Re: Database for EAV model

Hi again,

Don't worry about your English - it is just fine! 

Your application is interesting (rural community health care) ... I'd be interested in hearing how your project progresses. Maybe you even want to turn it into an open source project?

To answer your questions:

You are correct that RMS is limited on many platforms - also, performance can vary widely. But when you talk about "really huge records" for your application and say that 1 MB (on S40 devices) is not enough I am wondering if you will be able to process that amount of data on a low-end to mid-range phone even if you could store it. So the capability of the database may not be the limiting factor.

As for Perst/PerstLite - I am not an expert in it - you may want to contact the McObject people directly, I've found them to be quite helpful.

As you say JSR-75 is another option - if your requirements in terms of relational functionality are not too high then you could certainly create your own little flat-file database with a space-saving binary representation, indexing and caching. But watch out for file access times which can be long on devices that use non-volatile memory for file storage. 

SQL versions such as JavaDB typically require CDC-based platforms because they need Java SE-type language features and APIs. However, I found this

  http://developer.mimer.com/documentation/latest_javadoc_midp/overview-summary.html

which seems to be an SQL driver on CLDC/MIDP - but you will still need the actually SQL implementation underneath.

Finally, I think you may need to rethink your design. If the database is really that large you may want to offload the queries and processing to the server and just provide the UI and the results on the phone - this of course requires decent wireless connectivity and cost is a factor. I don't know if that is an option in your case.

-- Terrence
[Message sent by forum member 'terrencebarr' (terrencebarr)]

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