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Question 1

The concurrent transactions T1 and T2 can take a _____ lock on the same row

Answer 1

Shared

Question 2

A schedule is serializable when ____

Answer 2

The graph is acyclic

Question 3

After a rollback, the database restart a transaction

Answer 3

Sometimes

Question 4

When a transaction deletes a table row, an ______ record is written in the log

Answer 4

update

Question 5

Deadlock can be spotted by looking for which of the following in a wait-for graph?

Answer 5

A cycle

Question 6

Would T2 get a shared lock?

Answer 6

YES

Question 7

Each of the following is a well known concurrency control problem EXCEPT

Answer 7

The redundant data problem

Question 8

During the undo phase, the recovery system writes compensation records for

Answer 8

Transactions that do not commit or roll back following the most recent checkpoint

Question 9

CHECKPOINT statement syntax is specified in the SQL standard

Answer 9

False

Question 10

In recovery techniques, _____ requires that the effects of a commited transaction be permenant so they must survive the loss of main memory loss of disk storage and failures during data transfers to disk

Answer 10

durability

Question 11

When a deadlock occurs, a cycle of dependent transactions always exist

Answer 11

True

Question 12

Transactions A and B are both serializable, and A always starts before B, the results may vary

Answer 12

False

Question 13

After all updates have been reversed in a rollback, an _____ record is written in the log

Answer 13

transaction or rollback

Question 14

After a transaction commits, the transaction can be rolled back

Answer 14

Never

Question 15

A SERIALIZABLE transaction can run concurrently with READ COMMITTED transaction

Answer 15

True

Question 16

Phases in recovery using the ARIES method includes all of the following except

Answer 16

Synthesis

Question 17

Select statements 4 transaction boundry

Answer 17

Start and end

Question 18

Several transactions can hold concurrent exclusive locks on the same row

Answer 18

False

Question 19

The privelage list of the SQL Grant statement may include all of the following except

Answer 19

REPLACE

Question 20

How many transaction rollbacks are needed to break the deadlock

Answer 20

1

Question 21

A database uses basic two phase locking. Transaction A takes a exclusive lock on X. Transaction B requests a shared lock on X. When is the shared lock granted

Answer 21

During the contract phase of A