Redolog, log group

[Former Member]

Hi experts,

Can any one let me know in detail what is REDOLOG, LOG GROUP, CHECK POINT in DB. How does it works

Regards!!

[Former Member · Accepted solution]

Hi,

Check out the link below which will give sufficient documents on the same.

http://www.adp-gmbh.ch/ora/concepts/online_redo_logs.html

Rgds

Radhakrishna D S

[Former Member]

Hi Syed,

REDOLOG - when database transaction will happen then datawill be written to databuffer and the log for the database changes will be written logbuffer.Then data will be written to datafile and the the log will be written to logfile that is called redolog or online redolog file.

LOG GROUP - log group will combination of one original online redolog file and it's mirror copy.There can be more no of groups.

CHECK POINT in DB- check point will happen when the log writer will finish writing the logs from current active redolog and start writing to the next available log file.

Regards

Ashok

[Former Member]

Hi Ashok,

Thanks for the details - can u let me know how it works in SAP.

Actually we are getting message in Database Check as " BR0976W Database message alert - level: WARNING, line: 1952317, time: 2008-09-18 15.16.48, message:

Checkpoint not complete " and when i searched notes, it says me to increase the size of redologs.

Thanks & Regards!!

[Former Member]

Hi Syed,

You keep monitoring it.If happening regularly then take action unless you can ignore it.Normally this may have happened for one time heavy database update.

Regards

Ashok

[Former Member]

Hi Ashok,

It happens frequently in our Production server.

Yesterday i have changed the threshold value.

Again today the same problem arised.

Regards!!