CPSC6620 Final Practice Questions

Which property of the CAP theorem assumes that all transaction operations take place at the same time in all nodes, as if they were executing in a single-node database?

Consistency

_____ security breaches include database access by computer viruses and by hackers whose actions are designed to destroy or alter data.

Corrupting

A passive data dictionary is one that is updated automatically with every database access to keep its access information up to date. T/F

False

A system maintenance activity generated in response to changes in the business environment is referred to as corrective maintenance.T/F

False

A weak relationship exists if the primary key of the related entity contains at least one primary key component of the parent entity.T/F

False

_____ fragmentation refers to the division of a relation into subsets of tuples.

Horizontal

All relational tables satisfy the 1NF requirements.T/F

True

The completeness constraint can be partial or total.T/F

True

The only way to access the data in a database is through the DBMS.T/F

True

The attribute hierarchy provides a top-down data organization that is used for two main purposes: _____ and drill-down/roll-up data analysis.

aggregation

Distributed processing does not require:

an existing distributed database.

Big Data ______.

captures data in whatever format it naturally exists

A(n) _____ is optimized for decision support and is generally represented by a data warehouse or a data mart.

data store

Decision support data tends to be non-normalized, _____, and pre-aggregated.

duplicated

During the ____ phase, the DBMS retrieves the data and sends the result set back to the client.

fetch

In standard SQL, the optimizer hint FIRST_ROWS is generally used for _____ mode processes.

interactive

A disadvantage of a distributed database management system (DDBMS) is:

lack of standards.

Improving _____ leads to more flexible queries.

normalization

The reliance on _____ as the design methodology for relational databases is seen as a stumbling block to its use in OLAP systems.

normalization

In the optimistic approach, during the_____ phase, a transaction scans the database, executes the needed computations, and makes the updates to a private copy of the database values.

read

The _____ cache is used as a temporary storage area for ORDER BY or GROUP BY operations, as well as for index-creation functions.

sort

"A password must have a minimum of five characters" is an example of a _____.

standard

The information stored in the _____ is used by the DBMS for a recovery requirement triggered by a ROLLBACK statement, a program's abnormal termination, or a system failure such as a network discrepancy or a disk crash.

transaction log

At the implementation level, the supertype and its subtype(s) depicted in a specialization hierarchy maintain a(n) _____ relationship.

1:1

The _____ relationship should be rare in any relational database design.

1:1

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 _____.

1NF

_____ deals with ensuring that data is protected against unauthorized access, and if the data are accessed by an authorized user, that the data are used only for an authorized purpose.

Confidentiality

_____ fragmentation allows a user to break a single object into two or more segments, or fragments.

Data

_____ is a relational set operator.

EXCEPT

An alias cannot be used when a table is required to be joined to itself in a recursive query.T/F

False

Normalization is a process that is used for changing attributes to entities.T/F

False

Normalizing fact tables improves data access performance and saves data storage space.T/F

False

Structural dependence exists when it is possible to make changes in the file structure without affecting the application program's ability to access the data.T/F

False

The external model is the representation of the database as "seen" by the DBMS.T/F

False

If a designer wishes to create an inner join, but the two tables do not have a commonly named attribute, he can use a(n) _____ clause.

JOIN ON

_____ transparency allows the system to operate as if it were a centralized database management system.

Performance

_____ is the central activity during the parsing phase in query processing.

Query optimization

_____ are more detailed and specific than policies and describe the minimum requirements of a given DBA activity.

Standards

Which of the following is a specialization hierarchy disjoint constraint scenario in case of partial completeness?

Subtype discriminator can be null.

Which is a feature of a correlated subquery?

The outer subquery initiates the process of execution in a subquery.

_____ transparency allows data to be updated simultaneously at several network sites.

Transaction

What rule applies to the two-phase locking protocol?

Two transactions cannot have conflicting lock.

Which of the following is polyglot persistence?

Uses multiple data storage technologies

The tables on which a view, or a virtual table derived from a SELECT query, are based are called _____ tables.

base

A _____ attribute can be further subdivided to yield additional attributes.

composite

The entity relationship diagram (ERD) represents the _____ database as viewed by the end user.

conceptual

When introducing a database into an organization, the database approach creates a more controlled and structured information flow and thus affects people, functions, and interactions. This leads to a(n) _____ impact of the new database system.

cultural

The _____ schema must support complex (non-normalized) data representations.

decision support database

The basic star schema has four components: facts, _____, attributes, and attribute hierarchies.

dimensions

A diskpage, or page, is the equivalent of a _____.

diskblock

In a star schema, attributes are often used to search, filter, or classify _____.

facts

If there is no index, the DBMS will perform a _____ scan.

full table

From the performance point of view, _____ databases eliminate disk access bottlenecks.

in-memory

The _____ manager is responsible for assigning and policing the locks used by transactions.

lock

Coordinating, monitoring, and allocating database administration resources is included in a DBA's _____ role.

managerial

The _____ rule requires that all copies of data fragments be identical.

mutual consistency

In the wait/die scheme, the:

older transaction waits for the younger one to complete and release its locks.

When performing user access management, a DBA defines each user to the database at the _____ levels.

operating system and DBMS

An attribute that is part of a key is known as a(n) _____ attribute.

prime

A _____ lets a single SQL statement access the data that are to be processed by a single remote database processor.

remote request

The SQL data manipulation command HAVING:

restricts the selection of grouped rows based on a condition.

A(n) _____ phase in a two phase lock is when a transaction releases all locks and cannot obtain a new lock.

shrinking

The implicit beginning of a transaction is when _____.

the first SQL statement is encountered

The _____ approach to scheduling concurrent transactions assigns a global unique stamp to each transaction.

time stamping

A distributed _____ can reference several different local or remote data processing sites.

transaction

Operational data are commonly stored in many tables, and the stored data represents information about a given _____ only.

transaction

In the context of Big Data, ______ relates to changes in meaning.

variability