## Enhancement ### The o11y of storage layer memory cost * The bytes of overall mem-table for all segments in all physical tables * The number of overall segments in all physical tables * The bytes of overall DMFile meta in memory ### Enhance the `scan_details` * The parsed push_down_executor ### Unbalanced read/write panel among all TiFlash instance * Write throughput among all TiFlash instances * Read throughput among all TiFlash instances * SegmentReader CPU among all TiFlash instances