@Override protected void doPartialFill(Result result, String summaryClass) {
        if (result.getQuery().getTrace().isTraceable(2))
            result.getQuery().trace("Ignoring fill(" + summaryClass + "); streaming is single-pass", false, 2);
    }
The route to the storage cluster.
container-search/src/main/java/com/yahoo/vespa/streamingvisitors/StreamingBackend.java