From MathWeb

OMBase is the working title for an implementation of a system similar to MBase, i.e. a database for OMDoc.

Contents 1 Evaluation of MBase 2 Requirements 2.1 Simple Features 2.2 High-Level Features 3 Steps

Evaluation of MBase

• unable to test demo locally, error messages
• Online demo has less errors, but still some :-(
• Seems to depend on old MySQL libraries
• hard-coded dependencies on the OpenMath standard content dictionaries (for search heuristics?)
• database schema corresponds to OMDoc's XML schema -- i.e. not a generic XML database
• OMDoc is "relationalized" manually
• (Advantage: any fragment of a document is easily accessible)
• Term search uses pattern matching and heuristics (unlike MathWebSearch)
• does not support versioning

Requirements

Simple Features

• generic XML database that stores documents and allows for accessing fragments via XPath queries
• Add a cross-platform software layer for accessing the data (e.g. a RESTful web interface)
• Revision / Version management; it should be possible to create patches and pass them around
• Queries:
  • get document
  • get fragment (e.g. a symbol in a theory) by ID
  • get fragment by XPath
  • ...

High-Level Features

High-level features that depend on certain markup languages (e.g. OMDoc) should be implemented in the software layer only -- not in the database, as the database should be a generic XML database.

• for SciML-like languages (e.g. OMDoc)
  • Cross-references between different documents should be transparent when reading something in the database via its URI, e.g., when obtaining a theory, I should also get all theories it imports from.

See also our combined JOMDoc/OMBase Use Cases.

Steps

Implement OMDocStorage based on the PostgreSQL database behind SWiM

• Start with SWiM's current DB layout
• Evaluate PostgreSQL's XML features (partly done)
• Versioning is already available in SWiM/IkeWiki
• Restructure database (in parallel to SWiM's current layout):
  • one column per XML document (XML data type)
  • access smaller fragments via XPath
  • for SWiM (and potentially other applications): extract RDF not only on document, but also on fragment level
• Add a RESTful interface to access documents/fragments/theories/...
• later: connect MathWebSearch

Andrei Ioniţă is preparing this system in an internship from June to August 2007.