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INTRODUCTION TO DATABASES Hadhramout University College of Engineering and Petroleum Department of Computer Engineering First Semester - Third Level 2024/ 2025 Lecturer: Dr. Rasha Bin-Thalab Course syllabus Introduction Relational model SQL Relational...

INTRODUCTION TO DATABASES Hadhramout University College of Engineering and Petroleum Department of Computer Engineering First Semester - Third Level 2024/ 2025 Lecturer: Dr. Rasha Bin-Thalab Course syllabus Introduction Relational model SQL Relational algebra Entity relationship diagram Normalization Transaction management Trends in DB Reference book  Lecture 1 Databases and Database Users OUTLINE Types of Databases and Database Applications Basic Definitions Typical DBMS Functionality Example of a Database (UNIVERSITY) Main Characteristics of the Database Approach Types of Database Users Advantages & disadvantages of Using the Database Approach When Not to Use Databases  Numeric and Textual Biological and Genome Databases Types of DBs & application s Multimedia Data Warehouses Geographic Information System Mobile databases Real-time and Active Databases GIS  MS Sql Server GenBank Types of DBs & application s YouTube Amazon Redshift ArcGIS SQLite Apache Kafka  Recent development Social Networks Search Engines started capturing a lot of collect their own information about people repository of web and about pages for searching communications among purposes people-posts, tweets, photos, videos in systems All of the above constitutes data  Recent development Big Data NOSQL Storage systems (Non-SQL, Not Only involving large clusters SQL) A large amount of data of distributed computers now resides on the “cloud” which means it is in huge data centers using thousands of machines. Basic definitions Your Text Here You can simply impress your audience and add a unique zing and appeal to your Presentations. Database Data Database Database system Management Your Text Here A collection System (DBMS) A software You can simply impress your The DBMS Known facts that audience and add a unique zing and of related package/system to software together appeal to your Presentations. Easy can be recorded to change colors, photos and Text. data. and have an facilitate the with the data itself. creation and Sometimes, the implicit meaning. maintenance of a applications are computerized also included. database. Database: “a usually large collection of data organized especially for rapid search and retrieval (as by a computer)” (http://www.merriam-webster.com/dictionary/database) Simplified database system environment  What a DBMS Facilitates 1) Define a particular database in terms of its data types, structures, and constraints 2) Construct or load the initial database contents on a secondary storage medium 3) Manipulating the database: a) Retrieval: Querying, generating reports b) Modification: Insertions, deletions and updates to its content c) Accessing the database through Web applications 4) Processing and sharing by a set of concurrent users and application programs – yet, keeping all data valid and consistent  What a DBMS Facilitates – cont. 5) Protection or Security measures to prevent unauthorized access 6) “Active” processing to take internal actions on data 7) Maintenance of the database and associated programs over the lifetime of the database application 8) Presentation and visualization of data Example of a Simple Database that Stores student and course information  Main Characteristics of the Database Approach Self-describing nature of a database system: DBMS catalog stores the description of a particular database. Called Support of multiple views of the met-data data Each user may see a different view Insulation between programs & of the database, which describes data program-data Called only the data of interest to that user. independence. Allows changing data structures and storage organization without DB having to change the DBMS characteristi access programs cs Data Sharing of data and multi-user Abstraction A data model is used to hide transaction processing storage details and present Allowing a set of concurrent users the users with a conceptual to retrieve from and to update the view of the database database. Types of database users -1 Database End users administrators Responsible for authorizing They use the data for queries, access to the database, for reports and some of them update coordinating and monitoring the database content. its use, acquiring software and hardware resources, Casual controlling its use and access database occasionally monitoring efficiency of when needed operations Naïve or Parametric Users of Mobile Apps mostly Database fall in this category designers Bank-tellers or reservation Responsible to define the clerks are parametric users content, the structure, the who do this activity for an constraints, and functions entire shift of operations. or transactions against the Social Media Users post and database. They must read information from communicate with the websites Sophisticated end-users and understand use tools in the form of their needs. software packages that work closely with the stored  Types of database users – System Analysts: 2 They understand the user requirements of naïve and sophisticated users and design applications Application Programmers: Implement the specifications developed by analysts and test and debug them before deployment. System Analysts and Application Business Analysts: Developers There is an increasing need for such people who can analyze vast amounts of business data and real-time data (“Big Data”) for better decision making related to planning, advertising, Operators & Maintenance Personnel marketing etc. Advantages of Controlling redundancy and Sharing Using the of data among multiple users Database 01 Restricting unauthorized Enforcing integrity access to data. Only the DBA constraints on the 02 staff uses privileged database commands and facilities. 08 Providing persistent 03 storage for program Objects Representing complex 07 relationships among data Providing optimization 04 of queries for efficient processing 06 Providing multiple 05 interfaces to different Providing backup and classes of users recovery services Disadvantages of Using the Main inhibitors (costs) of using a DBMS Database 01 High initial investment and possible need for additional hardware When a DBMS may be 03 infeasible Overhead for providing generality, security, concurrency control, recovery, and integrity functions In embedded systems where a general purpose DBMS may not fit in available storage When a DBMS may be 02 unnecessary If access to data by multiple users is not required If the database and applications are simple, well defined, and not expected to change When not to use a DBMS Real time 1 If there are stringent real-time requirements that may not be met because of DBMS overhead (e.g., telephone switching systems) 2 Complexity data modeling limitations (e.g., in complex genome and protein databases) Not used Special operations 3 operations not supported by the DBMS (e.g., GIS and location based services). Quiz Write two main advantages of database and two limitations of database Explain end users?