Change the table comment after created the table is not supported now?
Like mysql : ALTER TABLE [tableName] COMMNET [comment]; 
The sql "ALTER TABLE `system`.tables UPDATE Comment='test' WHERE NAME='t1';" also not supported!!!
My version is '21.9.4.35'。
cluster = optimized_cluster;
            query_info.optimized_cluster = cluster;
            nodes = getClusterQueriedNodes(settings, cluster);
        }
        else
        {
            LOG_DEBUG(log, "Unable to figure out irrelevant shards from WHERE/PREWHERE clauses - the query will be sent to all shards of the cluster{}",
                    has_sharding_key ? "" : " (no sharding key)");
        }
    }
    if (settings.distributed_group_by_no_merge)
    {
        if (settings.distributed_group_by_no_merge == DISTRIBUTED_GROUP_BY_NO_MERGE_AFTER_AGGREGATION)
        {
            if (settings.distributed_push_down_limit)
                return QueryProcessingStage::WithMergeableStateAfterAggregationAndLimit;
            else
                return QueryProcessingStage::WithMergeableStateAfterAggregation;
        }
        else
        {
            
            
            if (to_stage != QueryProcessingStage::Complete)
                throw Exception("Queries with distributed_group_by_no_merge=1 should be processed to Complete stage", ErrorCodes::LOGICAL_ERROR);
            return QueryProcessingStage::Complete;
        }
    }