Re: [xml-dev] XML Database Decision Tree?

[Ronald Bourret <rpbourret@rpbourret.com>]

"Champion, Mike" wrote:


> I'm not sure if XML DBMS are "based on the hierarchical database model" in
> any formal sense, but there is clearly some overlap and inspiration.

Assuming I understand hierarchical databases correctly, there is one
significant difference. I have been told that in a hierarchical database
all of the nodes of a given parent are homogenous -- that is, the same
type. This is not necessarily true of a native XML database. For
example, an element parent node can have element, text, attribute,
entity reference, etc. child nodes.

>  Nevertheless, as the
> statistics I posted earlier in this thread indicate, hierarchical and other
> "pre-relational" DBMS keep chugging along, running the world economy in the
> back offices of the Fortune 1000.

I quoted the same (very impressive) statistics at a database user's
group meeting last week and somebody pointed out that one possible
reason for hierarchical databases still existing is not that they're
better at the problem they solve, just that it's not cost effective (or
perhaps even possible) to change all the code that's based on them.

-- Ron