@Override
    public List<SegmentFd> all() {
        List<SegmentFd> fds = new ArrayList<>(realtimeSegmentPool.all());
        List<SegmentFd> hisFds = historySegmentPool.all();
        for (SegmentFd fd : hisFds) {
            if (realtimeSegmentPool.get(fd.name()) == null) {
                fds.add(fd);
            }
        }
        return fds;
    }
A table combines realtime segments and history segments.
indexr-server/src/main/java/io/indexr/server/HybridTable.java