Backup Files Staus in archive log mode

[amolik]

Hello

Currently I have 3 destinations supplied for backup in init.ora file in my Windows NT Oracle Machine. When I explore thru the files I found that the sizes of files are very much different. At present I am just running a trial database where very few data entry activity is going on and my archivemode and automatic archival are properly set. In my all three destinations the files having same names are of same size. But the size of Arc00304.001 is much much less than Arc00306.001 which is created next day only while file Arc00305.001 is less than first which was also on next day only. Files created on next few days by the system are also varying in the size.
Can Anyone please explain what is the status there in these archive files ? Are these files are backup of only control files ? DO these Files I have to keep or old files has to be deleted?
Does these file backs up only data currently entered in the day or the old data as well in the tables ?
Which of these files will be required to store on the outside disks in case of disk or system crash. There are also 2 winzip files with .ARC extensions created for last two days Do I need to back them up as well ? What does these winzip file contain ?
Do I have to run the tablespace backup every day or any specific interval for datafiles ?

Thanks in Advance
Amol

[SANJAY_G]

What do you mean by three backup destination? What is the parameter_name for this in init.ora? Is it log_archive_dest ?

I am assuming that the *.ARC are archived redo log files. If they are archived redo logs then it may not be of same sizes. Because there are several events (hotbackup scripts etc) that may switch redo logfile or it can be switched manually by issuing command "alter system switch logfile"

These files are not backup of control files but are backup of redo log files that you will need in case of database recovery.

You need to define your backup strategy considering several factors like...
1. OLTP or DSS
2. Downtime availablity
3. how imortant is PIT recovery
and few more.

Hope this helps.

Sanjay