Chapter 8 Quiz

All of the following are valid datatypes in Oracle 12c EXCEPT: VARCHAR2. BOOLEAN. NUMBER. BLOB.

BOOLEAN.

Denormalization is the process of transforming relations with variable-length fields into those with fixed-length fields.

False

T/ F: 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

T/ F: Database applications are not very disk intensive.

False

T/ F: 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

T/ F: The Number datatype would be appropriate for a zip code.

False

T/ F: There are two principal types of authorization tables: one for subjects and one for facts.

False

T/ F: Horizontal partitioning is very different from creating a supertype/subtype relationship.

False

Which type of file is easiest to update? Indexed Clustered Hashed Sequential

Hashed

Which of the following is an objective of selecting a data type? Represent a small number of possible values Limit security Improve data integrity Maximize storage space

Improve data integrity

________ is used to undo unwanted database changes. Rollforward Encryption Rollback Restart

Rollback

Hash partitioning spreads data evenly across partitions independent of any partition key value.

True

T/ F: A typical cause of database destruction is a disk crash.

True

T/ F: Along with table scans, other elements of a query can be processed in parallel.

True

T/ F: Broad network access is a characteristic of cloud computing.

True

T/F: A hashing algorithm is a routine that converts a primary key value into a relative record address.

True

T/F: A view can be built to present only the data to which a user requires access.

True

All of the following are common denormalization opportunities EXCEPT: two entities with a one-to-one relationship. a many-to-many relationship with nonkey attributes. a one-to-many relationship. reference data.

a one-to-many relationship.

A method that speeds query processing by running a query at the same time against several partitions of a table using multiprocessors is called: perpendicular query processing. multiple partition queries. parallel query processing. query optimization.

parallel query processing.

Database access frequencies are estimated from: random number generation. user logins. security violations. transaction volumes.

transaction volumes.

Forward recovery is faster than restore/rerun because: transactions do not have to be repeated. images are mirrored. security can be avoided. systems are more complete.

transactions do not have to be repeated.