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- 【TiDB 版本】：v4.0.1
- 【问题描述】：metrics_summary 数据量600多条，执行查询非常慢,其它类似的元数据表也很慢，数据量都不大
explain select * from information_schema.metrics_summary;
+----------------+----------+------+-----------------------+---------------+
| id | estRows | task | access object | operator info |
+----------------+----------+------+-----------------------+---------------+
| MemTableScan_4 | 10000.00 | root | table:METRICS_SUMMARY | |
+----------------+----------+------+-----------------------+---------------+
1 row in set (0.01 sec)
mysql> select count(*) from information_schema.metrics_summary;
+----------+
| count(*) |
+----------+
| 612 |
+----------+
1 row in set (10.13 sec)