سؤال :Write the steps you would perform to recover your database

Question I
Edward uses an Oracle Database to maintain the inventory of his grocery store. Once every week, he runs a batch job to insert, update and delete data in his database. He uses a Windows machine running Oracle 9i R2. Edward starts the database up in the morning at 8 A.M., and shuts it down at 5 P.M., and operates the database all day in NOARCHIVELOG mode. He takes an offline backup (cold backup) of the database once a week, or every Sunday by copying all the datafiles, log files and control files to tape.

I.1. On a Wednesday morning, Edward realized that he had lost a datafile that contained all the user data. He tried to start up the database using the STARTUP OPEN command got the following error
ORA-01157 :cannot identify datafile 4 – file not found
ORA-01110: datafile 4 :’………………………/users01.dbf’
He realized that he had accidentally deleted one of the datafiles while trying to free some space on the disk.
a) How would he resolve this problem ?
How much data would you lose ?
c) Write down the steps you would perform to recover your database

I.2. Same as I.1 but the data file belonged to a temporary tablespace.
ORA-01157 :cannot identify data file 6 – file not found
ORA-01110 :datafile 6 : ‘…………………………./temp.dbf’
a) How would he resolve this problem ?
How much data would you lose ?
c) Write down the steps you would perform to recover your database