Due: Wednesday, August 19

Please upload your files to CSNS. Note that file uploading will be disabled automatically after 11:59PM of the due date, so please turn in your work on time.

1. (30pt) For a transaction T, consider the following sequence of operations performed by a DBMS:

Suppose a system crash may happen between any two operations in the sequence. Please answer the following questions:

(a) Can the DBMS recover from a system crash using Undo-only Recovery? If the answer is no, use an example to explain why.

(b) Can the DBMS recover from a system crash using Redo-only Recovery? If the answer is no, use an example to explain why.

(c) Can the DBMS recover from a system crash using Undo/Redo Recovery? Briefly explain why.

For this exercise, please put your answers in a file in TXT, PDF, DOC, or ODT format and upload it to CSNS.

2. (70pt) Implement Undo/Redo Recovery in SimpleDB, including test code to show that your implementation works correctly. For this exercise, you must submit two files:

• A zip file of the SimpleDB project. You can create the zip file using the launch file zip.launch included in the project.
• A document that describes your implementation and how to test it. This document should include a list of files that you added/modified, and a brief description of the functionality you implemented in each file. The document should also include instructions for testing your code and verifying the results.