Database t1

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The software that controls the database is called the

DBMS

both entities and relationships

In converting from an E-R diagram to a relational model, tables are used to represent.

many-to-many

When converting an E-R model to a relational model, the table for a binary relationship can be replaced by a foreign key provided the relationship is not.

A relation is first normal form if

all of the above

When mapping a hierarchy from E-R diagram to a relational model, which of the following methods can be used?

all of the above.

A relation is second normal form if it is 1NF

and every nonkey attribute is dependent on the entire key.

A relation is a Boyce-Codd Normal Form if

every determinant is a superkey

If X and Y are sets of attributes of relation R, we say that Y is functionally dependent on X if

for each X value there is only one Y value

Which of the following is not one of the major objectives of normalization?

improving efficiency

For relational decomposition the property of being able to get back exactly the original relation by joins is

lossless decomposition.

In the relational model every determinant is always

none of the above

In a database systems a question such as "Find the names of all students who take class ENG210" as called a

quarry

All of the following are functions performed by DBMS EXCEPT

spell checking

If A and B are entitiy which a one-to-one relationship A:B, all of the following are true of the relational model representation for them EXCEPT

the entities A and B may sometimes be combined into a single table with no relationship table needed


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