This is ColumnarBatchIdentityV1 with the authorization scope replaced
by its digest, which is the whole point: telemetry must never become a side
channel for the scope value the cache key deliberately excludes. Ordering and
freshness are omitted because a span reports what an operation cost, not what
the batch is; the four keyed identifiers plus the scope digest are what make
two observations of the same batch correlatable.
The batch identity a span is bound to.
This is ColumnarBatchIdentityV1 with the authorization scope replaced by its digest, which is the whole point: telemetry must never become a side channel for the scope value the cache key deliberately excludes. Ordering and freshness are omitted because a span reports what an operation cost, not what the batch is; the four keyed identifiers plus the scope digest are what make two observations of the same batch correlatable.