Introduction to database management

  t anagemen MtM

  Introduction to Database Outline Outline ƒ

  Database characteristics Database characteristics

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  DBMS features

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  Architectures

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  Architectures

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  Organizational roles

  1-2 Initial Vocabulary Initial Vocabulary ƒ

  Data: raw facts about things and events Data: raw facts about things and events

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  Information: transformed data that has value for decision making value for decision making

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  Essential to organize data for retrieval and maintenance maintenance

  1-3 Database Characteristics Database Characteristics ƒ

  Persistent : stable storage Persistent : stable storage

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  Shared : multiple users and uses

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  Shared : multiple users and uses

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  Interrelated : data stored as entities and

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  Interrelated : data stored as entities and relationships

  1-4 University Database University Database Faculty Registration Registration _{Entities: offerings, enrollments}

_{students, faculty, courses,}

Assignment _{faculty teach offerings,} Relationships: Relationships: _{students enroll in} Course Grade

_{offerings, offerings made}

Scheduling

  Recording g _{of courses, ...}

  University Database 1-5 Water Utility Database Water Utility Database Payment Billing g _{Entities: E titi customers, meters, bills,}

  Processing Processing _{bills sent to customers, Relationships : Relationships :} payments, meter readings

customers make payments,

  Meter _{customers use meters, ... ,} Service Start/ Reading Reading Stop Stop

  1-6 Database Management System (DBMS) ƒ

  Collection of components that support Collection of components that support data acquisition, dissemination, storage, maintenance, retrieval, and formatting maintenance, retrieval, and formatting

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  Enterprise DBMSs

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  Desktop DBMSs Desktop DBMSs

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  Embedded DBMSs

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  Major part of information technology infrastructure

  1-7 Database Definition Database Definition ƒ

  Define database structure before using a Define database structure before using a database

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  Tables and relationships

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  Tables and relationships

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  SQL CREATE TABLE statement G

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  Graphical tools

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  1-9 Database Database _{n sh ip s R} elatio _{Ta b le} s University Database (ERD) University Database (ERD) Student Offering

  Faculty _{StdSSN StdClass} StdMajor Student _{OfferNo OffLocation} OffTime Offering _{FacSSN FacSalary} FacRank Faculty

  Teaches _{j StdGPA} Accepts ^FacHireDate Has

  Supervises E ll t

  Registers Accepts C N Course

  EnrGrade Enrollment ^CourseNo _{CrsDesc CrsUnits}

  1-10 Nonprocedural Access Nonprocedural Access ƒ

  Query: request for data to answer a Query: request for data to answer a question

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  Indicate what parts of database to retrieve Indicate what parts of database to retrieve not the procedural details

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  Improve productivity and improve Improve productivity and improve accessibility

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  SQL SELECT statement and graphical SQL SELECT d hi l tools

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  1-12 Application Development Application Development ƒ

  Form: formatted document for data entry Form: formatted document for data entry and display

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  Report: formatted document for display Report: formatted document for display

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  Use nonprocedural access to specify data requirements of forms and reports requirements of forms and reports

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  1-14 Form Form Entry Entry Data Data

  1-15 Report Report Procedural Language Interface Procedural Language Interface ƒ

  Combine procedural language with Combine procedural language with nonprocedural access

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  Why

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  Why

  ƒ Batch processing

  ƒ Customization and automation ƒ Customization and automation ƒ Performance improvement 1-16 Transaction Processing Transaction Processing ƒ

  Transaction: unit of work that should be Transaction: unit of work that should be reliably processed

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  Control simultaneous users

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  Control simultaneous users

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  Recover from failures

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  _{Era Generation Orientation Major Features} Database Technology Evolution Database Technology Evolution _{1960s 1 Generation File File structures and} st _{proprietary program 1970 1970s 2 2 Generation G ti Network N t k N t Networks and hierarchies k d hi hi nd nd Navigation of related records,} interfaces _{1980s 3 Generation Relational Non-procedural rd interfaces} standard program _{1990s 4 Generation Object Multi-media, active, th transaction processing} languages, optimization, _{XML enabled} distributed processing, 1-18

  DBMS Marketplace DBMS Marketplace ƒ

  Enterprise DBMS Enterprise DBMS

  ƒ Oracle: dominates in Unix; strong in Windows ƒ SQL Server: strong in Windows SQL Server: strong in Windows ƒ DB2: strong in mainframe environment ƒ

  Significant open source DBMSs: MySQL, g p y , Firebird, PostgreSQL

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  Desktop DBMS

  ƒ Access: dominates

ƒ FoxPro, Paradox, Approach, FileMaker Pro 1-19 Data Independence Data Independence ƒ

  Software maintenance is a large part Software maintenance is a large part (50%) of information system budgets

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  Reduce impact of changes by separating Reduce impact of changes by separating database description from applications

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  Change database definition with minimal Change database definition with minimal effect on applications that use the database database

  1-20 Three Schema Architecture Three Schema Architecture External

  View 1 View 1 View 2 View 2 View n View n Level L l

  External to Conceptual Conceptual Conceptual

  Conceptual Mappings Level

  Schema Conceptual to Internal Mappings

  Internal Internal

  Level Level Schema

  1-21 Differences among Levels Differences among Levels ƒ

  External

  ƒ Forms ƒ Reports ƒ

  Conceptual

  ƒ Tables ƒ

  Internal

  ƒ Files needed to store the tables ƒ Extra files to improve performance 1-22

Client Server Architecture Client-Server Architecture

  a) Client, server, and _{same computer database on the d t b th on different computers diff t t b) Mulitple clients and 1 server Server Server} Client Client Server _{Client Database} Client _Database

  c) Multiple servers and databases on different computers _{Client Server Server Client Client} Client Database Database _1-23 Organizational Roles Organizational Roles

Specialization Specialization

Functional User Functional User

  Information Systems Information Systems

Indirect Indirect Parametric Parametric Power Power DBA DBA Analyst/Programmer Analyst/Programmer Management Management

Technical Technical Non Technical Non Technical

  1-24 Database Specialists Database Specialists ƒ

  Database administrator (DBA) Database administrator (DBA)

  ƒ More technical ƒ DBMS specific skills DBMS specific skills

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  Data administrator

  ƒ Less technical Less technical ƒ Planning role 1-25 Summary Summary ƒ

  Databases and database technology vital Databases and database technology vital to modern organizations

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  Database technology supports daily

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  Database technology supports daily operations and decision making

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  Nonprocedural access is a crucial feature

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  Nonprocedural access is a crucial feature

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  Many opportunities to work with databases

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