SpiceDB is an open source, Google Zanzibar-inspired, database system for creating and managing security-critical application permissions.

SpiceDB

I know it's called out in the documentation in regards to using subject relations with the arrow, but isn't using subject relations just a performance footgun in general, unless you only have a very small number of them for a given relation?

For example, given a schema like

```
definition user {}

definition membership {
  relation: user
  relation: organisation
}

definition organisation {
  relation member: membership#user

  permission view = member
}
```

With a large number of `member` you see a significant performance hit vs a direct `user` relation. Just wondering if it's worth calling this out in the `Subject Relations` section of the docs too if it's not a problem specific to arrows?