partho sarathi konar

• Oct 1st, 2006

 

Hi

  Redo Log in oracle is used to store all changes made in the database. It can contain both commited and non commited data. before changed data is written in the datafile, it is recorded in the redo log. so commited data is never lost in oracle as when the user commits a transaction it is been stored in the log files. So in case of media failure the data is always preserved in the log files.

thanks

partho.

satyam_Ora

 Profile Answers by satyam_Ora Questions by satyam_Ora

• May 21st, 2008

 

Oracle maintains logs of all transactions against the databse. These transactions are recorded in files called Online Redo log files.These logs are used to recover the database's transaction in their proper order in the evnt of database crash. The redo log information is stored in Redo log file which is external to the datafilesEach database have two or more online redo log files. oracle writes tedo log file in cyclic order after the first log is filled , it writes to the second log files, until that one is filled. whn all of the online redo log file have been filled it move to the first online redo log file and start overwriting the transaction recordNote : if the Databse is in ARCHIVE log mode then database will make the copy of the redo log file before overwriting the contents of the log file..These ARCHIEVED redo log file can then be used to recover any part of the database to any point of time.

rohitmisri

 Profile Answers by rohitmisri 

• Jun 17th, 2010

 

Hi,

Redo log information is the one of the major pard of the database , at any time if the oracle server instance get aborted and then it need recovery, so at that time redo log plays a role to recover the instance

Redo Buffer cahche a componenet of sga stores all the change and unchanged data or we can say all dirty blocks and it works on Lifo and Fifio concept once the blocks of buffer cahce gets full after every 3 seconds at that time LGwn ( a background procecss) comes in a picture and writes all blocks to online redo log member

and this online redolog memeber has the information to perform instance recovery

Dinesh Chandra

• Aug 27th, 2012

 

Redo log records the changes made in database. Redo logs is mainly used to recover data.