
B3
C3
A4
B4
A5
C5
Note:
1) '#' shows the Primary key of a relation.
In the relation R above, the primary key has null values in the tuples t1 & t3. NULL value in primary key is not allowed, therefore, relation instance is an invalid instance.
Define the Wait for graph Ans: The wait-for-graph is a directed graph and consist of nodes and directed arcs; the nodes of the graph are active transactions. An arc of the grap
When every condition appears with equality condition (=) only. c) Natural join (denoted by R*S) When two join attributes have the similar name in both relations. (Tha
Three Level Architecture of DBMS or Logical DBMS Architecture The logical architecture defines how data in the database is perceived by users. It is not deals with how the da
Determine the term- Active values An active value is that has dependent values. Every dependent value registers itself with active value that contains a set of dependent values
Research Value: 7% Due Date: 17-Sep-2018 Return Date: 11-Oct-2018 Length: 700 words Submission method options: Alternative submission method Task back to top You are required to
Name the metrics for selecting top algorithm There are a number of metrics for selecting top algorithm: i) Computational complexity: Computational complexity refers to eff
write an SQL statement to create the database in MYSQL server
Extend your CREATE TABLE statement from problem 3 with referential integrity constraints. Updates and deletes on related rows are restricted. 6. From examination of the sample data
Entities Let us first be aware of the question: What are entities? An entity is an object of concern used to show the things in the actual world, e.g., table, car, bo
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
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