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.