min(id)为什么走全表扫描

+------------------------------+---------+---------+-----------+-----------------+-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+----------------------------------------------+-----------+------+
| id                           | estRows | actRows | task      | access object   | execution info                                                                                                                                                                                                                                                                                                                                                                      | operator info                                | memory    | disk |
+------------------------------+---------+---------+-----------+-----------------+-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+----------------------------------------------+-----------+------+
| StreamAgg_9                  | 1.00    | 1       | root      |                 | time:1m0.7s, loops:2                                                                                                                                                                                                                                                                                                                                                                | funcs:min(order.data.id)->Column#12          | 160 Bytes | N/A  |
| └─Limit_13                   | 1.00    | 1       | root      |                 | time:1m0.7s, loops:2                                                                                                                                                                                                                                                                                                                                                                | offset:0, count:1                            | N/A       | N/A  |
|   └─TableReader_24           | 1.00    | 1       | root      |                 | time:1m0.7s, loops:1, cop_task: {num: 221, max: 491.7ms, min: 584.9µs, avg: 274.4ms, p95: 419.9ms, max_proc_keys: 1, p95_proc_keys: 0, tot_proc: 1m0.3s, tot_wait: 23ms, rpc_num: 221, rpc_time: 1m0.6s, copr_cache_hit_ratio: 0.00, distsql_concurrency: 1}                                                                                                                        | data:Limit_23                                | 547 Bytes | N/A  |
|     └─Limit_23               | 1.00    | 1       | cop[tikv] |                 | tikv_task:{proc max:491ms, min:0s, avg: 273.5ms, p80:409ms, p95:419ms, iters:221, tasks:221}, scan_detail: {total_process_keys: 1, total_process_keys_size: 27, total_keys: 153800520, get_snapshot_time: 108ms, rocksdb: {delete_skipped_count: 14402724, key_skipped_count: 168203023, block: {cache_hit_count: 2191, read_count: 240664, read_byte: 2.66 GB, read_time: 11.2s}}} | offset:0, count:1                            | N/A       | N/A  |
|       └─TableFullScan_22     | 1.00    | 1       | cop[tikv] | table:data      | tikv_task:{proc max:491ms, min:0s, avg: 273.5ms, p80:409ms, p95:419ms, iters:221, tasks:221}                                                                                                                                                                                                                                                                                        | keep order:true                              | N/A       | N/A  |
+------------------------------+---------+---------+-----------+-----------------+-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+----------------------------------------------+-----------+------+
5 rows in set (1 min 0.77 sec)