系统表介绍
events_statements_summary_by_digest 数据按照SQL语句模式与概要进行汇总
| 列名 | 含义 |
|---|---|
| SCHEMA_NAME | 所属模式 |
| DIGEST | 概要 |
| DIGEST_TEXT | 概要文本 |
| COUNT_STAR | 事件汇总数量 |
| SUM_TIMER_WAIT | 事件总等待时间 |
| MIN_TIMER_WAIT | 事件最小等待时间 |
| AVG_TIMER_WAIT | 事件平均等待时间 |
| MAX_TIMER_WAIT | 事件最大等待时间 |
| SUM_LOCK_TIME | 总锁等待事件 |
| SUM_ERRORS | 总报错数量 |
| SUM_WARNINGS | 总警告数量 |
| SUM_ROWS_AFFECTED | 总涉及的行数 |
| SUM_ROWS_SENT | 总语句返回行数 |
| SUM_ROWS_EXAMINED | 总在server层检查的行数（不包含在内部存储影响处理的数量） |
| SUM_CREATED_TMP_DISK_TABLES | 总内部创建磁盘临时表的数量 |
| SUM_CREATED_TMP_TABLES | 总内部创建临时表的数量 |
| SUM_SELECT_FULL_JOIN | 总由于没有索引引起全表连接的数量 |
| SUM_SELECT_FULL_RANGE_JOIN | 总在引用表发生大范围扫描的次数 |
| SUM_SELECT_RANGE | 总在初始表使用范围方式获取记录的次数 |
| SUM_SELECT_RANGE_CHECK | 总判断是否要使用范围扫描的次数 |
| SUM_SELECT_SCAN | 总全表扫描次数 |
| SUM_SORT_MERGE_PASSES | 总再排序次数 |
| SUM_SORT_RANGE | 总范围扫描时按顺序读取记录的次数 |
| SUM_SORT_ROWS | 总排序的行数 |
| SUM_SORT_SCAN | 总全表扫描是按顺序读取的次数 |
| SUM_NO_INDEX_USED | 总标识是否使用索引 |
| SUM_NO_GOOD_INDEX_USED | 总标识是否使用好的索引 |
| FIRST_SEEN | 最先发现的时间 |
| LAST_SEEN | 最后遇见的时间 |
实例
mysql> select * from events_statements_summary_by_digest limit 2 \G ;
*************************** 1. row ***************************
mysql> select * from events_statements_summary_by_digest where SCHEMA_NAME is not null limit 2 \G ;
*************************** 1. row ***************************
SCHEMA_NAME: performance_schema
DIGEST: 6d711d488f3ed491a0d7610aa0d65038
DIGEST_TEXT: SHOW SCHEMAS
COUNT_STAR: 3
SUM_TIMER_WAIT: 20029379000
MIN_TIMER_WAIT: 682035000
AVG_TIMER_WAIT: 6676459000
MAX_TIMER_WAIT: 18396039000
SUM_LOCK_TIME: 766000000
SUM_ERRORS: 0
SUM_WARNINGS: 0
SUM_ROWS_AFFECTED: 0
SUM_ROWS_SENT: 18
SUM_ROWS_EXAMINED: 18
SUM_CREATED_TMP_DISK_TABLES: 0
SUM_CREATED_TMP_TABLES: 3
SUM_SELECT_FULL_JOIN: 0
SUM_SELECT_FULL_RANGE_JOIN: 0
SUM_SELECT_RANGE: 0
SUM_SELECT_RANGE_CHECK: 0
SUM_SELECT_SCAN: 3
SUM_SORT_MERGE_PASSES: 0
SUM_SORT_RANGE: 0
SUM_SORT_ROWS: 0
SUM_SORT_SCAN: 0
SUM_NO_INDEX_USED: 3
SUM_NO_GOOD_INDEX_USED: 0
FIRST_SEEN: 2021-08-08 09:40:20
LAST_SEEN: 2021-08-09 08:28:07
*************************** 2. row ***************************
SCHEMA_NAME: performance_schema
DIGEST: 99477144cf0254f505964804b180db5c
DIGEST_TEXT: SHOW TABLES
COUNT_STAR: 4
SUM_TIMER_WAIT: 2333859000
MIN_TIMER_WAIT: 504765000
AVG_TIMER_WAIT: 583464000
MAX_TIMER_WAIT: 721078000
SUM_LOCK_TIME: 367000000
SUM_ERRORS: 0
SUM_WARNINGS: 0
SUM_ROWS_AFFECTED: 0
SUM_ROWS_SENT: 348
SUM_ROWS_EXAMINED: 348
SUM_CREATED_TMP_DISK_TABLES: 0
SUM_CREATED_TMP_TABLES: 4
SUM_SELECT_FULL_JOIN: 0
SUM_SELECT_FULL_RANGE_JOIN: 0
SUM_SELECT_RANGE: 0
SUM_SELECT_RANGE_CHECK: 0
SUM_SELECT_SCAN: 4
SUM_SORT_MERGE_PASSES: 0
SUM_SORT_RANGE: 0
SUM_SORT_ROWS: 0
SUM_SORT_SCAN: 0
SUM_NO_INDEX_USED: 4
SUM_NO_GOOD_INDEX_USED: 0
FIRST_SEEN: 2021-08-08 09:40:20
LAST_SEEN: 2021-08-09 08:28:07
2 rows in set (0.00 sec)