Homework assignment #2
CS 643, Spring 2002
Due: Wednesday, Feb. 20, 2002
Total points: 100

In class, You're asked to perform the following backup/recovery tasks:

1. Fill each table with several records.
2. Export an entire database to the file dba.dmp with all GRANTS and all data.
3. Drop one table from the database and import from the file dba.dmp to recover.
4. Use Export/Import to copy two tables belonging to the default user scott to a different user of the database. 
5. Identify the datafiles, control files, and online redo log files for one tablespace of your choice. 
6. Make sure the database is running in NOARCHIVELOG mode. Delete one datafile and perform recovery.
7. Run the database in ARCHIVELOG mode. Perform offline tablespace backup. Delete one datafile and perform recovery.
8. Run the database in ARCHIVELOG mode. Perform backup for an online read/write tablespace. Delete one datafile and perform recovery.

For the homework assignment, you're asked to answer the following questions. It is very important that you use concrete examples to illustrate the concepts.

1. What would you consider as a backup? Explain the similarities and difference between logical and physical backups.
2. Discuss the relationship between restore and recovery.
3. Define media failure. Give an example media failure and explain the backup/recovery procedure that can be used to minimize the impact of such failure.
4. Discuss the relationship between online redo log and archive redo log. Explain their roles in backup/recovery in the case of a media failure.
5. List two items in control file that are crucial in recovery of a media failure. Explain how those two pieces of information be used.
6. List the facilities that a DBMS has to support in order to assist recovery (section 19.3.3). For each facility, indicate how it is supported by Oracle or SQL Server.