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How do you calculate redo log size?
I discovered that I have 15 groups of 2 GB, so the redo log group size is 30 GB. Oracle says that “In general we recommend adding an additional 30% on top of the peak rate”, so that would mean I am expected to have 245mb/s*1.3 = 318.5 MB/S.
What is the minimum number of redo log files used to store log information?
The redo log of a database consists of two or more redo log files. The database requires a minimum of two files to guarantee that one is always available for writing while the other is being archived (if the database is in ARCHIVELOG mode). See “Managing Archived Redo Logs” for more information.
What is redo log multiplexing?
Multiplexing the redo log: To protect against a failure involving the redo log itself, Oracle Database allows a multiplexed redo log, meaning that two or more identical copies of the redo log can be automatically maintained in separate locations. To multiplex your redo log, you must add members to each redo log group.
How to determine if online redo logs are sized properly?
WRITES_LOGFILE_SIZE is the number of writes driven by the smallest redo log file size. WRITES_LOGFILE_SIZE drives the checkpoint process if your redo log file size is under sized. Consider a small redo log file where the value of FAST_START_MTTR_TARGET initialization parameter is set to 30.
How to determine if the Oracle redo log file size is a problem?
By monitoring the date and time of the online redo logs at the operating system level (or querying V$LOG_HISTORY), you can determine whether to increase the size or number of online redo logs to reach an optimum switching interval. Here is a query that shows you the time between log switches. It can be handy in determining if you have a problem:
How big are redo log files in ASM?
Could you help determine the right size of redo log files, right number of redo log files and steps to resize redo log files in ASM (DB size is approx. 6.5Gb) The recommendation is to have log switches occur a few times an hour.
How to check redo log size and switch frequency?
As a part of tuning, you must check the redo log size and switch frequency. For proper functioning of the Oracle database you must avoid frequent log switches. Oracle redo logs consists of two or more pre-allocated files which record all changes made to the database.