Information and Database Systems I

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Information and Database Systems I

• Spring 2009

January 6, 2009
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Basics
Instructor Alejandro Pauly, apauly_at_cise.ufl.edu T
A TBA Class website http//www.cise.ufl.edu/clas
s/cis4301sp09

• Textbook
• A First Course in Database Systems
• by Jeffrey Ullman and Jennifer Widom
• 3rd Edition (but 2nd should be sufficient)

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GradingExaminations

• 5 quizzes final exam (70). Option to drop one
  of those (if you do well on all five quizzes you
  can choose to not take the final).
• Quizzes cover only material that hasnt been
  covered in previous quizzes.
• Final exam covers all the material.
• Each quiz/final 14 of final grade.

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GradingAssignments

• 5 Assignments (30) some of which will include
  programming.
• Homework will be assigned and discussed in class
  but does not need to be turned in (so it doesnt
  count towards your grade but will help you
  understand the material and study for the
  quizzes).

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What is this course about?

• Introduction to database technology from an
  advanced users perspective. This means that you
  will learn to design and implement software that
  uses a database to manage the data.
• Some topics that will be covered
• The Entity-Relationship model
• Conceptual database design and modeling
• The relational model
• Relational query languages (relational algebra,
  relational calculus, and SQL)
• Logical database design (functional dependencies
  and normal forms)
• Object-relational databases and SQL-3

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What is a Database?

• Collection of related data items that are being
  stored for record-keeping analysis
• Contacts (could be in a Rolodex)
• Recipe book
• Store or business inventory of products
• Museum/Herbarium collections
• Flight reservation (flights, airlines,
  passengers, planes, seats, baggage, etc).

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What is a Database Management System (DBMS)?

• Computerized system to manage databases.
• Persistent storage Efficient, safe storage of
  large amounts of data
• Programming interface High-level language for
  specifying the operations the user wishes to
  perform on data
• Transaction management Concurrent access to
  data, provides recovery in light of failure

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Why are DBMS important?

• Imagine keeping track of flight reservations
  without a computerized system, or Walmarts
  inventory, Fedex packages, hospitals patient
  records.
• Amount of electronically available data is
  exploding cheaper storage, faster processing
• Organizations consider data to be one of their
  most valuable assets (decision making).
• User requirements for faster, more accurate, and
  more reliable access to all these data.

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Evolution of Database Systems

• Early DBMSs (late 1960s) evolved from file-based
  processing systems
• Need for supporting concurrent access to the data
  by many users, recovery, back-up,
• Roots in airline reservation systems (SABRE),
  banking systems, corporate record-storage systems
• Visualize the data much as it was stored
• Tree-based (hierarchical model)
• Graph-based (network model)
• Cumbersome to use, require lower level
  programming to access data

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Evolution of Database Systems

• Early 1970s Ted Codd proposed the relational
  data model
• Soon thereafter, team of IBMers invented SQL
  (Structured Query Language)
• De-facto standard for query languages based on
  the relational data model
• Commercial DBMS based on relational model are now
  widely accepted in industry
• e.g., Oracle, Sybase, MySQL, PostgresSQL, etc

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Evolution of Database SystemsCharacteristics of
current DBMS

• Support for concurrent access to data
• Safeguard data against accidentally loss
• Maintain integrity of database in light of
  changes
• Support for distributed data
• Control access to data
• Support for non-standard data
• Support for heterogeneous data
• Support for decision-support and analysis
• Fulfillment of new age requirements
• High availability, High reliability, High
  throughput, Low response time, Extensibility

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Evolution of Database SystemsTrends

• DBMSs are getting smaller and smaller
• desktop versions, small footprint, XML based
  systems for single user desktop applications
• Databases are getting bigger and bigger
• Web crawler data, satellite data, multimedia and
  non-traditional data (pictures, video, audio),
  GIS
• From megabytes, to gigabytes, to terabytes, now
  petabytes!
• Information Integration
• Consolidate heterogeneous data from various
  sources
• Intra-organization and also across organizations

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Terminology

• Database (DB)
• Collection of related data that exists over a
  long period of time
• Database Management System (DBMS)
• Collection of programs that
• allows users to create a new database and specify
  its structure
• gives users the ability to query and modify the
  data efficiently
• keeps the data secure from accidents or
  unauthorized use
• controls the access to the data for many users at
  once
• Database System (DBS)
• The database and DBMS software together make up
  what is known as the Database System

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Terminology

• Data Definition Language (DDL)
• Used to define the conceptual and internal
  schemas
• Includes constraint definition language (CDL) for
  describing conditions that database instances
  must satisfy
• Includes storage definition language (SDL) to
  influence layout of physical schema (some DBMSs)
• Data Manipulation Language (DML)
• Used to describe operations on the instances of a
  database
• Procedural DML (how) vs. declarative DML (what)
• Host Language
• General-purpose programming language which lets
  users embed DML commands (data sublanguage) into
  their code