Re: oracle 8.1.5 configuration

"Michel Cadot" <micadot{at}altern{dot}org> wrote in message news:<413e951a$0$29071$626a14ce_at_news.free.fr>...
> "Mark Bole" <makbo_at_pacbell.net> a écrit dans le message de
> news:47s%c.17196$JE1.9341_at_newssvr27.news.prodigy.com...
> <snip>
> >
> > Also, consider the following: how do you know it is Oracle that is
> > accessing the disk every second? Platform and version would help
> > greatly. Version 8.1.5 is obsolete.
> >
>
> I can answer about that for the OP.
> I tried it during the five or six past years on my laptop (WinNT4 SP3 to 6)
> with Oracle release 8.0, 8.1.5, 8.1.7 and 9.2. It's easy to see Oracle
> accesses the db when you are doing nothing, just start the instance
> and hear the disk every 2 seconds even with infinite log_checkpoint_timeout
> and so on.
> I searched several times the reasons for these IO and didn't find any.
> I asked for this on newsgroup for this issue and got several answers like
> "smon cleaning or coalescing", "lgwr writting log buffer entries"... but
> when there is no activity, there is no object, there is nothing why these IO?
> (just execute "create database" nothing else and you'll see them).

There are some decisions in the architecture of the database like "we will do this because we are making the assumption that the db will be used, they make no difference if the database is not being used, and help performance if the database is being used." So it is a lot simpler to just timeout every X seconds than to not timeout every X seconds. Performance is increased in some moderate-but-increasing load situations because the checkpoint can happen without having to hit or pass over some particular limit. Makes no difference in heavy load situations, because if you are getting "Checkpoint not complete" errors you have some tuning to do. Other housekeeping operations may also happen, and only be noticeable because nothing else is going on. As someone so entertainingly put it, "my database is bored out of it's gourd."

There are even more things happening with OAS, no database needed.

Does your smoke alarm have a flashing red light? Does it beep when the battery is about to go dead? What if the battery goes dead while you are away on vacation? These are architectural decisions, but still don't cover every circumstance and you still need to check the batteries twice a year and when coming home from vacation. But if you hear the beep, that's informative, and better than being dead for 3 months until you check it, right?

Perhaps the question you should be asking is why do you have a database that is not being used.

jg

--
@home.com is bogus.
"During periods when my database is bored out its gourd, control file
I/O waits are often the top waits." - Xho