CIS305_Ch.3

  1. Business Rule
    • a statment that defines or constrains some aspect of the business.
    • Is intended to assert business structure or to control or influence the behavior of the business
  2. Term
    a word or phrase taht has a specific meaning for the business
  3. Fact
    an association between two or more terms
  4. Data Names should
    • relate to business, not technical (HW or SW) characteristics
    • be meaningful
    • be unique
    • be readable
    • be composed of words taked from an approved list
    • be repeatable
    • follow a standard syntax
  5. E-R Model
    • Entity-Relationship model.
    • a logical representation of the data for an organization or for a business are using entities for categories of data and relationships for associations between entities
  6. E-R Diagram (ERD)
    • Entity-Relationship Diagram.
    • a graphical representation of an entity-relationship model.
  7. Entity
    a person, place, object, event, or concept in the user environment about which the organization wishes to maintain data
  8. Entity Type
    a collection of entities that share common properties or characteristics
  9. Entity Instance
    a single occurence of an entity type
  10. Strong Entity Type
    an entity that exists independently of other entity types
  11. Weak Entity Type
    an entity type whose existence depends on some other entity type
  12. Identifying Owner
    the entity type on which the weak entity type depends
  13. Identifying Relationship
    the relationship between a weak entity type and its owner
  14. Attribute
    a property or characteristic of an entity or relationship type that is of interest to the organization
  15. Required Attribute
    an attribute that must have a value for every entity (or relationship) instance with which it is associated
  16. Optional Attribute
    an attribute that may not have a value for every entity (or relationship) instance with which it is associated.
  17. Composite Attribute
    an attribute that has meaningful component part (attributes)
  18. Simple Attribute
    • (or Atomic).
    • an attibute that cannot be broken down into smaller components that are meaningful to the organization
  19. Multivalued Attribute
    an attribute that may take on more than one value for a given entity (or relationship) instance
  20. Derived Attribute
    an attribute whose values can be calculated from related attribute values
  21. Identifier
    an attribute (or combination of attributes) whose value distinguishes instances of an entity type
  22. Composite Identifier
    an identifier that consists of a composite attribute
  23. Relationship Type
    a meaningful association between (or among) entity types
  24. Relationship Instance
    an association between (or among) entity instances where each relationship instance associates exactly one entity instance from each participating entity type.
  25. Associative Entity
    an entity type that associates the instances of one or more entity types and contains attributes that are peculiar to the relationship between those entity instances
  26. Degree
    the number of entity types that participate in a relationship
  27. Unary Relationship
    a relationship betwen instances of a single entity type
  28. Binary Relationship
    a relationship between the instances of two entity types
  29. Ternary Relationship
    a simultaneous relationship among the instances of three entity types
  30. Cardinality Constraint
    specifies the number of instances of one entity that can (or must) be associated with each instnace of another entity
  31. Minimum Cardinality
    the minimum number of instances of one entity that may be associated with each instance of another entity
  32. Maximum Cardinality
    the maximum number of instances of one entity that may be associated with each instance of another entity
  33. Time Stamp
    a time value that is associated with a data value, often indicating when some event occurred that affected the data value
Author
swh136
ID
77856
Card Set
CIS305_Ch.3
Description
Modern Database Management
Updated