That an instance has been checked against every bucket (V204), when, and how many buckets held it.
Written by Storage.Workers.LocationBackfillJob for every instance it
visits (a miss included, found_in: 0), and by the writers that store an
object (they know every bucket they wrote). A read that finds a key in a
bucket its rows did not name records that location, but is not a check:
the other copies may be elsewhere.
Go through PhoenixKit.Modules.Storage.Locations.
Summary
Types
@type t() :: %PhoenixKit.Modules.Storage.LocationCheck{ __meta__: term(), checked_at: NaiveDateTime.t() | nil, file_instance_uuid: UUIDv7.t() | nil, found_in: non_neg_integer() }