setup_tables : Set up table leaves in the query block based on list of tables. resolve_placeholder_tables/merge_derived/setup_table_function/setup_materialized_derived : Resolve derived table, view or table function references in query block. setup_natural_join_row_types : Compute and store the...
| Tables_in_performance_schema (%setup%) | +---+ | setup_actors | | setup_consumers | | setup_instruments | | setup_objects | | setup_threads | +---+ 5 rows in set (0.01 sec) 查询性能表进行进行分析 两个基本概念 ● instruments:生产者,用于采集MySQL中各种操作产生的事件信息,对应配置...
未在setup_table调用之前,每个Query_block的leaf_tables是为0的。 该函数的作用就是构建leaf_tables,包括base tables和derived tables列表,用于后续的优化。setup_table并不会递归调用,而是只解决本层的tables,并统计出本层derived table的个数。但是随后会调用resolve_placeholder_tables()->resolve_derived()->derived...
更新setup_instruments和setup_consumers表 ,启用日志,就会实时生效。 代码语言:javascript 代码运行次数:0 运行 AI代码解释 UPDATEperformance_schema.setup_instrumentsSETENABLED='YES',TIMED='YES'WHERENAMElike'stage/%';UPDATEperformance_schema.setup_consumersSETENABLED='YES'WHERENAMELIKE'events_stages%'; ...
interactive_timeout = 28800 wait_timeout = 28800 # Recommended in standard MySQL setup sql_mode=NO_ENGINE_SUBSTITUTION,NO_AUTO_CREATE_USER,STRICT_TRANS_TABLES [mysqldump] quick max_allowed_packet = 16M [myisamchk] key_buffer_size = 8M sort_buffer_size = 8M read_buffer = 4M write_buffer ...
要防止root可写,设置flush tables with read lock;但这样的话,主从自动同步就挂逼了。。。因为主从同步是通过把主上的 sql 语句放在从上再执行一遍来实现的,锁表的话,sql 语句就不能执行了。 想要同步,需要把表解锁(执行unlock tables;)就可以了 log_slave_updates :https://dev.mysql.com/doc/refman/5.7/en...
mysql> show tables like '%setup%';+---+| Tables_in_performance_schema (%setup%) || setup_actors || setup_consumers || setup_instruments || setup_objects || setup_timers |+---+5 rows in set (0.00 sec)
mysql> SELECT TABLE_NAME FROM INFORMATION_SCHEMA.TABLES WHERE TABLE_SCHEMA = 'performance_schema' AND TABLE_NAME LIKE 'setup%'; setup表的作用 这里共有5种关于 setup 的表,下面大概简述一下其作用。 1)setup_actors,配置用户纬度的监控,默认监控所有用户。
// 关键代码是setup_semijoin_dups_elimination,主要对半连接关联的策略进行装配 if(make_join_readinfo(this, no_jbuf_after)) ... // 为处理group by/order by创建开辟临时表空间 if(make_tmp_tables_info())returntrue; ... // 生成访问方式AccessPath,供后续迭代器Iterator访问使用 ...