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!
Write short note on Events
Events consist of inputs, interrupts, decisions and actions performed by any external device or users. Every event always has a sender and receiver. In most of cases sender and receives are same object. A state with no a predecessor and successor are ambiguous and care would be taken to represent initiations and termination of the events. Events that have same effect on control flow must be grouped together even if value differs. The events are to be allocated to object classes that send or receive it.
Most of design issues of systems are concerned with steady-state behaviour of system.
However, system design phase must also address the initiation and finalization of system. This is addressed by a set of new uses cases known as administration use cases
The Conceptual Level or Global level The conceptual level presents a logical view of the complete database as a unified whole. It permits the user to bring all the data in th
why are older data models are being replaced by new data models
Security And Integrity After Reading the concepts of database recovery in the last section, let us now deal with a vital concept that helps in minimizing consistency errors in
Define NULL value NULL value NULL means something is unknown. It does NOT mean null (the digit 0). Null is as well employed as attribute value for a particular entity in which
What is meant by heuristic optimisation? Discuss the main heuristics that are applied during query optimisation. Ans: In heuristic optimization, heuristics are employed to r
What is a cascading update? Referential integrity constraints needs that foreign key values in one table correspond to primary key values in another. If the value of the primar
Differentiate between a subquery and a join If we need to acquire information from one or more tables after that either subquery or join can be used. If the columns which are t
Differentiate between logical database design and physical database design. Show how this separation leads to data independence? Basis Logical Databas
Explain the conventions (relationships) for displaying an ER schema as an ER diagram.
Sub query in the UPDATE command : Example : //Double the commission for employees, who have got at least 2 increments. UPDATE EMP SET COMM = COMM * 2 WHERE
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