Entity relationship model, Components of ER model, Mapping E-R model to Relational schema, Network and Object-Oriented Data models, Storage Strategies: Detailed Storage Architecture, Storing Data, Magnetic Disk, RAID, Other Disks, Magnetic Tape, Storage Access, File & Record Organization, File Organizations & Indexes, Order Indices, B+ Tree Index Files, Hashing Data Dictionary
This document provides an overview of database management systems (DBMS). It defines a DBMS as software that manages data and allows for data to be accessed by multiple users and applications. The document then covers the introduction, properties, benefits, types, entity relationship diagrams, and differences between DBMS and relational DBMS. It provides examples and definitions for each topic.
ESOFT Metro Campus - Diploma in Software Engineering - (Module IV) Database Concepts
(Template - Virtusa Corporate)
Contents:
Introduction to Databases
Data
Information
Database
Database System
Database Applications
Evolution of Databases
Traditional Files Based Systems
Limitations in Traditional Files
The Database Approach
Advantages of Database Approach
Disadvantages of Database Approach
Database Management Systems
DBMS Functions
Database Architecture
ANSI-SPARC 3 Level Architecture
The Relational Data Model
What is a Relation?
Primary Key
Cardinality and Degree
Relationships
Foreign Key
Data Integrity
Data Dictionary
Database Design
Requirements Collection and analysis
Conceptual Design
Logical Design
Physical Design
Entity Relationship Model
A mini-world example
Entities
Relationships
ERD Notations
Cardinality
Optional Participation
Entities and Relationships
Attributes
Entity Relationship Diagram
Entities
ERD Showing Weak Entities
Super Type / Sub Type Relationships
Mapping ERD to Relational
Map Regular Entities
Map Weak Entities
Map Binary Relationships
Map Associated Entities
Map Unary Relationships
Map Ternary Relationships
Map Supertype/Subtype Relationships
Normalization
Advantages of Normalization
Disadvantages of Normalization
Normal Forms
Functional Dependency
Purchase Order Relation in 0NF
Purchase Order Relation in 1NF
Purchase Order Relations in 2NF
Purchase Order Relations in 3NF
Normalized Relations
BCNF – Boyce Codd Normal Form
Structured Query Language
What We Can Do with SQL ?
SQL Commands
SQL CREATE DATABASE
SQL CREATE TABLE
SQL DROP
SQL Constraints
SQL NOT NULL
SQL PRIMARY KEY
SQL CHECK
SQL FOREIGN KEY
SQL ALTER TABLE
SQL INSERT INTO
SQL INSERT INTO SELECT
SQL SELECT
SQL SELECT DISTINCT
SQL WHERE
SQL AND & OR
SQL ORDER BY
SQL UPDATE
SQL DELETE
SQL LIKE
SQL IN
SQL BETWEEN
SQL INNER JOIN
SQL LEFT JOIN
SQL RIGHT JOIN
SQL UNION
SQL AS
SQL Aggregate Functions
SQL Scalar functions
SQL GROUP BY
SQL HAVING
Database Administration
SQL Database Administration
Week 3 Classification of Database Management Systems & Data Modelingoudesign
The document discusses different types of database management systems and data models. It provides information on the following:
- The relational data model is the most commonly used model today and is supported by popular DBMS like Oracle, SQL Server, DB2, and MySQL.
- Other traditional models like hierarchical and network models are not commonly used now due to their complexity.
- The advantages of data models include increased effectiveness, reduced costs, simplicity, minimum redundancy, data integrity, independence, faster performance, reduced errors and risks.
- The types of data models discussed are hierarchical, network, relational, E-R and object oriented models. The characteristics and advantages/disadvantages of each model are described
This presentation contains the concepts related to database design using ER Diagram. The content is adapted from the contents of the authors of the book mentioned in the reference.
This document contains information about a Relational Database Management Systems course prepared by D.GAYA, an Assistant Professor. It includes an introduction to database systems, definitions of key terms like data, information, databases, and database management systems. It describes characteristics of DBMS like data being stored in tables, reduced data redundancy, supporting multiple users, and providing security. It also discusses database structures like tables, records, fields, relationships, entities, attributes, and different types of relationships.
The document provides an introduction to database management systems (DBMS) and database models. It defines key terms like data, database, DBMS, file system vs DBMS. It describes the evolution of DBMS from 1960 onwards and different database models like hierarchical, network and relational models. It also discusses the roles of different people who work with databases like database designers, administrators, application programmers and end users.
This document provides an overview of database management systems (DBMS). It defines a DBMS as software that manages data and allows for data to be accessed by multiple users and applications. The document then covers the introduction, properties, benefits, types, entity relationship diagrams, and differences between DBMS and relational DBMS. It provides examples and definitions for each topic.
ESOFT Metro Campus - Diploma in Software Engineering - (Module IV) Database Concepts
(Template - Virtusa Corporate)
Contents:
Introduction to Databases
Data
Information
Database
Database System
Database Applications
Evolution of Databases
Traditional Files Based Systems
Limitations in Traditional Files
The Database Approach
Advantages of Database Approach
Disadvantages of Database Approach
Database Management Systems
DBMS Functions
Database Architecture
ANSI-SPARC 3 Level Architecture
The Relational Data Model
What is a Relation?
Primary Key
Cardinality and Degree
Relationships
Foreign Key
Data Integrity
Data Dictionary
Database Design
Requirements Collection and analysis
Conceptual Design
Logical Design
Physical Design
Entity Relationship Model
A mini-world example
Entities
Relationships
ERD Notations
Cardinality
Optional Participation
Entities and Relationships
Attributes
Entity Relationship Diagram
Entities
ERD Showing Weak Entities
Super Type / Sub Type Relationships
Mapping ERD to Relational
Map Regular Entities
Map Weak Entities
Map Binary Relationships
Map Associated Entities
Map Unary Relationships
Map Ternary Relationships
Map Supertype/Subtype Relationships
Normalization
Advantages of Normalization
Disadvantages of Normalization
Normal Forms
Functional Dependency
Purchase Order Relation in 0NF
Purchase Order Relation in 1NF
Purchase Order Relations in 2NF
Purchase Order Relations in 3NF
Normalized Relations
BCNF – Boyce Codd Normal Form
Structured Query Language
What We Can Do with SQL ?
SQL Commands
SQL CREATE DATABASE
SQL CREATE TABLE
SQL DROP
SQL Constraints
SQL NOT NULL
SQL PRIMARY KEY
SQL CHECK
SQL FOREIGN KEY
SQL ALTER TABLE
SQL INSERT INTO
SQL INSERT INTO SELECT
SQL SELECT
SQL SELECT DISTINCT
SQL WHERE
SQL AND & OR
SQL ORDER BY
SQL UPDATE
SQL DELETE
SQL LIKE
SQL IN
SQL BETWEEN
SQL INNER JOIN
SQL LEFT JOIN
SQL RIGHT JOIN
SQL UNION
SQL AS
SQL Aggregate Functions
SQL Scalar functions
SQL GROUP BY
SQL HAVING
Database Administration
SQL Database Administration
Week 3 Classification of Database Management Systems & Data Modelingoudesign
The document discusses different types of database management systems and data models. It provides information on the following:
- The relational data model is the most commonly used model today and is supported by popular DBMS like Oracle, SQL Server, DB2, and MySQL.
- Other traditional models like hierarchical and network models are not commonly used now due to their complexity.
- The advantages of data models include increased effectiveness, reduced costs, simplicity, minimum redundancy, data integrity, independence, faster performance, reduced errors and risks.
- The types of data models discussed are hierarchical, network, relational, E-R and object oriented models. The characteristics and advantages/disadvantages of each model are described
This presentation contains the concepts related to database design using ER Diagram. The content is adapted from the contents of the authors of the book mentioned in the reference.
This document contains information about a Relational Database Management Systems course prepared by D.GAYA, an Assistant Professor. It includes an introduction to database systems, definitions of key terms like data, information, databases, and database management systems. It describes characteristics of DBMS like data being stored in tables, reduced data redundancy, supporting multiple users, and providing security. It also discusses database structures like tables, records, fields, relationships, entities, attributes, and different types of relationships.
The document provides an introduction to database management systems (DBMS) and database models. It defines key terms like data, database, DBMS, file system vs DBMS. It describes the evolution of DBMS from 1960 onwards and different database models like hierarchical, network and relational models. It also discusses the roles of different people who work with databases like database designers, administrators, application programmers and end users.
FellowBuddy.com is an innovative platform that brings students together to share notes, exam papers, study guides, project reports and presentation for upcoming exams.
We connect Students who have an understanding of course material with Students who need help.
Benefits:-
# Students can catch up on notes they missed because of an absence.
# Underachievers can find peer developed notes that break down lecture and study material in a way that they can understand
# Students can earn better grades, save time and study effectively
Our Vision & Mission – Simplifying Students Life
Our Belief – “The great breakthrough in your life comes when you realize it, that you can learn anything you need to learn; to accomplish any goal that you have set for yourself. This means there are no limits on what you can be, have or do.”
Like Us - https://www.facebook.com/FellowBuddycom
The document discusses concepts related to entity-relationship modeling and database design. It covers:
1. Key concepts in entity-relationship modeling like entities, attributes, relationships and keys.
2. Different types of attributes, relationships and keys.
3. Storage concepts like primary and secondary storage, buffering, and placing records on disks.
4. File organization techniques like hashing, B-trees and file operations.
This document provides an overview of a Relational Database Management System (RDBMS) unit prepared by D.GAYA, an Assistant Professor of Computer Science at Pondicherry University Community College. It defines key RDBMS concepts and components, including database languages, the query processor, runtime and database managers, and the database engine. It also outlines benefits of RDBMS such as data security, sharing, integration and abstraction/independence. Applications mentioned include following ACID properties, multi-user access, multiple views, and security features. Finally, it briefly introduces data modeling and different data models.
This Presentation would make you understand the Fundamentals of Database Design, Data Models (Conceptual, Logical & Physical), ERD, ERM. Also, have real-life examples and case study to understand better.
This document provides information about database management systems and SQL. It discusses that a DBMS allows for the storage, manipulation and retrieval of data in a database. It also describes that SQL is the standard language used to communicate with relational databases and discusses some of its features and uses. Finally, it outlines some common data types used to define columns when creating tables in SQL*Plus such as CHAR, VARCHAR2, NUMBER, DATE and LONG.
This document contains study material prepared by D.GAYA, Assistant Professor of Computer Science at Pondicherry University Community College, for the subject Relational Database Management System. It covers various topics related to SQL including basic SQL reports and commands, data types, joins, DDL, DML, DCL commands, and binary data types. Examples are provided to explain concepts such as creating and dropping databases, creating tables, commenting in SQL, and using the TO_HEX and HEX_TO_BINARY functions for binary data.
Object-Relational Database Systems(ORDBMSs) can successfully deal with very large data volumes with great complexity. At present the vendors of all the major DBMS products have supported object-relational database management systems, but still its industrial adoption rate is relatively low.
Week 4 The Relational Data Model & The Entity Relationship Data Modeloudesign
The document discusses the relational data model and relational databases. It explains that the relational model organizes data into tables with rows and columns, and was invented by Edgar Codd. The model uses keys to uniquely identify rows and relationships between tables to link related data. SQL is identified as the most commonly used language for querying and managing data in relational database systems.
The document discusses several data models including flat file, hierarchical, network, relational, object-relational, and object-based models. It provides details on the flat file model, describing it as a single two-dimensional array containing data elements in columns and related elements in rows. The object-relational model combines relational and object-oriented features, allowing integration of databases with object-oriented data types and methods. The document also discusses the entity-relationship model, which is an object-based logical model that uses entities, attributes, and relationships to flexibly structure data and specify constraints.
Whenever you make a list of anything – list of groceries to buy, books to borrow from the library, list of classmates, list of relatives or friends, list of phone numbers and so o – you are actually creating a database.
An example of a business manual database may consist of written records on a paper and stored in a filing cabinet. The documents usually organized in chronological order, alphabetical order and so on, for easier access, retrieval and use.
Computer database are those data or information stored in the computer. To arrange and organize records, computer databases rely on database software
Microsoft Access is an example of database software.
The document provides an overview of different data models including hierarchical, network, entity-relationship, relational, object-oriented, and object-relational models. It describes the key components and features of each model. Examples are given to illustrate concepts like entities, attributes, relationships, and how data can be organized in different structures. The advantages and disadvantages of each model are also discussed. Overall, the document serves as a useful introduction to the main data models used in database management systems.
This document discusses database design and concepts related to high performance computing. It covers topics such as the components of a database including hardware, software, and users. Key database concepts are explained like atomicity, consistency, isolation, and durability. The document also discusses the entity-relationship model of database design including entities, relationships, attributes, and roles. It provides an example database for a college and illustrates its entity-relationship diagram.
This document discusses different data models used in database management systems including record-based, relational, network, hierarchical, and entity-relationship models. It provides details on each model such as how data is organized. A record-based model uses fixed-length records and fields. The relational model organizes data into tables with rows and columns. The network model links entities through multiple paths in a graph structure. The hierarchical model arranges data in a tree structure. Finally, the entity-relationship model views the real world as entities and relationships between entities.
Entity Integrity Constraint:
It states that in a relation no attribute of a primary key (K) can have a null value. If a K consists of a single attribute, this constraint obviously applies on this attribute, so it cannot have the Null value. However, if a K consists of multiple attributes, then none of the attributes of this K can have the Null value in any of the instances.
Referential Integrity Constraint :
This constraint is applied to foreign keys. Foreign key is an attribute or attribute combination of a relation that is the primary key of another relation. This constraint states that if a foreign key exists in a relation, either the foreign key value must match the primary key value of some tuple in its home relation or the foreign key value must be completely null.
Overview of Object-Oriented Concepts Characteristics by vikas jagtapVikas Jagtap
Object-oriented data base systems are proposed as alternative to relational systems and are aimed at application domains where complex objects play a central role.
The approach is heavily influenced by object-oriented programming languages and can be understood as an attempt to add DBMS functionality to a programming language environment
The document provides an overview of databases and database design. It defines what a database is, what databases do, and the components of database systems and applications. It discusses the database design process, including identifying fields, tables, keys, and relationships between tables. The document also covers database modeling techniques, normalization to eliminate redundant or inefficient data storage, and functional dependencies as constraints on attribute values.
An Introduction to Architecture of Object Oriented Database Management System and how it differs from RDBMS means Relational Database Management System
This document provides an overview of database management systems. It discusses what data is and how it differs from information. It then describes some issues with traditional file systems for data storage and how database management systems were created to overcome these deficiencies. The key characteristics of a database management system are then outlined, including using real-world entities, relation-based tables, isolation of data and application, normalization to reduce redundancy, consistency, and ACID properties. The document also discusses database architecture types, data models, the relational model, database schemas and instances, and SQL. Finally, it covers some database design concepts like entities and attributes, relationships and keys, and generalization and specialization.
The document discusses several books on database management systems and their authors. It also provides an overview of key concepts in DBMS including what a database and DBMS are, the purpose of database systems, levels of abstraction, instances and schemas, data independence, different data models, database languages, the roles of database administrators and users.
The document discusses database management systems and their advantages over traditional file systems. It covers key concepts such as:
1) Databases organize data into tables with rows and columns to allow for easier querying and manipulation of data compared to file systems which store data in unstructured files.
2) Database management systems employ concepts like normalization, transactions, concurrency and security to maintain data integrity and consistency when multiple users are accessing the data simultaneously.
3) The logical design of a database is represented by its schema, while a database instance refers to the current state of the data stored in the database tables at a given time.
database management system - overview of entire dbmsvikramkagitapu
What is DBMS? Database Management Systems (DBMS) are software systems used to store, retrieve, and run queries on data. A DBMS serves as an interface between an end-user and a database, allowing users to create, read, update, and delete data in the databas
FellowBuddy.com is an innovative platform that brings students together to share notes, exam papers, study guides, project reports and presentation for upcoming exams.
We connect Students who have an understanding of course material with Students who need help.
Benefits:-
# Students can catch up on notes they missed because of an absence.
# Underachievers can find peer developed notes that break down lecture and study material in a way that they can understand
# Students can earn better grades, save time and study effectively
Our Vision & Mission – Simplifying Students Life
Our Belief – “The great breakthrough in your life comes when you realize it, that you can learn anything you need to learn; to accomplish any goal that you have set for yourself. This means there are no limits on what you can be, have or do.”
Like Us - https://www.facebook.com/FellowBuddycom
The document discusses concepts related to entity-relationship modeling and database design. It covers:
1. Key concepts in entity-relationship modeling like entities, attributes, relationships and keys.
2. Different types of attributes, relationships and keys.
3. Storage concepts like primary and secondary storage, buffering, and placing records on disks.
4. File organization techniques like hashing, B-trees and file operations.
This document provides an overview of a Relational Database Management System (RDBMS) unit prepared by D.GAYA, an Assistant Professor of Computer Science at Pondicherry University Community College. It defines key RDBMS concepts and components, including database languages, the query processor, runtime and database managers, and the database engine. It also outlines benefits of RDBMS such as data security, sharing, integration and abstraction/independence. Applications mentioned include following ACID properties, multi-user access, multiple views, and security features. Finally, it briefly introduces data modeling and different data models.
This Presentation would make you understand the Fundamentals of Database Design, Data Models (Conceptual, Logical & Physical), ERD, ERM. Also, have real-life examples and case study to understand better.
This document provides information about database management systems and SQL. It discusses that a DBMS allows for the storage, manipulation and retrieval of data in a database. It also describes that SQL is the standard language used to communicate with relational databases and discusses some of its features and uses. Finally, it outlines some common data types used to define columns when creating tables in SQL*Plus such as CHAR, VARCHAR2, NUMBER, DATE and LONG.
This document contains study material prepared by D.GAYA, Assistant Professor of Computer Science at Pondicherry University Community College, for the subject Relational Database Management System. It covers various topics related to SQL including basic SQL reports and commands, data types, joins, DDL, DML, DCL commands, and binary data types. Examples are provided to explain concepts such as creating and dropping databases, creating tables, commenting in SQL, and using the TO_HEX and HEX_TO_BINARY functions for binary data.
Object-Relational Database Systems(ORDBMSs) can successfully deal with very large data volumes with great complexity. At present the vendors of all the major DBMS products have supported object-relational database management systems, but still its industrial adoption rate is relatively low.
Week 4 The Relational Data Model & The Entity Relationship Data Modeloudesign
The document discusses the relational data model and relational databases. It explains that the relational model organizes data into tables with rows and columns, and was invented by Edgar Codd. The model uses keys to uniquely identify rows and relationships between tables to link related data. SQL is identified as the most commonly used language for querying and managing data in relational database systems.
The document discusses several data models including flat file, hierarchical, network, relational, object-relational, and object-based models. It provides details on the flat file model, describing it as a single two-dimensional array containing data elements in columns and related elements in rows. The object-relational model combines relational and object-oriented features, allowing integration of databases with object-oriented data types and methods. The document also discusses the entity-relationship model, which is an object-based logical model that uses entities, attributes, and relationships to flexibly structure data and specify constraints.
Whenever you make a list of anything – list of groceries to buy, books to borrow from the library, list of classmates, list of relatives or friends, list of phone numbers and so o – you are actually creating a database.
An example of a business manual database may consist of written records on a paper and stored in a filing cabinet. The documents usually organized in chronological order, alphabetical order and so on, for easier access, retrieval and use.
Computer database are those data or information stored in the computer. To arrange and organize records, computer databases rely on database software
Microsoft Access is an example of database software.
The document provides an overview of different data models including hierarchical, network, entity-relationship, relational, object-oriented, and object-relational models. It describes the key components and features of each model. Examples are given to illustrate concepts like entities, attributes, relationships, and how data can be organized in different structures. The advantages and disadvantages of each model are also discussed. Overall, the document serves as a useful introduction to the main data models used in database management systems.
This document discusses database design and concepts related to high performance computing. It covers topics such as the components of a database including hardware, software, and users. Key database concepts are explained like atomicity, consistency, isolation, and durability. The document also discusses the entity-relationship model of database design including entities, relationships, attributes, and roles. It provides an example database for a college and illustrates its entity-relationship diagram.
This document discusses different data models used in database management systems including record-based, relational, network, hierarchical, and entity-relationship models. It provides details on each model such as how data is organized. A record-based model uses fixed-length records and fields. The relational model organizes data into tables with rows and columns. The network model links entities through multiple paths in a graph structure. The hierarchical model arranges data in a tree structure. Finally, the entity-relationship model views the real world as entities and relationships between entities.
Entity Integrity Constraint:
It states that in a relation no attribute of a primary key (K) can have a null value. If a K consists of a single attribute, this constraint obviously applies on this attribute, so it cannot have the Null value. However, if a K consists of multiple attributes, then none of the attributes of this K can have the Null value in any of the instances.
Referential Integrity Constraint :
This constraint is applied to foreign keys. Foreign key is an attribute or attribute combination of a relation that is the primary key of another relation. This constraint states that if a foreign key exists in a relation, either the foreign key value must match the primary key value of some tuple in its home relation or the foreign key value must be completely null.
Overview of Object-Oriented Concepts Characteristics by vikas jagtapVikas Jagtap
Object-oriented data base systems are proposed as alternative to relational systems and are aimed at application domains where complex objects play a central role.
The approach is heavily influenced by object-oriented programming languages and can be understood as an attempt to add DBMS functionality to a programming language environment
The document provides an overview of databases and database design. It defines what a database is, what databases do, and the components of database systems and applications. It discusses the database design process, including identifying fields, tables, keys, and relationships between tables. The document also covers database modeling techniques, normalization to eliminate redundant or inefficient data storage, and functional dependencies as constraints on attribute values.
An Introduction to Architecture of Object Oriented Database Management System and how it differs from RDBMS means Relational Database Management System
This document provides an overview of database management systems. It discusses what data is and how it differs from information. It then describes some issues with traditional file systems for data storage and how database management systems were created to overcome these deficiencies. The key characteristics of a database management system are then outlined, including using real-world entities, relation-based tables, isolation of data and application, normalization to reduce redundancy, consistency, and ACID properties. The document also discusses database architecture types, data models, the relational model, database schemas and instances, and SQL. Finally, it covers some database design concepts like entities and attributes, relationships and keys, and generalization and specialization.
The document discusses several books on database management systems and their authors. It also provides an overview of key concepts in DBMS including what a database and DBMS are, the purpose of database systems, levels of abstraction, instances and schemas, data independence, different data models, database languages, the roles of database administrators and users.
The document discusses database management systems and their advantages over traditional file systems. It covers key concepts such as:
1) Databases organize data into tables with rows and columns to allow for easier querying and manipulation of data compared to file systems which store data in unstructured files.
2) Database management systems employ concepts like normalization, transactions, concurrency and security to maintain data integrity and consistency when multiple users are accessing the data simultaneously.
3) The logical design of a database is represented by its schema, while a database instance refers to the current state of the data stored in the database tables at a given time.
database management system - overview of entire dbmsvikramkagitapu
What is DBMS? Database Management Systems (DBMS) are software systems used to store, retrieve, and run queries on data. A DBMS serves as an interface between an end-user and a database, allowing users to create, read, update, and delete data in the databas
The document provides an overview of the syllabus for a Data Structures course. It discusses topics that will be covered including arrays, linked lists, stacks, queues, trees, and graphs. It also outlines the course grading breakdown and covers basic terminology related to data structures such as data, data items, records, and files. Common data structure operations like traversing, searching, inserting, and deleting are also defined. Lastly, it provides guidance on selecting appropriate data structures based on the problem constraints and required operations.
Database System Concepts AND architecture [Autosaved].pptxKoteswari Kasireddy
The document discusses key concepts in database systems and architecture. It defines what a data model is and describes different types of data models including high-level conceptual models, low-level physical models, and representation models. It also outlines several common data models like hierarchical, network, relational, object-oriented, and object-relational models. Finally, it provides a simplified overview of the key components of a database system, including the database, DBMS software, catalog, and users/applications.
The document discusses several data models including flat file, hierarchical, network, relational, object-relational, and object-based models. It provides details on the flat file model, describing it as a single two-dimensional array containing data elements in columns and related elements in rows. The object-relational model combines relational and object-oriented features, allowing integration of complex data types. The object-based model uses entities, attributes, and relationships, with the entity-relationship model being a commonly used object-based logical model.
The document provides an overview of the syllabus and topics covered in a data structures course, including data structure types, operations, and selecting appropriate data structures. It discusses linear data structures like arrays and linked lists, non-linear structures like trees and graphs, and operations like traversing, searching, inserting, and deleting. The goals of the course are to prepare students for advanced courses and teach implementing operations on different data structures using algorithms.
This document provides an overview of a database management systems course. The course objectives are to understand the purpose and concepts of DBMS, apply database design and languages to manage data, learn about normalization, SQL implementation, transaction control, recovery strategies, storage, and indexing. The outcomes are knowledge of various data models, database design process, transaction management, users and administration. Key topics covered include the relational and entity-relationship data models, database design, transactions, and database users and administration.
This document provides an introduction and overview of an IS220 Database Systems course. It outlines that the course will cover topics like database design, file organization, indexing and hashing, query processing and optimization, transactions, object-oriented and XML databases. It notes that the class will be 70% theory and 30% hands-on assignments completed in pairs. Assessment will include group work, tests, and a final exam. Class rules require punctuality, use of English, dressing professionally, and minimum 80% attendance.
This document provides an overview of database management systems (DBMS). It defines key concepts like data, database, entity, attribute, and examples of DBMS like Oracle. It describes the goals and advantages of DBMS, including data independence, efficient data access, data integrity and security. Applications of DBMS discussed include banking, airlines, universities, and more. Finally, it introduces different views of data in a DBMS and various data models used to describe database structure, like the entity-relationship model.
The document discusses database essentials including database management systems, database applications, the purpose of database systems, data models, database languages, database architecture, and the relational data model. Specifically, it defines what a DBMS is, provides examples of common database applications, describes why databases were developed to address limitations of file processing systems, outlines several data models including the relational model, discusses database languages for defining and manipulating data, presents the client-server architecture of database systems, and explains key concepts of the relational model including tables, tuples, attributes, relations, and domains.
Lecture 1. Data Structure & Algorithm.pptxArifKamal36
Data structures allow us to organize and store data in an efficient manner. Some common linear data structures include arrays, linked lists, stacks, and queues. Arrays use contiguous memory locations to store data while linked lists connect nodes using pointers. Stacks follow LIFO principles for insertion and deletion while queues follow FIFO. These data structures find applications in areas like recursion, expression evaluation, memory management, and more.
This document provides an overview of database management systems (DBMS) including their characteristics and applications. It discusses why DBMS are used, their ACID properties, support for multi-user access, multiple views, security features, use of relational tables, isolation of data and applications, normalization to reduce redundancy, consistency, query languages, and types of users. Entity relationship modeling and the relational data model are also introduced.
The document provides an overview of database management systems (DBMS). It begins with introducing the presenters and objective to make the audience knowledgeable about DBMS fundamentals and improvements. The contents section outlines topics like introduction, data, information, database components, what is a DBMS, database administrator, database languages, advantages and disadvantages of DBMS, examples of DBMS like SQL Server, and applications of DBMS.
This document introduces database management systems. It defines a database as a collection of interrelated data used to efficiently retrieve, insert, and delete data organized in tables, schemas, views, and reports. A database management system (DBMS) is software that manages databases and provides interfaces to perform operations like creating, storing, updating, and querying data. The document outlines characteristics, applications, and components of DBMS, as well as conceptual, representational, and physical data models used to design databases at different levels of abstraction.
This document provides an overview of database management systems and different data models. It defines key concepts like data, database, DBMS, file management system, and data redundancy. The goals of a DBMS are listed as reducing data redundancy and inconsistency while facilitating data sharing and security. DBMS is compared to a file management system, noting advantages like lower redundancy, higher consistency, and easier data sharing with DBMS. Finally, several data models are introduced, including hierarchical, network, entity-relationship, relational, object-oriented, and object-relational models.
The document provides an overview of database management systems (DBMS). It discusses the need for DBMS, different database architectures including centralized, client-server and distributed. It also covers data models, ER diagrams, relational models, and SQL. Key advantages of DBMS over file systems include reducing data redundancy, improving data integrity and security, and enabling concurrent access.
This document discusses data structures and provides an introduction and overview. It defines data structures as specialized formats for organizing and storing data to allow efficient access and manipulation. Key points include:
- Data structures include arrays, linked lists, stacks, queues, trees and graphs. They allow efficient handling of data through operations like traversal, insertion, deletion, searching and sorting.
- Linear data structures arrange elements in a sequential order while non-linear structures do not. Common examples are discussed.
- Characteristics of data structures include being static or dynamic, homogeneous or non-homogeneous. Efficiency and complexity are also addressed.
- Basic array operations like traversal, insertion, deletion and searching are demonstrated with pseudocode examples
What is Data ?
What is Information?
Data Models, Schema and Instances
Components of Database System
What is DBMS ?
Database Languages
Applications of DBMS
Introduction to Databases
Fundamentals of Data Modeling and Database Design
Database Normalization
Types of keys in database management system
Distributed Database
Virtualization: A Key to Efficient Cloud ComputingHitesh Mohapatra
The document discusses various types of virtualization used in cloud computing. It describes virtualization as a technique that allows sharing of physical resources among multiple customers. There are two main types of hypervisors - Type 1 hypervisors run directly on hardware while Type 2 hypervisors run on a host operating system. The document also summarizes different types of virtualization including hardware, software, memory, storage, network, and desktop virtualization. Benefits of virtualization include improved efficiency, outsourcing of hardware costs, testing software in isolated environments, and emulating machines beyond physical availability.
Automating the Cloud: A Deep Dive into Virtual Machine ProvisioningHitesh Mohapatra
Virtual machine provisioning allows users to quickly provision new virtual machines through a self-service interface in minutes, rather than the days it previously took to provision physical servers. Virtual machine migration also allows live migration of virtual machines between physical hosts in milliseconds for maintenance or upgrades. Standards like OVF and OCCI help ensure interoperability and portability of virtual machines across platforms. The virtual machine lifecycle includes provisioning, serving requests, and deprovisioning resources when the service is ended.
Harnessing the Power of Google Cloud Platform: Strategies and ApplicationsHitesh Mohapatra
The document discusses Google Cloud Platform (GCP), a suite of cloud computing services provided by Google. It provides infrastructure as a service (IaaS), platform as a service (PaaS), and software as a service (SaaS). GCP allows users to access computing power, storage, databases, and other applications through remote servers on the internet. It offers advantages like scalability, security, redundancy, and cost-effectiveness compared to traditional data centers. Example applications of GCP include enabling collaborative document editing in real-time.
Scheduling refers to allocating computing resources like processor time and memory to processes. In cloud computing, scheduling maps jobs to virtual machines. There are two levels of scheduling - at the host level to distribute VMs, and at the VM level to distribute tasks. Common scheduling algorithms include first-come first-served (FCFS), shortest job first (SJF), round robin, and max-min. FCFS prioritizes older jobs but has high wait times. SJF prioritizes shorter jobs but can starve longer ones. Max-min prioritizes longer jobs to optimize resource use. The choice depends on goals like throughput, latency, and fairness.
This document provides a template for submitting case studies to a case study compendium on cloud computing solutions. The template requests information on the customer organization, industry, location, the cloud solution provider, area of application of the cloud solution, challenges addressed, objectives, timeline of implementation, solution approach, challenges during implementation, benefits to the customer, innovation enabled, partnerships involved, and a customer testimonial. It requests details on the cloud solution type (IaaS, PaaS, or SaaS), quantitative and qualitative benefits realized by the customer, and how the solution helped boost innovation. Contact details of the submitter are also requested. The focus is on how cloud platforms and solutions enabled customer enterprises to innovate and
RAID (Redundant Array of Independent Disks) uses multiple hard disks or solid-state drives to protect data by storing it across the drives in a way that if one drive fails, the data can still be accessed from the other drives. There are different RAID levels that provide varying levels of data protection and performance. A RAID controller manages the drives in an array, presenting them as a single logical drive and improving performance and reliability. Common RAID levels include RAID 0 for performance without redundancy, RAID 1 for disk mirroring, and RAID 5 for striping with parity data distributed across drives. [/SUMMARY]
Cloud load balancing distributes workloads and network traffic across computing resources in a cloud environment to improve performance and availability. It routes incoming traffic to multiple servers or other resources while balancing the load. Load balancing in the cloud is typically software-based and offers benefits like scalability, reliability, reduced costs, and flexibility compared to traditional hardware-based load balancing. Common cloud providers like AWS, Google Cloud, and Microsoft Azure offer multiple load balancing options that vary based on needs and network layers.
ITU-T requirement for cloud and cloud deployment modelHitesh Mohapatra
List and explain the functional requirements for networking as per the ITU-T technical report. List and explain cloud deployment models and list relative strengths and weaknesses of the deployment models with neat diagram.
The document contains descriptions of several LeetCode problems ranging from Medium to Hard difficulty. It provides details about the Maximum Level Sum of a Binary Tree, Jump Game III, Minesweeper, Binary Tree Level Order Traversal, Number of Operations to Make Network Connected, Open the Lock, Sliding Puzzle, and Trapping Rain Water II problems. It also includes pseudocode and explanations for solving the Number of Operations to Make Network Connected and Open the Lock problems.
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Trie Data Structure
LINK: https://leetcode.com/tag/trie/
Easy:
1. Longest Word in Dictionary
Medium:
1. Count Substrings That Differ by One Character
2. Replace Words
3. Top K Frequent Words
4. Maximum XOR of Two Numbers in an Array
5. Map Sum Pairs
Hard:
1. Concatenated Words
2. Word Search II
The document discusses the basics of relational databases. It defines what a database is, the advantages it provides over file-based data storage, and some disadvantages. It also covers relational database concepts like tables, records, fields, keys, and normalization. The document explains how to design a relational database by determining the purpose and entities, modeling relationships with E-R diagrams, and following steps to normalize the data.
The document discusses measures of query cost in database management systems. It explains that query cost can be measured by factors like the number of disk accesses, size of the table, and time taken by the CPU. It further breaks down disk access time into components like seek time, rotational latency, and sequential vs. random I/O. The document then provides an example formula to calculate estimated query cost based on these components.
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Introduction- e - waste – definition - sources of e-waste– hazardous substances in e-waste - effects of e-waste on environment and human health- need for e-waste management– e-waste handling rules - waste minimization techniques for managing e-waste – recycling of e-waste - disposal treatment methods of e- waste – mechanism of extraction of precious metal from leaching solution-global Scenario of E-waste – E-waste in India- case studies.
ACEP Magazine edition 4th launched on 05.06.2024Rahul
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Embedded machine learning-based road conditions and driving behavior monitoringIJECEIAES
Car accident rates have increased in recent years, resulting in losses in human lives, properties, and other financial costs. An embedded machine learning-based system is developed to address this critical issue. The system can monitor road conditions, detect driving patterns, and identify aggressive driving behaviors. The system is based on neural networks trained on a comprehensive dataset of driving events, driving styles, and road conditions. The system effectively detects potential risks and helps mitigate the frequency and impact of accidents. The primary goal is to ensure the safety of drivers and vehicles. Collecting data involved gathering information on three key road events: normal street and normal drive, speed bumps, circular yellow speed bumps, and three aggressive driving actions: sudden start, sudden stop, and sudden entry. The gathered data is processed and analyzed using a machine learning system designed for limited power and memory devices. The developed system resulted in 91.9% accuracy, 93.6% precision, and 92% recall. The achieved inference time on an Arduino Nano 33 BLE Sense with a 32-bit CPU running at 64 MHz is 34 ms and requires 2.6 kB peak RAM and 139.9 kB program flash memory, making it suitable for resource-constrained embedded systems.
A SYSTEMATIC RISK ASSESSMENT APPROACH FOR SECURING THE SMART IRRIGATION SYSTEMSIJNSA Journal
The smart irrigation system represents an innovative approach to optimize water usage in agricultural and landscaping practices. The integration of cutting-edge technologies, including sensors, actuators, and data analysis, empowers this system to provide accurate monitoring and control of irrigation processes by leveraging real-time environmental conditions. The main objective of a smart irrigation system is to optimize water efficiency, minimize expenses, and foster the adoption of sustainable water management methods. This paper conducts a systematic risk assessment by exploring the key components/assets and their functionalities in the smart irrigation system. The crucial role of sensors in gathering data on soil moisture, weather patterns, and plant well-being is emphasized in this system. These sensors enable intelligent decision-making in irrigation scheduling and water distribution, leading to enhanced water efficiency and sustainable water management practices. Actuators enable automated control of irrigation devices, ensuring precise and targeted water delivery to plants. Additionally, the paper addresses the potential threat and vulnerabilities associated with smart irrigation systems. It discusses limitations of the system, such as power constraints and computational capabilities, and calculates the potential security risks. The paper suggests possible risk treatment methods for effective secure system operation. In conclusion, the paper emphasizes the significant benefits of implementing smart irrigation systems, including improved water conservation, increased crop yield, and reduced environmental impact. Additionally, based on the security analysis conducted, the paper recommends the implementation of countermeasures and security approaches to address vulnerabilities and ensure the integrity and reliability of the system. By incorporating these measures, smart irrigation technology can revolutionize water management practices in agriculture, promoting sustainability, resource efficiency, and safeguarding against potential security threats.
Comparative analysis between traditional aquaponics and reconstructed aquapon...bijceesjournal
The aquaponic system of planting is a method that does not require soil usage. It is a method that only needs water, fish, lava rocks (a substitute for soil), and plants. Aquaponic systems are sustainable and environmentally friendly. Its use not only helps to plant in small spaces but also helps reduce artificial chemical use and minimizes excess water use, as aquaponics consumes 90% less water than soil-based gardening. The study applied a descriptive and experimental design to assess and compare conventional and reconstructed aquaponic methods for reproducing tomatoes. The researchers created an observation checklist to determine the significant factors of the study. The study aims to determine the significant difference between traditional aquaponics and reconstructed aquaponics systems propagating tomatoes in terms of height, weight, girth, and number of fruits. The reconstructed aquaponics system’s higher growth yield results in a much more nourished crop than the traditional aquaponics system. It is superior in its number of fruits, height, weight, and girth measurement. Moreover, the reconstructed aquaponics system is proven to eliminate all the hindrances present in the traditional aquaponics system, which are overcrowding of fish, algae growth, pest problems, contaminated water, and dead fish.
Using recycled concrete aggregates (RCA) for pavements is crucial to achieving sustainability. Implementing RCA for new pavement can minimize carbon footprint, conserve natural resources, reduce harmful emissions, and lower life cycle costs. Compared to natural aggregate (NA), RCA pavement has fewer comprehensive studies and sustainability assessments.
1. DATABASE SYSTEM
Entity relationship model, Components of ER model, Mapping E-R
model to Relational schema, Network and Object Oriented Data
models, Storage Strategies: Detailed Storage Architecture, Storing
Data, Magnetic Disk, RAID, Other Disks, Magnetic Tape, Storage
Access, File & Record Organization, File Organizations & Indexes,
Order Indices, B+ Tree Index Files, Hashing Data Dictionary
By Hitesh Mohapatra
2. Network and Object Oriented Data models
“A data model is a way of finding the tools for both business and IT professionals, which
uses a set of symbols and text to precisely explain a subset of real information to improve
communication within the organization and thereby lead to a more flexible and stable
application environment”.
A data model is an idea which describes how the data can be represented and accessed
from software system after its complete implementation.
• It is a simple abstraction of complex real world data gathering environment.
• It defines data elements and relationships among various data elements for a specified
system.
• The main purpose of data model is to give an idea that how final system or software will
look like after development is completed.
3. Types of Data Model
Following are the types of Data Model,
1. Hierarchical Model
2. Relational Model
3. Network Database Model
4. Entity Relationship Model
5. Object Model
4. Hierarchical Model
• Hierarchical model was developed by IBM and North
American Rockwell known as Information Management
System.
• It represents the data in a hierarchical tree structure.
• This model is the first DBMS model.
• In this model, the data is sorted hierarchically.
• It uses pointer to navigate between the stored data.
5. Relational Model
• Relational model is based on first-order predicate logic.
• This model was first proposed by E. F. Codd.
• It represents data as relations or tables.
• Relational database simplifies the database structure by making
use of tables and columns.
6. Network Database Model
• Network Database Model is same like Hierarchical Model, but the only
difference is that it allows a record to have more than one parent.
• In this model, there is no need of parent to child association like the hierarchical
model.
• It replaces the hierarchical tree with a graph.
• It represents the data as record types and one-to-many relationship.
• This model is easy to design and understand.
7. Entity Relationship Model
•Entity Relationship Model is a high-level data model.
•It was developed by Chen in 1976.
•This model is useful in developing a conceptual design for the database.
•It is very simple and easy to design logical view of data.
•The developer can easily understand the system by looking at an ER model
constructed.
• In this diagram Rectangle represents the entities. Eg. Doctor
and Patient.
• Ellipse represents the attributes. Eg. DocId, Dname, PId, Pname.
Attribute describes each entity becomes a major part of the
data stored in the database.
• Diamond represents the relationship in ER diagrams. Eg.
Doctor diagnoses the Patient.
8. Object Model
• Object model stores the data in the form of objects, classes and inheritance.
• This model handles more complex applications, such as Geographic
Information System (GIS), scientific experiments, engineering design and
manufacturing.
• It is used in File Management System.
• It represents real world objects, attributes and behaviours.
• It provides a clear modular structure.
• It is easy to maintain and modify the existing code.
9. Ex.
Imagine we have to design database for college. What is the real world entities involved with
college? They are college, Students, Lecturer, Course, Subject, Marks etc. Once all the entities
are listed, we find out the relationship between them and try to map all of them. Also we list
what are the attributes related to each entity like student id, name, lecturer name, course
that he is teaching, different subjects, pass mark, grade levels etc. Here we are not bothered
about what data value is stored, what is the size of each data etc. We know only entities
involved, their attributes and mapping at this stage.
11. Object Oriented Data Models
• This data model is another method of representing real world objects.
• It considers each object in the world as objects and isolates it from each other.
• It groups its related functionalities together and allows inheriting its functionality to other
related sub-groups.
12. Ex.
Let us consider an Employee database to understand this model better. In this database we have
different types of employees – Engineer, Accountant, Manager, Clark. But all these employees belong
to Person group. Person can have different attributes like name, address, age and phone. What do we
do if we want to get a person’s address and phone number? We write two separate procedure
sp_getAddress and sp_getPhone.
13. Ex..Cont..
What about all the employees above? They too have all the attributes what a person has. In addition, they
have their EMPLOYEE_ID, EMPLOYEE_TYPE and DEPARTMENT_ID attributes to identify them in the
organization and their department. We have to retrieve their department details, and hence we
sp_getDeptDetails procedure. Currently, say we need to have only these attributes and functionality. Since
all employees inherit the attributes and functionalities of Person, we can re-use those features in Employee.
But do we do that? We group the features of person together into class. Hence a class has all the attributes
and functionalities. For example, we would create a person class and it will have name, address, age and
phone as its attribute, and sp_getAddress and sp_getPhone as procedures in it. The values for these
attributes at any instance of time are object. i.e. ; {John, Troy, 25, 2453545 : sp_getAddress (John),
sp_getPhone (John)} forms on person object. {Mathew, Fraser Town, 28, 5645677: sp_getAddress (Mathew),
sp_getPhone (Mathew} forms another person object.
Now, we will create another class called Employee which will inherit all the functionalities of Person class. In
addition it will have attributes EMPLOYEE_ID, EMPLOYEE_TYPE and DEPARTMENT_ID, and sp_getDeptDetails
procedure. Different objects of Employee class are Engineer, Accountant, Manager and Clerk.
14. Ex.Cont..
It would be a black box to any other
classes. This feature of this model is
called encapsulation. It binds the
features in one class and hides it
from other classes. It is only visible to
its objects and any inherited classes.
15. Advantages of OOM
• Because of its inheritance property, we can re-use the attributes and functionalities. It reduces the
cost of maintaining the same data multiple times. Also, these information are encapsulated and, there
is no fear being misused by other objects. If we need any new feature we can easily add new class
inherited from parent class and adds new features. Hence it reduces the overhead and maintenance
costs.
• Because of the above feature, it becomes more flexible in the case of any changes.
• Codes are re-used because of inheritance.
• Since each class binds its attributes and its functionality, it is same as representing the real world
object.
• We can see each object as a real entity. Hence it is more understandable.
16. Disadvantages of OOM
• It is not widely developed and complete to use it in the database systems. Hence it is not accepted by
the users.
• It is an approach for solving the requirement. It is not a technology. Hence it fails to put it in the
database management systems.
17. Storage Strategies
1. Detailed Storage Architecture
2. Storing Data
3. Magnetic Disk
4. RAID
5. Other Disks, Magnetic Tape, Storage Access
6. File & Record Organization, File Organizations & Indexes
18. DBMS - Storage System
• Databases are stored in file formats, which contain records. At physical level, the actual data is stored in
electromagnetic format on some device. These storage devices can be broadly categorized into three
types −
19. Primary Storage
• The memory storage that is directly accessible to the CPU comes under this category.
• CPU's internal memory (registers), fast memory (cache), and main memory (RAM) are directly accessible
to the CPU, as they are all placed on the motherboard or CPU chipset.
• This storage is typically very small, ultra-fast, and volatile. Primary storage requires continuous power
supply in order to maintain its state.
• In case of a power failure, all its data is lost.
20. Secondary Storage
• Secondary storage devices are used to store data for future use or as backup.
• Secondary storage includes memory devices that are not a part of the CPU chipset or motherboard,
for example, magnetic disks, optical disks (DVD, CD, etc.), hard disks, flash drives, and magnetic tapes.
21. Tertiary Storage
• Tertiary storage is used to store huge volumes of data.
• Since such storage devices are external to the computer system, they are the slowest in speed.
• These storage devices are mostly used to take the back up of an entire system.
• Optical disks and magnetic tapes are widely used as tertiary storage.
22. Memory Hierarchy
A computer system has a well-defined hierarchy of memory. A CPU has direct access to it main
memory as well as its inbuilt registers. The access time of the main memory is obviously less
than the CPU speed. To minimize this speed mismatch, cache memory is introduced. Cache
memory provides the fastest access time and it contains data that is most frequently accessed
by the CPU.
The memory with the fastest access is the costliest one. Larger storage devices offer slow speed
and they are less expensive, however they can store huge volumes of data as compared to CPU
registers or cache memory.
23. Magnetic Disks
Hard disk drives are the most common secondary storage
devices in present computer systems. These are called
magnetic disks because they use the concept of
magnetization to store information. Hard disks consist of
metal disks coated with magnetizable material. These
disks are placed vertically on a spindle. A read/write head
moves in between the disks and is used to magnetize or
de-magnetize the spot under it. A magnetized spot can
be recognized as 0 (zero) or 1 (one).
Hard disks are formatted in a well-defined order to store
data efficiently. A hard disk plate has many concentric
circles on it, called tracks. Every track is further divided
into sectors. A sector on a hard disk typically stores 512
bytes of data.
24. Redundant Array of Independent Disks
RAID or Redundant Array of Independent Disks, is a technology to connect multiple secondary
storage devices and use them as a single storage media.
RAID consists of an array of disks in which multiple disks are connected together to achieve
different goals. RAID levels define the use of disk arrays.
25. RAID 0
In this level, a striped array of disks is implemented. The data is broken down into blocks and
the blocks are distributed among disks. Each disk receives a block of data to write/read in
parallel. It enhances the speed and performance of the storage device. There is no parity and
backup in Level 0.
RAID 0
26. RAID 1
RAID 1 uses mirroring techniques. When data is sent to a RAID controller, it sends a copy of data to all the
disks in the array. RAID level 1 is also called mirroring and provides 100% redundancy in case of a failure.
27. RAID 2
RAID 2 records Error Correction Code using Hamming distance for its data, striped on different
disks. Like level 0, each data bit in a word is recorded on a separate disk and ECC codes of the
data words are stored on a different set disks. Due to its complex structure and high cost, RAID
2 is not commercially available.
28. RAID 3
RAID 3 stripes the data onto multiple disks. The parity bit generated for data word is stored on a
different disk. This technique makes it to overcome single disk failures.
29. RAID 4
In this level, an entire block of data is written onto data disks and then the parity is generated
and stored on a different disk. Note that level 3 uses byte-level striping, whereas level 4 uses
block-level striping. Both level 3 and level 4 require at least three disks to implement RAID.
30. RAID 5
RAID 5 writes whole data blocks onto different disks, but the parity bits generated for data block
stripe are distributed among all the data disks rather than storing them on a different dedicated
disk.
31. RAID 6
RAID 6 is an extension of level 5. In this level, two independent parities are generated and stored
in distributed fashion among multiple disks. Two parities provide additional fault tolerance. This
level requires at least four disk drives to implement RAID.
32. DBMS - File Structure
Relative data and information is stored collectively in file formats. A file is a sequence of records
stored in binary format. A disk drive is formatted into several blocks that can store records. File
records are mapped onto those disk blocks.
33. File Organization
File Organization defines how file records are mapped onto disk blocks. We have four types of
File Organization to organize file records −
34. Heap File Organization
When a file is created using Heap File Organization, the Operating System allocates memory
area to that file without any further accounting details. File records can be placed anywhere in
that memory area. It is the responsibility of the software to manage the records. Heap File does
not support any ordering, sequencing, or indexing on its own.
35. Sequential File Organization
Every file record contains a data field (attribute) to uniquely identify that record. In sequential
file organization, records are placed in the file in some sequential order based on the unique key
field or search key. Practically, it is not possible to store all the records sequentially in physical
form.
36. Hash File Organization
Hash File Organization uses Hash function computation on some fields of the records. The
output of the hash function determines the location of disk block where the records are to be
placed.
37. Clustered File Organization
Clustered file organization is not considered good for large databases. In this mechanism,
related records from one or more relations are kept in the same disk block, that is, the ordering
of records is not based on primary key or search key.
38. File Operations
Operations on database files can be broadly classified into two categories −
• Update Operations
• Retrieval Operations
Update operations change the data values by insertion, deletion, or update. Retrieval operations,
on the other hand, do not alter the data but retrieve them after optional conditional filtering. In
both types of operations, selection plays a significant role.
39. Other Operations
Other than creation and deletion of a file, there could be several operations, which can be done
on files.
Open − A file can be opened in one of the two modes, read mode or write mode. In read mode,
the operating system does not allow anyone to alter data. In other words, data is read only. Files
opened in read mode can be shared among several entities. Write mode allows data
modification. Files opened in write mode can be read but cannot be shared.
Locate − Every file has a file pointer, which tells the current position where the data is to be
read or written. This pointer can be adjusted accordingly. Using find (seek) operation, it can be
moved forward or backward.
Read − By default, when files are opened in read mode, the file pointer points to the beginning
of the file. There are options where the user can tell the operating system where to locate the
file pointer at the time of opening a file. The very next data to the file pointer is read.
40. Other Operations
Write − User can select to open a file in write mode, which enables them to edit its contents. It
can be deletion, insertion, or modification. The file pointer can be located at the time of opening
or can be dynamically changed if the operating system allows to do so.
Close − This is the most important operation from the operating system’s point of view. When a
request to close a file is generated, the operating system
• removes all the locks (if in shared mode),
• saves the data (if altered) to the secondary storage media, and
• releases all the buffers and file handlers associated with the file.
The organization of data inside a file plays a major role here. The process to locate the file
pointer to a desired record inside a file various based on whether the records are arranged
sequentially or clustered.
41. DBMS - Indexing
We know that data is stored in the form of records. Every record has a key field, which helps it to
be recognized uniquely.
Indexing is a data structure technique to efficiently retrieve records from the database files
based on some attributes on which the indexing has been done. Indexing in database systems is
similar to what we see in books.
42. Indexing
Indexing is defined based on its indexing attributes. Indexing can be of the following types −
Primary Index − Primary index is defined on an ordered data file. The data file is ordered on a
key field. The key field is generally the primary key of the relation.
Secondary Index − Secondary index may be generated from a field which is a candidate key
and has a unique value in every record, or a non-key with duplicate values.
Clustering Index − Clustering index is defined on an ordered data file. The data file is ordered
on a non-key field.
Ordered Indexing is of two types −
Dense Index
Sparse Index
43. Dense Index
In dense index, there is an index record for every search key value in the database. This makes
searching faster but requires more space to store index records itself. Index records contain
search key value and a pointer to the actual record on the disk.
44. Sparse Index
In sparse index, index records are not created for every search key. An index record here
contains a search key and an actual pointer to the data on the disk. To search a record, we first
proceed by index record and reach at the actual location of the data. If the data we are looking
for is not where we directly reach by following the index, then the system starts sequential
search until the desired data is found.
45. Multilevel Index
Index records comprise search-key values
and data pointers. Multilevel index is stored
on the disk along with the actual database
files. As the size of the database grows, so
does the size of the indices. There is an
immense need to keep the index records in
the main memory so as to speed up the
search operations. If single-level index is
used, then a large size index cannot be
kept in memory which leads to multiple
disk accesses.
Multi-level Index helps in breaking down the index into several
smaller indices in order to make the outermost level so small
that it can be saved in a single disk block, which can easily be
accommodated anywhere in the main memory.
46. B+ Tree Index Files
A B+ tree is a balanced binary search tree that follows a multi-level index format. The leaf nodes
of a B+ tree denote actual data pointers. B+ tree ensures that all leaf nodes remain at the same
height, thus balanced. Additionally, the leaf nodes are linked using a link list; therefore, a B+ tree
can support random access as well as sequential access.
47. Structure of B+ Tree
Every leaf node is at equal distance from the root node. A B+ tree is of the order n where n is fixed for every
B+ tree.
Internal nodes −
Internal (non-leaf) nodes contain at least ⌈n/2⌉
pointers, except the root node. At most, an
internal node can contain n pointers.
Leaf nodes −
Leaf nodes contain at least ⌈n/2⌉ record pointers and
⌈n/2⌉ key values. At most, a leaf node can contain n
record pointers and n key values. Every leaf node
contains one block pointer P to point to next leaf
node and forms a linked list.
48. B+ Tree Insertion
•If a leaf node overflows −
•Split node into two parts.
•Partition at i = ⌊(m+1)/2⌋.
•First i entries are stored in one node.
•Rest of the entries (i+1 onwards) are moved to a new node.
•ith key is duplicated at the parent of the leaf.
•If a non-leaf node overflows −
•Split node into two parts.
•Partition the node at i = ⌈(m+1)/2⌉.
•Entries up to i are kept in one node.
•Rest of the entries are moved to a new node.
•B+ trees are filled from bottom and each entry is done at the leaf node.
49. B+ Tree Deletion
•B+ tree entries are deleted at the leaf nodes.
•The target entry is searched and deleted.
•If it is an internal node, delete and replace with the entry from the left position.
•After deletion, underflow is tested,
•If underflow occurs, distribute the entries from the nodes left to it.
•If distribution is not possible from left, then
•Distribute from the nodes right to it.
•If distribution is not possible from left or from right, then
•Merge the node with left and right to it.
50. DBMS - Hashing
For a huge database structure, it can be almost next to impossible to search all the index values
through all its level and then reach the destination data block to retrieve the desired data.
Hashing is an effective technique to calculate the direct location of a data record on the disk
without using index structure.
Hashing uses hash functions with search keys as parameters to generate the address of a data
record.
51. Hash Organization
Bucket − A hash file stores data in bucket format. Bucket is considered a unit of storage. A
bucket typically stores one complete disk block, which in turn can store one or more records.
Hash Function − A hash function, h, is a mapping function that maps all the set of search-keys
K to the address where actual records are placed. It is a function from search keys to bucket
addresses.
52. Static Hashing
In static hashing, when a search-key value is provided, the hash function always computes the same
address. For example, if mod-4 hash function is used, then it shall generate only 5 values. The output
address shall always be same for that function. The number of buckets provided remains unchanged at all
times.
53. Operations
Insertion − When a record is required to be entered using static hash, the hash function h
computes the bucket address for search key K, where the record will be stored.
Bucket address = h(K)
Search − When a record needs to be retrieved, the same hash function can be used to retrieve
the address of the bucket where the data is stored.
Delete − This is simply a search followed by a deletion operation.
54. Bucket Overflow
The condition of bucket-overflow is known as collision. This is a fatal state for any static hash
function. In this case, overflow chaining can be used.
Overflow Chaining − When buckets are full, a new bucket is allocated for the same hash result and is
linked after the previous one. This mechanism is called Closed Hashing.
Linear Probing − When a hash function generates an address at which data is already stored, the next free
bucket is allocated to it. This mechanism is called Open Hashing.
55. Dynamic Hashing
The problem with static hashing is
that it does not expand or shrink
dynamically as the size of the
database grows or shrinks.
Dynamic hashing provides a
mechanism in which data buckets
are added and removed
dynamically and on-demand.
Dynamic hashing is also known
as extended hashing.
Hash function, in dynamic
hashing, is made to produce a
large number of values and only a
few are used initially.
56. Organization
The prefix of an entire hash value is taken as a hash index. Only a portion of the hash value is used for
computing bucket addresses. Every hash index has a depth value to signify how many bits are used for
computing a hash function. These bits can address 2n buckets. When all these bits are consumed − that is,
when all the buckets are full − then the depth value is increased linearly and twice the buckets are
allocated.
57. Operation
•Querying − Look at the depth value of the hash index and use those bits to compute the
bucket address.
•Update − Perform a query as above and update the data.
•Deletion − Perform a query to locate the desired data and delete the same.
•Insertion − Compute the address of the bucket
• If the bucket is already full.
• Add more buckets.
• Add additional bits to the hash value.
• Re-compute the hash function.
• Else
• Add data to the bucket,
• If all the buckets are full, perform the remedies of static hashing.
Hashing is not favorable when the data is organized in some ordering and the queries require a
range of data. When data is discrete and random, hash performs the best.
Hashing algorithms have high complexity than indexing. All hash operations are done in
constant time.