Elisa Usai

MySQL 8.0 – Roles are finally there

Roles have been existing on many RDBMS for a long time by now. Starting from version 8.0, this functionality is finally there for MySQL. The most important advantage is to define only once a role that includes a “set(…)

MySQL – Time mismatch between system and log files

I was working on MySQL upgrades to version 5.7 at a customer, when I found out that for my instance, time in the error log file didn’t correspond to local system time: mysql@test1:/u01/app/mysql/admin/mysqld1/log/ [mysqld1] mysql -uroot -p Enter password: ERROR(…)

MySQL – Foreign keys and “Cannot delete or update a parent row: a foreign key constraint fails” error

As you know, foreign keys establish a sort of relationship between 2 tables. MySQL requires InnoDB storage engine to support foreign keys. In our example, we have the following parent table in a MySQL 5.7.21 server: mysqld3-(root@localhost) [sakila]> show create(…)