private static String getStr(Record record, int col) {
        CharSequence charSequence = record.getStrA(col);
        return charSequence != null ? charSequence.toString() : "";
    }
An implementation of the metrics Db backed by Quest:
This provides local persistent storage of metrics with fast, multi-threaded lookup and write,
suitable for production.

@author bratseth
node-repository/src/main/java/com/yahoo/vespa/hosted/provision/autoscale/QuestMetricsDb.java