Most databases tell you what matched. They can't prove that's everything, with nothing held back. This page can: your browser downloads every public record and works out the answer itself, so the proof that nothing's missing doesn't depend on us.
Streams number their records 1, 2, 3…, so a missing number shows up as a gap. A separate version of the same check: check_stream_v2 in log-server. A stream with no gaps proves nothing was held back. It never proves any record is true.