The third part of this series shows how transactions work when the REPEATABLE READ and SERIALIZABLE transaction levels are used. I show these two together, because they work very similar and can easily be shown in one example. REPEATABLE READ is the default transaction level in MySQL and the one that’s most commonly used. We […]

The last article of this series shows, how to produce an artificial deadlock. We have to make a little modification to the table that we’ve used for the examples before – we need to add a primary key. Without primary key, the whole table will be locked, which makes it impossible to produce a deadlock […]

Lets continue this series about transaction isolation levels and table a look at READ COMMITTED. We start with the same data and perform the same steps as we did with READ UNCOMMITTED and take a look at the differences. So prepare the table ‘tt’ that it looks like this: mysql> select * from tt; +——+ […]

This series of articles will show you how the different transaction isolation levels work in practice. Most people who work with databases on a regular basis might have heared that there is a distiction how transactions can deal with concurrent reads and writes. However, their names and exact (but simular) functionality differ between the database […]