Which of the Following Properties Should Be Satisfied When the Identifier

question 227

Multiple Choice

Which of the following properties should be satisfied when the identifier of the entity type becomes the primary key of the corresponding relation?

• A) The value of the key must uniquely identify every row in the relation.
• B) The key should serve as a foreign key in at least two other relations.
• C) The key must be a composite of a primary key and a secondary key.
• D) The key should be an intelligent key.
• E) The key should allow for null values.

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Definitions:

Cash

Liquid currency including coins and banknotes that is used to facilitate transactions and settle debts.

Stocks

Shares of ownership in a company, representing a claim on part of the company's assets and earnings.

Fiat Money

Currency that a government has declared to be legal tender, but it is not backed by a physical commodity.

The Euro

The official currency of 19 out of the 27 European Union countries, which forms a significant part of the world's economy.