CREATE TABLE assessor_import_fingerprints (
  sha256 text PRIMARY KEY CHECK (sha256 ~ '^[a-f0-9]{64}$'),
  file_name text NOT NULL CHECK (btrim(file_name) <> ''),
  size_bytes bigint NOT NULL CHECK (size_bytes >= 0),
  last_modified bigint NOT NULL CHECK (last_modified >= 0),
  first_imported_at timestamptz NOT NULL,
  last_imported_at timestamptz NOT NULL,
  import_count integer NOT NULL DEFAULT 1 CHECK (import_count >= 1),
  data jsonb NOT NULL CHECK (jsonb_typeof(data) = 'object')
);

CREATE INDEX assessor_import_fingerprints_last_imported_idx
  ON assessor_import_fingerprints (last_imported_at DESC);