Knowledge check

Choose the best response for each of the questions below. Then select Check your answers.

Which one of the following statements is a characteristic of a relational database?

All columns in a table must be of the same data type.

A row in a table represents a single instance of an entity.

Rows in the same table can contain different columns.

Which SQL statement is used to query tables and return data?

QUERY

READ

SELECT

What is an index?

A structure that enables queries to locate rows in a table quickly

A virtual table based on the results of a query

A predefined SQL statement that modifies data

You must answer all questions before checking your work.

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