Many applications today go beyond the functionalities offered by the platform on which the data is stored. This is because there is no platform that can fit all the data analytics spectrum (following the one-size-does-not-all dictum). Imagine for example that a dataset is stored on a relational database and a user needs to perform a clustering query. Doing so inside the relational database might simply be disastrous in terms of performance. Thus, the user needs to move the data out of the relational database to perform the clustering task. Read more here in our LinkedIn article.