Explaination

[Diggers12]

Hello,

can someone help me with the explaination of what the section of script below is doing?

sql 'alter system archive log current';
backup
format 'c:\temp\al_t%t_s%s_p%p'
archivelog all
delete input;

Thanks

[kgb]

Archive current log, Archive archived redo logs result goes in one file with unique name then delete archived redo logs.
Best wishes.

[Diggers12]

OK,

so if I then loose the redo logfile from the hard disk how do I recreate the file?

Thanks

[kgb]

run {
allocate channel ch1 type disk;
resore archivelog all;
}

[Diggers12]

This recovers the archievelog but what about the redo log files?

Thanks

[kgb]

It is the same,
'archivelog' = 'archived redo logs' it is almost the same as 'redo log'

[Diggers12]

I know but I have physically deleted one of the online redo logs to see how I recover from that and I get the following after restoreing the database :

SVRMGR> STARTUP;
ORACLE instance started.
Total System Global Area 73242652 bytes
Fixed Size 75804 bytes
Variable Size 20631552 bytes
Database Buffers 52428800 bytes
Redo Buffers 106496 bytes
Database mounted.
ORA-00313: open failed for members of log group 1 of thread 1
ORA-00312: online log 1 thread 1: 'F:\ORACLE\ORA817\DATABASE\LOGPICIS1A.ORA'

The LOGPICIS1A.ORA is the redo log.

[kgb]

You shoud not delete online redo logs. I told about archived redo logs.
You should delete info from the db about your log member and add new member to log group.

[Diggers12]

Ok what I am doing is creating different senarios and trying to recover from them, but this one is tricky. I had assumed that you could rebulid the redo logs somehow after said a hard disk failure. Is this not possible? What do you do if you loose the online redo logs?

[kgb]

It is possible rebuild online redo logs if you have lost them. Just recriate them. If I lose one online redo log from log group - I have another member on another HD, I hope 2 HD cant crush in the same time. So I just copy or rename log member.