show variables like'long_query_time';设置慢查询时间setlong_query_time=0.5; 分析执行情况 EXPLAIN详解 代码语言:javascript 代码运行次数:0 运行 AI代码解释 分析查询语句的执行情况,可以分析出所查询的表的一些特征:EXPLAIN/DESCRIBE/DESCSELECT*FROM...; 每个字段说明: id:SELECT标识符。这是SELECT的查询序列号。
代码语言:javascript 代码运行次数:0 运行 AI代码解释 SHOW VARIABLES LIKE 'optimizer_trace'; -- 启用优化器的追踪 SET optimizer_trace='enabled=on'; -- 执行一条查询语句 SELECT * FROM information_schema.optimizer_trace; -- 用完关闭 SET optimizer_trace="enabled=off"; SHOW VARIABLES LIKE 'optimizer...
2mysql> SHOW variables like '%tmp_table_size%'; 3 4# 2. 查看 max_heap_table_size 大小, max_heap_table_size: 用户可以创建的内存表 (memory table) 的大小. 这个值用来计算内存表的最大行数值 5mysql> SHOW VARIABLES LIKE '%max_heap_table_size%'; 6 7# 3. 修改 tmp_table_size 大小 8...
(<materialize>(/* select#2 */ select `test`.`t2`.`a` from `test`.`t2` where 1 having 1 ),<primary_index_lookup>(`test`.`t1`.`a` in<temporarytable>on<auto_key>where ((`test`.`t1`.`a` = `materialized-subquery`.`a`))) AS `t1.a IN (SELECT t2.a FROM t2)` from `te...
%';查看是否关闭 set global slow_query_log=off; 第二种 通过my.cnf 设置 先查寻是否开启了慢查询的相关项 show variables like 'slow_query%'; 查看开启慢查询的超时记录时间阈值show variables like 'long_query_time'; find / -name my.cnf vim /etc/my.cnf 编辑 mysql (二) 慢查询日志 :set gl...
The joke isthe examples in the image all use variable names that are more than one letter, and so technically follow the rule, but are still useless because they don’t tell you anything about the variables’ data. Instead of usinga, b, c, the maths guy uses theGreek alphabet, the pi...
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While declaration multiple variables and providing multiple arguments in a function, comma works as a separator.Example:int a,b,c;In this statement, comma is a separator and tells to the compiler that these (a, b, and c) are three different variables....
John, that is correct. This is a perfect example of why its important to clearly and properly name your variables. As we can see naming your variable the same as the id name of the div might not be the best choice, for people who are beginning to learn jQuery. So outside of knowing...
docker-compose.override.yml.examplecan be copied todocker-compose.override.ymland use it to override environment variables or work with a local copy of thesplainer-searchJS library during development defined indocker-compose.yml. Example is included. Just update the path tosplainer-searchwith your...