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introduction

A database system is basically just a computerized record-keeping system the
database itself can be regarded as a kind of electronic filing cabinet; that is, it is a
repository or con-trainer for a collection of computerized data files. Users of a
system can perform(or request the system to perform, rather) a variety of
operations involving such files- for example
1-Adding new files to the database
2-Inserting data into existing files
3-Retrieving data form existing files
4-Deleting data from existing files
5-Changing data in existing files
6-Removing existing files from the database

A Database Management System (DBMS) is a software system that is designed to
manage and organize data in a structured manner. It allows users to create,
modify, and query a database, as well as manage the security and access controls
for that database. In addition Database is a collection of interrelated data which
helps in the efficient retrieval, insertion, and deletion of data from the database
and organizes the data in the form of tables, views, schemas, reports, etc. For
Example, a university database organizes the data about students, faculty, admin
staff, etc. which helps in the efficient retrieval, insertion, and deletion of data
from it.
Some key features of a DBMS include:
1 Data modeling
2 Data storage and retrieval
3 Concurrency control
4 Data integrity and security
Types of databases ( DBMS )

1-Relational Databases
A relational database is one of the most common and widely used types of databases
It is a collection of properly organized information with clearly defined relationships
so that it can be easily accessed and retrieved. It is a type of database that stores and
manages data using tables and the relationships between them.
2- Non-relational databases
Non-relational databases that do not use tables to store data. Developers store
information in different types of NoSQL databases, such as graphs and documents. It
is popular for modern applications because it can be expanded horizontally, and is
characterized by its simplicity of construction, as it does not require a schema,
structure, or links.
3- Object Oriented Databases
It is a type of database based on the concept of objects and combines the principles of
object-oriented programming (OOP) with the concepts of relational databases. It is a
database system that can work with complex data objects - that is, objects that reflect
those used in object-oriented programming languages. Object-oriented databases are
used in applications that require high performance and need to retrieve data quickly,
such as research and scientific fields, in the field of communications, and other fields
that require Storing complex data, quickly retrieving it, and performing complex
calculations on it.
4-Cloud Databases:
Cloud databases are a type of database that is hosted and managed on the cloud.
These databases rely on data centers and cloud resources to store and manage
data instead of hosting it on local resources. Cloud databases can be accessed
from anywhere over the internet, providing great flexibility and scalability.

5- Centralized Databases:
Centralized databases are a type of database that is stored and managed on a
single server or a group of servers in one location. This means that all data and
processing occur in one place, often suitable for small to medium-sized
applications. Centralized databases are known for their organization and ease of
management.
6- Distributed Databases:
Distributed databases are a type of database where data is distributed and
managed across multiple locations or servers. Data structures and applications
can vary in different locations. This type of database provides the ability to
process data efficiently and is suitable for large and distributed applications.
Features of a Database Management System
)DBMS(
A Database Management System (DBMS) is a software tool that facilitates the
efficient organization, storage, retrieval, and management of data. It plays a crucial
role in modern information systems, providing a structured and controlled
:environment for data management. The following are key features of a DBMS

Data Storage and Organization: DBMSs excel in storing data in a structured and
organized manner. They use various data models, such as relational, hierarchical,
.or NoSQL, to represent and organize data according to user requirements

Data Retrieval: DBMSs offer powerful querying capabilities, allowing users to
retrieve specific data from large datasets using SQL (Structured Query Language)
or other query languages. This feature simplifies data retrieval tasks and ensures
.data accuracy

Data Integrity: Maintaining data integrity is vital, and DBMSs enforce data
integrity constraints, such as unique keys, foreign keys, and data validation
rules. These constraints prevent data inconsistencies and ensure data
.accuracy

Concurrency Control: DBMSs support concurrent access to data by multiple
users or applications. They implement mechanisms like locking and
timestamp-based protocols to manage data access and avoid conflicts
.
Security: DBMSs provide robust security features to protect data from
unauthorized access and tampering. Access control mechanisms,
authentication, and encryption are employed to safeguard sensitive
.information

Data Backup and Recovery: DBMSs offer tools for data backup and recovery,
ensuring that data can be restored in case of hardware failures, human
errors, or other disasters. These features contribute to data reliability and
.availability
Scalability: DBMSs are designed to handle growing data volumes. They offer
mechanisms for vertical and horizontal scaling, allowing organizations to
.expand their databases as needed without compromising performance

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Query Optimization: To enhance performance, DBMSs employ query
optimization techniques that analyze and improve the execution plans of
.complex queries. This ensures efficient data retrieval and processing

Transaction Management: DBMSs support transaction management to
maintain the consistency and integrity of data. ACID (Atomicity, Consistency,
Isolation, Durability) properties guarantee that transactions are processed
.reliably

Data Redundancy Reduction: Redundant data can lead to inconsistencies and
increased storage requirements. DBMSs reduce data redundancy through
.normalization techniques, improving data efficiency and maintainability

Data Modeling Tools: Many DBMSs provide data modeling tools that help
users design and visualize the database schema. These tools simplify the
.process of creating and modifying database structures

Multi-user Collaboration: DBMSs enable multiple users to work
collaboratively on shared data. Version control and access control
.mechanisms help manage concurrent access and changes
In conclusion, a Database Management System is a fundamental tool for efficient
and organized data management. Its features encompass data storage, retrieval,
integrity, security, scalability, and more. These features collectively empower
organizations to leverage their data effectively, making DBMSs a cornerstone of
.modern information systems
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advantages Databases
The following list includes the top 6 databases on the market:
1: MySQL
The relational database management system MySQL is free and open source. This
aids in the storage of all your blog posts, users, plugin data, etc. for WordPress
websites.It's relational due to how it organizes that data into distinct "tables" and links
them together with "keys."

2:PostgreSQL
Object-Relational Database Management System (ORDBMS) PostgreSQL was
created by Michael Ralph Stonebraker in 1996 and is free and open-source. It places a
strong emphasis on extensibility and SQL compliance. Windows, Linux, MacOSX,
Unix, and additional operating systems each of them compatible with it.
One of the best libraries out there, PostgreSQL has a ton of features including
Function Loading and Inheritance. When processing data, these qualities help to
improve extensibility, dependability, and data integrity. Businesses can accomplish
their data handling goals with its wide range of data formats and powerful feature
sets.

3:Microsoft SQL Server
In 1989, Microsoft Corporation developed Microsoft SQL Server. The Relational
Database Management System, or (RDBMS) is now regarded as being excellent for
both on-premise and cloud-based systems. This enterprise-tested versatile database
has intelligence built-in that enables companies to automatically scale its
performance, availability, and security based on their needs. On Linux and Windows
platforms, it is accessible.
Microsoft SQL Server and Sybase SQL Server 4.2 are the same. They are related to
Transact-SQL Procedural languages in terms of their fundamental architecture
approach. This database holds a distinct position in the analytics market thanks to a
number of competitive features.

4: Oracle
Common numerous domains, Relational Database Management Systems (RDBMS)
like Oracle Database are in use. It is one of the most popular databases since it is
considered to be a cost-optimizing and high-performance solution. It is the first
enterprise relational database that is both converged and available in the market.
Structured Query Language, also called SQL, is supported by Oracle Database for
database communication. Enterprise Grid Computing was the main focus of the
development of this multi-model a Relational Database Management System (
(RDBMS). Following the popularity of its 19C database, Oracle released its 21C

version earlier this year, bringing with it a wide range of capabilities like Multi-
workload Improvement utilizing AutoML.

Due to its support for all data types, including relational, graph, structured, and
unstructured information, Oracle Database is one of the most popular databases on the
market.

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5:Elasticsearch
Any sort of data in JSON format can be stored and indexed using Elasticsearch, an
open-source full-text search engine-based database. Lucene, an open-source Java
library for searching and storing data, is the foundation upon which Elasticsearch is
based. It is a multi-tenant document-based search engine with a REST API.
Scalability is one of the primary factors contributing to Elasticsearch's enormous
popularity. Automatic sharing and the REST API make horizontal scaling simple. In

order to evaluate logging or monitoring data, it also supports organized and schema-
less data (JSON).

6: MariaDB
is a well-known Relational Database Management System (DBMS) that works with
MySQL Protocol and Clients. Without any coding requirements, MariaDB may
quickly replace the MySQL server.
In addition to having a massively parallel distributed data construction, which
MariaDB provides columnar storage. A sizable user base of MariaDB's users can help
you with your problems and discussions

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Disadvantages of database management systems

Although there are many advantages to database management systems, no system is
without some disadvantages. The most prominent limitations and disadvantages of
database management systems are:

• High cost
Individuals and small organizations may not pay any costs when using database
systems, but the situation is different for large organizations that possess a huge
amount of data, as they need a powerful system with large space and high security to
save and store that data.
• Ongoing maintenance
If the database system crashes, no user will be able to access and benefit from the
data, so the system needs regular and continuous maintenance to prevent it from
stopping.
• The need for a number of trained employees
The system requires a number of employees, such as: a systems programmer, a
database manager, a designer and a systems analyst. In addition to the excellent
competence and skill of these employees, to ensure that the system continues to
operate as required.

• Regulated boundaries
Relational databases impose domain constraints, while designing the database, it
is necessary to specify the amount of data you intend to enter in any field, since
some search queries are precise, this may result in data loss

• Security
as large companies require data requirements for security against viruses and network
hackers