Skip to content

description of NaturalKey constraint #81

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Draft
pahjbo wants to merge 1 commit into
base: 20-update-vo-dml-standard-document
Choose a base branch
from
Draft

description of NaturalKey constraint #81

Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
6 changes: 6 additions & 0 deletions doc/std/VO-DML.md
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -2629,6 +2629,12 @@ a **semanticconcept** with a **topConcept** defined on it, the subtype
may restrict the values to a narrower concept than that assigned to it
on the super-type.

## NaturalKey extends Constraint

This is a special class of constraint that can be used to indicate that an **Attribute** is naturally the identifier
for its owning **ObjectType**. If so constrained then the **Attribute** would be expected to be globally unique for each **ObjectType** within the domain of the model. This has particular relevance in serializations of the model instances to relational databases, where it can be used to indicate the primary key for the **ObjectType** rather than using a surrogate key.


# The *ivoa* base model \[Normative\]

Ultimately all types in a VO-DML model are defined as hierarchies of
Expand Down