2 Shares 1K Share Facebook 1K Share Twitter 1K Share LinkedIn 1K Share Facebook Messenger 2 Share WhatsApp 1K Share Email What is redo? Let’s look briefly at the redo process. When Oracle blocks (the smallest unit of storage in a database) are changed, including UNDO blocks, Oracle records the changes in vector changes, which…
Category: Redo Logs
Back-to-Basics: Understanding Backup and Recovery plus High Availability(Part I)
3 Shares 1K Share Facebook 1K Share Twitter 1 Share LinkedIn 1K Share Facebook Messenger 2 Share WhatsApp 1K Share Email The constant evolution of IT has, among other things, affected the role of a database administrator (DBA). Today the DBA is not merely a Database Administrator anymore but is morphing more into the Database…
LOGGING or NOLOGGING, that is the question – Part VIII
0 Shares 1K Share Facebook 1K Share Twitter 1K Share LinkedIn 1K Share Facebook Messenger 1K Share WhatsApp 1K Share Email By Francisco Munoz Alvarez How to find Sessions Generating Lots of Redo To find sessions generating lots of redo, you can use either of the following methods. Both methods examine the amount of undo…
LOGGING or NOLOGGING, that is the question – Part VII
0 Shares 1K Share Facebook 1K Share Twitter 1K Share LinkedIn 1K Share Facebook Messenger 1K Share WhatsApp 1K Share Email By Francisco Munoz Alvarez Redo Logging I/O-Related Wait Events There are a number of Wait Events that happen during Redo Logging activities and most of them are I/O-related. The two most important ones are…
LOGGING or NOLOGGING, that is the question – Part VI
0 Shares 1K Share Facebook 1K Share Twitter 1K Share LinkedIn 1K Share Facebook Messenger 1K Share WhatsApp 1K Share Email By Francisco Munoz Alvarez TIPS USING NOLOGGING MODE DIRECT PATH INSERT To use Direct Path Insert use the /*+ APPEND */ hint as follow: INSERT /*+ APPEND */ into … SELECT … When direct…
LOGGING or NOLOGGING, that is the question – Part V
0 Shares 1K Share Facebook 1K Share Twitter 1K Share LinkedIn 1K Share Facebook Messenger 1K Share WhatsApp 1K Share Email 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…
LOGGING or NOLOGGING, that is the question – Part IV
0 Shares 1K Share Facebook 1K Share Twitter 1K Share LinkedIn 1K Share Facebook Messenger 1K Share WhatsApp 1K Share Email 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…
LOGGING or NOLOGGING, that is the question – Part III
0 Shares 1K Share Facebook 1K Share Twitter 1K Share LinkedIn 1K Share Facebook Messenger 1K Share WhatsApp 1K Share Email 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…
LOGGING or NOLOGGING, that is the question – Part II
0 Shares 1K Share Facebook 1K Share Twitter 1K Share LinkedIn 1K Share Facebook Messenger 1K Share WhatsApp 1K Share Email 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…
LOGGING or NOLOGGING, that is the question – Part I
0 Shares 1K Share Facebook 1K Share Twitter 1K Share LinkedIn 1K Share Facebook Messenger 1K Share WhatsApp 1K Share Email 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…