[jdom-interest] rdms & jdom

[philip.nelson at omniresources.com]

> I want to know which is the best way to store xml for jdom. 
> My working plan
> has always been to store xml as a clob and deliver up the 
> jdom document as
> needed. We could also serialize the jdom object as a blob. The second
> approach shortens the response time on delivering the jdom 
> object...but
> increases the storage requirements on the database.
> 
> A third approach is to map the jdom object into the rdms.

Though this list has been quiet, it seems people have pretty strong feelings
about this issue.  There are very reasonable reasons to do this IMHO and
some problems I ran into that I can share.

Positive
- In any load balanced scenario, the file system won't do.  
- clob/blob is conceptually very simple
- you get to avoid long fruitless normalization discussions with insane
dba's :^)
- versioning is simpler though not simple
- simple transaction model depending on the DB

Negatives
- I had a rotten time with clobs in Oracle 8i.  Major data corrupting bugs
actually.  Your mileage may vary.
- you may still have to map some of the fields
- database queries are not straightforward at all.
- query tools often cannot deal with clobs
- *very* database dependent implementations and you are usually on your own
for help
- your dba may not speak to you again

You have missed option 4, a shared file system with database tracking.
Oracle has a system like this already but I don't have any personal
experience with it.  Mapping is good if you don't have lots of different
document types or don't have to change your document versions very often.
Better check your performance parameters if you go the clob route because
it's not easy to upgrade your database compared to other parts of the
system.