RE: [xml-dev] XML Database Decision Tree? [xml-dev-help@lists.xml.org: Not authorized to submit to elist:xml-dev]

[Dan Weinreb <dlw@exceloncorp.com>]

   From: Leigh Dodds <ldodds@ingenta.com> 
   Date: Thu, 18 Oct 2001 16:16:08 +0100 

   There might be something in here about schema evolution as
   well. However I'm not familiar enough with native XML products to say
   how they'd handle this.

   E.g. if your schema is in a constant state of change (and they
   probably all are over time) or has yet to be finalized/standardised
   then locking it into a database structure might be unwise. Or am I off
   track on that one?

Well, I can tell you how it works in eXcelon's XIS; unfortunately I'm
not familiar enough with any of the others to say.  In XIS, an XML
document stored in the database need not be "locked" into the
constraints of a schema.  You can store XML documents that don't even
have any schema (nor DTD, et. al.).  You can then add new elements and
attributes at will (and it's cheap to do so, and existing indexes are
not affected, XPath expressions work, etc.).  Validation is optional.