This is a very specific problem related to AppArmor and MySQL with non-standard data and temp directories. I just upgraded a database server to Ubuntu 10.04.1 LTS and ran up against a problem related to AppArmor. AppArmor is… “…a kernel enhancement to confine programs to a limited set of resources. AppArmor’s unique security model is [...]

When you create a model in Magento that reads and writes data ( $model->load() and $model->save() ) to a database table, by default, Magento expects the primary key of the table to be an auto_increment field called ‘id’. If you want to use a primary key that is not an auto_increment field then you need to [...]

If you are using the expire_logs_days setting for automatic binary log removal in MySQL and your binary logs are not automatically deleting themselves (SHOW MASTER LOGS), it’s probably because the index is out of sync with the actual log folder. Manually remove the logs (/var/log/mysql) and then do RESET MASTER to get things back in [...]

So I thought I was losing my mind when a simple LEFT JOIN on a new table was taking forever to complete: SELECT email FROM a LEFT JOIN b ON b.email=a.email WHERE b.email is null That’s about the simplest LEFT JOIN you can write to get all rows in a that are not in b. [...]

DBDesigner 4 “DBDesigner 4 is a visual database design system that integrates database design, modeling, creation and maintenance into a single, seamless environment.” Looks very robust. One of the few tools that supports reverse engineering. MySQL Workbench “MySQL Workbench is a cross-platform, visual database design tool developed by MySQL. It is the highly anticipated successor [...]