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.
What is the need for triggers? Triggers are useful mechanisms for alerting humans or for starting particular tasks automatically when particular conditions are met.
Explain query execution plan? - Optimizer available in SQL Server optimizes code to be effectively executed. - A query execution plan demonstrates how this optimizer would r
What are the various forms of data transparency? a) fragmentation transparency b) replication transparency c) location transparency
Describe the various types of Online Analytical Processing (OLAP) tools and briefly discuss how the support common analytical operations.
Ask question #MinimRead Dennis et al. Chapter 6: Minicase 2. Work through it and answer the questions. See the attached example. SequenceDiagram.png Based on the structural mod
Database design Database tables will be created for you on the Technology web server. The schema will be as follows. Please note that this is a simplified database structure, d
Define Network DBMS The NDBMS is built primarily on a one-to-many relationship, but where a parent-child representation between the data items cannot be ensured. This may occur
What is self-transition? If there is a transition which goes back to same state, it is known as "self- transition." With a trigger action exit action would be executed f
What is the difference among a primary index and a secondary index? Primary Index: A primary index is an ordered file whose records are of fixed length along with two fields.
WHAT IS SQL
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