RE: [xml-dev] When to Validate XML?

[Michael Kay <michael.h.kay@ntlworld.com>]

> Hi JJ  ... now that you're out there in the Real World
> <grin>, maybe you
> could help us understand the role of RDBMS-level validation
> vs application
> logic.  I suspect that will be the pattern that XML B2B/A2A
> systems will
> tend to follow once XML Schema implementations and
> applications mature.  Are
> you saying that the RDBMS triggers, rules, etc. are mostly
> used during the
> debugging phase, and perhaps that application logic
> (JavaBeans in an app
> server or whatever) tends to handle the validation in the production
> applications?  If so, is that because the DB
> triggers/rules/etc. have too much of a performance burden?

Actually I think a lot of people use database-level validation during normal
running, and then duplicate most of the checks at application level. The
main reason for doing the checks at the application level (or somewhere
close to the user interface) is that you can give much more responsive
diagnostics to the person who made the mistake. By the time a database
integrity check squeals, you've no idea where to position the cursor so the
user can correct the data.

Mike Kay