Re: rpg sql timeout question

[Charles Wilt <charles.wilt@xxxxxxxxx>]

Rob's link gives the reasons IBM doesn't provide a true time-out.

The ability of the governor to predict and stop queries before they
are started is important because:

    * Operating a long-running query and abnormally ending the query
before obtaining any results wastes system resources.
    * Some CQE operations within a query cannot be interrupted by the
End Request (ENDRQS) CL command. The creation of a temporary index or
a query using a column function without a GROUP BY clause are two
examples of these types of queries. It is important to not start these
operations if they will take longer than the user wants to wait.


HTH,
Charles

On Tue, Mar 3, 2009 at 10:18 AM,  <rob@xxxxxxxxx> wrote:
> http://publib.boulder.ibm.com/infocenter/systems/scope/i5os/topic/rzajq/cqa.htm?tocNode=%74%6f%63%3a%72%7a%61%68%67%2f%69%35%6f%73%2f%34%2f%35%2f%35%2f%31%32%2f&searchQuery=%71%61%71%71%69%6e%69&searchRank=%31&pageDepth=%34
>
> Rob Berendt
> --
> Group Dekko Services, LLC
> Dept 01.073
> Dock 108
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> http://www.dekko.com
>
>
>
>
>
> From:
> "tim" <tim2006@xxxxxxxxxxx>
> To:
> "'RPG programming on the IBM i / System i'" <rpg400-l@xxxxxxxxxxxx>
> Date:
> 03/02/2009 07:02 PM
> Subject:
> RE: rpg sql timeout question
> Sent by:
> rpg400-l-bounces@xxxxxxxxxxxx
>
>
>
> Tom,
>
> Its possible that a query such as "select * from customer where custname
> like %a_b%" is possible. The file has close to 1 million records. I was
> wondering if I could put a time limit on the execution of the query. So,
> say
> after 30 seconds the query stops querying and returns a time allotted has
> expired or something like that.
>
> I am using service calls to my iseries. These jobs are running in batch.
>
> -----Original Message-----
> From: rpg400-l-bounces@xxxxxxxxxxxx [mailto:rpg400-l-bounces@xxxxxxxxxxxx]
> On Behalf Of Armbruster, Tom
> Sent: Monday, March 02, 2009 5:45 PM
> To: RPG programming on the IBM i / System i
> Subject: RE: rpg sql timeout question
>
> Good question, but a dangerous one at the same time.  For what reason
> would you want to time out a request to the database?  There are only a
> few reasons that SQL requests would time out:
>
> 1) CPU utilization is too high.
> 2) The query is written for updates on locked records.
> 3) The query is processing a large amount of data without the necessary
> resources.
> 4) The query is not optimized.
>
> Before concerning yourself with timeouts in native RPG, you may want to
> ensure that you have optimized the data access methods.  Running SQL
> interactively can be a slow process if the files and the query
> statements are not optimized.  If the queries do not need to run
> interactively, consider pushing them to a batch process.  If interactive
> is required, optimize the queries as much as possible.
>
> What is the situation you are referring to for which you want to
> consider time outs?
>
> Tom Armbruster
>
> -----Original Message-----
> From: rpg400-l-bounces@xxxxxxxxxxxx
> [mailto:rpg400-l-bounces@xxxxxxxxxxxx] On Behalf Of tim
> Sent: Monday, March 02, 2009 11:57 AM
> To: 'RPG programming on the IBM i / System i'
> Subject: rpg sql timeout question
>
> Is there a way to have a possibly long running sql performed  in an
> SQLRPGLE
> program, to time out after running for a certain amount of time?
>
>
>
>
>
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