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!
Creating views with check option: This option limits those updates of data values that cause records to go off the view. The following instance tells this in more detail:
Example: To produce a view for employees of Department = 30, such that user cannot alter the department number from the view:
CREATE OR REPLACE VIEW EMPD30 AS
SELECT EMPNO EMPL_NUM, ENAME NAME, SAL SALARY FROM EMP
WHERE DEPTNO=30
WITH CHECK OPTION;
Now the user cannot alter the department number of any record of view EMPD30. If this change is permitted then the record in which the change has been made will go off the view as the view is only for department-30. This restricted due to use of WITH CHECK OPTION clause
For each 1: n relationship type R involving two entities E1 and E2, we recognize the entity type (say E1) at the n-side of the relationship type R and contain primary key of the en
Define the concept of aggregation. Give two examples where this concept is useful. Ans: Aggregation transforms a relationship among the objects into a higher-level object. A
Define and differentiate between ordered indexing and hashing. Ans: Ordered indexing: To gain fast random access to records in a file, we can make of an index structure. Every
What is the need of a log in a DBMS? Briefly describe the various types of records that are normally present in a log. Ans: The system log, which is generally writt
What is E-R model? This data model is based on real world that having of basic objects called entities and of relationship between these objects. Entities are explained in a da
Describe queries with complex types? The present extension of the SQL query language deal with the complex type Let us start with the simple example: Find the title and t
Examples:- Hierarchical Model: It tells data as and relationships by hierarchy of data values. Figure illustrates an example of hierarchical model. Now a day's these models are
Describe association design of an object by giving one suitable example of it. The Design of Associations Associations are "glue" of advanced object oriented analysis and
FDs in Relationships: Enrols Relationship: None as it is many to many Teaches Relationship : Course code → Instructor Instructor → Course code The next question is:
Problem : (b) A deductive database system is essentially the outcome of applying mathematics logic to database management, where logic is used for both data representation and
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