This article analyzes extensive data libraries and how they benefit when completed. This research has results, namely library data can be called big data if the data fulfills the three characteristics of big data: volume, speed, and variety. Data mining can process big data, for example, by associations that create links between objects. If an extensive data library contains borrowed data, this means being able to establish connections between borrowed collections. Librarians, in particular, can use the results of this comprehensive data work to decide how to proceed. Therefore, it is essential to play a role in improving the library. This research aims to increase discussion between readers and librarians about using Big Data, especially in libraries. The benefit of this research is to broaden the knowledge of readers and librarians about how to utilize big data. The research method used is library research which analyzes writings from various sources.