Top 1000+ Solved DataBase Management System (DBMS) MCQ Questions Answer
Q. If a node is locked in the subtree rooted by that node is locked explicitly in shared mode, and that explicit locking is being done at a lower level with exclusive-mode locks.
a. intention lock modes
b. shared and intention-exclusive (six) mode
c. intention-exclusive (ix) mode
d. intention-shared (is) mode
Q. denotes the largest timestamp of any transaction that executed write(Q) successfully.
a. w-timestamp(q)
b. r-timestamp(q)
c. rw-timestamp(q)
d. wr-timestamp(q)
Q. The most recent version of standard SQL prescribed by the American National Standards Institute is
a. sql 2016
b. sql 2002
c. sql – 4
d. sql2
Q. A lock that prevents the use of any tables in the database from one transaction while another transaction is being processed is called a
a. database-level lock
b. table-level lock
c. page-level lock
d. row-level lock
Q. A condition that occurs when two transactions wait for each other to unlock data is known as a(n)
a. shared lock
b. exclusive lock
c. binary lock
d. deadlock
Q. The extent of the database resource that is included with each lock is called the level of
a. impact
b. granularity
c. management
d. dbms control
Q. Snapshot isolation is used to give
a. transaction a snapshot of the database
b. database a snapshot of the transaction
c. database a snapshot of committed values in the transaction
d. transaction a snapshot of the database and database a snapshot of committed values in the transaction
Q. Each of a pair of transactions has read data that is written by the other, but there is no data written by both transactions, is referred to as
a. read skew
b. update skew
c. write lock
d. none of the mentioned
Q. Which statements are correct regarding indexes?
a. when a table is dropped, the corresponding indexes are automatically dropped
b. for each dml operation performed, the corresponding indexes are automatically updated
c. a non-deferrable primary key or unique key constraint in a table automatically creates a unique index
d. all of the mentioned
Q. Which statement is true regarding synonyms?
a. synonyms can be created for tables but not views
b. synonyms are used to reference only those tables that are owned by another user
c. a public synonym and a private synonym can exist with the same name for the same table
d. the drop synonym statement removes the synonym, and the status of the table on which the synonym has been created becomes invalid
Q. The method of access that uses key transformation is called as
a. direct
b. hash
c. random
d. sequential
Q. Why do we need concurrency control on B+ trees ?
a. to remove the unwanted data
b. to easily add the index elements
c. to maintain accuracy of index
d. all of the mentioned
Q. How many techniques are available to control concurrency on B+ trees?
a. one
b. three
c. four
d. none of the mentioned
Q. In crabbing protocol locking
a. goes down the tree and back up
b. goes up the tree and back down
c. goes down the tree and releases
d. goes up the tree and releases