Table 3.9: Probabilistic `Customer`

and `CustomerLoc`

relations.

(a) Probabilistic `Customer`

relation (tuple-level uncertainty)

(b) Probabilistic `CustomerLoc`

relation (attribute-level uncertainty), where N(μ, 𝜎2) is normal distribution with probabilistic density function $f\left(\text{x}\right)=\frac{1}{\sqrt{2\pi \sigma}}{e}^{-\frac{{\left(x-\mu \right)}^{2}}{2{\sigma}^{2}}},$ μ is mean and 𝜎2 is variance.

ID | CName | Location |

l1 | Lily | N(2, 1) |

l2 | Tom | N(5, 1) |

l3 | Jessica | N(3, 1) |

The probability of each possible world can be computed by multiplying its tuples’ probabilities.

Besides tuple-wise uncertainty, attribute-level uncertainty (e.g., Location attribute in the CustomerLoc relation in Table 3.9(b)) ...

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