DATABASE REDESIGN QUIZ

Because of the need for extensive knowledge of SQL, many database developers choose to automate the redesign process.

True

False

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Which is not true of a correlated subquery?

They are very similar to a regular subquery.

EXISTS/NOT EXISTS is a form of a correlated subquery.

The processing of the SELECT statements is nested.

They can be used to verify functional dependencies.

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Which of the following SQL statements are helpful in database redesign?

None of these

Correlated subqueries only

Both of the above are helpful

EXISTS/NOT EXISTS expressions only

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A correlated subquery is processed as a nested subquery.

False

True

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Dependency graphs are diagrams that consist of nodes and arcs that show the dependencies of a database.

False

True

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Typically, there should be at least two different copies of the database schema used in the redesign process.

False

True

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The EXISTS keyword will be true if:

all rows in the subquery fail the condition only.

any row in the subquery meets the condition only.

both of these two conditions are met.

neither of these two conditions is met.

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Because of the importance of making data model changes correctly, many professionals are ________ about using an automated process for database redesign.

skeptical

optimistic

ambivalent

None of these

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Although creating test databases is a critical and necessary job, there are few career opportunities in this area.

False

True

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Before any changes to database structure are attempted one should first:

clearly understand the current structure and contents of the database only.

test any changes on a test database only.

All of these

create a complete backup of the operational database only.

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