Data Model Vision (OSAF)

This page offers some background "vision" documents that describe the high level goals for Chandler that we had in mind as we designed the details of the OldDataModelPage.

• "Chandler ... should be thought of, as the poster child application for the Semantic Web, i.e., we're the first major legacy-free app to embrace a point of view extremely consistent with what W3C is trying to do here."

Vision Documents for the Data Model

• Mitch's weblog -- 24 Oct 2002
• Mitch's weblog -- 15 Dec 2002
• General Information Management
• ..."data types are richly integrated"
• ...ad-hoc attributes
• ChandlerDataMixingGoals

Crib Notes about our Goals

cribbed from Katie's prep notes for the July 2003 OSCON presentation...

Goals for Data in Chandler: End User

• Flexible Data Model
  • A user can easily create and share a custom list as needed
• Not a relational database or object database
  • formal schema, hard to change
• Not a spreadsheet
  • flexible, no semantics
• Data Framework
  • Data Mode and Item Repository
  • Flexible, semi-structured data
  • Includes some semantic information

User's Data

• Flexibly create new data
• Add semantics to data (schema)
• Schema is just more data
• Create relationships between new data and existing data
• Semantic Web: share data with semantics

Python Programmer

• Data Model
  • Define schema with XML
• Python Mapping
  • Access data as objects
  • Associate methods with objects
• Repository
  • sharing, security, replication
  • BerkeleyDB^? for storage
  • object cache with transparent navigational access (like ZODB)

Flexible Data

• Add additional attributes to an item
• Add additional attributes to a kind
• Global attributes
• Symmetical item references

Goals for Data in Chandler: Programmer

• Easy to add new schema for a new parcel
• Object-oriented programming (python)
• Scalable, reasonable performance
• Programming not onerous for python parcel programmer

Inspired by RDF

• Triples: (subject, predicate, object)
• Schema is data, expressed in triples
• Semantic Web goals are appealing

Chandler: Items

• Items are like a collection of triples with the same subject
• Items are indexed, not triples
• Searches return items, not triples
• Performance, scalability implications

Contributors

• BrianDouglasSkinner - 24 Jun 2003, 24 Sep 2003