IVOA, Trieste, DM Gerard Lemson Data Modelling Standards (contd.) IVOA interop, DM WG session Trieste,

IVOA, Trieste, DM Gerard Lemson Data models How to define them Analysis  Logical  Physical Cambridge, MA What to do with them store instances send them around manipulate them in code look at them on a screen Can we standardise this process? WG task: check for compatibility

IVOA, Trieste, DM Gerard Lemson Model definition in UML UML profile subset of UML package, class, datatype enumeration, composition, inheritance, few more primitive data types string,integer, real, date,... stereotypes+tag definitions >+ontologyURI design rules “concrete classes final”,...

IVOA, Trieste, DM Gerard Lemson UML Profile for logical model

IVOA, Trieste, DM Gerard Lemson Physical models Representation of model for use in particular context XML (messaging) Database (storage) Java (manipulation) HTML (documentation) UTYPE (pointing)

IVOA, Trieste, DM Gerard Lemson Mapping rules Useful/efficient to derive physical models from logical one Define rules Automate “meta-specification”

IVOA, Trieste, DM Gerard Lemson Examples: UML->DDL “standard” ORM class->table attribute->column reference->foreign key etc In IVOA: VODataService (?)

IVOA, Trieste, DM Gerard Lemson Examples: UML->XML Kyoto hema.ppt hema.ppt

IVOA, Trieste, DM Gerard Lemson Example: Mapping Classes Every class -> globally defined complexType isAbstract -> abstract=“true” Attribute -> element of simplish-type, either built-in, or also generated

IVOA, Trieste, DM Gerard Lemson Problem: references Links to objects inside documents: ID/IDREF Links to objects outside document ? IVO Identifier ?

IVOA, Trieste, DM Gerard Lemson Examples: UTYPE Represent model in custom serialisations attribute ":" [ "/" ]* "/" "." [ "." ]* reference ":" [ "/" ]* "/" "."

IVOA, Trieste, DM Gerard Lemson Suggestions Define UML profile for use in IVOA DM efforts Define rules for mapping to XML relational model (VODataService) UTYPE others? TCG “Topic” (GL, ML) and then?

IVOA, Trieste, DM Gerard Lemson Proof of concept Implemented this procedure in SimDB m/ m/ UML profile Rules in XSLT DDL, XML, Java, HTML doc Applicable to other DMs e.g. registry Demo by Laurent

IVOA, Trieste, DM Gerard Lemson Suggestions (contd) Define IVOA analysis model where do different models fit in design patterns How do we “reuse” models import and “derive” (?) import and “link” represent