Re: Creating objects in the database

Hi,

If you're doing SCADA it does not make sense to insert each object in
its own transaction. Create a few hundred objects per transaction and
observe a massive increase in speed.

If you're doing OLTP and you need massive scalability, you want your
benchmarks to run on hundreds of threads, with hundreds of
simultaneous transactions being submitted to Prevayler. There is no
realistic singlethreaded massively-intensive OLTP scenario (it becomes
a SCADA scenario).

Prevayler will easily handle 1500 simultaneous requests on 1500
different threads and gives you aprox 1000 transactions per second
throughput for medium-sized object inserts.

See you, Klaus.


On Mon, Feb 9, 2009 at 3:41 PM, William Pietri <[email protected]> wrote:
> Just to be clear, each object is saved in its own transaction, so that's
> 20000 separate transactions.
>
> William
>
> Khayundi, Peter wrote:
>
> The objects are created in a single transaction.
> -----Original Message-----
> From: Klaus Wuestefeld [mailto:[email protected]]
> Sent: Friday, February 06, 2009 11:04 PM
> To: Open discussion about the Prevayler project.
> Subject: Re: [Prevayler-discussion] Creating objects in the database
> Also: Are you creating 20000 objects in a single transaction or in
> 20000 separate transactions?
> On Fri, Feb 6, 2009 at 6:49 PM, Klaus Wuestefeld
> <[email protected]> wrote:
>
>
> Are you doing SCADA or OLTP?
> On Fri, Feb 6, 2009 at 3:24 PM, William Pietri <[email protected]>
>
>
> wrote:
>
>
> Khayundi, Peter wrote:
> I am doing some timings with the Prevayler database. I inserted 20000
>
>
> items
>
>
> into the database and timed this operation. The experiment was
>
>
> repeated 10
>
>
> times. The resulting times differ widely and have a high standard
>
>
> deviation.
>
>
> Does anybody have an explanation as to why the same experiment should
>
>
> have
>
>
> such widely different timings?
> Hi, Peter. My first two guesses: other IO on the same disk and Java
>
>
> garbage
>
>
> collection. You can reduce problems with the first by using a
>
>
> separate disk,
>
>
> and with the latter by giving Java lots more RAM than necessary.
>
>
> There are
>
>
> also assorted tunings you can do, but those depend on OS and JDK
>
>
> version.
>
>
> William
> --
> William Pietri - [email protected] - +1-415-643-1024
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