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!
Differentiate between various levels of data abstraction?
Data Abstraction - Abstraction is the procedure to hide the irrelevant things from the users and represent the relevant things to the user. Database systems are frequent used through non-computer professionals so in which the complexity must be hidden from database system users. This is done through defining levels of abstract as that the database may be viewed; there is logical view or external view, conceptual view and internal view or physical view.
1. External View - This is the highest level of abstraction as seen through a user. It describes only the part of whole database, that is relevant to a particular user.
2. Conceptual View - This is the next higher stages of abstraction that is the sum total of Database Management System user's views. It elaborates what data are in fact stored in the database. It contains information about whole database in terms of a small number of associatively easy structure.
3. Internal View - This is the lowest level of abstraction. It elaborates how the data are physically stored
For this application, we will consider IBM DB2 catalog data (i.e., metadata) for IBM's enterprise-class servers running the z/OS (formerly OS/390 or MVS) operating system. One of
How external/conceptual mapping and conceptual /internal mapping is performed
Compare three clustering algorithms in Weka. For this comparison, you will need to use at least two different datasets. Run the algorithms on the datasets, and use the visual
Define functional and multivalued dependencies. Ans: A functional dependency is a assets of the semantics of the attributes in a relation. The semantics point out how at
Introduction In large projects, we can have many different companies working together. Generally, the project or contract is awarded to one company (Principal Contractor), which
Analyzing Association Traversal Till now, we have supposed that associations are bi-directional. But in the case of traversal, it is in only one direction in any application,
Which language used in application programs to request data from the DBMS is referred? Language which is used in application program is DML to request data from the DBMS is ref
Example -GRANT CREATE SESSION TO MCA12; (This command gives system level permission on creating a session - not portable) GRANT SELECT ON EMP TO MCA12; (Object level permi
explain the steps for reduction of er model into relational model?
Consider the relations described below: PHYSICIAN (regno, name, telno, city) PATIENT (pname, street, city) VISIT (pname, regno, date_of_visit, fee) Where the regno and pname ide
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