[hibernate-dev] ORM, OGM and timing

[Steve Ebersole]

By "type system" do you mean the TypeDescriptor pull request?  If not, 
you'll have to clarify.

If so...

The idea is simple.  There are a number of things that the parser needs 
to know in order to figure out the semantics of the query; this 
question of "types" is just one thing.  However, ORM and OGM have 
different concrete contracts (Type versus GridType) there.  
TypeDescriptor is simply a "bridge" contract that the parser can use in 
making these semantic decisions.  Let's take a few simple examples:

1) ... where p.age + p.birthdate > p.name

Is that a valid restriction?

2) ... from Person p join p.aliases a

Is that a valid join (not as straight forward as I think you think)?

etc

Answering all those questions depends on access to "type information".

I cannot give you exact details on exactly how the parser determines 
"type information" for each expression yet because we still have other 
unanswered questions that affect the answer to that (most notably the 
question of heterogeneous trees versus homogeneous trees).


On Wed 05 Dec 2012 10:02:00 AM CST, Sanne Grinovero wrote:
> That's what I'm hoping too, but since I've not fully grasped the
> proposed solution for the type system I'm not sure: I need to read the
> new ORM code.
>
> If we really can just plug a different QueryTranslatorFactory in ORM,
> how does this affect our release options on OGM?
>
>
> On 5 December 2012 15:44, Steve Ebersole <steve at hibernate.org> wrote:
>> I am not completely understanding the question.  You don't *need* Hibernate
>> 5, you could just plug in a custom QueryTranslatorFactory as we discussed on
>> irc.  The discussion here was changing the standard QueryTranslatorFactory
>> to use this new Antlr parser.
>>
>> On Dec 5, 2012 8:46 AM, "Sanne Grinovero" <sanne at hibernate.org> wrote:
>>>
>>> Do we need Hibernate 5 to resolve those type system issues?
>>>
>>> If so, is there an alternative solution which wouldn't necessarily
>>> couple the OGM lifecycle with ORM ? (just for the time being)
>>>
>>>
>>> On 4 December 2012 18:19, Emmanuel Bernard <emmanuel at hibernate.org> wrote:
>>>> Moving to dev mailing list.
>>>>
>>>> On Tue 2012-12-04 12:09, Steve Ebersole wrote:
>>>>> Can we have such discussions on the dev list?
>>>>>
>>>>> Anyway, that's why I said about developing the parser separately but in
>>>>> tandem and synching later.  That gives us that flexibility.
>>>>>
>>>>> Because it's not been decided that the parser change will even go into
>>>>> 5.0...
>>>>> On Dec 4, 2012 11:35 AM, "Emmanuel Bernard" <emmanuel at hibernate.org>
>>>>> wrote:
>>>>>
>>>>>> Hey guys,
>>>>>>
>>>>>> Steve and I started a discussion on how to reuse Sanne's work around
>>>>>> the
>>>>>> new JP-QL parser. The crux of the problem is to be able to reuse the
>>>>>> type
>>>>>> of a given node in the parser even if Hibernate ORM and Hibernate OGM
>>>>>> use a
>>>>>> different type system. This looks doable but then the problem of
>>>>>> timing
>>>>>> arises.
>>>>>>
>>>>>> With Davide coming onboard, and even more after BV is behind us, I
>>>>>> expect
>>>>>> OGM to speed up significantly which means we will need to do fast
>>>>>> releases.
>>>>>> So the question is when are we targeting Hibernate ORM 5 final and
>>>>>> does
>>>>>> that fit Hibernate OGM's time goals.
>>>>>>
>>>>>> We have been promising query for ever now and I would hate to have to
>>>>>> delay it more than necessary.
>>>>>>
>>>>>> Thoughts?
>>>>>>
>>>>>> Emmanuel
>>>>>>
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