Databases are the backbone of most modern systems, and taking some time to understand how they work is a good investment for any developer! In this article I share some non-trivial tips about database development! Rules of thumb has been passed on from DBA to DBA for many years. Some of these rules may seem weird while others makes perfect sense. In this talk I present some of the "rules" I accumulated over the years, such as why you should always load sorted data into tables, how to make indexes invisible, and why you should always schedule long running processes in odd hours...