feat: Entity aggregation

[cvauclair]

Motivations

Spaces are logical groups of triples and by default, when querying the space, only entities that have triples in that space would be returned. If an entity described in another space is closely related to these defined in a given space, it would be natural to also include that entity in the space. This can be done by touching that entity in the given space. However, this process is tedious and requires editors to explicitly add relations for external entities one at a time. There is therefore a need for a more natural way to include entities in bulk from another space into a space, hence the idea of aggregation.

Aggregation refers to the process which determines which entities are considered when querying entities in a specific space. Specifically, the idea is that the entities considered when querying a space would not necessarily be restricted to any entity touched by the space (see [[Projects/GRC20/Entity Pluralism|Entity Pluralism]]) but could also include entities of other "verified" or "related" spaces.

For example, Coinbase makes a post that's related to DeFi. They specify DeFi as a Related space on the Post. The DeFi space has Coinbase added as a verified space. That allows us to create a query in the DeFi space that would include that post.

Initial Design

• A space S can have any number of verified spaces
• An entity e in any space can have a related space relation pointing to a space entity
• Given a space S, the entities visible from the perspective of S (i.e.: queryable in that space) are all entities touched by S, as well as all the related entities e such that:
  1. e is touched by space S' and S' is a verified space of S
  2. e has a related space relation defined in space S' pointing to space S

Open Questions

• Is aggregation always applied by default? Or should it be possible to toggle it on or off?
• What triples should be returned for a related entity e as defined above?