What is the precise definition of a primary key?
What will be an ideal response?
Column A (or a collection of columns) is the primary key for a table if:
Property 1: All columns in the table are functionally dependent on A.
Property 2: No subcollection of the columns in A (assuming A is a collection of columns and not just a single column) also has property 1.
Computer Science & Information Technology
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Computer Science & Information Technology