Introduction to Database Systems

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Lecture-1 (08/30/2005)

• Introduction to Database Systems

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Daily Interaction with Databases

• Trip to a bank
• Processes conducted?
• Withdraw, deposit, etc
• Stored data?
• Customers, accounts , balances, employees, etc
• Airline/Hotel reservation?
• Customer, airlines, airports, flights, times,
  captains, payment information
• Book purchase from Amazon.com?
• Book inventory, customer, credit card, credit
  card company, Amazons balance, your balance, etc
  

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Basic Definitions

• Database A collection of related data
• Article? Phonebook?
• Data Known facts that can be recorded and have
  an implicit meaning
• Information
• Knowledge
• Mini-world Some part of the real world about
  which data is stored in the database
• Universe of Discourse (UoD)
• For example, student grades and transcripts at a
  university
• This aspect of the university

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Basic Definitions

• An integrated shared repository of operational
  data of interest to an enterprise
• INTEGRATED it must be the unification of several
  distinct files
• SHARED same data can be used by more than 1 user
  (concurrently)
• REPOSITORY implies persistence
• OPERATIONAL DATA data on accounts, parts,
  patients, students, employees, genes, stocks,
  pixels,...
• Non-operational data I/O data, transient data in
  buffers, queues...
• ENTERPRISE bank, warehouse, hospital, school,
  corp., gov. agency, person

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Basic Definitions

• Database Management System (DBMS) A collection
  of programs that facilitates the creation and
  maintenance of a computerized database
• Usually, general-purpose complex software
• Databases can also be manual
• e.g. a library database that stores cards on all
  available books usually sorted by authors name,
  subject, and title
• Database System The DBMS software together with
  the database itself
• Title of this course
• Sometimes, the applications are also included but
  this is not a rule

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Typical DBMS Functionality

• Define a database in terms of data types,
  structures and constraints
• Construct or load (with data) the database on a
  secondary storage medium
• Manipulating the database querying, generating
  reports, insertions, deletions and modifications
  to its content
• Concurrent processing and sharing by a set of
  users and programs
• yet, keeping all data valid and consistent!
• Other features (useful but not mandatory)
• Protection (against malfunction) or security
  measures to prevent unauthorized/malicious access

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(No Transcript)
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Example of a Database