Re: redo logs

>I just finished taking my ORACLE admin class and one of the things I
>have outstanding is sizing the redo logs.
>
>What is the best way to "size" these guys? Is there a rule of thumb
>for the number of redo logs?
>
>Is there and FAQ that would point this (and other items) out to me?
>
>JB

Oracle7 redo log files are organized in groups

A group must have one or more members. All members of a group have identical contents.

You should choose to have two or more members in each group for safety, unless you are mirroring all files at a hardware level.

Redo log files in the same group should ideally be on seperate, fast devices, because LGWR writes to them almost continuously.

Any waits for "log file parallel write" in V$SYSTEM_EVENT indicate a possible I/O problem with the log files.

Properly size redo log files to minimize contention and frequent log switches. - Oracle7 Server: Performance Tuning

Hope it helped- There is no standard for most settings in Oracle, it is all based on database activity. However the default for the LOG_BUFFER in your init<sid>.ora parameter is usually for times the maximum Oracle block size for the platform, which is far too low for a busy system. Satar Naghshineh
SatarNag_at_aol.com Received on Tue Aug 19 1997 - 00:00:00 CDT