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
Oracle & Distributed Databases 1. Differentiate between PL/SQL functions and procedures. 2. Draw the diagram of logical structure of oracle database and explain it in brief.
Write short notes on domain relational calculus The domain relational calculus uses domain variables that take on values from an attribute domain rather than values for whole
What is meant by mean time to failure? The mean time to failure is the amount of time that the system could run continuously without failure.
What is the function of IO/M signal in the 8085? It is a status signal. It is used to differentiate among memory locations and I/O operations. When this signal is low (IO/M = 0
What is meant by Physical blocks? The input and output operations are completed in block units. The blocks residing on the disk are referred to as physical blocks.
Differentiate between Key and superkey? Key and superkey - A key a single attribute or a combination of two or more attributes of an entity set in which is used to identify o
Consider a database schema consisting of four relations, whose schemas are: Product (maker, model, type) PC (model, speed, ram, hd, price) Laptop (model, speed, ram, hd, s
Problem 1 Why are the operational system keys not recommended for forming data warehouse primary keys? Give any two examples 2 Explain the following performance tuning techn
prototype of a distributed information system for a national car part retail outlet chain.
In Database software have only pure security or some dis secured by administrator?
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