DATABASE REDESIGN QUIZ

Changing cardinalities in a database is:

a database design task that never occurs.

is impossible to do, so a new database must be constructed and the data moved into it.

a rare database design task, but does occur.

a common database design task.

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A tool that can help designers understand the dependencies of database structures is a:

None of these

data model.

graphical display.

dependency graph.

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Which is not true of a correlated subquery?

They can be used to verify functional dependencies.

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.

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The NOT EXISTS keyword will be true if:

neither of these two conditions is met.

all rows in the subquery fail the condition.

any row in the subquery meets the condition.

both of these two conditions are met.

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How many copies of the database schema are typically used in the redesign process?

Three

One

Four

Two

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A correlated subquery is processed as a nested subquery.

False

True

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Database redesign is not terribly difficult if the:

database is relatively small.

database is structured.

database is well-designed.

database has no data.

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

True

False

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If a database is built correctly the first time, it will not have to be redesigned.

False

True

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The data model that is produced from reverse engineering is:

an internal model.

None of these

a logical model.

a conceptual model.

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