I recall seeing the same thing.  I'd have to look at the SQL again to see if it 
is possible to migrate the limit a sub-query in the pre-fetches.  My first 
guess is that it would not be trivial.

Chuck


On 2012-06-27, at 7:10 AM, Kieran Kelleher wrote:

> I don't have the answer to that off the top of my head. Interesting question 
> though.
> 
> On Jun 27, 2012, at 9:23 AM, Henrique Gomes wrote:
> 
>> 
>> Also, 
>> 
>> I had trouble some time ago, because a fetch *was* using LIMIT (on Postgres) 
>> but the subsequent fetch of  prefetchingRelationshipKeyPaths were NOT. 
>> Is that expected behavior? I assume so, the result of LIMITing the fetch 
>> might not bring the relation tuples corresponding to the initial LIMITed 
>> fetch. Right?
>> 
>> HG
>> 
>> On Jun 27, 2012, at 12:55 PM, Kieran Kelleher wrote:
>> 
>>> Also, you can verify by checking the SQL that is being sent to the database 
>>> rather than just guessing that LIMIT is not being applied. It might be a 
>>> big relationship that is causing OOM exception. Or maybe you have not 
>>> allocated enough memory to your app.
>>> 
>>> On Jun 27, 2012, at 7:52 AM, Kieran Kelleher wrote:
>>> 
>>>> LIMIT is supported by the Wonder MySQL PlugIn since Nov 22, 2011, commit 
>>>> 6c511bb. You would need the MySQLPlugIn in your build path.
>>>> 
>>>> 
>>>> On Jun 27, 2012, at 3:13 AM, Gennady Kushnir wrote:
>>>> 
>>>>> I assumed that (
>>>>> How can I force LIMIT to SQL statement in MySQL?
>>>>> 
>>>>> 2012/6/26 Kieran Kelleher <[email protected]>:
>>>>>> It depends on the database plugin you are using. Some plugins take the 
>>>>>> fetchSpec fetchLimit and incorporate it into the SQL statement in the 
>>>>>> plugin's EOSQLExpression subclass. The default behaviour of EOF is to 
>>>>>> limit in memory after the fetch.
>>>>>> 
>>>>>> On Jun 26, 2012, at 10:23 AM, Gennady Kushnir wrote:
>>>>>> 
>>>>>>> Hello all!
>>>>>>> I am fetching from a table that has lots of records. So I decided to
>>>>>>> fs.setFetchLimit(10) on my EOFetchSpecification, but nevertheless when
>>>>>>> I perform ec.objectsWithFetchSpecification(fs) I get
>>>>>>> JavaOutOfMemoryError.
>>>>>>> It seems to me that fetchLimit does not actually convert to a LIMIT
>>>>>>> clause in a SELECT statement in underlaying SQL. So the actual
>>>>>>> limitation is made in memory after fetch.
>>>>>>> Is it a conventional behavior or it is me doing something wrong?
>>>>>>> 
>>>>>>> Gennady
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>>>>> 
>>>>> 
>>>>> 
>>>>> -- 
>>>>> С уважением,
>>>>> Геннадий Кушнир
>>>> 
>>> 
>>> 
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> 
> 
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-- 
Chuck Hill             Senior Consultant / VP Development

Practical WebObjects - for developers who want to increase their overall 
knowledge of WebObjects or who are trying to solve specific problems.    
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