db-ddlutils-user mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Thomas Dudziak <tom...@gmail.com>
Subject Re: oracle database model dangerously broken
Date Mon, 06 Feb 2006 22:18:32 GMT
On 2/6/06, Tim Dudgeon <tdudgeon@informaticsmatters.com> wrote:

> thanks for that info. I understand your explaination, but doesn't this
> significantly limit the use of DDLUtils?
> If DDLUtils can make uncalled for changes to any database that has been
> created, or modified, by anything other than DDLUtils, then that's quite
> a high risk to accept?

Its not so much limiting but ruther a matter of focus. In its current
version DdlUtils primarily intends to allow Java applications to
create and initialize databases without having to care about the
actual database and its native types, SQL structure, etc.

One particular point is that DdlUtils must ensure that the native type
that a JDBC type is mapped to, is suited (large enough, the driver
accepts the corresponding Java type etc.). The problem now is that
when reading back a model, DdlUtils has to rely on the JDBC driver's
implementation of the database metadata. And if the driver decides
that multiple types map to the same JDBC type (think Oracle which maps
numeric types back to JDBC type DECIMAL), then we're in trouble
because DdlUtils has no way to distinguish between them (perhaps only
via the size as DdlUtils does in the case of Oracle) and hence
problems as in your case are bound to arise.

That being said, it would surely be possible to invest more work and
make this more robust. But this means a lot of work, and thus cannot
be a target for the 1.0 release which should come out
real-soon-now(tm).

Tom

Mime
View raw message