DatasetAccessSpec

The access restriction of a dataset bound to an aggregate (DatasetAccess) on a dataset backend: each row is read by the current access attributes of the aggregate it is of, as the kernel's AccessPredicate.allows decides on them, over every predicate of AccessFilterSpec's matrix and its documents.

Each document has two rows in the caller's tenant, so a row shows exactly when its aggregate does; one more row is of an aggregate whose access the storage holds no record of, and the same document id in another tenant has other attributes there. Some records arrive older than the one before them, which never replaces it. A backend's test supplies its bindings (createDatasetBindings), loads the table (createTable) and the access records (storeAccess) where those bindings read them.