Consider the following schema Booksisbn String title String

Consider the following schema: Books(isbn: String, title: String, Publisher, publishYear, String, edition: String) The number of candidate keys for the relation books is

Solution

Answer: b) 3

explanation:

candidate key is a column or set of columns in a table, which can be used uniquely identify a row..or record

so here candidate keys are isbn, [title,edition], [publisher,year,edition]

isbn - a number which uniquely identifies a book