Illustrate the definition of the classes and operation, Database Management System

The definition of the classes and operation can often be adjusted to increase the amount of inheritance". Justify the above statement.  

Adjustment of Inheritance

The definition of classes and operations can often be adjusted to increase amount of inheritance among the objects. The object designer can rearrange and adjust classes to increase inheritance between the different objects and classes. Sometimes same operation is defined across several classes and can easily be inherited from the common ancestor. By slightly modifying definitions of the operations or classes, the operation often could be made to match. We also can extract common behaviour out of groups of classes to increase inheritance. Similar attributes in various classes may have different names, but by giving some common name and moving them to the ancestor class we can increase inheritance. An operation may be defined on many different classes in a group but be undefined on other classes. To increase inheritance, we can define it on common ancestor class and declare it as a no-op on classes that do not care about it. We can also use the DELEGATION instead of inheritance to share only meaningful attributes among a super class and its sub class.

 

Posted Date: 8/30/2013 6:41:28 AM | Location : United States







Related Discussions:- Illustrate the definition of the classes and operation, Assignment Help, Ask Question on Illustrate the definition of the classes and operation, Get Answer, Expert's Help, Illustrate the definition of the classes and operation Discussions

Write discussion on Illustrate the definition of the classes and operation
Your posts are moderated
Related Questions
What is B-Tree? A B-tree eliminates the redundant storage of search-key values .It permits search key values to appear only once.

Describe the two alternatives for specifying structural constraints on relationship kinds? Relationship kinds have certain constraints in which limit the possible combination o

Differance between DDL and SDL? DDL and SDL - The data definition language (DDL) is used through DBA and database designers to describe internal schema, conceptual schema, and

What is a query tree?     Ans:  A query tree, as well known as operator graph, is a tree data structure that corresponds to a relational algebra expression. It denotes the inpu

Explain the difference between using functions along with and without grouping attributes in relational algebra. Give examples. Ans: Group functions are used to group data of

Data Fragmentation "Fragmentation includes decomposing the data in relation to non-overlapping component relations". Why do we require fragmenting a relation?


What is DDL? Make a list of commands with short description used in DDL Ans: Data Definition Language that is abbreviated as DDL is a computer language for defining data struct

What is meant by functional dependencies? Consider a relation schema R and α C R and β C R. The functional dependency α ->β  holds on relational schema R if in any legal relati

What is a Data Flow Diagram?  Data Flow Diagram: A data flow diagram is the graph that shows flow of data values from their sources in objects in the course of processes whic