Why it matters
Traversing a reverse direct relation (inwards direction) requires an index on the target direct relation property. Without this index, queries will be inefficient, potentially leading to timeouts over time, as they won’t scale well with data volume. The exception is when the target direct relation is a list property. In that case, this validator will not flag them, as reverse direct relations targeting lists of direct relations need to be traversed using theinstances/search endpoint instead,
which does not directly benefit from adding indexes to container properties.
Example
ViewWindFarm has a reverse property turbines through WindTurbine.windFarm.
Container WindTurbine should have a cursorable B-tree index on the windFarm
property to enable efficient traversal from WindFarm to its turbines.