presto-raptor-legacy/src/main/java/io/prestosql/plugin/raptor/legacy/metadata/ShardDao.java/ShardDao/getCleanableShardsBatch
class ShardDao:    @SqlQuery("SELECT shard_uuid\n" +
            "FROM deleted_shards\n" +
            "WHERE delete_time < :maxDeleteTime\n" +
            "LIMIT " + CLEANABLE_SHARDS_BATCH_SIZE)
    Set<UUID> getCleanableShardsBatch(@Bind("maxDeleteTime") Timestamp maxDeleteTime);