Re: Archive mode

In article <HXkN5.1044$7a1.79415_at_nnrp1.sbc.net>,   "spencer" <spencerp_at_swbell.net> wrote:
> "Howard J. Rogers" <howardjr_at_www.com> wrote in message
 news:3a033949_at_news.iprimus.com.au...
> >
> > So the solution becomes obvious: adding more redo log groups will
 help
> > prevent system hangs.
> >
> > Making the log files almost certainly won't help at all -yes, it
 takes
> > longer to fill up a bigger log, and hence the switch will be
 delayed. But
> > once it *does* switch, ARCH has more work to do, copying a bigger
 file. In
> > the general case, the two are likely to cancel each other out, and
 achieve
> > precisely nothing.
> >
>
> precisely. increasing the size of the redo log files, however, CAN
> potentially reduce the frequency of log switches.
>

I don't know about "potentially"! My recommended method of getting the 'right' size for Redo Logs is almost entirely dependent on keeping an eye on the Alert Log, and making sure you are log switching at an appropriate rate (which varies on the circumstances, of course). If you switch every 3 minutes, add bigger logs and drop the old ones, until the rate slows down.

So, I'd go further than you and say that there's a *direct* correlation between log size and frequency of switching.

But, as we've known for aeons: size isn't everything. And, as you say, it certainly isn't when it comes to hangs due to switching back on top of yourself!

Regards
HJR
> > Regards
> > HJR
> >
>
>

--
======================================================
'Baldric, you wouldn't recognise a cunning plan if it
painted itself blue, and danced naked on top of a
harpsichord singing 'Cunning Plans Are Here Again!'


Sent via Deja.com http://www.deja.com/
Before you buy.