Models

FactDb uses ActiveRecord models for data persistence.

Core Models

• Source - Immutable source content
• Entity - Resolved identities with aliases
• Fact - Temporal assertions

Supporting Models

EntityAlias

Stores alternative names for entities.

class EntityAlias < ActiveRecord::Base
  belongs_to :entity
end

Column	Type	Description
entity_id	bigint	Parent entity
name	string	Alternative name
type	string	Type (nickname, abbreviation, etc.)
confidence	float	Match confidence

EntityMention

Links facts to mentioned entities.

class EntityMention < ActiveRecord::Base
  belongs_to :fact
  belongs_to :entity
end

Column	Type	Description
fact_id	bigint	Parent fact
entity_id	bigint	Referenced entity
mention_text	string	How entity was mentioned
mention_role	string	Role (subject, object, etc.)
confidence	float	Resolution confidence

FactSource

Links facts to source content.

class FactSource < ActiveRecord::Base
  belongs_to :fact
  belongs_to :source
end

Column	Type	Description
fact_id	bigint	Parent fact
source_id	bigint	Source content
kind	string	Kind (primary, supporting, corroborating)
excerpt	text	Relevant text excerpt
confidence	float	Source confidence

Model Relationships

erDiagram
    Source ||--o{ FactSource : "sourced by"
    Entity ||--o{ EntityAlias : "has"
    Entity ||--o{ EntityMention : "mentioned in"
    Fact ||--o{ EntityMention : "mentions"
    Fact ||--o{ FactSource : "sourced from"