Comprehensive Analysis of Database Systems: History, Concepts, and SQL

This report provides a comprehensive overview of database systems, starting with a historical perspective and progressing through core concepts. It introduces the evolution of database systems, from early file-based systems to modern DBMS. The report delves into key topics such as entity-relationship modeling, relational schema, and normalization, explaining their roles in organizing and structuring data. It also explores the fundamentals of SQL, including data definition language (DDL) and data manipulation language (DML), illustrating how SQL is used to create, modify, and retrieve data from databases. Furthermore, the report touches upon advanced SQL concepts, emphasizing the importance of SQL in data analysis and business intelligence. References to relevant literature are included to support the presented information.

Table of Contents
Database Systems History...................................................................................................................2
Introduction of Database Systems......................................................................................................2
Entity Relational Modelling................................................................................................................3
Relational Schema...............................................................................................................................4
Normalization......................................................................................................................................4
Introduction to DBMS.........................................................................................................................5
Introduction to SQL............................................................................................................................5
SQL Data Definition Language..........................................................................................................6
SQL Data Manipulation Language....................................................................................................6
Advanced SQL.....................................................................................................................................7
References............................................................................................................................................8
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Database Systems History
Data contains the block of information. The systems of the database contains the set of
databases. The collection of data is called as database and it manipulates the data in a basic
way (CORONEL, 2017). It provides the proper storage and it requires the large amount of
data.
 In Ancient History of data base systems, data are not stored on the disk. The database
programmers are defining the physical and logical data structure like I/O modes,
access methods and more. It requires the high data redundancy. It very expensive and
limited.
 In 1968 (file based), data are maintained in a flat file by using the magnetic tape
medium. It does not provide the security and maintenance cost is high.
 1968-1980 (Non- relational database), It provides the collection of integrated and
structured stored data. The database can be used and shared by application systems. It
uses hierarchical and network data model to store the data. But it is very complex and
difficult to manage.
 Above 1970 (DBMS), Using the various database methods like object oriented, object
relational, java, XML, Embedded, IMDM and mobile. It effectively manages the data.
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Introduction of Database Systems
A database is a collection of related data and it typically stored on the disk and stored
information is accessible only by the concurrent users. It is basically separated into
applications area.
For example,
 One database may contain the human resource
 Another database contains the sales data
 Another database may contain the accounting data and more.
The Database systems are used for managing the database by using the database
management system. The Database systems manages the various number of database. IT has
following responsible. They are listed below.
 Security
 Insert, update and delete the data
 Maximizing the data availability
 Transaction and concurrency Control
 Easy to use interface language like SQL
 Integrity and more.
Entity Relational Modelling
The Entity relationship modelling is used to describe the most important things based
on domain knowledge of a database. It is a graphical representation of entities and their
relationships. It is basically used for the organization of data and information. The
relationship between the entities classified into following types. They are,
 One to one
 One to Many
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 Many to Many
Relational Schema
The relational schema is used to create the relational database that contains tables,
columns and relationships. It helps to organize and understand the database structure. It
supports the existing database functionality and build the integration between the databases.
To create the relational schema by creating the physical and logical schema. The
logical schema is used to depict the database structure and it is used to display the tables,
relationships and columns with other tables in the data. The physical schema is used for
generating the tables, relationships and columns by using relational database management
software (Connolly & Begg, 2015).
Normalization
In database, normalization is used for organizing the data. It is also used to avoid data
redundancy, insertion, deletion, modify and update anomaly. The Normalization is classified
into five types such as 1 NF, 2 NF, 3NF, 4NF and 5 NF.
 The First normal form does not hold the multiple values in attributes of a table.
 The second normal form uses two conditions to create the normalization. They are,
 It must be able to use 1NF table
 No non-prime attributes should be dependent on the subnet.
 The 3 NF also use two conditions. They are,
 It must use second normal form table
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 It should be able to remove transitive functional dependency.
Introduction to DBMS
DBMS stands for Database Management Systems. The collection of data is called as
Database. The management systems are a collection of programs and it is used to store and
retrieve the data in database. The Database management system contains the data collection
and collection of programs to store and access the data in easy and effective way. Many
organizations use the database management system to store large amount of data. It optimises
the data by the data storage and retrieval of the data. It also creates and manages the database.
It easily organizes the data in a database. It has the various features. These are listed below.
 Data security
 Data integrity
 Data recovery
 concurrent access
 User friendly
 Less time to develop a software application
 Data independence.
Introduction to SQL
The structured query language is the standard language for manipulating and accessing
the database. The structured query language can do following the activities. They are,
 It executes the queries against a database.
 It makes the new databases.
 It also makes the new tables
 Insert, update, retrieve and delete the records in a database.
 It makes the views and stored procedures in a database.
 It set the permissions on tables, procedures and view in a database.
To do data manipulation in SQL by using the following languages,
 Data Description or definition language
 Data manipulation Language
 Transaction Control language
 Data control language
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 Data query language
SQL Data Definition Language
The SQL data definition language or data description language is used to define the
data types and columns in a database. It modifies the database schema by inserting, updating,
modifying and deleting the definition of tables or elements. The Data Definition language
commands are listed below.
 CREATE
 RENAME
 TRUNCATE
 DROP
 ALTER
 COMMENT
SQL Data Manipulation Language
The data manipulation language is used to manipulate data in a database by using the
commands. The manipulation involves the inserting, retrieving and delating the data from
existing tables. The DML commands are listed below.
 INSERT
 MERGE
 UPDATE
 DELETE
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Advanced SQL
The advanced SQL is used to display the brief overview of SQL. It increases the need
for data analysts and scientists to understand the relational data stores. Th advanced SQL
database also store the transaction data and business intelligence related data. The Advanced
SQL also creates the procedures, functions, views, triggers and indexes. It easily optimizes
the data in a database. It provides the detailed knowledge about the following topics. They
are,
 SQL statistics
 SQL data preparation
 Data Aggregation
 Advanced filtering
 Window Functions
It uses following commands.
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References
Connolly, T., & Begg, C. (2015). Database systems. Boston [u.a.]: Pearson.
CORONEL, C. (2017). DATABASE SYSTEMS. [S.l.]: CENGAGE LEARNING.
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