Re: Queueing Theory in Oracle

The TPC test runs 5 different type of transactions,

1. *New Order Transaction*
2. *Payment Tansaction*
3. *Order Status Transaction*
4. *Delivery Transaction*
5. *Stock Level Transaction*

From the results Payment had an avg of 5ms service time, New Order 13ms, Delivery 15ms, Stock-Level 30ms and finally order status 261ms

On Tue, Mar 11, 2014 at 9:36 PM, Jonathan Lewis <jonathan_at_jlcomp.demon.co.uk
> wrote:

>
> I was thinking more of the way the data might introduce variability in the
> time required to execute queries - for example in an order placing system a
> "product pick" query that supplies 20 full names and product IDs for the
> user to choose from will take longer than a query that supplies only one
> option. Was there enough variation in the required service time to allow a
> non-normal distribution ?
>
>
> Regards
> Jonathan Lewis
> http://jonathanlewis.wordpress.com
> _at_jloracle
> ------------------------------
> *From:* Ls Cheng [exriscer_at_gmail.com]
> *Sent:* 11 March 2014 20:23
> *To:* Jonathan Lewis
> *Cc:* Oracle Mailinglist
>
> *Subject:* Re: Queueing Theory in Oracle
>
> Hi
>
> I thought the reasons of getting normal data distribution was probably
> how the test is run. Since it's a constant 300/420 users running probably
> 30 or 40 different SQL statements ( I dont know how many are there in a TPC
> test), the server was only 18% loaded, the database metric I used were
> gathered from v$sysmetrc (so I have metric rates in per second unit
> gathered every minute), all mix together the distribution I got was normal,
> I even took the sample data and used Cary's mdist.pl to see if the data
> was exponentially distributed and all were rejected. After checking that
> and think a bit then I think the normal data distribution is expected, if I
> am running 16 TPC transactions per second and there are few in the lower
> side a few in the higher side and most were in the middle then of course
> it's a normal data distribution, why should I expect it to be exponentially
> distributed?
>
> I used TPS as arrival rate and little's law to get the service time (used
> host cpu as utilization)
>
> system utilization = (arrival rate * service time) / number of servers
>
> The service time was normal distributed as well
>
> So using the TPC test sample data, the formulas I could find (I have
> downloaded probably 20 PPT from 7 or 8 universities statistics courses)
> they just dont "glue" together in an Oracle Database and that is why I am
> asking if anyone has successfully used queueing theory in Oracle so at
> least I can get some points and see what I am dong wrong :-)
>
>
> Thanks
>
>
>
>
>
>
> On Tue, Mar 11, 2014 at 9:07 PM, Jonathan Lewis <
> jonathan_at_jlcomp.demon.co.uk> wrote:
>
>>
>>
>> That's an interesting observation - but (viewed from the outside) I
>> would be a little suspicious that the normal distribution was an artifact
>> of the data generation mechanism and the test mechanism.
>>
>>
>>
>> Regards
>> Jonathan Lewis
>> http://jonathanlewis.wordpress.com
>> _at_jloracle
>> ------------------------------
>> *From:* Ls Cheng [exriscer_at_gmail.com]
>> *Sent:* 11 March 2014 20:01
>> *To:* Karl Arao
>> *Cc:* Jonathan Lewis; Oracle Mailinglist
>>
>> *Subject:* Re: Queueing Theory in Oracle
>>
>>
>> I ran last week a couple of TPC load with 300 and 420 users then I used
>> both transaction per second and logical reads per second metric and both
>> showed normal data distribution and that is why I have doubts of how to use
>> queueing theory in Oracle.
>>
>> From your paper was you able to predict the change from v1 to x2 without
>> run the actual test? Then run the test and validate the prediction?
>>
>>
>

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