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Operations for Nd Select

N-dimensional select queries = condition on ≥1 attributes.

  • pmr = partial-match retrieval (equality tests), e.g. 

    select * from Person
where  name = 'John' and age = 50;


  • space = tuple-space queries (range tests), e.g. 

    select * from Person
where 20 ≤ age ≤ 50 and 'Charles' ≤ name ≤ 'John'