Re: Mixing OO and DB
Date: Fri, 29 Feb 2008 18:58:30 +0000
Message-ID: <slrnfsglem.6qe.eric_at_tasso.deptj.demon.co.uk>
On 2008-02-29, Patrick May <pjm_at_spe.com> wrote:
> frebe <frebe73_at_gmail.com> writes:
>>> I tried to be very clear with what I was saying. In the large
>>> OO systems that I've worked on, there was no problem with
>>> proliferation of finder methods in practice.
>>
>> In applications there problem with proliferation of finder methods
>> doesn't exists, the find methods have to be very simple, like
>> "select * from employee where id=?". Otherwise the problem do
>> exists.
>
> Not true. The state of each element in the set of root objects
> may be constructed from complex queries over multiple tables. The
> objects reached from those root objects may be lazily loaded, again
> with complex queries. Regardless of the complexity of those queries,
> there is typically no proliferation of finder methods.
>
>>> Typically, once a core set of objects have been instantiated,
>>> access to related objects is via reference rather than repeated,
>>> explicit database access.
>>
>> And obviously introducing synchronization issues...
>
> You are assuming that the database is always the system of record
> and that the system is data-centric. Those assumptions are not always
> valid so your "obvious" synchronization issues do not occur. There
> are more ways of building large scale distributed systems than are
> dreamt of in your RDBMS.
>
So what is the system of record?
Eric Received on Fri Feb 29 2008 - 19:58:30 CET