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Re: Indexing XML documents
On Wed, 28 Jun 2000, Ashvil wrote:
> I am new to Object/XML databases so I am not sure if this question
> makes sense.
>
> Is there any way to tell Ozone to index certain nodes, similarly to
> specifying indexes on SQL tables.
>
> For example, If I am storing Contact Information about people in xml
> formats. Then I want indexes built on Name and Company Name only for
> faster queering.
ozone/XML just provided the persistent DOM implementation. You can use any DOM
based tool on top of it, including Xalan or Xt for XPath querying. (currently Xt
is the default for ozone/XML) Xalan is very slow where Xt is very fast. I don't
know which techniques (indexing or whatever) both packages use.
Anyway, why do you want to store Contact Information in XML? An dedicated
object model seems to be much better suited. Such a simple object model would
allow you to implement as access paths (indexes, trees, whatever) to the data
as you like.
> Actually, What I would like even better would be for the database to
> automatically add indexes by learning about the queries I make. SQL
> Server 7 claims to do something like that. Any plans to add a feature
> like that to ozone db ?
Indexing XML data is out of the scope of ozone/XML. We are relying on third
party tools like Xt here.
Automatically indexing raw objects in ozone makes no sense because there is
no way to use such an index - ozone does not have a query language like OQL.
Query langs other than the underlying programming language totally violaty any
OO ideas. In some cases they may be fast because they can be optimized - but
they are not OO!
However, of course it is no problem to implement any kind of data access path
in your application. Just put your data in a hashmap... or a treemap... or an
array or whatever meets the needs of your application.
Falko
--
______________________________________________________________________
Falko Braeutigam mailto:falko@softwarebuero.de
softwarebuero m&b (SMB) http://www.softwarebuero.de