Information = Conjunctive Constraints

• Information object consists of attribute-value pairs.

• Constraint specifies the value of an attribute, e.g.,

  • [lname “Smith”], or
  • [lname = “Smith”].

• Information about an object is a set of constraints satisfied by the object.

[lname “Smith”]

[fname “John”]

[license “4HDQ973”]

[price 9000]

[car-type “ford-taurus”]

[year 1994]

[mileage 80000]

[unit “km”]

[color “blue”]

a Used-Car record:

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