Re: Redo Log help

Hi Rogbacker,

All things being equal, a log switch every 30 seconds is too frequent.

I use 30 ish switches a day under normal load as a rough guide (as it's my age although I look years younger). Many fewer (say 1,2,3 ...) *may* suggest your redo logs are too big and depending on your DB version and how you have configured checkpointing, *may* indicate excessive instance recovery times. Many more (say 100s, 1000s) *may* suggest your redo logs are too small and that you *may* have checkpointing issues, again depending on DB version, checkpointing configuration, etc.

So I would recommend increasing the size of your logs as a first step (say around 200M)

Also I have yet to hear a good reason why you should have different sized redo log groups (other than being in the middle of resizing them). I would suggest making them all uniform in size while you're at it.

Cheers

Richard

"Rogbaker" <rogbaker_at_gdi.net> wrote in message news:1645ceca.0208291745.255435f9_at_posting.google.com...
> ...But we are not in Archive Log Mode
>
> Svend Jensen <svend.jensen_at_it.dk> wrote in message
news:<3D6E7C44.7040301_at_it.dk>...
> > Rogbaker wrote:
> >
> > > We are using Oracle 8.1.7 and are in the process of a PeopleSoft
> > > upgrade test move. We have an APP Engine program running very long and
> > > and sql script running very long simultaneously. Looking in the alert
> > > log, I have seen multiple
> > > 'Cannot allocate new log' and 'Checkpoing not complete' messages.
> > > These upgrade scripts/programs do move a ton of data. I have added
> > > more 2 more log groups, which seem to have handled the error messages,
> > > but how frequently should the database advance to a new log group? It
> > > is happening like every 30 seconds.
> > > Right now I have:
> > > groups #1-5 with 2 10M members
> > > group #6 with 2 15M members
> > > group #7 with 2 20M members
Received on Thu Aug 29 2002 - 21:14:48 CDT