redo log switch

[Sureshy]

Hi Friends..

Are there any disadvantages in having log switch occur every 90mins ?

Doesn't oracle recommend 1 every 30 - 60 mins ?

Thanks

Suresh

[pando]

instance recovery will be longer, that is the drawback

[Sureshy]

Cheers Pando..

Isn't Instance recovery/any recovery also based on checkpoints though.

Oracle only starts applying redo info after the last checkpoint doesn't it ?

If checkpoints are regular, this will decrease time to recover wouldn't it ?

please confirm

Thanks in advance

Suresh.

[pando]

well the point is when there is a log switch there is a checkpoint, the reason to make log swith less often is to avoid excess checkpoints, so if your log switch is every 90 minutes and checkpoint every 5 minutes then it is pointless setting your log so large so it switches log every 90 minutes

[Sureshy]

Thanks for the info Pando.

[Irfkhan]

Oracle Recommends 20-30 Minutes but I would say it depends on the amount of transactions, Concurrently executing in the database.