Re: Reducing redolog switch frequence

100.17706_at_germanynet.de wrote:
>
> Hello
>
> We use a data warehouse application (PL/SQL) and produce over 100 redo log
> files 10 MB in size each per hour. In the init parameter file, we have
> log_buffer = 20979712.
>
> What can I do to try to reduce the redo log switch frequence to a healthy
> value of about one per half an hour?
>
> Because this application runs very slow, we assume that harddisk I/O due
> to redo log operations could be a bottleneck.
>
> How can I improve performance by somehow tuning parameters related to
> the redo log files?
>
> The same question would apply to parameters related to rollback segments,
> I guess.
>
> ANY suggestion will be welcome!

In init.ora set

log_checkpoint_interval = 100000000
log_checkpoint_timeout = 0

but most important, create new redo logs which are much bigger (I guess 500 MB should be fine). Put your redo logs on a separate disk and don't forget to mirror your redo logs (create redo log groups with min 2 members).

Regards,

Knut

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