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https://issues.apache.org/jira/browse/ATLAS-1410?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15942395#comment-15942395
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Stefhan van Helvoirt commented on ATLAS-1410:
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With regards to the term relationships.
I think there is a difference between conceptual relationships such as 'Is a
Type Of / Has Types', 'Is Of / Has A' and contextual relationships. Where are
contextual relationship could be a 'Is a'.
The relationship 'Is a' is very specific and directing and therefor can only be
used when describing a specific context or in the scenario in which the
relationship is always true. Example of the relationship as described in the
document 'Customer is a Person'. In most situations this might not be universal
true as for example an Organization can also be a Customer and not every Person
is a customer. It should not be possible to have more than one 'Is a' of a
particular type. Example, it should not be possible to have both 'Customer is a
Person' and 'Customer is an Organization' as both Person and Organization are
from the same taxonomy and per instance it can be either the one or the other
but not both.
Furthermore, i think it's worthwhile to add a new relationship similar to the
'Has a' namely 'Has an'.
Example:
- House has a Room
- House has an Occupant
Whereas the 'Has a' is an composition which implies that the child object
cannot live withouth the context of its parent. Destroy the house and the rooms
disappear.
The 'Has an' is an aggregation which implies that the child can exist on its
own. Destroy the house and the occupant goes elsewhere.
In database modelling the 'Has an' can be seen as a foreign key instead of a
normal attribute.
> V2 Glossary API
> ---------------
>
> Key: ATLAS-1410
> URL: https://issues.apache.org/jira/browse/ATLAS-1410
> Project: Atlas
> Issue Type: Improvement
> Reporter: David Radley
> Assignee: David Radley
> Attachments: Atlas Glossary V2 proposal v1.0.pdf, Atlas Glossary V2
> proposal v1.1.pdf, Atlas Glossary V2 proposal v1.2.pdf, Atlas Glossary V2
> proposal v1.3.pdf
>
>
> The BaseResourceDefinition uses the AttributeDefintion class from typesystem.
> There are newer more funcitonal versions of this capability in the atlas-intg
> project. This Jira is changing over the glossary implementation to the newer
> entity / type classes.
> Instread of the instanceProperties and collectionProperties in the
> BaseResourceDefintions we should use something in this sort of style :
> "
> AtlasEntityDef deptTypeDef =
> AtlasTypeUtil.createClassTypeDef(DEPARTMENT_TYPE,
> "Department"+_description, ImmutableSet.<String>of(),
> AtlasTypeUtil.createRequiredAttrDef("name", "string"),
> new AtlasAttributeDef("employees",
> String.format("array<%s>", "Person"), true,
> AtlasAttributeDef.Cardinality.SINGLE, 0, 1,
> false, false,
>
> Collections.<AtlasStructDef.AtlasConstraintDef>emptyList()));
> AtlasEntityDef personTypeDef =
> AtlasTypeUtil.createClassTypeDef("Person", "Person"+_description,
> ImmutableSet.<String>of(),
> AtlasTypeUtil.createRequiredAttrDef("name", "string"),
> AtlasTypeUtil.createOptionalAttrDef("address", "Address"),
> AtlasTypeUtil.createOptionalAttrDef("birthday", "date"),
> AtlasTypeUtil.createOptionalAttrDef("hasPets", "boolean"),
> AtlasTypeUtil.createOptionalAttrDef("numberOfCars", "byte"),
> AtlasTypeUtil.createOptionalAttrDef("houseNumber", "short"),
> AtlasTypeUtil.createOptionalAttrDef("carMileage", "int"),
> AtlasTypeUtil.createOptionalAttrDef("age", "float"),
> "
> For the parent child relationships with glossary categories and terms we
> should be able to have the type system manage edge deletion. As part of this,
> we will need to investigate whether we could get rid of the disconnect and
> connect methods added in ATLAS-1186
>
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