Database applications and implications

Transcription

1 Database applications and implications Miguel Rebollo Introduction to Computer Science

2 Aims Explaining what a database is and describe its structure Identifying the problems that are best solved with DB s Describing different kinds of DB software Describing DB operations for storing, sorting, updating, querying and summarising of information Explaining the ways DB threaten our privacy

3 Contents 1. The Electronic File Cabinet: Database Basics 2. Beyond the Basics: DB Management Systems 3. Database Trends 4. No Secrets: Computers and Privacy

4 Database essentials Databases: manage of information overload Store, organise, retrieve, communicate and manage information Information at your fingertips (excerpt from NYT) Some information is personal (privacy)

5 Electronic File Cabinet Application software (as word processing) Designed to maintain collections of information Several complexity levels Examples: phone / address books cooking book book, music or film catalogues notes and student information

6 Advantages of DB Make it easier to store large quantities of information to retrieve inf. quickly and flexibly to organise and reorganise information to print and distribute information in a variety of ways

7 Database Anatomy Database(DB): collection of organised information stored in a computer DB program: sw for organising the storage and retrieval of information table: collection of related information record: information related to an element field: each discrete piece of information in a record field type: data type a field can hold

8 Database Operations Browse: navigate though information Query: find records that match specific criteria Sort: rearrange records Printing reports or labels: ordered lists of selected records in an easy-to-read format Complex queries using advanced languages (SQL)

9 Special Purpose DB Directories (telephone, street maps) GIS (Geographic Information System): combine demographic and geographic information PIM (Personal Information Managers) address/phone books Appointment calendars To-do lists Miscellaneous notes

10 Personal Information Systems

11 DB Management System (DBMS) File managers: enable users to work with one file at a time DMBSs: manipulate data in large collections of files, cross-referencing them as needed.

12 DB Management System (DBMS) A DBMS can be use interactively or controlled by other programs Key fileds to relate information through tables

13 Relational Databases To most users, a relational DB program allows tables to be related to each other changes in one table are reflected automatically in other tables To computer scientists, it has a technical definition related to underlying structure of the data the rules specifying how data can be manipulated

14 Relational Databases The structure of a relational DB is based on the relational model a mathematical model that combines data in tables

15 Database Trends 1. Real-time processing 2. Distributed databases 3. Data mining 4. Databases and the Web 5. Object-oriented databases 6. Multimedia Databases 7. Databases in natural language

16 Real-time Processing Batch processing: accumulated transactions sent to the computer in large batches Real-time computing: instant access to informa. Interactive proc.: replacement of batch proc. users can interact through terminals, viewing and changing values online at real-time batch proc. still used for jobs in which it makes sense o do a lot of transactions at once

17 Distributed DB Downsizing and decentralising: using a client/server approach today, many business use a client/server approach using DB it enables users to take advantage of PC s interface (simple) while accessing to data stored on large server systems (data warehouses) distributed DB: data spread in different computers in a network (e.g. Google datacenter)

18 Data Mining discovering and extraction of hidden, predictive inform. from large databases using statistical methods and artificial intelligence technology locating trends and patterns in data that could be overlooked by normal DB queries Companies manages too much information

19 DB and the Web Information available on Internet HTML wasn t designed to build database queries XML, a newer, more powerful data description language Web DB strategies around directories Broad real-time access to DB rapid-response e-commerce possibilities but it increases the probability of errors

20 Object-oriented DB New programming paradigm (80s): objects instead of relationships Make DB construction and usage more flexible Store software objects that contain procedures along with data Often used in conjunction with object-oriented programming languages

21 Multimedia DB Currently, computers store multimedia information Professionals need tools to catalogue art, photographies, maps, video or sound Problem: their size multimedia DB are indexes to access the real files, stored in the computer. Content-based retrieval

22 DB in Natural Language Improves interfaces to access to a DB Incorporates artificial intelligence techniques Uses natural language to query the DB It s related with data mining search engines for Internet (Lexxe )

23 Privacy. Personal Data Marketing: investment in obtaining information about customers Other areas: banking, administration, subscription to publications or telephonic records Abuse of information Not only related with technology

24 The Privacy Problem Data mining extracts information about individuals without their explicit consent Centralised information is not needed (networks) European Directive about data protection: Directive 95/46/EC and other materials Problems: mistakes in data are common data can be inmortal data are not safe

25 Other Technologies Affecting Our Privacy Internet: instantaneous transmission of inform. MS Passport (Hotmail, Messenger): centralised DB with passwords, credit card numbers and other personal information Monitoring of working environment Surveillance cameras Surveillance satellites Positioning for cell phones or GPS tracking