DATABASE Lecture 1 and 2.pptx
- 1. DATABASE By: Rubab Instructor Computer Science IBA Sukkur- Institute of Emerging Technologies
- 2. What is a Data? Data: A collection of raw facts and figures. Raw material that can be processed by any computing machine. A collection of facts from which conclusions may be drawn. Data can be represented in the form of numbers and words which can be stored in computer’s language.
- 3. What is Information Information: Systematic and meaningful form of data. Knowledge acquired through study or experience. Information helps human beings in their decision making.
- 4. What is Database Database: A repository of logically related and similar data. • An organized collection of related information so that it can easily be accessed, managed and updated. E.g Dictionary, Airline Database, Student Database, Library, Railways Timetable YouTube
- 5. Entity •Person •Place •Object An entity is an object that exists, and Data can be stored about it. An entity can be
- 6. Attribute An attribute is characteristics or properties that describes an entity Example: A Person is an Entity, and it has Attributes like : Name Age Height
- 7. Example we have Entity Chair Legs Material Color
- 8. Column (field, attribute): A column is the smallest unit of storage in a database. A column stores an Attribute about an object. Every column has a name and a data type. Columns run vertically. They are grouped to form a Row.
- 9. Row (Record, Tuple) A row is a collection of column values Row is composed of the same set of columns A row represents the information of a real-world entity based on its attributes Rows run horizontally.
- 10. What is a Table? A table (relation, class, file) is responsible for storing data in the database. Database tables consist of rows and columns. Row 1 Row 2 Row 3 Row 4 Row 5 Column 1 Column 2 Column 3
- 11. Entities
- 12. Attributes
- 13. Types of Databases 1. Hierarchical databases 2. Centralized databases 3. Distributed databases 4. Flat File Database 6. Relational databases 7. Object oriented databases 8. NoSQL databases 9. Cloud databases 10. Network Databases 11. Enterprise Database 12. Personal Database 13. Operational Database
- 14. Centralized Database It is the type of database that stores data at a centralized database system. It allows users to access the stored data from different locations through several applications. These applications contain the authentication process to let users access data securely. An example of a Centralized database can be Central Library that carries a central database of each library in a college/university.
- 15. Distributed Databases Unlike a centralized database system, in distributed systems, data is distributed among different database systems of an organization. These database systems are connected via communication links. Such links help the end-users to access the data easily. Examples of the Distributed database are Apache Cassandra, HBase, Ignite, etc.
- 16. Distributed Databases There are two types of Distributed Databases Homogeneous DDB: Those database systems which execute on the same operating system and use the same application process and carry the same hardware devices. Heterogeneous DDB: Those database systems which execute on different operating systems under different application procedures and carries different hardware devices.
- 17. Relational Database This database is based on the relational data model, which stores data in the form of rows(tuple) and columns(attributes), and together forms a table(relation). A relational database uses SQL for storing, manipulating, as well as maintaining the data. E.F. Codd invented the database in 1970. Each table in the database carries a key that makes the data unique from others. Examples of Relational databases are MySQL, Microsoft SQL Server, Oracle, etc.
- 18. ACID Properties of Relational Database Atomicity: This ensures the data operation will complete either with success or with failure. It follows the 'all or nothing' strategy. For example, a transaction will either be committed or will abort. Consistency: If we perform any operation over the data, its value before and after the operation should be preserved. For example, the account balance before and after the transaction should be correct, i.e., it should remain conserved. Isolation: There can be concurrent users for accessing data at the same time from the database. Thus, isolation between the data should remain isolated. For example, when multiple transactions occur at the same time, one transaction effects should not be visible to the other transactions in the database. Durability: It ensures that once it completes the operation and commits the data, data changes should remain permanent.
- 19. NoSQL Database Non-SQL/Not Only SQL is a type of database that is used for storing a wide range of data sets. It is not a relational database as it stores data not only in tabular form but in several different ways. It came into existence when the demand for building modern applications increased. Thus, NoSQL presented a wide variety of database technologies in response to the demands
- 20. Types of NoSQL DB 1. Key-value storage: It is the simplest type of database storage where it stores every single item as a key (or attribute name) holding its value, together. 2. Document-oriented Database: A type of database used to store data as JSON-like document. It helps developers in storing data by using the same document-model format as used in the application code. 3. Graph Databases: It is used for storing vast amounts of data in a graph-like structure. Most commonly, social networking websites use the graph database. 4. Wide-column stores: It is like the data represented in relational databases. Here, data is stored in large columns together, instead of storing in rows.
- 21. Cloud Database A type of database where data is stored in a virtual environment and executes over the cloud computing platform. It provides users with various cloud computing services (SaaS, PaaS, IaaS, etc.) for accessing the database. There are numerous cloud platforms, but the best options are: Amazon Web Services(AWS), Microsoft Azure and Google cloud.
- 22. Object Oriented Database The type of database that uses the object-based data model approach for storing data in the database system. The data is represented and stored as objects which are like the objects used in the object-oriented programming language.
- 23. Hierarchical Databases It is the type of database that stores data in the form of parent-children relationship nodes. Here, it organizes data in a tree-like structure. Data get stored in the form of records that are connected via links. Each child record in the tree will contain only one parent. On the other hand, each parent record can have multiple child records.
- 24. Network Database It is the database that typically follows the network data model. Here, the representation of data is in the form of nodes connected via links between them. Unlike the hierarchical database, it allows each record to have multiple children and parent nodes to form a generalized graph structure.
- 25. Personal Databases Collecting and storing data on the user's system defines a Personal Database. This database is basically designed for a single user.
- 26. Operational Database The type of database which creates and updates the database in real- time. It is basically designed for executing and handling the daily data operations in several businesses. For example, An organization uses operational databases for managing per day transactions.
- 27. Enterprise Database Large organizations or enterprises use this database for managing a massive amount of data. It helps organizations to increase and improve their efficiency. Such a database allows simultaneous access to users.
- 28. Flat File Database A flat file/ flat form database is a system that stores data within a single table. It is known as a flatform database due to it only containing a two-dimensional structure (data fields and records). The database contains data fields which is the name of each piece of data being collected example address meaning that there will be a list of multiple addresses contained within that column. The database also contains records which is the information of each individual for example when you want to find out information about a particular person you could search their name and the database will show all the data collected within each data field for that certain individual. Example MS Excel
- 29. DBMS Database Management System (DBMS) is a software for storing and retrieving users’ data while considering appropriate security measures. It consists of a group of programs which manipulate the database. The DBMS accepts the request for data from an application and instructs the operating system to provide the specific data. In large systems, a DBMS helps users and other third- party software to store and retrieve data. DBMS allows users to create their own databases as per their requirement. The term “DBMS” includes the user of the database and other application programs. It provides an interface between the data and the software application.
- 30. DBMS
- 31. RDBMS RDBMS stands for Relational Database Management System An RDBMS is a type of database management system (DBMS) that stores data in a row-based table structure which connects related data elements. An RDBMS includes functions that maintain the security, accuracy, integrity and consistency of the data. This is different than the file storage used in a DBMS.
- 32. RDBMS Database application Relational Database Management System Database User 1 User 2 User n