[jdom-interest] rdms & jdom
edoardo at knowledgeview.co.uk
Fri Apr 6 02:13:26 PDT 2001
I was also going to store xml documents in the RDB. my xml documents will be
"data" (thrird-party and custom documents, like NewsML), "rules" (complex
user objects described in XML) and lots of XSLT stylesheets (used by the
my concern was that storing xml on the RDB, I lose the ability of easily
referring from one xml doc to another via relative URIs.
a rule element can contain an attribute stylesheet="util/mystyle.xsl"
a stylesheet is likely to use <xsl:import> and the document() function
"navigation" via reltive URIs is straightforward if everything is stored on
the file system.
how can it be done simply if we use an RDB ?
> -----Original Message-----
> From: jdom-interest-admin at jdom.org
> [mailto:jdom-interest-admin at jdom.org]On Behalf Of
> philip.nelson at omniresources.com
> Sent: 06 April 2001 03:40
> To: jdom-interest at jdom.org
> Subject: RE: [jdom-interest] rdms & jdom
> > 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.
> - 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
> - 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
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