@Override
    public SegmentFd get(String segmentName) {
        SegmentFd fd = historySegmentPool.get(segmentName);
        if (fd == null) {
            fd = realtimeSegmentPool.get(segmentName);
        }
        return fd;
    }
A table combines realtime segments and history segments.
indexr-server/src/main/java/io/indexr/server/HybridTable.java