| Teneo und Deep Objektgraphs [message #632342] |
Tue, 12 October 2010 10:59  |
Eclipse User |
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Hi,
I'm not sure this is really a problem of Teneo or more general a problem
of Hibernate itself.
Suppose you have the following Containment-Structure (ie a bidirectional
relation).
Company
Country
Region
Store
Department
When you now issue a HQL-Query "FROM Department" you'll notice that
Hibernate is executing after the first fetch an SQL-Statement which
JOINS Store, Region, Country, Company to follow up the the parent path.
Now imaging the Object-Graph is getting 10-times deeper and you'll get a
SQL-Statement with a lot, a lot of JOINS (in my case it even goes beyond
the limit of the database).
Anybody an idea how this could be solved?
Tom
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| Re: Teneo und Deep Objektgraphs [message #632359 is a reply to message #632342] |
Tue, 12 October 2010 12:17  |
| Eclipse User |
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Hi Tom,
Yes the parent econtainer relations are mapped using a hibernate custom type, apparently these are eagerly fetched. I
need to check if they support lazy loading. Can you enter a bugzilla for this? If you have a focused test model that
would be great, I can also create one myself (sounds pretty reproducable...).
gr. Martin
On 10/12/2010 04:59 PM, Tom Schindl wrote:
> Hi,
>
> I'm not sure this is really a problem of Teneo or more general a problem
> of Hibernate itself.
>
> Suppose you have the following Containment-Structure (ie a bidirectional
> relation).
>
> Company
> Country
> Region
> Store
> Department
>
> When you now issue a HQL-Query "FROM Department" you'll notice that
> Hibernate is executing after the first fetch an SQL-Statement which
> JOINS Store, Region, Country, Company to follow up the the parent path.
>
> Now imaging the Object-Graph is getting 10-times deeper and you'll get a
> SQL-Statement with a lot, a lot of JOINS (in my case it even goes beyond
> the limit of the database).
>
> Anybody an idea how this could be solved?
>
> Tom
--
With Regards, Martin Taal
Springsite/Elver.org
Office: Hardwareweg 4, 3821 BV Amersfoort
Postal: Nassaulaan 7, 3941 EC Doorn
The Netherlands
Cell: +31 (0)6 288 48 943
Tel: +31 (0)84 420 2397
Fax: +31 (0)84 225 9307
Mail: mtaal@springsite.com - mtaal@elver.org
Web: www.springsite.com - www.elver.org
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| Re: Teneo und Deep Objektgraphs [message #632424 is a reply to message #632359] |
Tue, 12 October 2010 16:22 |
| Eclipse User |
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Hi Martin,
So modeling them as bi-directional and not as containment this would not
happen?
I'm not sure that this is a teneo specific problem because when i read
the Hibernate-Docs correct hibernate has to fetch resolve bi-directional
references.
I'll file a bugzilla with a model that should reproduce the problem.
Tom
Am 12.10.10 18:17, schrieb Martin Taal:
> Hi Tom,
> Yes the parent econtainer relations are mapped using a hibernate custom
> type, apparently these are eagerly fetched. I need to check if they
> support lazy loading. Can you enter a bugzilla for this? If you have a
> focused test model that would be great, I can also create one myself
> (sounds pretty reproducable...).
>
> gr. Martin
>
> On 10/12/2010 04:59 PM, Tom Schindl wrote:
>> Hi,
>>
>> I'm not sure this is really a problem of Teneo or more general a problem
>> of Hibernate itself.
>>
>> Suppose you have the following Containment-Structure (ie a bidirectional
>> relation).
>>
>> Company
>> Country
>> Region
>> Store
>> Department
>>
>> When you now issue a HQL-Query "FROM Department" you'll notice that
>> Hibernate is executing after the first fetch an SQL-Statement which
>> JOINS Store, Region, Country, Company to follow up the the parent path.
>>
>> Now imaging the Object-Graph is getting 10-times deeper and you'll get a
>> SQL-Statement with a lot, a lot of JOINS (in my case it even goes beyond
>> the limit of the database).
>>
>> Anybody an idea how this could be solved?
>>
>> Tom
>
>
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| Re: Teneo und Deep Objektgraphs [message #632507 is a reply to message #632424] |
Wed, 13 October 2010 04:52 |
| Eclipse User |
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Hi Tom,
Yes guess so, the problem is that the custom user type used for econtainer associations does eager fetching, for normal
associations this eager fetching can be controlled by annotations.
I will react in the bugzilla.
gr. Martin
On 10/12/2010 10:22 PM, Tom Schindl wrote:
> Hi Martin,
>
> So modeling them as bi-directional and not as containment this would not
> happen?
>
> I'm not sure that this is a teneo specific problem because when i read
> the Hibernate-Docs correct hibernate has to fetch resolve bi-directional
> references.
>
> I'll file a bugzilla with a model that should reproduce the problem.
>
> Tom
>
> Am 12.10.10 18:17, schrieb Martin Taal:
>> Hi Tom,
>> Yes the parent econtainer relations are mapped using a hibernate custom
>> type, apparently these are eagerly fetched. I need to check if they
>> support lazy loading. Can you enter a bugzilla for this? If you have a
>> focused test model that would be great, I can also create one myself
>> (sounds pretty reproducable...).
>>
>> gr. Martin
>>
>> On 10/12/2010 04:59 PM, Tom Schindl wrote:
>>> Hi,
>>>
>>> I'm not sure this is really a problem of Teneo or more general a problem
>>> of Hibernate itself.
>>>
>>> Suppose you have the following Containment-Structure (ie a bidirectional
>>> relation).
>>>
>>> Company
>>> Country
>>> Region
>>> Store
>>> Department
>>>
>>> When you now issue a HQL-Query "FROM Department" you'll notice that
>>> Hibernate is executing after the first fetch an SQL-Statement which
>>> JOINS Store, Region, Country, Company to follow up the the parent path.
>>>
>>> Now imaging the Object-Graph is getting 10-times deeper and you'll get a
>>> SQL-Statement with a lot, a lot of JOINS (in my case it even goes beyond
>>> the limit of the database).
>>>
>>> Anybody an idea how this could be solved?
>>>
>>> Tom
>>
>>
>
--
With Regards, Martin Taal
Springsite/Elver.org
Office: Hardwareweg 4, 3821 BV Amersfoort
Postal: Nassaulaan 7, 3941 EC Doorn
The Netherlands
Cell: +31 (0)6 288 48 943
Tel: +31 (0)84 420 2397
Fax: +31 (0)84 225 9307
Mail: mtaal@springsite.com - mtaal@elver.org
Web: www.springsite.com - www.elver.org
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