DATA BASE MANAGEMNT SYSTEM
1)Introduction to Database Management Systems:
Database Management System (DBMS) Definition
A DBMS is a software system that allows users to define, construct, and
manipulate databases. It provides a way to organize, store, and retrieve data
efficiently and conveniently.
Database System Environment
A database system environment consists of:
The hardware and software platform on which the database resides
The database management system software
The database itself
The applications that access the database
The users who use the applications
Database Design and Construction
Database design is the process of creating a conceptual schema for a database. This
involves identifying the data requirements, determining the logical relationships
between the data, and specifying the physical characteristics of the database. The
construction phase involves implementing the conceptual schema using the DBMS
software.
Basic Definitions in DBMS
Here are some basic definitions in DBMS:
Database (DB): A collection of related data.
Table: A structured set of data items (rows) with the same attributes (columns).
Column: A named data element that is shared by all rows in a table.
Row: A set of related data items represented as a single record.
Primary key: A column or set of columns that uniquely identifies each row in a
table.
Foreign key: A column or set of columns in one table that refers to the primary
key of another table.
, Schema: The overall structure of a database, consisting of the tables and their
relationships.
2)Properties of a Database System:
Data Integration: A database system integrates data from multiple sources,
providing a unified view of the data.
Consistency: A database system ensures that the data it manages is consistent,
meaning that it does not contain any contradictions or errors.
Concurrency: A database system allows multiple users to access and
manipulate the data at the same time, while ensuring that the data remains
consistent.
Durability: A database system guarantees that once a transaction is committed,
the changes made by that transaction will persist, even in the event of a system
failure.
Database Management System (DBMS)
A DBMS is a software system that allows users to define, create, maintain, and
manipulate databases.
Database Design and Construction
Conceptual Design: The process of creating a high-level model of the data
requirements and relationships.
Logical Design: The process of mapping the conceptual design to a specific
database management system.
Physical Design: The process of choosing the specific data types, storage
structures, and indexes to use in the implementation.
Database Manipulation and Sharing
Data Definition Language (DDL): Used to define and modify the structure of a
database.
Data Manipulation Language (DML): Used to query and manipulate the data
in a database.
Data Sharing: A database system allows multiple users to access and share the
data concurrently, ensuring consistency and security.
1)Introduction to Database Management Systems:
Database Management System (DBMS) Definition
A DBMS is a software system that allows users to define, construct, and
manipulate databases. It provides a way to organize, store, and retrieve data
efficiently and conveniently.
Database System Environment
A database system environment consists of:
The hardware and software platform on which the database resides
The database management system software
The database itself
The applications that access the database
The users who use the applications
Database Design and Construction
Database design is the process of creating a conceptual schema for a database. This
involves identifying the data requirements, determining the logical relationships
between the data, and specifying the physical characteristics of the database. The
construction phase involves implementing the conceptual schema using the DBMS
software.
Basic Definitions in DBMS
Here are some basic definitions in DBMS:
Database (DB): A collection of related data.
Table: A structured set of data items (rows) with the same attributes (columns).
Column: A named data element that is shared by all rows in a table.
Row: A set of related data items represented as a single record.
Primary key: A column or set of columns that uniquely identifies each row in a
table.
Foreign key: A column or set of columns in one table that refers to the primary
key of another table.
, Schema: The overall structure of a database, consisting of the tables and their
relationships.
2)Properties of a Database System:
Data Integration: A database system integrates data from multiple sources,
providing a unified view of the data.
Consistency: A database system ensures that the data it manages is consistent,
meaning that it does not contain any contradictions or errors.
Concurrency: A database system allows multiple users to access and
manipulate the data at the same time, while ensuring that the data remains
consistent.
Durability: A database system guarantees that once a transaction is committed,
the changes made by that transaction will persist, even in the event of a system
failure.
Database Management System (DBMS)
A DBMS is a software system that allows users to define, create, maintain, and
manipulate databases.
Database Design and Construction
Conceptual Design: The process of creating a high-level model of the data
requirements and relationships.
Logical Design: The process of mapping the conceptual design to a specific
database management system.
Physical Design: The process of choosing the specific data types, storage
structures, and indexes to use in the implementation.
Database Manipulation and Sharing
Data Definition Language (DDL): Used to define and modify the structure of a
database.
Data Manipulation Language (DML): Used to query and manipulate the data
in a database.
Data Sharing: A database system allows multiple users to access and share the
data concurrently, ensuring consistency and security.
