데이터베이스 커뮤니티

꿈꾸는 개발자, DBA 커뮤니티 구루비

MySQL

Join의 차이점

-- SHOW VARIABLES WHERE  Variable_Name LIKE 'slow_query_log' OR  
-- Variable_Name LIKE 'long_query_time' OR Variable_Name LIKE 'log_output';

-- Select * from mysql.slow_log;

-- Select * from mysql.general_log;

-- EXPLAIN SELECT * 
-- FROM 
-- WHERE

-- SELECT * FROM INFORMATION_SCHEMA.PROCESSLIST;

-- SET FOREIGN_KEY_CHECKS = 0;
-- SET FOREIGN_KEY_CHECKS = 1;

-- set sql_safe_updates=0;
-- set sql_safe_updates=1;

-- CREATE TABLE `tooth_M`.`customType` (
--   `custom_id` varchar(255) NOT NULL,
--   `custom_nm` varchar(255) NOT NULL,
--   `cost` int(11) NOT NULL,
--   `supply_price` int(11) NOT NULL,
--   `status` varchar(45) DEFAULT NULL,
--   `createdAt` datetime(6) DEFAULT current_timestamp(6),
--   `updatedAt` datetime(6) DEFAULT NULL ON UPDATE current_timestamp(6),
--   `deletedAt` datetime(6) DEFAULT NULL,
--   PRIMARY KEY (`custom_id`)
-- ) ENGINE=InnoDB DEFAULT CHARSET=utf8

-- alter table tooth_M.custom_settle add foreign key (writer_id) references tooth_M.user(user_id);
-- alter table tooth_M.custom_settle add foreign key (cnc_id) references tooth_M.cnc(cnc_id);
-- alter table tooth_M.custom add foreign key (writer_id) references tooth_M.user(user_id);

  
-- show full columns from tooth_M.cnc;

-- alter table tooth_M.custom convert to character set utf8 collate utf8_general_ci;

-- show engine innodb status;

-- SHOW PROCESSLIST;

-- show full processlist;

-- SHOW GLOBAL variables LIKE 'wait_timeout';

-- show variables like 'general%';

-- SELECT * FROM INFORMATION_SCHEMA.PROCESSLIST;

쿼리튜닝

[MySQL] 쿼리 최적화 1. 실행 계획

database와 USER

[MySQL] Query 성능 확인

MySQL 쓰면서 하지 말아야 할 것 17가지

MySQL 쓰면서 하지 말아야 할 것 17가지

PostgresSQL