Database for Event Sourcing is a storage and query engine for event-sourced systems. In addition to storing the raw event logs, Database for Event Sourcing allows developers to create so-called views—virtual datasets that are derived from the event data using pre-defined reducers and can be queried "as at" any point in time.
The preview of Database for Event Sourcing is based on a hypothetical event log generated by an application that lets users upvote/downvote popular movies.