Role of Database susytem AICT (lec# 4).pptx

Its Database system about ppt file.

1. Role Of Database System Lecture#4 Course Instructor: Hina Sattar

2. Data vs Information Data: Raw facts; building blocks of information Unprocessed information Information: Data processed to reveal meaning Accurate, relevant, and timely information is key to good decision making Good decision making is key to survival in global environment 2

3. Manual File System Traditionally composed of collection of file folders kept in file cabinet Organization within folders was based on data's expected use (ideally logically related) System was adequate for small amounts of data with few reporting requirements Finding and using data in growing collections of file folders became time-consuming and cumbersome 3

4. Files and File Systems A collection of programs that perform services for the end-users such as the production of reports. Each program defines and manages its own data. Although managing data through file systems is largely obsolete Understanding relatively simple characteristics of file systems makes complexity of database design easier to understand Awareness of problems that plagued file systems can help prevent similar problems in DBMS Knowledge of file systems is helpful if you plan to convert an obsolete file system to a DBMS 4

5. Conversion from Manual File System to Computer File System Could be technically complex, requiring hiring of data processing (DP) specialists DP specialists created file structures, wrote software, and designed application programs Resulted in numerous “home-grown” systems being created Initially, computer files were similar in design to manual files 5

6. Disadvantages of File System Program-Data Dependence All programs maintain metadata for each file they use Duplication of Data Different systems/programs have separate copies of the same data Limited Data Sharing No centralized control of data Lengthy Development Times Programmers must design their own file formats Excessive Program Maintenance 80% of information systems budget 6

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8. DATABASE A database is a shared collection of logically related data, usually designed to meet the information needs of different users in an organization. A database is a self-describing collection of integrated records. Organized collection of logically related data in which redundancy is minimum. Examples: NADRA Database University Database 8

9. DBMS Database Management System (DBMS): A software that is used to create, maintain and provide controlled to user databases. A software that handles all access to the database A software that is responsible for applying the authorisation checks and validation procedures Ex: Oracle, SQL Server, MySQL, MS Access 9

10. Data Warehouse A data warehouse is an enterprise system used for the analysis and reporting of structured and semi-structured data from multiple sources, such as point-of-sale transactions, marketing automation, customer relationship management, and more. A data warehouse is suited for ad hoc analysis as well custom reporting.

11. Purpose of Database: In the early days, database applications were built on top of file systems Drawbacks of using file systems to store data: Data redundancy and inconsistency Multiple file formats, duplication of information in different files Difficulty in accessing data Need to write a new program to carry out each new task Data isolation — multiple files and formats Integrity problems Integrity constraints (e.g. account balance > 0) become part of program code Hard to add new constraints or change existing ones 11

12. DBMS Makes Data Management More Efficient and Effective End users have better access to more and better-managed data Promotes integrated view of organization's operations Probability of data inconsistency is greatly reduced Possible to produce quick answers to ad hoc queries Possible to share data among multiple applications or users Makes data management more efficient and effective 12

13. Interaction Between the End User and the Database 13

14. Components of the Database Environment Application Programs–software using the data User Interface–text and graphical displays to users Data Administrators: are persons who are responsible for the overall management of data resources in an organization. End Users: are persons who add, delete and modify data in the database and who request or receive information from it. All user interactions with the database must be routed through the DBMS. people who use the applications and databases 14

15. Types of Database Single-user: Supports only one user at a time Desktop: Single-user database running on a personal computer Multi-user: Supports multiple users at the same time Workgroup: Multi-user database that supports a small group of users or a single department Enterprise: Multi-user database that supports a large group of users or an entire organization 15

16. Location of Database Centralized: Supports data located at a single site Distributed: Supports data distributed across several sites 16

17. Basic Terminology File: File containing record. Record: A record is all of the data or information about one person or one thing. Field: One piece of data or information about a person or thing. Key field: a field in a record that holds the unique data which identifies that record from all the other records in the file or database. Data: Facts concerning things, such as people, objects, or events Information: Data that have been processed and presented in a form suitable for human interpretation Metadata: data that describes the properties and context of user data including data types, field sizes, allowable values 17

18. Database Architecture The term “Database Architecture" refers to the structural design and methodology of a database system, which forms the core of a Database Management System (DBMS). This architecture describe how data is stored, organized, and retrieved, playing a crucial role in the efficiency and effectiveness of data management. Database architecture describes how a database management system (DBMS) will be integrated with your application.  Centralized databases store all data in a single location, often managed by one entity; decentralized databases distribute data across multiple locations or nodes.  18

19. Types of Database Models The architecture of a database is not a one-size-fits-all solution. It varies significantly based on the needs of the organization, the type of data being managed, and the specific applications that interact with the database. From simple structures that manage daily transactions in a small business to complex architectures that handle massive amounts of data in large enterprises, the spectrum of database architecture is broad and diverse. One-tier Architecture Two-tier architecture Three-tier architecture 19

20. One-tier Architecture In one-tier Architecture, the database, user interface, and application logic all reside on the same machine or server. It's typically used for small-scale applications where simplicity and cost-effectiveness are priorities. Because there are no network delays involved, this type of tier architecture is generally a fast way to access data. In that case, both the application and the database are running on the user’s mobile device. 20

21. Two-tier Architecture Two-tier architecture consists of multiple clients connecting directly to the database. This tier architecture is also known as client-server architecture. This tier architecture used to be more common when a desktop application would connect to a single database hosted on an on-premise database server for example, an in-house customer relationship management (CRM) that connects to an Access database. 21

22. Three-tier Architecture Most modern web applications use a three-tier architecture. In this architecture, the clients connect to a back end, which in turn connects to the database. Using this approach has many benefits: Security: Keeping the database connection open to a single back end reduces the risks of being hacked. Scalability: Because each layer operates independently, it is easier to scale parts of the application. 22

23. Data Model Process of creating a logical representation of the structure of the database is called Data Modeling. A semantic data model, used for the graphical representation of the conceptual database design. Database Design represents logical structure of the database. Data Model: is a set of tools or constructs that is used to construct a database design Semantic: Entity-Relationship, Object-Oriented Record based: Hierarchical, Network, Relational 23

24. Need for Database Data organization: DBMS allow users to organize large amounts of data in a structured and systematic way. Data is organized into tables, fields, and records, making it easy to manage, store, and retrieve information. Data scalability: DBMS are designed to handle large amounts of data and are scalable to meet the growing needs of organizations. As organizations grow, DBMS can scale up to handle increasing amounts of data and user traffic. 24

25. Advantages of DBMS Data organization: A DBMS allows for the organization and storage of data in a structured manner, making it easy to retrieve and query the data as needed. Data integrity: A DBMS provides mechanisms for enforcing data integrity constraints, such as constraints on the values of data and access controls that restrict who can access the data. Concurrent access: A DBMS provides mechanisms for controlling concurrent access to the database, to ensure that multiple users can access the data without conflicting with each other. 25

26. Advantages of DBMS Data security: A DBMS provides tools for managing the security of the data, such as controlling access to the data and encrypting sensitive data. Backup and recovery: A DBMS provides mechanisms for backing up and recovering the data in the event of a system failure. Data sharing: A DBMS allows multiple users to access and share the same data, which can be useful in a collaborative work environment. 26

27. Disadvantages of DBMS: Complexity: DBMS can be complex to set up and maintain, requiring specialized knowledge and skills. Scalability: The use of a DBMS can limit the scalability of an application, since it requires the use of locking and other synchronization mechanisms to ensure data consistency. Cost: The cost of purchasing, maintaining and upgrading a DBMS can be high, especially for large or complex systems. Limited Use Cases: Not all use cases are suitable for a DBMS, some solutions don’t need high reliability, consistency or security and may be better served by other types of data storage. 27

28. Applications of DBMS Enterprise Information: Sales, accounting, human resources, Manufacturing, online retailers. Banking and Finance Sector: Banks maintaining the customer details, accounts, loans, banking transactions, credit card transactions. Finance: Storing the information about sales and holdings, purchasing of financial stocks and bonds. University: Maintaining the information about student course enrolled information, student grades, staff roles. Airlines: Reservations and schedules. Telecommunications: Prepaid, postpaid bills maintance . 28

29. Anomalies Modification anomalies Occur when changes must be made to existing records Insertion anomalies Occur when entering new records Deletion anomalies Occur when deleting records 29

30. Thank You