events_statements_summary_by_thread_by_event_name 详解

Posted by 道行尚浅 on October 2, 2021

系统表介绍

events_statements_summary_by_thread_by_event_name 包含了语句事件按线程与事件的分组

列名 含义
THREAD_ID 线程编号
EVENT_NAME 事件名称
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

实例


mysql> select * from events_statements_summary_by_thread_by_event_name where SUM_NO_INDEX_USED > 0 limit 2 \G ;
*************************** 1. row ***************************
                  THREAD_ID: 40
                 EVENT_NAME: statement/sql/select
                 COUNT_STAR: 49
             SUM_TIMER_WAIT: 115954994000
             MIN_TIMER_WAIT: 133612000
             AVG_TIMER_WAIT: 2366428000
             MAX_TIMER_WAIT: 31364102000
              SUM_LOCK_TIME: 7484000000
                 SUM_ERRORS: 0
               SUM_WARNINGS: 0
          SUM_ROWS_AFFECTED: 0
              SUM_ROWS_SENT: 8997
          SUM_ROWS_EXAMINED: 38156
SUM_CREATED_TMP_DISK_TABLES: 0
     SUM_CREATED_TMP_TABLES: 1
       SUM_SELECT_FULL_JOIN: 0
 SUM_SELECT_FULL_RANGE_JOIN: 0
           SUM_SELECT_RANGE: 0
     SUM_SELECT_RANGE_CHECK: 0
            SUM_SELECT_SCAN: 45
      SUM_SORT_MERGE_PASSES: 0
             SUM_SORT_RANGE: 0
              SUM_SORT_ROWS: 54
              SUM_SORT_SCAN: 8
          SUM_NO_INDEX_USED: 45
     SUM_NO_GOOD_INDEX_USED: 0
*************************** 2. row ***************************
                  THREAD_ID: 40
                 EVENT_NAME: statement/sql/show_databases
                 COUNT_STAR: 1
             SUM_TIMER_WAIT: 682035000
             MIN_TIMER_WAIT: 682035000
             AVG_TIMER_WAIT: 682035000
             MAX_TIMER_WAIT: 682035000
              SUM_LOCK_TIME: 225000000
                 SUM_ERRORS: 0
               SUM_WARNINGS: 0
          SUM_ROWS_AFFECTED: 0
              SUM_ROWS_SENT: 6
          SUM_ROWS_EXAMINED: 6
SUM_CREATED_TMP_DISK_TABLES: 0
     SUM_CREATED_TMP_TABLES: 1
       SUM_SELECT_FULL_JOIN: 0
 SUM_SELECT_FULL_RANGE_JOIN: 0
           SUM_SELECT_RANGE: 0
     SUM_SELECT_RANGE_CHECK: 0
            SUM_SELECT_SCAN: 1
      SUM_SORT_MERGE_PASSES: 0
             SUM_SORT_RANGE: 0
              SUM_SORT_ROWS: 0
              SUM_SORT_SCAN: 0
          SUM_NO_INDEX_USED: 1
     SUM_NO_GOOD_INDEX_USED: 0
2 rows in set (0.01 sec)