I imagined forced writes to simply issue an OS I/O flush to disk after
each commits. If that's the case, then the load should be on the OS,
not IB itself.

I might be wrong, as I never looked as the FB sources before.
As I said...I "imagined" forced writes to be that way :-)

Regards
Kenneth

----- Original Message -----
From: "Michael Grabinski" <mgrabinski@...>
To: <ib-support@yahoogroups.com>
Sent: Thursday, March 21, 2002 11:03 AM
Subject: RE: [ib-support] High CPU usage AFTER bulk insert completed


> I've seen this behavior too, after turning forced-writes OFF and slamming
> the database with a lot of inserts. You mentioned that forced-writes
were
> OFF for your database. I'd chalk up the "after the fact" processor
activity
> to Interbase finally getting around to writing your inserts to disk.
>
> I imagine your insert statements return very quickly, but the data doesn't
> actaully get written to disk until later. So Interbase is still chugging
> away, writing to disk, even after your program has exited. I'll bet that
> you would _not_ see the "after the fact" processor utilization if you
turned
> forced writes back ON. You'd probably see a 20x drop in performance
though.
> At least that's what I've seen in my testing, but what do I know :-)
>
> -----Original Message-----
> From: Kenneth Foo [mailto:kenneth@...]
> Sent: Wednesday, March 20, 2002 7:06 PM
> To: ib-support@yahoogroups.com
> Subject: Re: [ib-support] High CPU usage AFTER bulk insert completed
>
>
>
> ----- Original Message -----
> From: "Ann W. Harrison" <aharrison@...>
> To: <ib-support@yahoogroups.com>
> Sent: Thursday, March 21, 2002 1:08 AM
> Subject: Re: [ib-support] High CPU usage AFTER bulk insert completed
>
>
> > Are you also doing a commit after each insert? That's making things
> > slower than they need to be ... at least in most cases.
>
> Yes, I did. :-)
>
> I have a system that sends out messages and store some information in a DB
> to keep track of messages that has been sent. In case of a server crash,
> the system needs to know where it left off, thus the need for commits
often.
> Basically, I was testing the average sustained rate of insertion for FB.
>
> But I didn't expect the processor usage to linger even after the operation
> though.
> I thought once commit has been performed, there aren't any more
significant
> cpu-intensive operations to perform?
>
>
> > >Just wondering if this has something to do with some internal memory
> > >management?
> > >But then again, it's just 2000 prepared statements. It can't possibly
> take
> > >25 seconds to free them all right?
> >
> > Have you traced the memory usage of the server?
>
> Well, I think it goes up till 144Mb, according to Windows Task Manager.
> This on a machine with 384Mb RAM.
>
> Regards
> Kenneth
>
>
>
>
>
>
>
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