presto-raptor-legacy/src/main/java/io/prestosql/plugin/raptor/legacy/storage/organization/ShardCompactor.java/ShardCompactor/updateStats
class ShardCompactor:    private void updateStats(int inputShardsCount, int outputShardsCount, long latency)
    {
        inputShards.update(inputShardsCount);
        outputShards.update(outputShardsCount);

        inputShardsPerCompaction.add(inputShardsCount);
        outputShardsPerCompaction.add(outputShardsCount);

        compactionLatencyMillis.add(latency);
    }