Data exploration is about efficiently extracting knowledge from data even if we do not know exactly what we are looking for. This has numerous side-effects on (a) how we design database systems at their core, i.e., at the storage and query processing layers and (b) how users or applications interact with systems.
In this tutorial, we survey recent developments in the emerging area of database systems tailored for data exploration. We discuss new ideas on how to store and access data as well as new ideas on how to interact with a data system to enable users and applications to quickly figure out which data parts are of interest. In addition, we discuss how to exploit lessons-learned from past research, the new challenges data exploration crafts, emerging applications and future directions.