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From "Howard W. Smith, Jr." <smithh032...@gmail.com>
Subject Re: TomEE performance degrades gradually
Date Fri, 04 Apr 2014 10:39:12 GMT
On Fri, Apr 4, 2014 at 5:46 AM, ivan nikitsenka <nikitsenka@gmail.com>wrote:

>
>       <query>
>         <description></description>
>         <query-method>
>           <method-name>findAll</method-name>
>           <method-params></method-params>
>         </query-method>
>         <ejb-ql>select object(o) from BreakReason o order by
> o.reasonDesc</ejb-ql>
>       </query>


Seriously? ORDER BY a 'reasonDesc'?

Every now and then, I am opening jvisualvm (Java Visual VM) and profiling
(or checking the performance) on certain parts of my app, and more and
more, I am removing,

ORDER BY ...

from my queries, and reverting to Collections.sort() + Comparator.

Is there an index on this 'reasonDesc'? What is 'reasonDesc'.length(), on
average?

If this is the reason why TomEE [and your app] is degrading, then please
change your query, and remove the ORDER BY ..., and sort your data some
other way.

Refer to your database tuning document. I use Apache Derby, and they have a
very nice/comprehensive 'Tuning Derby' guide that I have referred to in the
past, when my app went to production.

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