Fluent Essays

Discussion 1 (Chapter 1):  Give examples of systems in which it may make sense to use traditional file processing instead of a database approach.  Instructions: Your response to the initial question should be 250-300 words.  Next respond to two postings provided by your classmates. The first post should be made by Wednesday 11:59 p.m., EST. I am looking for active engagement in the discussion.  Please engage early and often. You are require to create your initial thread in order to view and respond to the threads posted by other students.  There must be at least one APA formatted reference (and APA in-text citation) to support the thoughts in the post as needed.  Do not use direct quotes, rather rephrase the author's words and continue to use in-text citations. Fundamentals of Database Systems Seventh Edition Chapter 1 Databases and Database Users Copyright © 2016, 2011, 2007 Pearson Education, Inc. All Rights Reserved If this PowerPoint presentation contains mathematical equations, you may need to check that your computer has the following installed: 1) MathType Plugin 2) Math Player (free versions available) 3) NVDA Reader (free versions available) 1 Learning Objectives 1.1 Types of Databases and Database Applications 1.2 Basic Definitions 1.3 Typical D B M S Functionality 1.4 Example of a Database (University) 1.5 Main Characteristics of the Database Approach 1.6 Types of Database Users 1.7 Advantages of Using the Database Approach 1.8 Historical Development of Database Technology 1.9 Extending Database Capabilities 1.10 When Not to Use Databases Copyright © 2016, 2011, 2007 Pearson Education, Inc. All Rights Reserved Types of Databases and Database Applications Traditional Applications: Numeric and Textual Databases More Recent Applications: Multimedia Databases Geographic Information Systems (G I S) Biological and Genome Databases Data Warehouses Mobile databases Real-time and Active Databases First part of book focuses on traditional applications A number of recent applications are described later in the book (for example, Chapters 24,25,26,27,28,29) Copyright © 2016, 2011, 2007 Pearson Education, Inc. All Rights Reserved Recent Developments (1 of 2) Social Networks started capturing a lot of information about people and about communications among people-posts, tweets, photos, videos in systems such as: Facebook Twitter Linked-In All of the above constitutes data Search Engines- Google, Bing, Yahoo : collect their own repository of web pages for searching purposes Copyright © 2016, 2011, 2007 Pearson Education, Inc. All Rights Reserved Recent Developments (2 of 2) New Technologies are emerging from the so-called non-database software vendors to manage vast amounts of data generated on the web: Big Data storage systems involving large clusters of distributed computers (Chapter 25) N O S Q L (Not Only S Q L) systems (Chapter 24) A large amount of data now resides on the “cloud” which means it is in huge data centers using thousands of machines. Copyright © 2016, 2011, 2007 Pearson Education, Inc. All Rights Reserved Basic Definitions Database: A collection of related data. Data: Known facts that can be recorded and have an implicit meaning. Mini-world: Some part of the real world about which data is stored in a database. For example, student grades and transcripts at a university. Database Management System (D B M S): A software package/ system to facilitate the creation and maintenance of a computerized database. Database System: The D B M S software together with the data itself. Sometimes, the applications are also included. Copyright © 2016, 2011, 2007 Pearson Education, Inc. All Rights Reserved Impact of Databases and Database Technology Businesses: Banking, Insurance, Retail, Transportation, Healthcare, Manufacturing Service Industries: Financial, Real-estate, Legal, Electronic Commerce, Small businesses Education: Resources for content and Delivery More recently: Social Networks, Environmental and Scientific Applications, Medicine and Genetics Personalized Applications: based on smart mobile devices Copyright © 2016, 2011, 2007 Pearson Education, Inc. All Rights Reserved Figure 1.1 Simplified database system environment Copyright © 2016, 2011, 2007 Pearson Education, Inc. All Rights Reserved Typical D B M S Functionality Define a particular database in terms of its data types, structures, and constraints Construct or Load the initial database contents on a secondary storage medium Manipulating the database: Retrieval: Querying, generating reports Modification: Insertions, deletions and updates to its content Accessing the database through Web applications Processing and Sharing by a set of concurrent users and application programs – yet, keeping all data valid and consistent Copyright © 2016, 2011, 2007 Pearson Education, Inc. All Rights Reserved Application Activities Against a Database Applications interact with a database by generating Queries: that access different parts of data and formulate the result of a request Transactions: that may read some data and “update” certain values or generate new data and store that in the database Applications must not allow unauthorized users to access data Applications must keep up with changing user requirements against the database Copyright © 2016, 2011, 2007 Pearson Education, Inc. All Rights Reserved Additional D B M S Functionality D B M S may additionally provide: Protection or Security measures to prevent unauthorized access “Active” processing to take internal actions on data Presentation and Visualization of data Maintenance of the database and associated programs over the lifetime of the database application Called database, software, and system maintenance Copyright © 2016, 2011, 2007 Pearson Education, Inc. All Rights Reserved Example of a Database (with a Conceptual Data Model) (1 of 2) Mini-world for the example: Part of a UNIVERSITY environment. Some mini-world entities: STUDENTs COURSEs SECTIONs (of COURSEs) (academic) DEPARTMENTs INSTRUCTORs Copyright © 2016, 2011, 2007 Pearson Education, Inc. All Rights Reserved Example of a Database (with a Conceptual Data Model) (2 of 2) Some mini-world relationships: SECTIONs are of specific COURSEs STUDENTs take SECTIONs COURSEs have prerequisite COURSEs INSTRUCTORs teach SECTIONs COURSEs are offered by DEPARTMENTs STUDENTs major in DEPARTMENTs Note: The above entities and relationships are typically expressed in a conceptual data model, such as the ENTITY-RELATIONSHIP data model (see Chapters 3, 4) Copyright © 2016, 2011, 2007 Pearson Education, Inc. All Rights Reserved Figure 1.2 Example of a simple database (1 of 4) COURSE Course_name Course_number Credit_hours Department Intro to Computer Science C S1310 4 C S Data Structures C S3320 4 C S Discrete Mathematics MATH2410 3 MATH Database C S3380 3 C S Copyright © 2016, 2011, 2007 Pearson Education, Inc. All Rights Reserved Figure 1.2 Example of a simple database (2 of 4) SECTION Section_identifier Course_number Semester Year Instructor 85 MATH2410 Fall 07 King 92 CS1310 Fall 07 Anderson 102 CS3320 Spring 08 Knuth 112 MATH2410 Fall 08 Chang 119 CS1310 Fall 08 Anderson 135 CS3380 Fall 08 Stone Copyright © 2016, 2011, 2007 Pearson Education, Inc. All Rights Reserved Figure 1.2 Example of a simple database (3 of 4) GRADE_REPORT Student_number Section_identifier Grade 17 112 B 17 119 C 8 85 A 8 92 A 8 102 B 8 135 A Copyright © 2016, 2011, 2007 Pearson Education, Inc. All Rights Reserved Figure 1.2 Example of a simple database (4 of 4) PREREQUISITE Course_number Prerequisite_number C S3380 C S3320 C S3380 MATH2410 C S3320 C S1310 Copyright © 2016, 2011, 2007 Pearson Education, Inc. All Rights Reserved Main Characteristics of the Database Approach (1 of 3) Self-describing nature of a database system: A D B M S catalog stores the description of a particular database (e.g. data structures, types, and constraints) The description is called meta-data*. This allows the D B M S software to work with different database applications. Insulation between programs and data: Called program-data independence. Allows changing data structures and storage organization without having to change the D B M S access programs. * Some newer systems such as a few N O S Q L systems need no meta-data: they store the data definition within its structure making it self describing Copyright © 2016, 2011, 2007 Pearson Education, Inc. All Rights Reserved Figure 1.3 Example of a simplified database catalog (1 of 2) RELATIONS Relation_name No_of_columns STUDENT 4 COURSE 4 SECTION 5 GRADE_REPORT 3 PREREQUISITE 2 Copyright © 2016, 2011, 2007 Pearson Education, Inc. All Rights Reserved Figure 1.3 Example of a simplified database catalog (2 of 2) COLUMNS Column_name Data_type Belongs_to_relation Name Character (30) STUDENT Student_number Character (4) STUDENT Class Integer (1) STUDENT Major Major_type STUDENT Course_name Character (10) COURSE Course_number XXXXNNNN COURSE …. …. …. …. …. …. …. …. …. Prerequisite_number XXXXNNNN PREREQUISITE Note: Major_type is defined as an enumerated type with all known majors. XXXXNNNN is used to define a type with four alphabetic characters followed by four numeric digits. Copyright © 2016, 2011, 2007 Pearson Education, Inc. All Rights Reserved Main Characteristics of the Database Approach (2 of 3) Data Abstraction: A data model is used to hide storage details and present the users with a conceptual view of the database. Programs refer to the data model constructs rather than data storage details Support of multiple views of the data: Each user may see a different view of the database, which describes only the data of interest to that user. Copyright © 2016, 2011, 2007 Pearson Education, Inc. All Rights Reserved Main Characteristics of the Database Approach (3 of 3) Sharing of data and multi-user transaction processing: Allowing a set of concurrent users to retrieve from and to update the database. Concurrency control within the D B M S guarantees that each transaction is correctly executed or aborted Recovery subsystem ensures each completed transaction has its effect permanently recorded in the database O L T P (Online Transaction Processing) is a major part of database applications. This allows hundreds of concurrent transactions to execute per second. Copyright © 2016, 2011, 2007 Pearson Education, Inc. All Rights Reserved Database Users Users may be divided into Those who actually use and control the database content, and those who design, develop and maintain database applications (called “Actors on the Scene”), and Those who design and develop the D B M S software and related tools, and the computer systems operators (called “Workers Behind the Scene”). Copyright © 2016, 2011, 2007 Pearson Education, Inc. All Rights Reserved Database Users – Actors on the Scene (1of 2) Actors on the scene Database administrators: Responsible for authorizing access to the database, for coordinating and monitoring its use, acquiring software and hardware resources, controlling its use and monitoring efficiency of operations. Database Designers: Responsible to define the content, the structure, the constraints, and functions or transactions against the database. They must communicate with the end-users and understand their needs. Copyright © 2016, 2011, 2007 Pearson Education, Inc. All Rights Reserved Database End Users (1 of 2) Actors on the scene End-users: They use the data for queries, reports and some of them update the database content. End-users can be categorized into: Casual: access database occasionally when needed Naïve or Parametric: they make up a large section of the end-user population. They use previously well-defined functions in the form of “canned transactions” against the database. Users of Mobile Apps mostly fall in this category Bank-tellers or reservation clerks are parametric users who do this activity for an entire shift of operations Social Media Users post and read information from websites Copyright © 2016, 2011, 2007 Pearson Education, Inc. All Rights Reserved Database End Users (2 of 2) Sophisticated: These include business analysts, scientists, engineers, others thoroughly familiar with the system capabilities. Many use tools in the form of software packages that work closely with the stored database. Stand-alone: Mostly maintain personal databases using ready-to-use packaged applications. An example is the user of a tax program that creates its own internal database. Another example is a user that maintains a database of personal photos and videos. Copyright © 2016, 2011, 2007 Pearson Education, Inc. All Rights Reserved Database Users – Actors on the Scene (2 of 2) System Analysts and Application Developers This category currently accounts for a very large proportion of the I T work force. System Analysts: They understand the user requirements of naïve and sophisticated users and design applications including canned transactions to meet those requirements. Application Programmers: Implement the specifications developed by analysts and test and debug them before deployment. Business Analysts: 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, marketing etc. Copyright © 2016, 2011, 2007 Pearson Education, Inc. All Rights Reserved Database Users – Actors behind the Scene System Designers and Implementors: Design and implement D B M S packages in the form of modules and interfaces and test and debug them. The D B M S must interface with applications, language compilers, operating system components, etc. Tool Developers: Design and implement software systems called tools for modeling and designing databases, performance monitoring, prototyping, test data generation, user interface creation, simulation etc. that facilitate building of applications and allow using database effectively. Operators and Maintenance Personnel: They manage the actual running and maintenance of the database system hardware and software environment. Copyright © 2016, 2011, 2007 Pearson Education, Inc. All Rights Reserved Advantages of Using the Database Approach (1 of 2) Controlling redundancy in data storage and in development and maintenance efforts. Sharing of data among multiple users. Restricting unauthorized access to data. Only the D B A staff uses privileged commands and facilities. Providing persistent storage for program Objects E.g., Object-oriented D B M S s make program objects persistent– see Chapter 12. Providing Storage Structures (e.g. indexes) for efficient Query Processing – see Chapter 17. Copyright © 2016, 2011, 2007 Pearson Education, Inc. All Rights Reserved Advantages of Using the Database Approach (2 of 2) Providing optimization of queries for efficient processing. Providing backup and recovery services. Providing multiple interfaces to different classes of users. Representing complex relationships among data. Enforcing integrity constraints on the database. Drawing inferences and actions from the stored data using deductive and active rules and triggers. Copyright © 2016, 2011, 2007 Pearson Education, Inc. All Rights Reserved Additional Implications of Using the Database Approach (1 of 2) Potential for enforcing standards: This is very crucial for the success of database applications in large organizations. Standards refer to data item names, display formats, screens, report structures, meta-data (description of data), Web page layouts, etc. Reduced application development time: Incremental time to add each new application is reduced. Copyright © 2016, 2011, 2007 Pearson Education, Inc. All Rights Reserved Additional Implications of Using the Database Approach (2 of 2) Flexibility to change data structures: Database structure may evolve as new requirements are defined. Availability of current information: Extremely important for on-line transaction systems such as shopping, airline, hotel, car reservations. Economies of scale: Wasteful overlap of resources and personnel can be avoided by consolidating data and applications across departments. Copyright © 2016, 2011, 2007 Pearson Education, Inc. All Rights Reserved Historical Development of Database Technology (1 of 3) Early Database Applications: The Hierarchical and Network Models were introduced in mid 1960s and dominated during the seventies. A bulk of the worldwide database processing still occurs using these models, particularly, the hierarchical model using I B M’s I M S system. Relational Model based Systems: Relational model was originally introduced in 1970, was heavily researched and experimented within I B M Research and several universities. Relational D B M S Products emerged in the early 1980s. Copyright © 2016, 2011, 2007 Pearson Education, Inc. All Rights Reserved Historical Development of Database Technology (2 of 3) Object-oriented and emerging applications: Object-Oriented Database Management Systems (O O D B M S s) were introduced in late 1980s and early 1990s to cater to the need of complex data processing in C A D and other applications. Their use has not taken off much. Many relational D B M S s have incorporated object database concepts, leading to a new category called object-relational D B M S s (O R D B M S s) Extended relational systems add further capabilities (e.g. for multimedia data, text, X M L, and other data types) Copyright © 2016, 2011, 2007 Pearson Education, Inc. All Rights Reserved Historical Development of Database Technology (3 of 3) Data on the Web and E-commerce Applications: Web contains data in H T M L (Hypertext markup language) with links among pages. This has given rise to a new set of applications and E-commerce is using new standards like X M L (eXtended Markup Language). (see Chapter 13). Script programming languages such as P H P and JavaScript allow generation of dynamic Web pages that are partially generated from a database (see Chapter 11). Also allow database updates through Web pages Copyright © 2016, 2011, 2007 Pearson Education, Inc. All Rights Reserved Extending Database Capabilities (1 of 3) New functionality is being added to D B M S s in the following areas: Scientific Applications – Physics, Chemistry, Biology - Genetics Earth and Atmospheric Sciences and Astronomy X M L (eXtensible Markup Language) Image Storage and Management Audio and Video Data Management Data Warehousing and Data Mining – a very major area for future development using new technologies (see Chapters 28-29) Spatial Data Management and Location Based Services Time Series and Historical Data Management The above gives rise to new research and development in incorporating new data types, complex data structures, new operations and storage and indexing schemes in database systems. Copyright © 2016, 2011, 2007 Pearson Education, Inc. All Rights Reserved Extending Database Capabilities (2 of 3) Background since the advent of the 21st Century: First decade of the 21st century has seen tremendous growth in user generated data and automatically collected data from applications and search engines. Social Media platforms such as Facebook and Twitter are generating millions of transactions a day and businesses are interested to tap into this data to “understand” the users Cloud Storage and Backup is making unlimited amount of storage available to users and applications Copyright © 2016, 2011, 2007 Pearson Education, Inc. All Rights Reserved Extending Database Capabilities (3 of 3) Emergence of Big Data Technologies and N O S Q L databases New data storage, management and analysis technology was necessary to deal with the onslaught of data in petabytes a day (10**15 bytes or 1000 terabytes) in some applications – this started being commonly called as “Big Data”. Hadoop (which originated from Yahoo) and Mapreduce Programming approach to distributed data processing (which originated from Google) as well as the Google file system have given rise to Big Data technologies (Chapter 25). Further enhancements are taking place in the form of Spark based technology. N O S Q L (Not Only S Q L- where S Q L is the de facto standard language for relational D B M S s) systems have been designed for rapid search and retrieval from documents, processing of huge graphs occurring on social networks, and other forms of unstructured data with flexible models of transaction processing (Chapter 24). Copyright © 2016, 2011, 2007 Pearson Education, Inc. All Rights Reserved When not to use a D B M S (1 of 2) Main inhibitors (costs) of using a D B M S: High initial investment and possible need for additional hardware. Overhead for providing generality, security, concurrency control, recovery, and integrity functions. When a D B M S may be unnecessary: If the database and applications are simple, well defined, and not expected to change. If access to data by multiple users is not required. When a D B M S may be infeasible: In embedded systems where a general purpose D B M S may not fit in available storage Copyright © 2016, 2011, 2007 Pearson Education, Inc. All Rights Reserved When not to use a D B M S (2 of 2) When no D B M S may suffice: If there are stringent real-time requirements that may not be met because of D B M S overhead (e.g., telephone switching systems) If the database system is not able to handle the complexity of data because of modeling limitations (e.g., in complex genome and protein databases) If the database users need special operations not supported by the D B M S (e.g., G I S and location based services). Copyright © 2016, 2011, 2007 Pearson Education, Inc. All Rights Reserved Chapter Summary Types of Databases and Database Applications Basic Definitions Typical D B M S Functionality Example of a Database (University) Main Characteristics of the Database Approach Types of Database Users Advantages of Using the Database Approach Historical Development of Database Technology Extending Database Capabilities When Not to Use Databases Copyright © 2016, 2011, 2007 Pearson Education, Inc. All Rights Reserved Copyright Copyright © 2016, 2011, 2007 Pearson Education, Inc. All Rights Reserved