16. Enforcing serializability in concurrent schedules ensures which two of the four desired properties for transactions? (a) Atomicity and consistency (b) Atomicity and isolation (c) Atomicity and durability (d) Consistency and isolation (e) Consistency and durability (f) Isolation and durability 17. The recovery manager ensures which two of the four desired properties for transactions? (a) Atomicity and consistency (b) Atomicity and isolation (c) Atomicity and durability (d) Consistency and isolation (e) Consistency and durability (f) Isolation and durability 18. Suppose a database is read-only-no transactions change any data in the database. If serializability must be supported, which of the following is true? (a) No locking is necessary. (b) Only read locks are necessary and they need to be held until end of transaction. (c) Only read locks are necessary, but they can be released as soon as the read is complete. (d) Both read and write locks are necessary and locking must be done in two phases. (e) None of the above. 19. Checkpointing is a technique that can reduce recovery time after a crash. Which of the following is true? (a) When recovering, the log only needs to be scanned back to the most recent checkpoint. (b) Checkpointing is automatically performed after every transaction commit. (c) Checkpoints are saved after every update to the database. (d) a and c (e) a, b, and c 20. Which of the following is true about updated pages in the buffer pool? (a) Updated pages must be written immediately after the update. (b) Updated pages must be written after a transaction commits but before the transaction log is written to disk. (c) Updated pages must be written after a transaction commits but after the transaction log is written to disk. (d) An updated page must be written when it is swapped out of the buffer pool.
16. Enforcing serializability in concurrent schedules ensures which two of the four desired properties for transactions? (a) Atomicity and consistency (b) Atomicity and isolation (c) Atomicity and durability (d) Consistency and isolation (e) Consistency and durability (f) Isolation and durability 17. The recovery manager ensures which two of the four desired properties for transactions? (a) Atomicity and consistency (b) Atomicity and isolation (c) Atomicity and durability (d) Consistency and isolation (e) Consistency and durability (f) Isolation and durability 18. Suppose a database is read-only-no transactions change any data in the database. If serializability must be supported, which of the following is true? (a) No locking is necessary. (b) Only read locks are necessary and they need to be held until end of transaction. (c) Only read locks are necessary, but they can be released as soon as the read is complete. (d) Both read and write locks are necessary and locking must be done in two phases. (e) None of the above. 19. Checkpointing is a technique that can reduce recovery time after a crash. Which of the following is true? (a) When recovering, the log only needs to be scanned back to the most recent checkpoint. (b) Checkpointing is automatically performed after every transaction commit. (c) Checkpoints are saved after every update to the database. (d) a and c (e) a, b, and c 20. Which of the following is true about updated pages in the buffer pool? (a) Updated pages must be written immediately after the update. (b) Updated pages must be written after a transaction commits but before the transaction log is written to disk. (c) Updated pages must be written after a transaction commits but after the transaction log is written to disk. (d) An updated page must be written when it is swapped out of the buffer pool.
Database System Concepts
7th Edition
ISBN:9780078022159
Author:Abraham Silberschatz Professor, Henry F. Korth, S. Sudarshan
Publisher:Abraham Silberschatz Professor, Henry F. Korth, S. Sudarshan
Chapter1: Introduction
Section: Chapter Questions
Problem 1PE
Related questions
Question
Transcribed Image Text:16. Enforcing serializability in concurrent schedules ensures which two of the four desired properties for
transactions?
(a) Atomicity and consistency
(b) Atomicity and isolation
(c) Atomicity and durability
(d) Consistency and isolation.
(e) Consistency and durability
(f) Isolation and durability
17. The recovery manager ensures which two of the four desired properties for transactions?
(a) Atomicity and consistency
(b) Atomicity and isolation
(c) Atomicity and durability
(d) Consistency and isolation
(e) Consistency and durability
(f) Isolation and durability
18. Suppose a database is read-only-no transactions change any data in the database. If serializability
must be supported, which of the following is true?
(a) No locking is necessary.
(b) Only read locks are necessary and they need to be held until end of transaction.
(c) Only read locks are necessary, but they can be released as soon as the read is complete.
(d) Both read and write locks are necessary and locking must be done in two phases.
(e) None of the above.
19. Checkpointing is a technique that can reduce recovery time after a crash. Which of the following is
true?
(a) When recovering, the log only needs to be scanned back to the most recent checkpoint.
(b) Checkpointing is automatically performed after every transaction commit.
(c) Checkpoints are saved after every update to the database.
(d) a and c
(e) a, b, and c
20. Which of the following is true about updated pages in the buffer pool?
(a) Updated pages must be written immediately after the update.
(b) Updated pages must be written after a transaction commits but before the transaction log is
written to disk.
(c) Updated pages must be written after a transaction commits but after the transaction log is written
to disk.
(d) An updated page must be written when it is swapped out of the buffer pool.
Expert Solution
This question has been solved!
Explore an expertly crafted, step-by-step solution for a thorough understanding of key concepts.
This is a popular solution!
Trending now
This is a popular solution!
Step by step
Solved in 4 steps
Knowledge Booster
Learn more about
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, computer-science and related others by exploring similar questions and additional content below.Recommended textbooks for you
Database System Concepts
Computer Science
ISBN:
9780078022159
Author:
Abraham Silberschatz Professor, Henry F. Korth, S. Sudarshan
Publisher:
McGraw-Hill Education
Starting Out with Python (4th Edition)
Computer Science
ISBN:
9780134444321
Author:
Tony Gaddis
Publisher:
PEARSON
Digital Fundamentals (11th Edition)
Computer Science
ISBN:
9780132737968
Author:
Thomas L. Floyd
Publisher:
PEARSON
Database System Concepts
Computer Science
ISBN:
9780078022159
Author:
Abraham Silberschatz Professor, Henry F. Korth, S. Sudarshan
Publisher:
McGraw-Hill Education
Starting Out with Python (4th Edition)
Computer Science
ISBN:
9780134444321
Author:
Tony Gaddis
Publisher:
PEARSON
Digital Fundamentals (11th Edition)
Computer Science
ISBN:
9780132737968
Author:
Thomas L. Floyd
Publisher:
PEARSON
C How to Program (8th Edition)
Computer Science
ISBN:
9780133976892
Author:
Paul J. Deitel, Harvey Deitel
Publisher:
PEARSON
Database Systems: Design, Implementation, & Manag…
Computer Science
ISBN:
9781337627900
Author:
Carlos Coronel, Steven Morris
Publisher:
Cengage Learning
Programmable Logic Controllers
Computer Science
ISBN:
9780073373843
Author:
Frank D. Petruzella
Publisher:
McGraw-Hill Education