Cayenne cache and external changes

[Marek Šabo <ms...@buk.cvut.cz>]

Hi,

my app that uses cayenne got few rows changed externally in mysql 
database. I observed that app didn't behave according to these changes 
and after restarting it worked as expected (with those changed rows). 
Could this be due to cayenne caching mechanism. Or is it probably bug on 
my side? If former, is it possible to set time expiration on cache, or 
invoke expiration manually?

Thanks,

Regards,

Marek

On 11/30/2011 06:47 PM, Durchholz, Joachim wrote:
> On http://cayenne.apache.org/doc/modeling-inheritance.html , I see this statement:
> "As of this writing Cayenne does not support horizontal inheritance. It may in the future."
>
> Well, guess what, the first instance where I absolutely need inheritance does require horizontal modeling. Two legacy tables happen to have a very similar column structure and server very similar purposes, and since the processing is complicated and accesses many fields of each record, having a common superclass wired up would really simplify a lot of code.
>
> So the question is: Is there any realistic hope that this will be done soon?
> Would outside help speed up things?
> Limited help, unfortunately. I'll have to justify any time I sink into this :-(
>
> The other approach might be faking a vertical/joined scenario using views.
> However, I'd like to avoid that because I know that views tend to come with their own cans of worms (updateability and lack of useful metadata).
>
> Regards,
> Jo

Re: Cayenne cache and external changes

[Michael Gentry <mg...@masslight.net>]

Hi Marek,

Are you talking about saving or fetching?  On saving, optimistic
locking can help catch stale data issues.  On fetching, I always
prefer to go back to the DB and get fresh data (not use the cache).

mrg


On Wed, Nov 30, 2011 at 3:53 PM, Marek Šabo <ms...@buk.cvut.cz> wrote:
> Hi,
>
> my app that uses cayenne got few rows changed externally in mysql database.
> I observed that app didn't behave according to these changes and after
> restarting it worked as expected (with those changed rows). Could this be
> due to cayenne caching mechanism. Or is it probably bug on my side? If
> former, is it possible to set time expiration on cache, or invoke expiration
> manually?
>
> Thanks,
>
> Regards,
>
> Marek
>
> On 11/30/2011 06:47 PM, Durchholz, Joachim wrote:
>>
>> On http://cayenne.apache.org/doc/modeling-inheritance.html , I see this
>> statement:
>> "As of this writing Cayenne does not support horizontal inheritance. It
>> may in the future."
>>
>> Well, guess what, the first instance where I absolutely need inheritance
>> does require horizontal modeling. Two legacy tables happen to have a very
>> similar column structure and server very similar purposes, and since the
>> processing is complicated and accesses many fields of each record, having a
>> common superclass wired up would really simplify a lot of code.
>>
>> So the question is: Is there any realistic hope that this will be done
>> soon?
>> Would outside help speed up things?
>> Limited help, unfortunately. I'll have to justify any time I sink into
>> this :-(
>>
>> The other approach might be faking a vertical/joined scenario using views.
>> However, I'd like to avoid that because I know that views tend to come
>> with their own cans of worms (updateability and lack of useful metadata).
>>
>> Regards,
>> Jo