A relation is, in formal terms,
Aan ordered list of tuples sorted by primary key
Ban unordered set of tuples sharing the same shape
Ca single tuple with all attributes filled in
Da stream of inserts kept in the write-ahead log
Answer & Solution
Correct answer: B. an unordered set of tuples sharing the same shape
The lecture is explicit: 'A relation is an unordered set that contains the relationship of attributes that represent entities.' Order is the DBMS's freedom to optimise, not the model's promise. A single tuple is one row, not a relation; the WAL is a recovery concept.
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