AND MANAGEMENT EXAMINATION TEST 2026
FULL SOLUTION SET GUARANTEED PASS
◉ database request. Answer: The equivalent of a single SQL statement
in an application program or a transaction.
◉ Atomicity. Answer: The transaction property that requires all parts of
a transaction to be treated as a single, indivisible, logical unit of work.
All parts of a transaction must be completed, or the entire transaction is
aborted.
◉ Consistency. Answer: A database condition in which all data integrity
constraints are satisfied. To ensure consistency of a database, every
transaction must begin with the database in a known consistent state.
◉ Isolation. Answer: A database transaction property in which a data
item used by one transaction is not available to other transactions until
the first one ends.
◉ Durability. Answer: The transaction property that ensures that once
transaction changes are done and committed, they cannot be undone or
lost, even in the event of a system failure.
,◉ Serializability. Answer: A property in which the selected order of
concurrent transaction operations creates the same final database state
that would have been produced if the transactions had been executed in a
serial fashion.
◉ transaction log. Answer: A feature used by the DBMS to keep track of
all transaction operations that update the database. The information
stored in this log is used by the DBMS for recovery purposes.
◉ lost update. Answer: A concurrency control problem in which a data
update is lost during the concurrent execution of transactions.
◉ uncommitted data. Answer: A concurrency control problem in which a
transaction accesses uncommitted data from another transaction.
◉ Inconsistent retrievals. Answer: A concurrency control problem that
arises when a transaction calculating summary (aggregate) functions
over a set of data while other transactions are updating the data, yielding
erroneous results.
◉ Scheduler. Answer: The DBMS component that establishes the order
in which concurrent transaction operations are executed.
,◉ serializable schedule. Answer: In transaction management, a schedule
of operations in which the interleaved execution of the transactions
yields the same result as if they were executed in serial order.
◉ Lock. Answer: A device that guarantees unique use of a data item in a
particular transaction operation.
◉ pessimistic locking. Answer: The use of locks based on the
assumption that conflict between transactions is likely.
◉ lock manager. Answer: A DBMS component that is responsible for
assigning and releasing locks.
◉ lock granularity. Answer: The level of lock use. Locking can take
place at the following levels: database, table, page, row, and field
(attribute).
◉ database-level lock. Answer: A type of lock that restricts database
access to the owner of the lock and allows only one user at a time to
access the database. This lock works for batch processes but is
unsuitable for online multiuser DBMSs.
◉ table-level lock. Answer: A locking scheme that allows only one
transaction at a time to access a table. A table-level lock locks an entire
, table, preventing access to any row by transaction T2 while transaction
T1 is using the table.
◉ page-level lock. Answer: In this type of lock, the database
management system locks an entire diskpage, or section of a disk. A
diskpage can contain data for one or more rows and from one or more
tables.
◉ diskpage (page). Answer: In permanent storage, the equivalent of a
disk block, which can be described as a directly addressable section of a
disk. A diskpage has a fixed size, such as 4K, 8K, or 16K.
◉ row-level lock. Answer: A less restrictive database lock in which the
DBMS allows concurrent transactions to access different rows of the
same table, even when the rows are on the same page.
◉ field-level lock. Answer: A lock that allows concurrent transactions to
access the same row as long as they require the use of different fields
(attributes) within that row. This type of lock yields the most flexible
multiuser data access but requires a high level of computer overhead.
◉ binary lock. Answer: A lock that has only two states: locked (1) and
unlocked (0). If a data item is locked by a transaction, no other
transaction can use that data item.