This five-day course is aimed at Biologists (PhD students and Master students) who work with medium to large datasets. The course goal is to learn how to re-arrange and query the data and how to best manage data. This course will teach researchers how to use the Unix shell, Python programming language, what databases are for and how to use them, to become more efficient at the conduction of the common but often time-consuming scientific task to deal with data. We will spend two days learning different techniques, and then we will move on and deal with your own data sets for two days. We will develop solutions for individual problems in the group. If the time allows it, we will move on to relational databases on the last day. When signing up, please send an exemplary data file that you work with, and which you need to re-arrange or query on a regular basis, but that you find difficult or time-consuming to do in Excel. You do not need to send a complete dataset, what we need to know is the main structure of the dataset, and the task that needs doing. Incomplete or exemplary datasets are sufficient. This course will use the operating systems of OS X (on a Mac) or in a Linux environment. Windows users should be prepared to install Linux on a partition of their laptop, or to install a software that emulates Linux (both are free of charge). Requirements: None. This course aims at people who find using Excel for data management time-consuming, boring and inefficient, but do not know how to do better. No previous experience in scripting is required. After completing this course, you will be able to use the power of your computer to time-efficently handle your data, which will allow you to spend more time doing actual research and analyses.