Chapter 9 Database Information and Management

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Chapter 9 Database Information and Management
Chapter 9
Database and Information Management
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Presentation Overview

• Database Basics
• Databases and Information Systems
• Database Management System Software
• Types of Databases
• Planning and Designing Database Systems
• Using Databases
• Database Administration

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Database Basics

• What is a database?
• A database is a computerized system for storing
  information in an organized manner so that it can
  be searched for and retrieved when needed.
• How does a database organize information?
• Information is stored in the form of fields,
  records, and files.

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Database Basics

• Data vs. Information
• Data is a collection of raw, unorganized
  (unprocessed) content in the form of words,
  numbers, sounds, or images.
• Information is data associated with other useful
  data on the same topic.

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Database Basics

• Levels of Data within a Database
• An entity is a person, place, thing, or event.
• A field is a single value, such as a name,
  address, or dollar amount. A field generally has
  three attributes.
• Data type usually numeric or text
• Name assigned by the person developing the
  database
• Size the number of characters that can be entered

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Database Basics

• Level of Data within a Database
• A record is a collection of related fields
  describing an event or situation.
• A database file is a collection of records of the
  same type.

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Database Basics

• Traditional Database Hierarchy
• A traditional database organizes data in a
  hierarchy.
• Fields are the smallest elements.
• Fields make up records.
• Records make up data files.
• The database is a collection of data files.

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Database Basics

• Common Field Data Types

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Databases and Information Systems

• The most common database application is an
  information system, which is a system of computer
  hardware, software, and operating procedures.
• Information systems are designed to meet the
  needs of a company.
• A variety of information systems has evolved with
  software capabilities and market needs.

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Databases and Information Systems

• Management Information Systems
• A management information system (MIS) is used to
  track and control every transaction through a
  database.
• A transaction is a business activity central to
  the nature of an enterprise.

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Databases and Information Systems

• Office Information Systems
• First popularized in the 1960s, the concept of an
  office information system (OIS) was billed as a
  replacement for paper-based information systems.
• An electronic office is one that implements an
  OIS.
• The electronic office today is the norm rather
  than the exception.

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Databases and Information Systems

• Decision Support Systems
• A decision support system (DSS) is designed to
  help management make decisions about an
  operation.
• A DSS helps managers to work with what if
  situations.

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Databases and Information Systems

• Factory Automation Systems
• Computer-aided manufacturing (CAM) and
  computer-integrated manufacturing (CIM) are
  information systems that support factory
  automation.
• CAM refers to systems that run an assembly line
  directly.
• CAM systems form a portion of a complete CIM
  system, a higher-level system that controls a
  manufacturing process from beginning to end.

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Database Management System Software

• Software that allows a user to create and manage
  a computerized database is called database
  management system (DBMS) software.
• DBMS software also allows a user to create
  reports from stored data.

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Database Management System Software

• Database Keys
• A key is an attribute that can be used to
  identify a set of information and therefore
  provide a means to search a database.
• The most important field in a record is the
  primary key, which must be unique so that it can
  be used to locate a record quickly.
• Data browsing is moving through a database file
  and looking for information.

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Database Management System Software

• Query Tools
• Query tools help users help users narrow down
  large amounts of data to just the information
  that needs to be searched.
• A query allows users to ask questions designed to
  retrieve needed information.

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Database Management System Software

• The most popular database query language is
  Structured Query Language (SQL).
• The SELECT command asks a database to return
  records that match specified criteria.
• This SQL statement could be used to search for
  the top students in a college, with top defined
  as those students with a GPA above 3.49.

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Database Management System Software

• A process called joining matches data from fields
  in various database files.
• Here, both records files would have a common
  Student ID number field, allowing the information
  in both of them to be returned in a single query.

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Database Management System Software

• Information about data is called metadata.
• It often describes the significance of various
  elements of a database.
• A data dictionary is a body of metadata.
• A legacy database is a database that runs using
  languages, platforms, or models that are no
  longer supported by an organizations current
  database system.

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Types of Databases

• Databases Classified by Data Model
• A flat file database is a traditional data file
  storage system that cannot interrelate data in an
  organizational structure.
• It is called flat because it contains only one
  file.
• These databases are easy to use but consume more
  disk space and are slow to respond.

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Types of Databases

• Databases Classified by Data Model
• In a relational database, fields can be shared
  among all the files in the database, making it
  possible to connect them.
• In this type of database, a file is called a
  table, a record is called a tuple, and a field is
  called an attribute.
• A single change to an attribute will change that
  attribute in all the tables at once.

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Types of Databases

• Databases Classified by Data Model
• An object-oriented database stores data in the
  form of objects.
• Each object contains both the data related to the
  object and the actions a user might want to
  perform on that object.
• These databases allow for faster development and
  access time.

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Types of Databases

• Databases Classified by Data Model
• A multimedia database allows the storage of
  pictures, movies, sounds, and hyperlinked fields.
• A hybrid database employs multiple data models.
• A combination of relational and object-oriented
  models is a popular hybrid database.

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Types of Databases

• Databases Classified by Function
• An operational database offers a snapshot of a
  fluid situation.
• These databases are usually used to track an
  operation or situation, i.e. inventory.
• A distributed database is spread across multiple
  networked computers.
• These databases can hold more information, but
  dont operate as quickly as mainframe or
  supercomputer databases.

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Types of Databases

• Databases Classified by Function
• A data warehouse is used to store data gathered
  from one or more databases.
• They do not change, delete, or manipulate the
  information they store.
• Law enforcement records are an example of a data
  warehouse.

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Planning and Designing Database Systems

• How are databases designed?
• Using the database management approach, systems
  analysts follow three steps.
• Create an organizational structure for the data.
• Design an interface that makes the database
  user-friendly.
• Set up reporting capabilities to allow for
  inquiry and response.

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Planning and Designing Database Systems

• Accessing a Database
• The user requests and enters data through the
  front-end interface program.
• The database management system manages the
  retrieval and update of the database itself.

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Planning and Designing Database Systems

• Database Objects Tools in the DBMS
• A database object is an element within an
  object-oriented database.
• A form is a template that allows users to enter
  data into the database.
• A report is a formatted body of output from a
  database.
• A data filter is made up of filtering criteria
  that cause only a subset of the data to be
  presented.

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Using Databases

• The activities performed with a database are
  referred to as data processing.
• Batch processing occurs at a scheduled time or
  when a critical point has been reached.
• Transactional processing is more continuous.
• In a real-time system, data is constantly
  updated.
• E-commerce transactions use online transactional
  processing, which is in business 24 hours a day.
• Transactional and batch processing are often
  mixed in the same system.

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Using Databases

• Data Entry Operator
• Types data into databases and makes sure that it
  is accurate.
• He or she
• Adds records
• Modifies records
• Deletes records
• Sorts records

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Database Administration

• A database administrator is responsible for
  maintaining and updating the database and the
  DBMS software.
• Any changes in company policy often result in
  changes to the company database.
• Database administrators are also responsible for
  preventing computer downtimetime in which the
  system is unavailable.

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Database Administration

• Data Loss or Corruption
• Data loss occurs when data input can no longer be
  retrieved.
• Data corruption occurs when data is unreadable,
  incomplete, or damaged.
• A key part of any DBMS is a backup and recovery
  plan.
• Tape backups are a commonly used backup method.
• Backups must be stored separately from original
  material to lessen accidental data loss.

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Database Administration

• The lag time between a user issuing a command and
  the database system taking action is called
  database response time.

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Database Administration

• When users attempt to edit existing records in a
  multi-user system, record locking occurs.
• The system automatically checks to see if anyone
  else is working on the same record and only
  allows one user at a time to edit or delete the
  record.

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Database Administration

• Data Integrity
• The accuracy of the information provided to
  database users.
• Redundancy
• The duplication of data in several fields.
• An enemy of data integrity because it creates
  opportunities for error.
• Normalization
• A process intended to eliminate redundancy.

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Database Administration

• Data Contamination
• The spread of incorrect information.
• Can have serious consequences.
• Preventing it is one of the goals of data
  validation.

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Database Administration

• Data Validation
• The process of making certain that data entered
  into the system is both correct and complete.
• Referential Integrity
• Involves a check to make sure that deleting a
  record in one table will not affect other tables.

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Database Administration

• Data Validation
• A range check only allows a certain range of
  numbers to be entered.
• An alphanumeric check allows only letters of the
  alphabet and digits to be entered.
• A consistency check is made against previously
  entered data that has been validated.
• A completeness check ensures that every required
  field is filled out.

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On the Horizon

• Based on the information presented in this
  chapter and your own experience, what do you
  think is on the horizon?