This document provides an overview of different data models, including object-based models like the entity-relationship model and object-oriented model, and record-based models like the relational, network, and hierarchical models. It describes the key features of each model, such as how data and relationships are represented, and highlights some advantages and disadvantages. The presentation is intended to guide students in understanding different approaches to database design and logical data modeling.
Dbms classification according to data modelsABDUL KHALIQ
CLASSIFICATION ACCORDING TO DATA MODELS
Hierarchal Model
In a hierarchical data model, data are organized into a tree-like structure.
Network Model
based on an enlargement of the concept of hierarchical data bases.
Relational Model
Data are stored in tables
Object Oriented model
Object oriented data base systems are the most recent development in data base technology.
Introduction
Definations
Advantages and Disadvantages
PowerPoint Presentation
PowerPoint Presentation for free
Data modeling is a process used to define and analyze data requirements needed to support the business processes within the scope of corresponding information systems in organizations.
A database model refers to the structure of a database and determines how the data within the database can be organized and manipulated. Let’s explore some common types of database models:
Relational Model: The most popular example, the relational model, organizes data into tables (also known as relations). Each table contains rows representing records and columns representing attributes. Relationships between tables are established using keys.
Hierarchical Model: Developed by IBM for IMS (Information Management System), this model arranges data in a tree-like structure. Each record is a tree node, and relationships follow a one-to-many pattern. It’s predictable and efficient for data access.
Network Model: This model allows many-to-many relationships between records. It’s more flexible than the hierarchical model but less common.
Entity–Relationship Model (ER Model): It represents entities, their attributes, and the relationships between them. ER diagrams visually depict these components.
Object Model: Used in object-oriented databases, it treats data as objects with properties and methods. It’s suitable for complex data structures.
Document Model: Commonly used in NoSQL databases, it stores data as documents (e.g., JSON or XML). Each document can have varying attributes.
Entity–Attribute–Value (EAV) Model: A flexible model where data is stored in a sparse matrix. It’s useful for handling dynamic attributes.
Star Schema: Primarily used in data warehousing, it simplifies complex data structures into a central fact table connected to dimension tables.
Student POST Database processing models showcase the logical s.docxorlandov3
Student POST:
Database processing models showcase the logical structure of a database. The most commonly used model is the Relational database model that sorts the data in a table that consist of rows and columns. The column holds the attributes of the entity and rows hold the data of a particular instance of the entities. The major advantage of the Relational model is that it is in the table form and hence easier for users to understand, manage and work with the data. And, with the primary key and foreign key concepts, the data can be uniquely identified, stored in different entities and retrieved effectively with the relationships. The other advantage is that with the relational model, SQL language can be used to work with the data which is simple to understand and most widely used. The disadvantage of relational model could be the financial cost that is higher in comparison as the specific software needs to be in place and the regular maintenance needs to be performed that requires highly skilled manpower. And, the complexity of the database can be further increased when the volume of the data keep in increasing. Also, there is the limitation in the length of fields stored as different data types in relational model (Joseph & Paul, 2009).
The other processing model is the Object-oriented model that depicts database as the collection of objects. The advantage of this model is that it is compatible to work with complex data sets with the use of Object IDs and object-oriented programming. It’s disadvantage is that object databases are not commonly used and the complexity can hamper the performance of database. The other type of database model is the Entity-Relationship model which is mostly used for the conceptual design of database. It pictures the entities, several attributes that falls within the domain of that entity and the cardinality of relationship between them. It’s advantage is that the E-R diagram is easily understandable by the users at the first glance and thus can effectively work with the data in no time and can point out the discrepancies in the data. The other advantage is that it can be easily converted to other models if required by the business. The disadvantage of Entity-Relationship is that the industry standard notations for the diagram is not defined and thus can create confusion to the users. This model is only suitable for high-level database design (S.J.D.,2020).
2Nd Student POST :
Database models or commonly referred to as schemas help represent the structure of a database and its format which is run by a DBMS. Database model uses vary depending on user specifications.
Types of database models
1.
Network model
This network model uses a structure similar to that of a hierarchical model. The model permits multiple parents, which is a tree-like structure model. This model emphasizes two basic concepts; records and sets. Records hold file hierarchy and sets define the many-to-many relationship .
Dbms classification according to data modelsABDUL KHALIQ
CLASSIFICATION ACCORDING TO DATA MODELS
Hierarchal Model
In a hierarchical data model, data are organized into a tree-like structure.
Network Model
based on an enlargement of the concept of hierarchical data bases.
Relational Model
Data are stored in tables
Object Oriented model
Object oriented data base systems are the most recent development in data base technology.
Introduction
Definations
Advantages and Disadvantages
PowerPoint Presentation
PowerPoint Presentation for free
Data modeling is a process used to define and analyze data requirements needed to support the business processes within the scope of corresponding information systems in organizations.
A database model refers to the structure of a database and determines how the data within the database can be organized and manipulated. Let’s explore some common types of database models:
Relational Model: The most popular example, the relational model, organizes data into tables (also known as relations). Each table contains rows representing records and columns representing attributes. Relationships between tables are established using keys.
Hierarchical Model: Developed by IBM for IMS (Information Management System), this model arranges data in a tree-like structure. Each record is a tree node, and relationships follow a one-to-many pattern. It’s predictable and efficient for data access.
Network Model: This model allows many-to-many relationships between records. It’s more flexible than the hierarchical model but less common.
Entity–Relationship Model (ER Model): It represents entities, their attributes, and the relationships between them. ER diagrams visually depict these components.
Object Model: Used in object-oriented databases, it treats data as objects with properties and methods. It’s suitable for complex data structures.
Document Model: Commonly used in NoSQL databases, it stores data as documents (e.g., JSON or XML). Each document can have varying attributes.
Entity–Attribute–Value (EAV) Model: A flexible model where data is stored in a sparse matrix. It’s useful for handling dynamic attributes.
Star Schema: Primarily used in data warehousing, it simplifies complex data structures into a central fact table connected to dimension tables.
Student POST Database processing models showcase the logical s.docxorlandov3
Student POST:
Database processing models showcase the logical structure of a database. The most commonly used model is the Relational database model that sorts the data in a table that consist of rows and columns. The column holds the attributes of the entity and rows hold the data of a particular instance of the entities. The major advantage of the Relational model is that it is in the table form and hence easier for users to understand, manage and work with the data. And, with the primary key and foreign key concepts, the data can be uniquely identified, stored in different entities and retrieved effectively with the relationships. The other advantage is that with the relational model, SQL language can be used to work with the data which is simple to understand and most widely used. The disadvantage of relational model could be the financial cost that is higher in comparison as the specific software needs to be in place and the regular maintenance needs to be performed that requires highly skilled manpower. And, the complexity of the database can be further increased when the volume of the data keep in increasing. Also, there is the limitation in the length of fields stored as different data types in relational model (Joseph & Paul, 2009).
The other processing model is the Object-oriented model that depicts database as the collection of objects. The advantage of this model is that it is compatible to work with complex data sets with the use of Object IDs and object-oriented programming. It’s disadvantage is that object databases are not commonly used and the complexity can hamper the performance of database. The other type of database model is the Entity-Relationship model which is mostly used for the conceptual design of database. It pictures the entities, several attributes that falls within the domain of that entity and the cardinality of relationship between them. It’s advantage is that the E-R diagram is easily understandable by the users at the first glance and thus can effectively work with the data in no time and can point out the discrepancies in the data. The other advantage is that it can be easily converted to other models if required by the business. The disadvantage of Entity-Relationship is that the industry standard notations for the diagram is not defined and thus can create confusion to the users. This model is only suitable for high-level database design (S.J.D.,2020).
2Nd Student POST :
Database models or commonly referred to as schemas help represent the structure of a database and its format which is run by a DBMS. Database model uses vary depending on user specifications.
Types of database models
1.
Network model
This network model uses a structure similar to that of a hierarchical model. The model permits multiple parents, which is a tree-like structure model. This model emphasizes two basic concepts; records and sets. Records hold file hierarchy and sets define the many-to-many relationship .
The Roman Empire A Historical Colossus.pdfkaushalkr1407
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Under Augustus, the empire experienced the Pax Romana, a 200-year period of relative peace and stability. Augustus reformed the military, established efficient administrative systems, and initiated grand construction projects. The empire's borders expanded, encompassing territories from Britain to Egypt and from Spain to the Euphrates. Roman legions, renowned for their discipline and engineering prowess, secured and maintained these vast territories, building roads, fortifications, and cities that facilitated control and integration.
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Roman architecture and engineering achievements were monumental. They perfected the arch, vault, and dome, constructing enduring structures like the Colosseum, Pantheon, and aqueducts. These engineering marvels not only showcased Roman ingenuity but also served practical purposes, from public entertainment to water supply.
Embracing GenAI - A Strategic ImperativePeter Windle
Artificial Intelligence (AI) technologies such as Generative AI, Image Generators and Large Language Models have had a dramatic impact on teaching, learning and assessment over the past 18 months. The most immediate threat AI posed was to Academic Integrity with Higher Education Institutes (HEIs) focusing their efforts on combating the use of GenAI in assessment. Guidelines were developed for staff and students, policies put in place too. Innovative educators have forged paths in the use of Generative AI for teaching, learning and assessments leading to pockets of transformation springing up across HEIs, often with little or no top-down guidance, support or direction.
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The French Revolution, which began in 1789, was a period of radical social and political upheaval in France. It marked the decline of absolute monarchies, the rise of secular and democratic republics, and the eventual rise of Napoleon Bonaparte. This revolutionary period is crucial in understanding the transition from feudalism to modernity in Europe.
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4. DATA MODEL
‘ Data model are different models that can be used to design a
database. Design of database includes describing data, data
relationships, data semantics and consistency constrains. Various data
model have been proposed with different structure & abstractions.’
5.
6. Object-based data model
Object-based logical models are used in describing data at the logical and
view levels.They are characterized by the fact that they provide fairly
flexible structuring capabilities and allow data constraints to be
specified explicitly.There are many different models and more are likely
to come. Several of the more widely known ones are-
1. The entity-relationship model
2.The object-oriented model
3. The semantic data model
4. The functional data model
In this book, We examine the entity-relationship model and the object-
oriented model as representatives of the class of the object-based
logical models.
7.
8. 1. The Entity-Relationship Data Model
The entity-relationship (E-R) data models is based on a perception of a
real world that consists of a collection of basic objects, called entities
and of relationships among these objects. An entity is a ‘things’ or
‘object’ in the real world that is distinguishable form other objects.
Entities are described in a database by a set of attributes. A relationship
is an association among several entities. The set of all entities of the
same type, and the set of all relationships of the same type, respectively.
In addition to entities and relationships, the E-R Model
represents certain constraints to which the contents of a database must
conform. One important constraint is mapping cardinalities, which
express the number of entities to which another entity can be
associated via a relationship set.
9. 2. The Object-Oriented Data Model
Like the E-R model , the object-oriented model is based on a collection
of objects. An object contains values stored in instance variables within
the object. An object also contains bodies of code that operate on the
object. These bodies of code are called methods.
Object that contian
the same types of values and the same methods are grouped together
into classes. A class may be a type definition for objects. This
combination of data and methods comprising a type definition is
similar to a programming language abstract data type.
The only way in which one object can access the data of another
object is by invoking a method of that other object. This action is called
sending a message to the object.
10. Record – Based Data Model
Record-based logical models are used in describing data at the logical
and view levels. In contrest to object-based data models, they are used
both to specify the overall logical structure of the database and to
provide a higher-level description of the implementation .
Record –based models are so named because the database is
structured in fixed-format records of several types.
Typs of Record-based data model : 1. Relational Data Model
2. Network Data Model
3. Hiierarchical Data Model
The three most widely accepted record-based data models are the
relational, network and hierarchical models.
11. The relational model uses a collection of tables to represent both data
and the relationships among those data. Each table has multiple
columns and each column has a unique name . Figure 1.4 presents a
sample relational database comprising of two tables .
Relational database are powerful
because they require few assumptions about how data is related or how
it will be extracted from the database . As a result, the same database
can be viewed in different ways. Another feature of relational systems is
that a single database can be spread across several tables. This differs
foem flat-file database, in which each database is self- contained in a
single table.
Relational Data Model
12.
13. .Features of relational model.
This model has the following fearures-
1. All the data is represented in the form of table.
2. Each attributes of a relation has distinct name.
3. Tt eliminates the need to change application programs when a
change is made to the database.
4. User need not know the exact physical structures to use the database.
Advantages of relational model :
1. Structural independence
2. Conceptual simplicity
3. Design,Implementation,Maintenance and Usage Ease
4. Ad Hoc Query Capability
15. 2. Network Data Model
Data in the network model are represented by collections of records
and relationships among data are represented by links, which can be
viewed as pointers. The records in the database are organized as
collections of arbitrary graphs.
Figure presents a sample network database.
16. Features of Network Data Model
Network model is has the following features-
1. Data is represented by records and links.
2. Relationship among the data is represented by links or pointers.
3. All the records are organized in orbitaty form.
4. The set can have more than one member record but only one owner
record.
5. The set has one to many (1:M) relationship between the owner and
member record.
17. Advantages of Network Data Model:
1. Conceptual Simplicity
2. Capability to handle more relationships types
3. Ease to data access
4. Data Intergrity
5.Data Independence
6. Database Standards
Disadvantages of Network Data Model:
1. System Complexity
2. Absence of Structural Independence
18. The hierarchical model is similar to the network model in the sense that
data and relationships among data represented by records and links,
respectively. It .differs form the network model in that the records are
organized as collections of tress rather than arbitrary graphs. one of the
first hierarchical database information Management System (IBM) was
developed jointly by North American Rockwell Company and
IBM.Hierarchical Database model is one of the oldest database models,
dating from late 1950s.
Figure represents e sample hierarchical database.
.Hierarchical Data Model.
19. .Features of Hierarchical Model.
Hierarchical model has the following features-
1. It is very similar to network model except the records are organized
in tree form.
2. Hierarchical is an ordered tree and is easy to understand.
3. Again data is represented in the form of records.
4. Similarly relationship among the data is represented by records or
links.
5. At the root of the tree is the single parent, the parent can have none,
one or more children.
20. Advantages of hierarchical data model :
1. Simplicity
2. Data security
3. Data Integrity
4. Efficiency
:
Disadvantages of Hierarchical Data Model :
1. Implementation complexity
2.Database Management problems
3. Lack of Structural Independence
4. Programming Complexity
5. Implementation Limitation
21. .Physical Data Model.
Physical data models are used to describe data at the lowest level. In
contrast to logical data models, there are few physical data models in
use. Two of the widely known ones are the unifying model and the
frame memory model.
Types of physical data model :
1. Unifying Model
2. Frame Memory Model