Slow Query on mysql.stats_meta Table #64571
Description
Bug Report
Please answer these questions before submitting your issue. Thanks!
1. Minimal reproduce step (Required)
- Create a huge cluster with heavy workload.
- Check the slow logs.
2. What did you expect to see? (Required)
No slow queries on mysql.stats_meta table.
3. What did you see instead (Required)
SELECT version, table_id, modify_count, count, snapshot, last_stats_histograms_version FROM mysql.stats_meta WHERE version > 462255440511108949 ORDER BY version;
| id | estRows | estCost | actRows | task | access object | execution info | operator info | memory | disk |
| Sort_5 | 3333.33 | 2467712.52 | 587 | root | | time:2.87s, loops:2 | mysql.stats_meta.version | 42.1 KB | 0 Bytes |
| └─TableReader_10 | 3333.33 | 487159.13 | 587 | root | | time:2.87s, loops:2, cop_task: {num: 6, max: 2.87s, min: 2.42ms, avg: 499.4ms, p95: 2.87s, max_proc_keys: 85507, p95_proc_keys: 85507, tot_proc: 156ms, tot_wait: 861.5µs, copr_cache_hit_ratio: 0.00, build_task_duration: 22.9µs, max_distsql_concurrency: 6}, rpc_info:{Cop:{num_rpc:6, total_time:3s}} | data:Selection_9 | 11.5 KB | N/A |
| └─Selection_9 | 3333.33 | 6040186.91 | 587 | cop[tikv] | | tikv_task:{proc max:2.86s, min:0s, avg: 496.7ms, p80:50ms, p95:2.86s, iters:232, tasks:6}, scan_detail: {total_process_keys: 211785, total_process_keys_size: 14752565, total_keys: 293431, get_snapshot_time: 46.7µs, rocksdb: {delete_skipped_count: 192, key_skipped_count: 361746, block: {cache_hit_count: 2006}}}, time_detail: {total_process_time: 156ms, total_suspend_time: 2.83s, total_wait_time: 861.5µs, total_kv_read_wall_time: 2.98s, tikv_wall_time: 2.99s} | gt(mysql.stats_meta.version, 462255440511108949) | N/A | N/A |
| └─TableFullScan_8 | 10000.00 | 5541186.91 | 211785 | cop[tikv] | table:stats_meta | tikv_task:{proc max:2.86s, min:0s, avg: 496.7ms, p80:50ms, p95:2.86s, iters:232, tasks:6} | keep order:false, stats:pseudo | N/A | N/A |4. What is your TiDB version? (Required)
master, 8.5.x