> (1) If i have to store big sized objects, what
> is a better idea
> -> to store on to the file system and enter the
> file URL's into the database OR try to store
> the objects into the database as BLOBS
Hi there. I don't think there's one simple answer here as a large part of your solution depends on your requirements and the strategy you adopt to deal with them. But having said that, i think you'll get very poor performance from Hypersonic if you try to store 50MB files in it and, conversely, much better performance from the file system.
> (2) If we start storing the objects into the
> filesystem I feel that there is always a risk
> of someone tampering the data, and i dont want
> the data to be visible. In such a case what can
> we do ?
There's a security risk in any sort of data storage. In file systems, people can access data if you don't have the appropriate file permissions, etc. In databases, people can check your data if you don't have the appropriate database permissions. I think you have to identify the security needs that are specific to the application you are developing and see what options given your environment, skills, etc. can best meet them.
> (3) If i choose to store these huge objects
> into the database ... particularly Hypersonic,
> what are its limitations ? How big objects can
> i store in it, and do i need to make any
> changes in any of the jboss xml files ?
I recommend going to Hypersonic's website and downloading the specs for the version of the database you are using.
> (4) I also read in some forums that storing the
> data into files is away from the EJB spec .. is
> it right ?
I am not sure what you mean. If you want to represent your data as an entity bean, I guess it might be. But you can always manage the data with session or message driven beans, or you can delegate responsibility to regular
Java classes. I don't think the EJB specification should be viewed as locking you into some sort of storage system. It's strengths and weaknesses should be weighed against your needs and used or not used accordingly.
Cheers,
Darryl