- From: Tim Bray <tbray@textuality.com>
- Date: Fri, 24 Oct 2003 16:10:46 -0700
- To: "Joshua Allen" <joshuaa@microsoft.com>
- Cc: "Champion, Mike" <Mike.Champion@SoftwareAG-USA.com>, <www-tag@w3.org>
On Friday, October 24, 2003, at 12:44 PM, Joshua Allen wrote: >> Whoa! Are you getting confused about what people mean by "data >> model"? > RPC/DCOM interop was all about shared marshalling formats, and shared > interface definitions -- not about shared data models. Nobody in the > DCOM/Corba/RPC worlds deals with things at the data model level. Granted; although I tend to see APIs and data models as two sides of the same coin, especially when thinking in O-O terms. For example, the DOM is actually an API but nobody feels uncomfortable calling it an object model. > As an example of an "interoperable data model", think of the relational > data model. The existence of the relational data model means that I > can > learn SQL and use any of a number of great database engines. The > existence of relational data model means that I can convert my code > from > using SQL Server to use MySQL with no code changes necessary -- > regardless of which programming language or API (ODBC, JDBC, OLEDB) I > chose to use. Really? I have much personal bitter experience with porting apps from one database vendor's SQL to another's, and have observed serious breakage to be the rule rather than the exception. > The benefits of a shared data model in the case of relational are > completely undisputable. And the benefits of a shared semistructured > data model are already evident in enabling deployment of XPath, and > will > soon be far more evident in deployment of XQuery. I agree entirely. But what does this have to do specially with *networked* information systems in general and the Web in particular? The virtues of SQL are perfectly apparent when you're doing a master file update in COBOL under whatever IBM calls MVS these days. I assume the same will be true of XQuery. The Webarch document needs to highlight those architectural virtues that are particularly important in constructing *networked* information systems, and prominent among those is winning interoperability by defining the bits on the wire. Remember, this is about the architecture of the Web, not a general collection of sermons about goodness in technologies that are modern, or that W3C members use, etc. -Tim
Received on Friday, 24 October 2003 19:17:30 UTC