Question

when developing data models, some people suggest you should have all entities identified before you add attributes to each entity, while others suggest that you include the attributes in each entity when you start the conceptual model. explain the pros and cons of each approach.

Answer 1

DATA MODELS :

The data model is nothing but the process of creating a data model that is to be stored in the database. The data model is the conceptual representation and it includes many factors like

1.The Data objects

2.Association between the different objects

3.Some certain Rules.

This Data model is helpful for the visual representation of the data. It is having some specific values and some sort of cinematic and some type of security ensuring the quality of the data. In Database management, we are having two different types of data model techniques are there. Those are :

1.E-R model -Entity-Relationship model

2.UML - Unified Modelling Language

We need to identify the basic Primary Goal of the Data Model.

1. It ensures the all the data objects required by the database that is to be represented in the form of accurate.

2. It helps us to create the database in the format of the conceptual

3. It helps us to define the Relational Tables.

4. It also identifies to find the missing data and repeated data

Types of Data Models :

We ate having many of the numbers of data models in the database . some of them are mentioned below.

There are mainly three types of data models are presented in the database.Those are

Conceptual, Logical, and Physical data model

Conceptual Data Model :

1. It is helpful for the establishment and creating of the entities, their attributes and the relation between the items.

There are 3 items are presented in this conceptual model.

Entity, Attribute, Relationship.

The entity which deals with the Real world thing and object, Attribute tells about the properties of the entities and the Relationship tells about the two entities.

Logical Data Model :

The logical data model adds some of the information to the conceptual data model elements. Mainly it says about the structure of the data elements and it is used to set the relationship between them.

The main advantage of this logical data model is to provide the base to the physical model.

here there is no primary and secondary key is generated.

It can be designed and developed by the independently in the part of the DBMS

Physical Data Model :

The Physical data model describes the database specific implementation of modelling of the data.

The use to generate the abstraction with the help of the abstraction

It is happening only with the meta-data offered like the physical data

This model helps in the database column keys, indexes and triggers and so on.

It contains the relationship between the tables that are presented in the cardinal of the relationship.

Columns that have the exact datatypes, different data types

PROS of the DATA_MODEL :

1. It is used to make certain that data objects and the representation that can be processed very accurately

2. It is with a very keen and detailed model and this keenness is used to build the physical database

3. The info in the data model used to define the relationship between the tables,

4. It is used to bits of help to business to communicate within the organization

5. It helps to recognize the correct sources

CONS of the DATA_MODEL :

1.When we need to develop the data model we have to know about the physical data that should be stored i

2.It produces complex appliaction developmetn ,application managemnt .

3. Even the small change can affect the entire system application

4. There is no set data type functionality language in the database management system