Database chapter 8
A data management platform service is called:
Database-as-a-service.
A database management system needs to provide only three basic facilities for backup and recovery of a database: backup facilities, journalizing facilities, and a recovery manager.
False
A default value is the value that a field will always assume, regardless of what the user enters for an instance of that field.
False
A key is a data structure used to determine the location of rows in a file that satisfy some condition.
False
ACID support for database-as-a-service is easily provided in a cloud computing environment.
False
Adding notations to the EER diagram regarding data volumes and usage is of no value to the physical design process.
False
An extent is a named portion of secondary memory allocated for the purpose of storing physical records.
False
Backward recovery starts with an earlier copy of the database.
False
Database applications are not very disk intensive.
False
Free range partitioning is a type of horizontal partitioning in which each partition is defined by a range of values for one or more columns in the normalized table.
False
Horizontal partitioning is very different from creating a supertype/subtype relationship.
False
In order to perform a restore/rerun, the database must be mirrored.
False
Indexes are most useful on small, clustered files.
False
One method to handle missing values is to substitute an exact value.
False
Reduced uptime is a disadvantage of partitioning.
False
SOX stands for the Sorbet-Oxford Act.
False
The query processor always knows the best way to process a query.
False
The record log is a record of the essential data for each transaction that has been processed against the database.
False
The smallest unit of named application data is a record.
False
There are two principal types of authorization tables: one for subjects and one for facts.
False
Using an index for attributes referenced in ORDER BY and GROUP BY clauses has no significant impact upon database performance.
False
In which data model would a code table appear?
Physical
________ is used to undo unwanted database changes.
Rollback
Which type of file is most efficient with storage space?
Sequential
Which of the following is a principal type of authorization table?
Subject
A trigger can be used as a security measure in which of the following ways?
To cause special handling procedures to be executed
A business transaction is a sequence of steps that constitute some well-defined business activity
True
A hashing algorithm is a routine that converts a primary key value into a relative record address.
True
A pointer is a field of data that can be used to locate a related field or record of data.
True
A range control limits the set of permissible values that a field may assume.
True
A trigger can be used for security purposes to prohibit inappropriate actions, such as changing a salary value outside of a business day
True
A view can be built to present only the data to which a user requires access.
True
Along with table scans, other elements of a query can be processed in parallel.
True
An audit trail of transactions and database changes is kept by a journalizing facility.
True
Broad network access is a characteristic of cloud computing.
True
Efficient database structures will be beneficial only if queries and the underlying database management system are tuned to properly use the structures.
True
Fast data retrieval is one factor to consider when choosing a file organization for a particular database file.
True
Hash partitioning spreads data evenly across partitions independent of any partition key value.
True
In a sequential file, the records are stored in sequence according to a primary key value.
True
Keeping the zip code with the city and state in a table is a typical form of denormalization.
True
Live migration from one environment to another in cloud computing is a challenge.
True
One decision in the physical design process is selecting structures.
True
With a one-key encryption standard, both the sender and the receiver need to know the key that is used to scramble the transmitted or stored data.
True
________ partitioning distributes the columns of a table into several separate physical records.
Vertical
The preferred method of fixing an aborted transaction is:
backing out the transaction.
Sensitivity testing involves:
checking to see if missing data will greatly impact results.
The storage format for each attribute from the logical data model is chosen to maximize ________ and minimize storage space.
data integrity
A form of denormalization where the same data are purposely stored in multiple places in the database is called:
data replication.
With ________, the database itself is lost, destroyed, or cannot be read.
database destruction
A contiguous section of disk storage space is called a(n):
extent.
A disadvantage of partitioning is:
extra space and update time.
The smallest unit of application data recognized by system software is a:
field.
A file organization where files are not stored in any particular order is considered a:
heap file organization.
An index on columns from two or more tables that come from the same domain of values is called a:
join index.
A requirement to begin designing physical files and databases is:
normalized relations.
While Oracle has responsibility for managing data inside a tablespace, the tablespace, as a whole, is managed by the:
operating system.
A method that speeds query processing by running a query at the same time against several partitions of a table using multiprocessors is called:
parallel query processing.
A discrete unit of work that must be processed completely or not at all within a computer system is called a:
transaction.
Forward recovery is faster than restore/rerun because:
transactions do not have to be repeated.
All of the following are characteristics of cloud technologies EXCEPT:
unlimited bandwidth.