When Selecting an Identifier, One Should

question 52

Multiple Choice

When selecting an identifier, one should:

• A) use intelligent keys.
• B) use large composite keys instead of single-attribute surrogate keys.
• C) choose a candidate key that will not change its value over the life of each instance of the entity type.
• D) choose a candidate key such that for each instance of the entity, the attribute is guaranteed to have valid values or is null.
• E) choose a candidate key that allows for duplicate values.

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Definitions:

Low-Powered Objective

An objective lens on a microscope with a relatively low magnification power, used for initial scanning and location of specimen details.

Scanning Objective

A low-power objective lens on a microscope used to scan the whole slide to find the specimen before using higher magnification.

Field Diameter

The visible area observed through the lens of a microscope or other viewing instrument.

Objective

Unbiased, not influenced by personal feelings or opinions in considering and representing facts.