Apache Atlas uses the JanusGraph graph database at the heart of its metadata repository. This graph is used to show the interconnected relationships between data sources; the data sets they host; the business meaning of the data elements within each data set; the classification of these elements in terms of quality, confidentiality, retention; who (people and processes) are using them and for which purposes.
JanusGraph uses a pluggable persistence store to save the metadata content and a search index for its search API. Apache Atlas can take advantage of this configurability to support a range of size, scalability and performance requirements.