| 用途 | 运行态性能数据 |
|---|---|
| 开关 | performance_schema=ON（默认开启） |
| 常用表 | events_statements_current / summary_by_digest |
看当前最慢语句
看当前最慢语句
SELECT thread_id, event_name, timer_wait/1e12 AS sec, sql_text
FROM performance_schema.events_statements_current
WHERE sql_text IS NOT NULL
ORDER BY timer_wait DESC
LIMIT 10;按语句模板聚合
按语句模板聚合
SELECT schema_name, digest_text, count_star,
avg_timer_wait/1e12 AS avg_sec
FROM performance_schema.events_statements_summary_by_digest
ORDER BY sum_timer_wait DESC
LIMIT 10;digest_text 已归一化（常量替换成问号），适合聚合统计；要原文请查 events_statements_history_long。