Use DB + Hibernate instead of plain XML-Files?

chmul · **Posted:** Wed Nov 17, 2004 11:21 am

Hi @ all,

i need to find the right way to store (and retrieve) some very complex datastructures and keep in mind to be able to build some queries for whatever.
Ok so far. Let me try to explain these datastructures xml-like:

<Object>
<Attribute type="foo">bar</Attribute>
... // unknown amount of "Attribute" possible !

<item>
<foo type="string">bar</foo>
<foo type="float">bar</foo>
<foo type="bool">bar</foo>
... // unknown amount of "foo

christian · **Posted:** Wed Nov 17, 2004 11:24 am

XML files are never the right tool for data management. I recommend following the rules for data model design, using a relational logical data model that has been normalized and secured with proper constraints in a SQL implementation. Forget XML if you talk about data, its just a file format. It has the same support for data management as a CSV file.

eg344 · **Joined:** Thu Oct 14, 2004 9:50 am **Posts:** 43

Take a look at castor for oql for xml.

sjivan · **Posted:** Wed Nov 17, 2004 7:06 pm

The XML folks may claim that using an XML database is the right tool for this :)

PS: I'm not in the XML camp with respect to this issue.

christian · **Posted:** Wed Nov 17, 2004 7:07 pm

An XML database is a collection of XML documents. Uhm, great.

sjivan · **Posted:** Wed Nov 17, 2004 7:32 pm

Sure - An XML database is a collection of XML documents but it does provide several services such as an XPath based query service, efficient retrieval of XML without requiring the client to parse the document, specifying constraints on XML documents via an XML Schema, which is more expressive than relational constraints.

An XML database is not suitable in many applications but it does provide value in certain applications that are inherently XML centric. Consider a WSDL catalog where the original data (the wsdl file itself) is XML. It would be more efficient to retrieve and query for services in the catalog was stored in an XML database as opposed to a relational database.

christian · **Posted:** Thu Nov 18, 2004 4:48 am

This sounds like it was copied from an XML database vendords marketing slide. Start here: http://www.amazon.com/exec/obidos/tg/de ... 0321197844

chmul · **Posted:** Thu Nov 18, 2004 9:47 am

ok, thanks for your replies. lets take it from another point. the example i give you above is very abstract. Let me explain some details.
I

ernst_pluess · **Posted:** Thu Nov 18, 2004 4:25 pm

From the technical point of view I have a similar project. We were foreced to import/export complex XML data into/from a DB.
We did the XML stuff with Castor and the DB access with hibernate.

Castor is fine if you have DTD/Schema and you want to be able to read/write the XML Data in a more convenient way than a simple DOM parser gives you. If you want to use it as a full XML-to-OO-Mapper its feature set is limited. Maybe JAXP is better we didn't try.

I guess you have the chance to create your DB from scratch. Then Hibernate 2 is great and chances are high, that you will save time compared to do everythin in plain JDBC.

I've put the XML and the Hibernate stuff underneath a DAO layer. This way the business logic is completely unaware of the data sources.

An other approach is to use XML DB features which give you the possibility to access XML data as if it's a DB table. Guess hibernate could help here as well. But I didn't really investigate a lot on this.

HTH
Ernst