Re: NT PERFMON Answer and question

"Harald Henkel" <Harald_at_Henkel.DAH.UUnet.DE> wrote in message news:95cqbt$h6g10$1_at_ID-56141.news.dfncis.de...
> Hello Sybrand.
>
> "Sybrand Bakker" <postbus_at_sybrandb.demon.nl> schrieb im Newsbeitrag
> news:t7jpmumc25762a_at_beta-news.demon.nl...
>
> > It's a feature of Oracle 8i and you can't AFAIK configure it.
>
> You mean this writing every 3 seconds is FIXED ?
> What for ?
> What's it writing there ?
>
> Anyway, some collegues (those who wrote the application) - unfortunately
 in
> Italy, while I'm in Germany - told me, that they don't seem to have this
> behaviour on their Oracle 8.1.6.3 installations (which they use for
> development only at the moment).
>
> I'm really confused now. Can it be, they simply didn't realize this ?
> I only realized it, because the disk's are as loud to realize these
 frequent
> accesses and - being curious - checked it with FileMon.
>
> Of course - a heavy loaded DB (or any server) will access its disks all
 the
> time.
> It's just some "strange" feeling that this frequent and IMHO unnessessary
> access - shouldn't be normal.
>
> Is this for security / recovery ?
>

In a word, yes.

The idea is that no-one in their right mind would want to go three seconds without a minor checkpoint, on the grounds that -since you're using Oraclethis  is likely to mean a million and half transactions having to be repeated if you ever have an Instance Failure. (If you were using SQL Server, clearly there would only be three-and-a-half transactions, so who would care?)

Now: the good news is that in the training documentation, it clearly states, time and time again (and has done so since version 8.0) that this 3 seconds is the "default" time for minor checkpoints.... and we all know that defaults can be changed, right?

The bad news is that I haven't a clue off the top of my head how to change the said default. Other than to make sure that log_checkpoint_timeout is set to 0 and log_checkpoint_interval is set to something utterly huge.

But then it occurs to me that worrying about a wee bit of disk activity is a bit like the dinosaurs in 65 million BC worrying about how warm it was getting...

Regards
HJR
> <SNIP>
>
> > > It (FileMon) showed me, that Oracle writes to its control files
 ctl1orcl.ora
> > > and ctl2orcl.ora every 3 seconds on one Oracle 8.1.6.3 installation -
 for
 no
> > > obvious reason (since the DB isn't doing much at the moment).
> > >
> > > Anybody has an idea what might be going on ?
> > > (it's WinNT 4 SP5)
> > >
> > > Can this be some installation / configuration problem ?
> > >
> > > It really looks like a configured interval. It's not "about" every 3
> > > seconds - it's exactly 3 seconds as far as I can see.
> > > Where would I configure this ?
>
>
>
Received on Fri Feb 02 2001 - 08:48:42 CST