Re: Re: Re: Configuring Oracle on RAID 5

In article <EBBA6D3A81229C42981E3AEA79BF5A4E111239_at_jshemail.herold.com>, aminocha_at_herold.com says...
> Writes are not all that important in our system because we run a batch
> process nightly to update the database. The users use the database mainly
> for querying from the web site.
>
> When I run performance tuning scripts it shows me that there is a reo log
> contention of 77% and more. Also there is a contention for rollback undo
> header. Do I need to seriously take a look in these issues or can i ignore
> them because of the fact that the read speed is what that counts and not the
> write speed.
>
> Please suggest.
>
> Also let me tell you that we have 2 logical partitions across the same set
> of drives and the database is on the D partition. (All of it).
>
> Thanks
> Anurag
>
>
>

I assume that you are in archive mode. If Oracle adds data faster than the redo's can be moved, the instance hangs until there is an available redo log. This means that neither readers or writers can use the database. Redo logs should never be put on raid-5 devices. This is stated in the Oracle documentation.

Yes I would take it seriously.

Liz Received on Wed Mar 14 2001 - 15:17:38 CST