63) A series of actions to be taken on the database such that either all actions are completed
successfully, or none of them can be completed, is known as a ________.
A) checkpoint
B) log
C) lock
D) transaction
64) When two transactions are being processed against the database at the same time ________.
A) they are called concurrent transactions
B) they are usually interleaved
C) they always result in a lost update problem
D) Both A and B are correct
65) The situation that occurs when one user’s changes to the database are lost by a second user’s
changes to the database is known as the ________.
A) lost update problem
B) deadly embrace problem
C) inconsistent read problem
D) inconsistent write problem
66) One remedy for the inconsistencies caused by concurrent processing is ________.
A) concurrency
B) checkpointing
C) rollback
D) resource locking
67) A lock placed automatically by the DBMS is called a(n) ________ lock.
A) exclusive
B) explicit
C) shared
D) implicit
68) Which of the following is not true about locks?
A) Locks with large granularity are easier for the DBMS to administer.
B) Locks with small granularity cause more conflicts.
C) Locks may have a database-level granularity.
D) Locks may have a table-level granularity.
69) Which type of lock prevents all types of access to the locked resource?
A) Exclusive lock
B) Shared lock
C) Explicit lock
D) Implicit lock
70) Which type of lock still allows other transactions to have read-only access to the locked
resource?
A) Exclusive lock
B) Shared lock
C) Explicit lock
D) Implicit lock
71) Which of the following is not true about two-phased locking?
A) Cannot obtain a new lock once a lock has been released
B) Uses only shared locks
C) Has a growing phase
D) Has a shrinking phase
72) The situation that occurs when two users are each waiting for a resource that the other person
has locked is known as a(n) ________.
A) lost update problem
B) deadlock
C) inconsistent read problem
D) checkpoint
73) Requiring all application programs to lock resources in the same order is a technique for
preventing what problem?
A) Concurrent update
B) Lost update
C) Deadlock
D) Exclusive locks
74) Locks that are placed assuming that a conflict will occur are called ________.
A) explicit locks
B) implicit locks
C) optimistic locks
D) pessimistic locks
75) Locks that are placed assuming that a conflict will not occur are called ________.
A) dynamic
B) shared
C) pessimistic
D) optimistic
76) Ensuring that all rows impacted by the actions of a transaction are protected from changes
until the entire transaction is completed is called ________.
A) statement level consistency
B) optimistic locking
C) transaction level consistency
D) durable transactions
77) When a transaction reads a row that has been changed, but the change has not been
committed, is known as a ________.
A) Clean read
B) Dirty read
C) Nonrepeatable read
D) Phantom read
78) When a transaction rereads data that has been changed and finds changes due to committed
transactions, is known as a ________.
A) Clean read
B) Dirty read
C) Nonrepeatable read
D) Phantom read
79) Which of the following is allowed by “Repeatable Read Isolation”?
A) Nonrepeatable reads
B) Dirty reads
C) Phantom reads
D) Both A and B are correct
80) Which of the following is true of forward only cursors?
A) Current values for each row are retrieved when the application accesses a row.
B) All changes of any type from any source are visible.
C) Changes made by the transaction are visible only if they occur on rows ahead of the cursor.
D) It requires the greatest overhead of any cursor type.
81) Which of the following cannot be enforced in the DBMS or application programs?
A) Processing rights
B) Security
C) Processing responsibilities
D) Cursors
E) Transaction isolation
82) Once processing rights have been defined, they may be implemented at any of these levels
except ________.
A) network
B) operating system
C) data
D) application
83) Which of the following is not true of DBMS security features?
A) Users may be assigned to one or more roles.
B) A role may be assigned to only one user.
C) Both users and roles can have many permissions.
D) Objects have many permissions.
84) Recovering a database via reprocessing involves ________.
A) restoring the database from the save and reprocessing all the transactions since the save
B) restoring the database from the save and reapplying all the changes made by transactions
since the save
C) undoing the changes made by erroneous or partially processed transactions and restarting the
valid transactions that were in process at the time of the failure
D) recreating the database by reentering all of the data from the beginning, and then reprocessing
all of the transactions
85) Recovering a database via rollforward involves ________.
A) restoring the database from the save and reprocessing all the transactions since the save
B) restoring the database from the save and reapplying all the changes made by transactions
since the save
C) undoing the changes made by erroneous or partially processed transactions and restarting the
valid transactions that were in process at the time of the failure
D) re-creating the database by re-entering all of the data from the beginning, and then
reprocessing all of the transactions
86) Recovering a database via rollback involves ________.
A) restoring the database from the save and reprocessing all the transactions since the save
B) restoring the database from the save and reapplying all the changes made by transactions
since the save
C) undoing the changes made by erroneous or partially processed transactions and restarting the
valid transactions that were in process at the time of the failure
D) re-creating the database by re-entering all of the data from the beginning and, then
reprocessing all of the transactions
87) Which of the following would not be contained in a transaction log?
A) Before images
B) Type of operation
C) Time of the action
D) Permissions
88) Which of the following would a DBA typically NOT do in managing the DBMS?
A) Analyze system performance statistics
B) Install new versions of the operating system, as needed
C) Evaluate new DBMS product features
D) Tune DBMS product options to accommodate other software in use
89) Which of the following is not true of data repositories?
A) They are usually created after the database has been implemented and optimized for
performance.
B) They may be virtual.
C) They may contain metadata about database applications.
D) They may contain metadata about users.
90) Which type of data repository is composed of metadata that is created automatically as the
system components are created?
A) Passive
B) Dynamic
C) Active
D) Automatic
91) Explain the importance of documenting changes in database structure.
92) Explain the concept of serializable transactions.
93) Briefly explain the strategy of two-phased locking.
94) Explain the concept of an atomic transaction.
95) Distinguish between statement-level consistency and transaction-level consistency.
96) Briefly define the three problems that can occur because of concurrent processing that are
addressed by resource locking.
97) Briefly define the four isolation levels and the problems they prevent.
98) Explain the process of using optimistic locking.
99) Which are more commonly used: implicit or explicit locks? Why?
100) Distinguish between the four cursor types.
101) Discuss the DBMS security model.
102) Explain the purpose of transaction logs and checkpoints.