DBDBDB

In an SQL query, which built-in function is used to compute the average value of numeric columns? A)MIN B) AVG C) MEAN D) MAX E) SUM

AVG

In an SQL query, which SQL keyword must be used to remove duplicate rows from the result table? A)DISTINCT B)NOT EXISTS C)UNIQUE D)DELETE E)KEY

DISTINCT

In an SQL query, which SQL keyword is used to specify the names of tables to be joined? A)HAVING B)JOIN C)FROM D)SELECT E)WHERE

FROM

In an SQL query, which SQL keyword is used with GROUP BY to select groups meeting specified criteria? A)EXISTS B)AND C)IN D)HAVING E)WHERE

HAVING

In an SQL query, which SQL keyword is used to determine if a column value is equal to any one of a set of values? A)OR B)EXISTS C)HAVING D)IN E)AND

IN

For a relationship to be considered a binary relationship it must satisfy which of the following conditions? A) It must have a maximum cardinality of 1:1. B) It must involve exactly two entity classes. C) It must have a maximum cardinality of 1:N. D) It must involve exactly two entity classes and it must have a maximum cardinality of 1:1 E) It must involve exactly two entity classes and it must have a maximum cardinality of 1:N

It must involve exactly two entity classes

In an SQL query, which SQL keyword is used to sort the result table by the values in one or more columns? A) WHERE B) SELECT C) SORT BY D) ORDER BY E )GROUP BY

ORDER BY

Which of the following is not a key element of an E-R model? A) Identifiers B) Objects C) Entities D) Relationships E) Attributes

Objects

Which of the following is not true about surrogate keys? A)They can be problematic when combining databases. B)The DBMS will not allow their values to be changed. C)They are identifiers that are supplied by the system, not the users. D)They are nonunique within a table. E)They have no meaning to the users.

They are nonunique within a table.

Attributes may be ________. A) multivalued B) element C) composite D) both composite and multivalued E) both element and multivalued

both composite and multivalued

Many-to-many relationships are represented by ________. A) by an intersection table which has M:N relationships with the two tables B) by two intersection table which each have 1:N relationships with the two tables C) two tables with an M:N relationship D) two tables with a 1:N relationship E) by an intersection table which has 1:N relationships with the two tables

by an intersection table which has 1:N relationships with the two tables

A referential integrity constraint policy that insures that foreign key values in a table are correctly maintained when there is a change to the primary key value in the parent table is called ________. A)controlled key adjustments B)cascading updates C)incremental deletes D)incremental updates E)cascading deletes

cascading updates

Each attribute of an entity becomes a _______ of a table. A) primary key B) alternate key C) foreign key D) column E) primary key or alternate key

column

To represent an association pattern in an E-R model, ________. A)create a new strong entity with a 1:1 relationship to one other entity B)create a new weak, but not ID-dependent entity with a 1:N relationship to one of two parent entities C)create a new weak, but not ID-dependent entity with a 1:1 relationship to one other entity D)create a new ID-dependent entity with a 1:1 relationship to one other entity E)create a new ID-dependent entity with 1:N relationships to the two parent entities

create a new ID-dependent entity with 1:N relationships to the two parent entities

To represent a multivalued attribute in an E-R model, ________. A)create a new weak, but not ID-dependent entity with a 1:1 relationship B)create a new strong entity with a 1:1 relationship C)create a new weak, but not ID-dependent entity with a 1:N relationship D)create a new ID-dependent entity with a 1:1 relationship E)create a new ID-dependent entity with a 1:N relationship

create a new ID-dependent entity with a 1:N relationship

The first step in transforming an extended E-R model into a relational database design is to ____. A) evaluate the entities against the normalization criteria B) document referential integrity constraints C) create a table for each relationship D) remove any recursive relationships E) create a table for each entity

create a table for each entity

In a relational database design, all relationships are expressed by ________. A)creating a supertype B)creating a subtype C)creating a line between entities D)creating a foreign key E)creating a primary key

creating a foreign key

Entities of a given type are grouped into a(n) ________. A) entity attribute B) entity class C) entity relationship D) entity instance E) None of the above.

entity class

The occurrence of a particular entity is called a(n) ________. A) entity relationship B) entity attribute C) entity class D) entity instance E) None of the above.

entity instance

A referential integrity constraint policy that guarantees that a row in a parent table always has a required entry in a child table ________. A)is known as a minimum cardinality enforcement action B)needs to be documented by the database development team C)is enforced in most DBMS products D)is known as a minimum cardinality enforcement action and needs to be documented by the database development team E)is known as a minimum cardinality enforcement action, needs to be documented by the database development team and is enforced in most DBMS products

needs to be documented by the database development team

In many-to-many relationships in a relational database design ________. A) the intersection table is ID-dependent on one of the parents B) one of the parents is always required for a child in the intersection table C) the intersection table is ID-dependent on both of the parents D) both of the parents are always required for a child in the intersection table E) the intersection table is ID-dependent on both of the parents and both of the parents are always required for a child in the intersection table

the intersection table is ID-dependent on both of the parents

In many-to-many relationships in a relational database design ________. A)the intersection table is ID-dependent on one of the parents B)the intersection table is ID-dependent on both of the parents C)the minimum cardinality from the intersection table to the parents is always M D)the intersection table is ID-dependent on one of the parents and the intersection table is ID-dependent on both of the parents E)the intersection table is ID-dependent on both of the parents and the minimum cardinality from the intersection table to the parents is always M

the intersection table is ID-dependent on both of the parents

A surrogate key should be considered when ________. A) a composite key is required B) a relationship is M:N C) an index needs to be created D) the key contains a lengthy text field E) the key contains a number

the key contains a lengthy text field

When representing a 1:1 relationship in a relational database design ________. A)the key of each table must be placed as foreign keys into the other B)the intersection table gets the key from both relations C)the key of either table may be placed as a foreign key into the other D)the key of both tables must be the same E)both the key of either table may be placed as a foreign key into the other and the key of both tables must be the same

the key of either table may be placed as a foreign key into the other

In many-to-many relationships in a relational database design ________. A)the key of the child is placed as a foreign key into the parent B)the key of the parent is placed as a foreign key into the child C)the keys of both tables are placed in a third table D)the keys of both tables are joined into a composite key E)the keys of both tables are placed in a third table and the keys of both tables are joined into a composite key

the key of the parent is placed as a foreign key into the child

To represent a one-to-many relationship in a relational database design ________. A) the keys of both tables are joined into a composite key B) the key of the parent is placed as a foreign key into the child C) the key of the child is placed as a foreign key into the parent D) an intersection table must be created

the key of the parent is placed as a foreign key into the child

In many-to-many relationships in a relational database design ________. A) the key of the parent is placed as a foreign key into the child B) the key of the child is placed as a foreign key into the parent C) the keys of both tables are placed in a third table D) the keys of both tables are joined into a composite key E) the keys of both tables are placed in a third table and the keys of both tables are joined into a composite key

the keys of both tables are placed in a third table and the keys of both tables are joined into a composite key

Maximum cardinality refers to ________. A) the minimum number of entity classes involved in a relationship B) whether or not an instance of one entity class is required to be related to an instance of another entity class C) the most instances of one entity class that can be involved in a relationship instance with another entity class D) whether or not an entity is a weak entity E) None of the above.

the most instances of one entity class that can be involved in a relationship instance with another entity class

When representing a one-to-many relationship in a relational database design ________. A)the child is always on the one side of the "one-to-many" relationship B)the parent is always on the one side of the "one-to-many" relationship C)either parent or child can be on the one side of the "one-to-many" relationship, and the choice is arbitrary D)either parent or child can be on the one side of the "one-to-many" relationship, and special criteria indicate which table should be on the one side. E)None of the above is correct.

the parent is always on the one side of the "one-to-many" relationship

An entity whose existence depends on the presence of another entity, but whose identifier does not include the identifier of the other entity is a(n) ________. A) ID-dependent entity B) weak entity C) strong entity D) strong entity and ID-dependent entity E) weak entity and ID-dependent entity

weak entity

When transforming an E-R data model into a relational database design, the key of the parent entity should be placed as part of the primary key into the child entity ________. A) when the child entity is ID-dependent B) when the child entity is non-ID-dependent C) when the child entity has a 1:N relationship with the parent entity D) when the child entity has a recursive relationship with the parent entity E) when the child entity has a 1:1 relationship with the parent entity

when the child entity is ID-dependent