The Titanic dataset

Publicly available data about 891 passengers:

extensional passenger(id: integer,          # unique ID
                      survived: integer,    # 0: no, 1: yes
                      class: integer,       # 1-3 (first to third class)
                      sex: string,          # "male" or "female"
                      fare: float).         # how much they paid for their ticket

We don’t know every passenger’s age, so ages live in a separate relation:

extensional age(id: integer,                # refers to an id in passenger
                years: float).              # age at the time of the sinking (but check this later!)

Source: the Kaggle Titanic dataset.