Topic 3 Flashcards
_____ logic, used extensively in mathematics, provides a framework in which an assertion (statement of fact) can be verified as either true or false
a. Predicate
b. Database
c. Relational
d. Index
Predicate
Each table _____ represents an attribute
a. column
b. row
c. dimension
d. value
column
Date attributes contain calendar dates stored in a special format known as the _____ date format
a. Epoch
b. calendar
c. Julian
d. logical
Julian
In the relational model, _____ are important because they are used to ensure that each row in a table is uniquely identifiable
a. relations
b. keys
c. indexes
d. logical structures
keys
A _____ is any key that uniquely identifies each row
a. superkey
b. special key
c. foreign key
d. candidate key
superkey
A _____ key can be described as a minimal superkey, a superkey without any unnecessary attributes
a. secondary
b. candidate
c. primary
d. foreign
candidate
A _____ is the primary key of one table that has been placed into another table to create a common attribute
a. superkey
b. composite primary key
c. candidate key
d. foreign key
foreign key
A _____ key is defined as a key that is used strictly for data retrieval purposes
a. lookup
b. foreign
c. candidate
d. secondary
secondary
Referential _____ dictates that the foreign key must contain values that match the primary key in the related table, or must contain null
a. integrity
b. uniqueness
c. model
d. attribute
integrity
The CUSTOMER table’s primary key is CUS_CODE. The CUSTOMER primary key column has no null entries, and all entries are unique. This is an example of _____ integrity
a. entity
b. referential
c. relational
d. null
entity
The _____ constraint can be placed on a column to ensure that every row in the table has a value for that column
a. UNIQUE
b. NOT NULL
c. VALUE
d. EMPTY
NOT NULL
To be considered minimally relational, the DBMS must support the key relational operators _____, PROJECT, and JOIN
a. INTERSECT
b. UNION
c. DIFFERENCE
d. SELECT
SELECT
_____, also known as RESTRICT, yields values for all rows found in a table that satisfy a given condition
a. INTERSECT
b. UNION
c. DIFFERENCE
d. SELECT
SELECT
_____ returns only the attributes requested, in the order in which they are requested
a. PROJECT
b. SELECT
c. UNION
d. DIFFERENCE
PROJECT
When two or more tables share the same number of columns, and when their corresponding columns share the same or compatible domains, they are said to be _____
a. intersect-compatible
b. union-compatible
c. difference-compatible
d. select-compatible
union-compatible
A (n) _____ join links tables by selecting only the rows with common values in their common attribute(s)
a. attribute
b. unique
c. foreign
d. natural
natural
_____ are especially useful when you are trying to determine what values in related tables cause referential integrity problems
a. Inner joins
b. Outer joins
c. Equijoins
d. Theta joins
Outer joins
A (n) _____ only returns matched records from the tables that are being joined
a. outer join
b. inner join
c. equijoin
d. theta join
inner join
A _____ contains at least all of the attribute names and characteristics for each table in the system
a. data dictionary
b. relational schema
c. logical schema
d. database
data dictionary
The _____ is actually a system-created database whose tables store the user/designer-created database characteristics and contents
a. database tuple
b. systematic database
c. unique index
d. system catalog
system catalog
In a database context, the word _____ indicates the use of the same attribute name to label different attributes
a. redundancy
b. homonym
c. duplicate
d. synonym
homonym
In a database context, a(n) _____ indicates the use of different names to describe the same attribute
a. entity
b. duplicate
c. synonym
d. homonym
synonym
The _____ relationship is the “relational model ideal.”
a. 1:1
b. 1:M
c. M:1
d. M:N
1:M
The _____ relationship should be rare in any relational database design
a. 1:1
b. 1:M
c. M:1
d. M:N
1:1
