DB Exam 1

  1. Database
    collection of interrelated data organized in such a way that it corresponds to the needs and structure of an organization and can be used by more than one person for more than one application
  2. DBMS
    Database management system, enables storage of data in the database, retrieval of data from the database and control of the database
  3. Data
    Raw facts that can be recorded and perserved
  4. Focuses on the proper generation, storage, and retrieval of data and is a core activity of any organization
    Data management
  5. Difference between information and data
    • Data is raw facts that can be recorded and information is the result of the raw data that emphasises a MEANING in a given context
    • -Data generates information
  6. What are some of the issues with file-based systems
    • -Data redundancy (same info across multiple files)
    • -Isolation of data in separate systems
    • -Data inconsistency (lack in data integrity so if you change it in one file it won't apply to other files with the same data)
    • -Data Anomalies
    • -Program-data dependence
    • -Implies "flat" data files / two types of data in one table
  7. Defining features of a database system
    • -Security: collection of programs that manages the database structure and controls access to the data
    • -Provides access to the data via a query language
    • -Makes data management more efficient and effective
    • -Produce quick answers to ad hoc queries
    • -Probability of data inconsistency is reduced
    • -Promotes integrated view of organization's operations
  8. Advantages of a database system
    • -Minimize data redudancy
    • -Data consistency
    • -Integration of data
    • -Improve data sharing
    • -Enforcement of standards
    • -Ease of application development
    • -Uniform security, privacy, and integrity
    • -Data independence from applications
  9. Components of a database system are
    • Hardware
    • Software
    • People
    • Procedures
    • Data
  10. What are some examples of a the software component of database systems
    • Microsoft access
    • Microsoft SQL
    • Oracle
    • MySQL
    • Systems that are easier but often more limited
  11. What are some examples of people involved with database systems
    • System administrators
    • Database administrators (DBAs)
    • Database designers
    • System analyst and programmers
    • End users
  12. Database classification dealing with determination of single user or multi user databases
    Number of users
  13. Database classification dealing with whether the system is centralized or distributed
    Database location
  14. Database Classification dealing with whether it's operational or data warehouse
    Type of use
  15. Describe a parent - child based database model and it's issues
    Hierarchical database model, can be difficult to find data because there's only one way to get there, ex. windows registry
  16. Describe a parent child based database model where that allows more than one parent
    Network database model, tried to solve the problem of hierarchical to access from multiple points
  17. Updating single publisher's phone number requires you to update multiple entires is an example of
    Update anomalies, a problem with flat databases
  18. Describe the components of a relational database model
    • Table- "relation" matrix of intersecting rows
    • Entity - which data is collected and stored
    • Attributes - characteristics
    • Relationships - connections
  19. You cannot insert information about an author until we have a book by that author is an example of
    Insertion anomalies, problem with flat databases
  20. If we remove a record of a book we loose information about the publisher too is an example of
    Deletion anomalies, a problem with flat database
  21. Set of relations
  22. Row of a relation, with each cell consisting of specific values for a particular variable or attribute
  23. Set of tuples
  24. Properties of relations
    • Every relation must have a distinct name
    • each cell is atomic
    • Each attribute in a table must have distinct name
    • Values of any attribute must be from the same domain
    • There should not be any duplicate tuples
    • Order of tuples has no significance
    • Order of attributes has no significance
Card Set
DB Exam 1