archivelog/nonarchivelog [message #58008] |
Thu, 24 July 2003 13:31 |
Raj
Messages: 411 Registered: November 1998
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Senior Member |
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hi
i had a confusion
In nonarchivelog mode also the commited data with changes will write to the disk when a checkpoint ocurs.if it is archivelog mode it will archived when a logswitch occurs.when
a logswitch occurs there will be checkpoint so the modified data will be written to disk.
when a logfile will be overwritten.If a check point occurs the the changes will be written to datafiles.
pls hlp
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Re: archivelog/nonarchivelog [message #58024 is a reply to message #58008] |
Fri, 25 July 2003 21:21 |
Shiv
Messages: 20 Registered: May 2002
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Junior Member |
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ARCHIVE:
Lets take 2 logfiles ,
logfile 1,logfile 2:
IN archived mode irrespective of commit or rollback all the transactions are archived when the log switch occurs.
No ARCHIVE :
This does not happen in this mode , (This is the major difference).
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Re: archivelog/nonarchivelog [message #58026 is a reply to message #58024] |
Sat, 26 July 2003 04:09 |
Raj Mathur
Messages: 11 Registered: April 2002
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Junior Member |
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hi i am asking about checkpointing.IF the checkpoint occurs the changes will be permanaently stored in datafiles.when a logswitch occurs automatcially there
will be a checkpoint.so it means it will be saved
permanently to disk.i had confusion How much archivelogs will helpful compared to non archivelog.
WH
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Re: archivelog/nonarchivelog [message #58056 is a reply to message #58026] |
Tue, 29 July 2003 03:05 |
Dhiren
Messages: 43 Registered: July 2002
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Member |
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Hi
There are two modes of DATABASE
1) NOARCHIVEMODE
You are right that whenever CKPT occurs there will be auto commit so all the data will be written to datafiles.Main Thing is that if MEDIA RECOVERY is required for database then this changes will no longer usefull,u will get the DATABASE IS STATE till LAST BACKUP,this is the not case in ARCHIVE MODE.
2) ARCHIVEMOD
The database which is in archive mode will contains the all the changes that are due to CKPT,COMMIT,.....etc in archived log files so we will get the database in consistent state even is database crash.so whenever CKPT process occurs oracle will IMIPLICITY writes to datafile and redolog files from database buffer cache and log buffer cache respectively by DBWn and LGWR respectively.
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