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JSON_TABLE – The Best of Both Worlds

2018-09-16 KENNETH 0

JSON_TABLE – The Best of Both Worlds One of the new JSON functions in MySQL 8.0 is JSON_TABLE. It is also MySQL’s first table function. That is, the return value is not a scalar value, but a result set. JSON_TABLE will convert (part of) a JSON document into a relational table.… Source: JSON_TABLE – The Best of Both Worlds

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MySQL Shell 8.0.12 – What’s New?

2018-08-30 KENNETH 0

MySQL Shell 8.0.12 – What’s New? Pluggable Password Store This feature which is enabled by default, allows the Shell using an external component “Secret Store”, to persist session passwords in a secure way. Whenever a new session is created while working with the shell in interactive mode, the option to persist the password for the session will be made available.… Source: MySQL Shell 8.0.12 – What’s New?

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Getting Help in MySQL Shell

2018-08-30 KENNETH 0

Getting Help in MySQL Shell The MySQL Shell has a collection of commands and APIs that allow performing a variety of tasks on MySQL instances  interactively or through scripts. Although there’s documentation for the JavaScript and Python APIs as well as the User Guide, it comes handy being able to get help about how to use specific elements of the application while working with it, this is what the centralized help system does.… Source: Getting Help in MySQL Shell

mysqld_safe error: log-error set to however file don’t exists on compiled mysql8.0

2018-08-20 KENNETH 0

환경 OS : CentOS7 DB : mysql-8.0.11, mysql-8.0.12 (8.0.11 이전에도 문제가 있었는지는 모르지만 아마 있을듯)   문제점 mysql  실행시 아래와 같은 메세지와 함께 실행 불가 # mysql.server start Starting MySQL.2018-08-20T04:33:38.742995Z mysqld_safe error: log-error set to ‘/var/log/mysql/mysql_error.log’, however file don’t exists. Create writable for user ‘mysql’. The server quit without updating PID file (/var/lib/mysql/myserver.pid).   원인 보통의 원인이라면 로그가 쌓여야 하는 위치(예제 : /var/log/mysql)가 존재하지 않을 경우 로그가 쌓여야 하는 위치의 권한이 mysql 유저가 “쓰기(write)” 가능하지 않을 경우   여야 하지만.. 현재 시스템의 상황은 이런 문제가 있지 않음… my.cnf 설정중 log_error 옵션을 손대지 않고 그대로 실행했을 경우는 문제가 없지만 log_error=/var/log/mysql/mysql_error.log 등으로 기본값이 아닌 “수정”이 이루어졌을 경우에 발생 하고 있음   해결 touch /var/log/mysql/mysql_error.log chown mysql.mysql /var/log/mysql/mysql_error.log 이렇게 생성 & 권한부여 를 해주면 정상 구동이 됨… 듣는 사람은 당연히 황당 하겠지만… 지금 이 결과가 mysql-8.0.11, mysql-8.0.12 를 소스컴파일 설치 했을 때 발생 [ more… ]

Difference between MySQL Connector/J 5.1 and MySQL Connector/J 8.0

2018-08-01 KENNETH 0

Difference between MySQL Connector/J 5.1 and MySQL Connector/J 8.0   Summary of Connector/J Versions Connector/J version JDBC version MySQL Server version JRE Supported JDK Required for Compilation Status 8.0 4.2 5.5, 5.6, 5.7, 8.0 1.8.x 1.8.x General availability. Recommended version. 5.1 3.0, 4.0, 4.1, 4.2 5.5, 5.6*, 5.7*, 8.0* 1.5.x, 1.6.x, 1.7.x, 1.8.x* 1.5.x and 1.8.x General availability   Difference ClassName MySQL Connector/J 5.1 package name : java.sql (java.sql.*) class name : com.mysql.jdbc.Driver MySQL Connector/J 8.0 package name : java.sql (java.sql.*) class name : com.mysql.cj.jdbc.Driver