DBS Final Exam 1
How many rows would be returned from a cross join of tables A and B, if A contains 8 rows and B contains 18? - 18 - 26 - 144 - 8
144
A dependency of one nonprime attribute on another nonprime attribute is a partial dependency.
False
A growing phase in a two-phase lock is when a transaction acquires all the required locks without locking any data.
False
A persistent stored module is stored and executed on the database client machine.
False
A system maintenance activity generated in response to changes in the business environment is referred to as corrective maintenance.
False
A table is in BCNF if every determinant in the table is a foreign key.
False
All SQL commands must be issued on a single line.
False
Comparison operators cannot be used to place restrictions on character-based attributes.
False
Data and information are essentially the same thing.
False
Just like database triggers, stored procedures are stored in the database.
True
M:N relationships are not appropriate in a relational model.
True
A noun in a business rule translates to a(n) _____ in the data model. - entity - relationship - attribute - constraint
entity
Referential _____ dictates that the foreign key must contain values that match the primary key in the related table, or must contain null. - integrity - attribute - uniqueness - model
integrity
Database design is a(n) _____ process based on repetition. - sequential - iterative - linear - intermittent
iterative
Most SQL implementations yield case-insensitive searches.
False
A table that has all key attributes defined, has no repeating groups, and all its attributes are dependent on the primary key is said to be in _____. - 4NF - 3NF - 2NF - 1NF
1NF
From a structural point of view, 3NF is better than _____. - 5NF - 6NF - 2NF - 3NF
2NF
A table that is in 2NF and contains no transitive dependencies is said to be in _____. -1NF -3NF -4NF -2NF
3NF
A table where all attributes are dependent on the primary key but are independent of each other, and no row contains two or more multivalued facts about an entity is said to be in _____. - 4NF - 3NF - 2NF - 1NF
4NF
Some very specialized applications may require normalization beyond the _____. -2NF -3NF -1NF -4NF
4NF
ANSI has defined standards that govern SQL database transactions. Transaction support is provided by two SQL statements _____ and ROLLBACK. -UPDATE -RETRIEVE -COMMIT -ASSIGN
COMMIT
The SQL command that allows a user to permanently save data changes is _____. - UPDATE - INSERT - COMMIT - SELECT
COMMIT
The SQL aggregate function that gives the number of rows containing non-null values for a given column is _____. - COUNT - SUM - MAX - MIN
COUNT
An explicit cursor must return two or more rows.
False
Business rules apply to businesses and government groups, but not to other types of organizations such as religious groups or research laboratories.
False
Corporations use only structured data.
False
Data is the result of processing raw facts to reveal its meaning.
False
Database programming languages receive all application requests and translates them into the complex operations required to fulfill those requests.
False
Every PL/SQL block must be given a name.
False
Field refers to a collection of related records.
False
In a natural join, the column on which the join was made occurs twice in the new table.
False
Most real-world database transactions are formed by only one database request.
False
MySQL allows multiple triggering conditions per trigger.
False
Normalization is a process that is used for changing attributes to entities.
False
One disadvantage of the DBMS is that it increases the risk of data security breaches.
False
Only a single attribute, not multiple attributes, can define functional dependence.
False
Referential integrity and participation are both bidirectional, meaning that they must be addressed in both directions along a relationship.
False
Relationships between entities always operate in one direction.
False
SQL is considered difficult to learn; its command set has a vocabulary of more than 300 words.
False
The DBMS guarantees that the semantic meaning of a transaction truly represents the real-world event.
False
The DBMS reveals much of the database's internal complexity to the application programs and users.
False
The SELECT operator yields a vertical subset of a table.
False
The entity relationship model (ERM) is dependent on the database type.
False
The multiuser DBMS must implement controls to ensure serializability and isolation of transactions, in addition to atomicity and durability, in order to guard the database's consistency and integrity.
False
The one-to-many (1:M) relationship is easily implemented in the relational model by putting the foreign key of the "1" side in the table of the "many" side as a primary key.
False
The order of the rows and columns is important to the DBMS.
False
The overall purpose of the database initial study is to create the conceptual design.
False
The testing and evaluation phase of the Database Life Cycle (DBLC) occurs after applications programming.
False
Triggers can only be used to update table values.
False
The entity relationship model uses the associative entity to represent a(n) _____ relationship between two or more entities. - M:N - 1:M - N:1 - M:1
M:N
_____ relationships can be implemented by creating a new entity in 1:M relationships with the original entities. - 1:1 - 1:N - M:N - M:1
M:N
Which of the following is true of NoSQL databases? - They are not based on the relational model. - They are geared toward transaction consistency rather than performance. - They do not support distributed database architectures. - They do not support very large amounts of sparse data.
They are not based on the relational model.
Which of the following is true of business rules? - They allow the designer to develop business processes. - They allow the designer to set company policies with regard to data. - They provide a framework for the company's self-actualization. - They can serve as a communication tool between the users and designers.
They can serve as a communication tool between the users and designers.
A field-level lock allows concurrent transactions to access the same row, as long as they require the use of different fields within that row.
True
A scheduler facilitates data isolation to ensure that two transactions do not update the same data element at the same time.
True
A trigger is procedural SQL code that is automatically invoked by the RDBMS upon the occurrence of a given data manipulation event.
True
A view is a virtual table based on a SELECT query.
True
All relational tables satisfy the 1NF requirements.
True
Although SQL commands can be grouped together on a single line, complex command sequences are best shown on separate lines, with space between the SQL command and the command's components.
True
An optimistic approach is based on the assumption that the majority of the database operations do not conflict.
True
Business rules must be rendered in writing.
True
Data constitutes the building blocks of information.
True
Data integrity is enforced by the database management system (DBMS) through the proper use of primary and foreign key rules.
True
Denormalization produces a lower normal form.
True
Each row in the relational table is known as an entity instance or entity occurrence in the ER model.
True
In a page-level lock, the DBMS will lock an entire diskpage.
True
In order to meet performance requirements, portions of the database design may need to be occasionally denormalized.
True
In the context of data models, an entity is a person, place, thing, or event about which data will be collected and stored.
True
In the context of partial dependencies, data redundancies occur because every row entry requires duplication of data.
True
In the detailed systems design phase of the Systems Development Life Cycle (SDLC), steps are laid out for the conversion of a database from an old system to a new system.
True
In the entity relationship model, a table row corresponds to an entity instance.
True
It is possible for a table in 2NF to exhibit transitive dependency, where the primary key may rely on one or more nonprime attributes to functionally determine other nonprime attributes.
True
Metadata describes the data characteristics and the set of relationships that links the data found within the database.
True
Normalization works through a series of stages called normal forms
True
One disadvantage of a database system over previous data management approaches is increased costs.
True
RDBMSs enforce integrity rules automatically.
True
Relational algebra defines the theoretical way of manipulating table contents using relational operators.
True
Relational models view data as part of a table or collection of tables in which all key values must be identified
True
Relational models view data as part of a table or collection of tables in which all key values must be identified.
True
String comparisons are made from left to right.
True
Systems analysis establishes the need for an information system and its extent.
True
The combination of normalization and ER modeling yields a useful ERD, whose entities can be translated into appropriate table structures.
True
The database contents might be loaded interactively or in batch mode using a variety of methods and devices including customized user programs.
True
The phenomenon of uncommitted data occurs when two transactions are executed concurrently and the first transaction is rolled back after the second transaction has already accessed the uncommitted data—thus violating the isolation property of transactions.
True
The practical significance of taking the logical view of a database is that it serves as a reminder of the simple file concept of data storage.
True
The primary objective in database design is to create complete, normalized, nonredundant, and fully integrated conceptual, logical, and physical database models.
True
An atomic attribute _____. -displays multiplicity -is always chosen to be a foreign key -cannot be further subdivided -cannot exist in a relational table
cannot be further subdivided
The first step in building an entity-relationship diagram (ERD) is _____. - developing the initial ERD - creating a detailed narrative of the organization's description of operations - identifying the attributes and primary keys that adequately describe the entities - identifying the business rules based on the description of operations
creating a detailed narrative of the organization's description of operations
In organizations that generate large number of transactions, _____ are often a top priority in database design. - relationships among entities - logical design standards - naming conventions - high processing speeds
high processing speeds
Coding, testing, and debugging are part of the _____ phase of the Systems Development Life Cycle (SDLC). -analysis -implementation -planning -detailed systems design
implementation
The existence of a(n) _____ entity indicates that its minimum cardinality is zero. - ternary - optional - strong - weak
optional
When writing SQL table-creating command sequences, the entire table definition is enclosed in _____. -quotations -parentheses -asterisks -commas
parentheses
Dependencies based on only a part of a composite primary key are known as _____ dependencies. - primary - partial - incomplete - composite
partial
"Should the existing system be replaced?" is a question that is asked during the _____ stage of the Systems Development Life Cycle (SDLC). -planning -maintenance -implementation -analysis
planning
MySQL is an example of the ______. - hierarchical model - file system data model - XML data model - relational data model
relational data model
A verb associating two nouns in a business rule translates to a(n) _____ in the data model. - relationship - entity - constraint - attribute
relationship
A relational table must not contain a(n) _____. -relationship -entity -repeating group -attribute
repeating group
A(n) ______ is a query that is embedded (or nested) inside another query. - alias - subquery - view - operator
subquery
When the specific cardinalities are not included on the diagram in Crow's Foot notation, cardinality is implied by the use of _____. - symbols - attributes - images - tables
symbols
The CREATE TABLE command lets you define constraints when you use the CONSTRAINT keyword, known as a(n) _____ constraint. -cell -table -column -index
table
