Lecture01 257
- 1. Database Management: Introduction Ray R. Larson University of California, Berkeley School of Information IS 257: Database Management
- 2. Overview Announcements Course Description Database Concepts and Terminology Database Models Database Life Cycle
- 3. Overview Announcements Course Description Database Concepts and Terminology Database Models Database Life Cycle
- 4. Course Overview Description of the Course Assignments Readings Grading Schedule Web site: http://courses.ischool.berkeley.edu/i257/f09
- 5. Course Description This course is concerned with the design of the database itself -- not with the design of database system software. We will discuss DBMS internals only as they relate to the database and its design and structure We will spend a fair amount time on database application design, especially on options for Web application database support -- but this will not be primary focus.
- 6. Assignments Two kinds of assignments Using a pre-built database for search and retrieval and database modification queries Designing, populating, and running queries against your own personal (or group) database Types of database project Individual Work related Course only Projects from around campus that need doing… Group Course related Final Master’s project
- 7. Readings Textbook is: Jeffrey A. Hoffer, Mary B. Prescott and Heikki Topi. Modern Database Management (Ninth Edition). Prentice Hall (Pearson Educational) : Upper Saddle River, NJ, 2008. ISBN 978-0-13-600391-5
- 8. Grading Grades will be based on: Assignments (30%) Personal/Group Database project (60%) Class participation (10%) (No midterm or final)
- 9. Schedule On website: http://courses.ischool.berkeley.edu/i257/f09/
- 10. Overview Announcements Course Description Database Concepts and Terminology Database Models Database Life Cycle
- 11. What is a Database? ?
- 12. Files and Databases File: A collection of records or documents dealing with one organization, person, area or subject. (Rowley) Manual (paper) files Computer files Database: A collection of similar records with relationships between the records. (Rowley) bibliographic, statistical, business data, images, etc.
- 13. Database A Database is a collection of stored operational data used by the application systems of some particular enterprise. (C.J. Date) Paper “Databases” Still contain a large portion of the world’s knowledge Changing as, for example, book scanning projects like Google Books and the Open Content Aliance convert paper docs File-Based Data Processing Systems Early batch processing of (primarily) business data would not be too surprised to find some these still out there Database Management Systems (DBMS) Some old ones still in use, but most modern DBMS are relational, object or object-relational
- 14. Terms and Concepts Database Management System -- DBMS Software system used to define, create, maintain and provide controlled access to the database and its metadata
- 15. Terms and Concepts Data Dictionary AKA Repository (old usage) The place where all metadata for a particular database is stored may also include information on relationships between files or tables in a particular database
- 16. Terms and Concepts Metadata Data about data In DBMS means all of the characteristics describing the attributes of an entity, E.G.: name of attribute data type of attribute size of the attribute format or special characteristics Characteristics of files or relations name, content, notes, etc.
- 17. Why DBMS? History 50’s and 60’s all applications were custom built for particular needs File based Many similar/duplicative applications dealing with collections of business data Early DBMS were extensions of programming languages 1970 - E.F. Codd and the Relational Model 1979 - Ashton-Tate & first Microcomputer DBMS
- 18. From File Systems to DBMS Problems with File Processing systems Inconsistent Data Inflexibility Limited Data Sharing Poor enforcement of standards Excessive program maintenance
- 19. DBMS Benefits Minimal Data Redundancy Consistency of Data Integration of Data Sharing of Data Ease of Application Development Uniform Security, Privacy, and Integrity Controls Data Accessibility and Responsiveness Data Independence Reduced Program Maintenance
- 20. Terms and Concepts Data Independence Physical representation and location of data and the use of that data are separated The application doesn’t need to know how or where the database has stored the data, but just how to ask for it. Moving a database from one DBMS to another should not have a material effect on application program Recoding, adding fields, etc. in the database should not affect applications
- 21. Database Environment CASE Tools DBMS User Interface Application Programs Repository Database
- 22. Database Components DBMS =============== Design tools Table Creation Form Creation Query Creation Report Creation Procedural language compiler (4GL) ============= Run time Form processor Query processor Report Writer Language Run time User Interface Applications Application Programs Database Database contains: User’s Data Metadata Indexes Application Metadata
- 23. Types of Database Systems PC Databases Centralized Database Client/Server Databases Distributed Databases Database Models
- 24. PC Databases E.G. Access FoxPro Dbase Etc.
- 25. Centralized Databases Cental Computer
- 26. Client Server Databases Network Client Client Client Database Server
- 27. Distributed Databases computer computer computer Location A Location C Location B Homogeneous Databases
- 28. Distributed Databases Local Network Database Server Client Client Comm Server Remote Comp. Remote Comp. Heterogeneous Or Federated Databases
- 29. Terms and Concepts Database activities: Create Add new data to the database Read Read current data from the database Update Update or modify current database data Delete Remove current data from the database
- 30. Terms and Concepts Database Application An application program (or set of related programs) that is used to perform a series of database activities: Create Read Update Delete On behalf of database users
- 31. Range of Database Applications PC databases Usually for individual WorkGroup databases Small group use where everyone has access to the database over a LAN Departmental databases Larger than a workgroup – but similar Enterprises databases For the entire organization over an intranet (or sometimes the internet)
- 32. Terms and Concepts Enterprise Organization Entity Person, Place, Thing, Event, Concept... Attributes Data elements (facts) about some entity Also sometimes called fields or items or domains Data values instances of a particular attribute for a particular entity
- 33. Terms and Concepts Records The set of values for all attributes of a particular entity AKA “tuples” or “rows” in relational DBMS File Collection of records AKA “Relation” or “Table” in relational DBMS
- 34. Terms and Concepts Key an attribute or set of attributes used to identify or locate records in a file Primary Key an attribute or set of attributes that uniquely identifies each record in a file
- 35. Terms and Concepts DA Data adminstrator - person responsible for the Data Administration function in an organization Sometimes may be the CIO -- Chief Information Officer DBA Database Administrator - person responsible for the Database Administration Function
- 36. Terms and Concepts Models (1) Levels or views of the Database Conceptual, logical, physical (2) DBMS types Relational, Hierarchic, Network, Object-Oriented, Object-Relational
- 37. Overview Announcements Course Description Database Concepts and Terminology Database Models Database Life Cycle
- 38. Models (1) Conceptual Model Logical Model External Model Conceptual requirements Conceptual requirements Conceptual requirements Conceptual requirements Application 1 Application 1 Application 2 Application 3 Application 4 Application 2 Application 3 Application 4 External Model External Model External Model Internal Model
- 39. Data Models(2): History Hierarchical Model (1960’s and 1970’s) Similar to data structures in programming languages. Books (id, title) Publisher Subjects Authors (first, last)
- 40. Data Models(2): History Network Model (1970’s) Provides for single entries of data and navigational “ links ” through chains of data. Subjects Books Authors Publishers
- 41. Data Models(2): History Relational Model (1980’s) Provides a conceptually simple model for data as relations (typically considered “tables”) with all data visible.
- 42. Data Models(2): History Object Oriented Data Model (1990’s) Encapsulates data and operations as “Objects” Books (id, title) Publisher Subjects Authors (first, last)
- 43. Data Models(2): History Object-Relational Model (1990’s) Combines the well-known properties of the Relational Model with such OO features as: User-defined datatypes User-defined functions Inheritance and sub-classing
- 44. Overview Announcements Course Description Database Concepts and Terminology Database Models Database Life Cycle
- 45. Database System Life Cycle Growth, Change, & Maintenance 6 Operations 5 Integration 4 Design 1 Conversion 3 Physical Creation 2
- 46. The “Cascade” View See Hoffer, p. 41 Project Identifcation and Selection Project Initiation and Planning Analysis Logical Design Physical Design Implementation Maintenance
- 47. Design Determination of the needs of the organization Development of the Conceptual Model of the database Typically using Entity-Relationship diagramming techniques Construction of a Data Dictionary Development of the Logical Model
- 48. Physical Creation Development of the Physical Model of the Database data formats and types determination of indexes, etc. Load a prototype database and test Determine and implement security, privacy and access controls Determine and implement integrity constraints
- 49. Conversion Convert existing data sets and applications to use the new database May need programs, conversion utilities to convert old data to new formats.
- 50. Integration Overlaps with Phase 3 Integration of converted applications and new applications into the new database
- 51. Operations All applications run full-scale Privacy, security, access control must be in place. Recovery and Backup procedures must be established and used
- 52. Growth, Change & Maintenance Change is a way of life Applications, data requirements, reports, etc. will all change as new needs and requirements are found The Database and applications and will need to be modified to meet the needs of changes
- 53. Another View of the Life Cycle Operations 5 Conversion 3 Physical Creation 2 Growth, Change 6 Integration 4 Design 1
- 54. Next Time Introduction to the Diveshop database Introduction to Database Design