Database t1
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