2:48 p.m.
Hi hibernate-dev,
I have an interest in modifying hibernate core to support an
alternative persistence model common in some domains like the medical
domain. how do I go about it?
here is a small description of the problem and a solution:
problem:
Objects map one to one to tables as specified at design time which is
normally what most applications require. Object relational mapping
runtimes like hibernate core cater well for this common case. However,
some applications require a catalog of entities and their attributes.
Other applications require a more dynamic mapping to a set of few
fixed tables regardless of the number of domain objects.
solution:
Persist entities to an EAVCR meta-model which stores values of
attributes in a generic Data table. The values can only be stored as a
generic type (String) but types can be tightened at runtime. This also
means that all dynamic entities, heterogeneous as they maybe, are
stored in one table and cataloged by a few more. Using such model
complicates the native SQL to access the data so it maybe necessary to
map the SQL to hide such complexity. Fortunately, domains using this
model require entity centric queries (load all data for a patient)
which is more coarse grained.
does this sound interesting to anyone on this list?
Thanks.
--Iyad
---------------------------------
Ahhh...imagining that irresistible "new car" smell?
Check outnew cars at Yahoo! Autos.
4:19 p.m.
On Apr 30, 2007, at 9:48 PM, Iyad Elian wrote:
alternative persistence model common in some domains like the
medical
domain. how do I go about it?
So data consistency and integrity is not important in the medical
domain and the EAV stuff is used as the main model for data
management? I can't believe that. EAV is just a synonym for "I don't
like to think about data management and schema evolution, therefore
let me break it right away in the design phase." Of course, it has
its uses but it's rare to see it applied properly.
Implementing an EAV pattern on top of Hibernate is trivial. Attached
some source you may use if you promise never to design a system with
this that runs my pacemaker.
4:37 p.m.
very funny. I had similar skepticism until I worked in such domain. I understand the
issues surrounding such a model, I spent 15 years working for Oracle. implementing it is
not that trivial. there is a real need and I explain the details if I have more serious
replies.
Christian Bauer <christian(a)hibernate.org> wrote:
On Apr 30, 2007, at 9:48 PM, Iyad Elian wrote:
alternative persistence model common in some domains like the
medical
domain. how do I go about it?
So data consistency and integrity is not important in the medical
domain and the EAV stuff is used as the main model for data
management? I can't believe that. EAV is just a synonym for "I don't
like to think about data management and schema evolution, therefore
let me break it right away in the design phase." Of course, it has
its uses but it's rare to see it applied properly.
Implementing an EAV pattern on top of Hibernate is trivial. Attached
some source you may use if you promise never to design a system with
this that runs my pacemaker.
---------------------------------
Ahhh...imagining that irresistible "new car" smell?
Check outnew cars at Yahoo! Autos.
5:22 p.m.
Christians answer was actually serious ;)
My background is medical systems and both HL7, GEPJ and the european
DH<something I can' remember anymore>
has a great deal of genericity because the medical domain has it...but I
don't see how it requires
the level of dynamicity you are referring too.
/max
very funny. I had similar skepticism until I worked in such domain.
I
understand the issues surrounding such a model, I spent 15 years working
for Oracle. implementing it is not that trivial. there is a real need
and I explain the details if I have more serious replies.
Christian Bauer <christian(a)hibernate.org> wrote:
On Apr 30, 2007, at 9:48 PM, Iyad Elian wrote:
> alternative persistence model common in some domains like the medical
> domain. how do I go about it?
So data consistency and integrity is not important in the medical
domain and the EAV stuff is used as the main model for data
management? I can't believe that. EAV is just a synonym for "I don't
like to think about data management and schema evolution, therefore
let me break it right away in the design phase." Of course, it has
its uses but it's rare to see it applied properly.
Implementing an EAV pattern on top of Hibernate is trivial. Attached
some source you may use if you promise never to design a system with
this that runs my pacemaker.
---------------------------------
Ahhh...imagining that irresistible "new car" smell?
Check outnew cars at Yahoo! Autos.
--
--
Max Rydahl Andersen
callto://max.rydahl.andersen
Hibernate
max(a)hibernate.org
http://hibernate.org
JBoss a division of Red Hat
max.andersen(a)jboss.com
8:45 p.m.
sorry I don't see how Christian answer was serious brushing me off with few classes to
insert into EAV. granted the way I landed this on you deserves such a reply but can we
skip to the serious phase.
well spotted that I am talking about a deep level of dynamic. Serveral domains not just
the medical field have thousands of objects with subsets needed in different
circumstances. some domains use domain specific languages with runtimes to interpret
content. There are many reasons why you can't map objects to tables at design time.
There are many other reasons why you can't have a static domain model. I am not here
to argue the problem but explore the solution with you.
do I have your ears?
Max Rydahl Andersen <max.andersen(a)redhat.com> wrote:
Christians answer was actually serious ;)
My background is medical systems and both HL7, GEPJ and the european
DH
has a great deal of genericity because the medical domain has it...but I
don't see how it requires
the level of dynamicity you are referring too.
/max
very funny. I had similar skepticism until I worked in such domain.
I
understand the issues surrounding such a model, I spent 15 years working
for Oracle. implementing it is not that trivial. there is a real need
and I explain the details if I have more serious replies.
Christian Bauer wrote:
On Apr 30, 2007, at 9:48 PM, Iyad Elian wrote:
> alternative persistence model common in some domains like the medical
> domain. how do I go about it?
So data consistency and integrity is not important in the medical
domain and the EAV stuff is used as the main model for data
management? I can't believe that. EAV is just a synonym for "I don't
like to think about data management and schema evolution, therefore
let me break it right away in the design phase." Of course, it has
its uses but it's rare to see it applied properly.
Implementing an EAV pattern on top of Hibernate is trivial. Attached
some source you may use if you promise never to design a system with
this that runs my pacemaker.
---------------------------------
Ahhh...imagining that irresistible "new car" smell?
Check outnew cars at Yahoo! Autos.
--
--
Max Rydahl Andersen
callto://max.rydahl.andersen
Hibernate
max(a)hibernate.org
http://hibernate.org
JBoss a division of Red Hat
max.andersen(a)jboss.com
---------------------------------
Ahhh...imagining that irresistible "new car" smell?
Check outnew cars at Yahoo! Autos.
1:18 a.m.
You got two replies already and you still want to argue if you have our
ears.
Either speak up or don't ;)
As I said my background is medical systems and I disagreed with the level
of dynamacity you referring to...
you take it from there.
/max
sorry I don't see how Christian answer was serious brushing me
off with
few classes to insert into EAV. granted the way I landed this on you
deserves such a reply but can we skip to the serious phase.
well spotted that I am talking about a deep level of dynamic. Serveral
domains not just the medical field have thousands of objects with
subsets needed in different circumstances. some domains use domain
specific languages with runtimes to interpret content. There are many
reasons why you can't map objects to tables at design time. There are
many other reasons why you can't have a static domain model. I am not
here to argue the problem but explore the solution with you.
do I have your ears?
Max Rydahl Andersen <max.andersen(a)redhat.com> wrote:
Christians answer was actually serious ;)
My background is medical systems and both HL7, GEPJ and the european
DH
has a great deal of genericity because the medical domain has it...but I
don't see how it requires
the level of dynamicity you are referring too.
/max
> very funny. I had similar skepticism until I worked in such domain. I
> understand the issues surrounding such a model, I spent 15 years working
> for Oracle. implementing it is not that trivial. there is a real need
> and I explain the details if I have more serious replies.
>
> Christian Bauer wrote:
> On Apr 30, 2007, at 9:48 PM, Iyad Elian wrote:
>
>> alternative persistence model common in some domains like the medical
>> domain. how do I go about it?
>
> So data consistency and integrity is not important in the medical
> domain and the EAV stuff is used as the main model for data
> management? I can't believe that. EAV is just a synonym for "I don't
> like to think about data management and schema evolution, therefore
> let me break it right away in the design phase." Of course, it has
> its uses but it's rare to see it applied properly.
>
> Implementing an EAV pattern on top of Hibernate is trivial. Attached
> some source you may use if you promise never to design a system with
> this that runs my pacemaker.
>
>
>
> ---------------------------------
> Ahhh...imagining that irresistible "new car" smell?
> Check outnew cars at Yahoo! Autos.
--
--
Max Rydahl Andersen
callto://max.rydahl.andersen
Hibernate
max(a)hibernate.org
http://hibernate.org
JBoss a division of Red Hat
max.andersen(a)jboss.com
1:22 p.m.
nevermind. thank and Christian for the replies.
Max Rydahl Andersen <max.andersen(a)redhat.com> wrote:
You got two replies already and you still want to argue if you have our
ears.
Either speak up or don't ;)
As I said my background is medical systems and I disagreed with the level
of dynamacity you referring to...
you take it from there.
/max
sorry I don't see how Christian answer was serious brushing me
off with
few classes to insert into EAV. granted the way I landed this on you
deserves such a reply but can we skip to the serious phase.
well spotted that I am talking about a deep level of dynamic. Serveral
domains not just the medical field have thousands of objects with
subsets needed in different circumstances. some domains use domain
specific languages with runtimes to interpret content. There are many
reasons why you can't map objects to tables at design time. There are
many other reasons why you can't have a static domain model. I am not
here to argue the problem but explore the solution with you.
do I have your ears?
Max Rydahl Andersen wrote:
Christians answer was actually serious ;)
My background is medical systems and both HL7, GEPJ and the european
DH
has a great deal of genericity because the medical domain has it...but I
don't see how it requires
the level of dynamicity you are referring too.
/max
> very funny. I had similar skepticism until I worked in such domain. I
> understand the issues surrounding such a model, I spent 15 years working
> for Oracle. implementing it is not that trivial. there is a real need
> and I explain the details if I have more serious replies.
>
> Christian Bauer wrote:
> On Apr 30, 2007, at 9:48 PM, Iyad Elian wrote:
>
>> alternative persistence model common in some domains like the medical
>> domain. how do I go about it?
>
> So data consistency and integrity is not important in the medical
> domain and the EAV stuff is used as the main model for data
> management? I can't believe that. EAV is just a synonym for "I don't
> like to think about data management and schema evolution, therefore
> let me break it right away in the design phase." Of course, it has
> its uses but it's rare to see it applied properly.
>
> Implementing an EAV pattern on top of Hibernate is trivial. Attached
> some source you may use if you promise never to design a system with
> this that runs my pacemaker.
>
>
>
> ---------------------------------
> Ahhh...imagining that irresistible "new car" smell?
> Check outnew cars at Yahoo! Autos.
--
--
Max Rydahl Andersen
callto://max.rydahl.andersen
Hibernate
max(a)hibernate.org
http://hibernate.org
JBoss a division of Red Hat
max.andersen(a)jboss.com
---------------------------------
Ahhh...imagining that irresistible "new car" smell?
Check outnew cars at Yahoo! Autos.
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6 comments
3 participants
participants (3)
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Max Rydahl Andersen