By Francisco Munoz Alvarez REDUCING REDO GENERATION TIPS While Backing Up As mentioned in the redo generation and recoverability section, user managed backups could generate a lot of redo. The best way to eliminate this problem is to use RMAN. RMAN does not need to write the entire block to redo because it knows when…
LOGGING or NOLOGGING, that is the question – Part IV
By Francisco Munoz Alvarez Disabling Redo Generation (NOLOGGING) The NOLOGGING attribute tells the Oracle that the operation being performed does not need to be recoverable in the event of a failure. In this case Oracle will generate a minimal number of redo log entries in order to protect the data dictionary, and the operation will…
NZOUG 2008 National Conference
I’m pleased to confirm that my paper ” Logging or Nologging: That is the Question!” submitted to the New Zealand OUG National conference 2008 was accepted. See you at: October,20 and 21 – NZOUG National Conference at Rotorua, NZ For more information, please refer to NZOUG Website . Cheers, Francisco Munoz Alvarez
Oracle ACE
It’s an honor for me, to announce that I have been awarded with the Oracle ACE Award. I’m now the first Oracle Professional in New Zealand and Chile to receive this award. This award is not only for me, is for all the Professionals around the world that are constantly helping me to develop my Oracle knowledge…
LOGGING or NOLOGGING, that is the question – Part III
By Francisco Munoz Alvarez Important points about LOGGING and NOLOGGING Despite the importance of the redo entries, Oracle gave users the ability to limit redo generation on tables and indexes by setting them in NOLOGGING mode. NOLOGGING affect the recoverability. Before going into how to limit the redo generation, it is important to clear…
Australia 2008 National Conference Series
I’m pleased to confirm that my paper ” Logging or Nologging: That is the Question!” submitted to the Perth and Gold Coast conferences was accepted. See you at: October,6 and 7 – AUSOUG National Conference Series at Perth, AU October,13 and 14 – AUSOUG National Conference Series at Gold Coast, Conrad Jupiters, AU For more…
What I need to know to become a DBA?
About the DBA job: Most of the people that I talk to who have difficulties starting out in their DBA career really have an issue trying to absorb the mountainous volumes of information that a DBA needs to know. After all, System Administrators make a whole career out of learning the ins and outs of…
LOGGING or NOLOGGING, that is the question – Part II
By Francisco Munoz Alvarez Redo Generation and Recoverability The purpose of redo generation is to ensure recoverability. This is the reason why, Oracle does not give the DBA a lot of control over redo generation. If the instance crashes, then all the changes within SGA will be lost. Oracle will then use the redo…
LOGGING or NOLOGGING, that is the question – Part I
By Francisco Munoz Alvarez Introduction The main question about NOLOGGING I hear all the time is: does creating a table with the NOLOGGING option means there is “no generation of redo ever”, or just that the initial creation operation has no redo generation, but that DML down the road generates redo? How and when can…
Differences between UNDO and REDO
To clear this question we have this table: UNDO REDO Record of How to undo a change How to reproduce a change Used for Rollback, Read-Consistency Rolling forward DB Changes Stored in Undo segments Redo log files Protect Against Inconsistent reads in multiuser systems Data loss UNDO Undo tablespaces are special tablespaces used solely for…