LokiJS is an in-memory database which priorities performance over everything *
LokiJS supports field indexing for faster document access and performs really well (near 500,000 ops/s on an average dev machine) on those. Its built-in DynamicView class also enables to utilize indexes on data subsets for even faster performance.
DynamicView has the very handy feature of detecting changes in the database and recomputing itself to contain the most up-to-date data, and data is always readily available through the data() method.
Among the features that make LokiJS attractive are:
Website – http://lokijs.org/
npm install lokijs
bower install lokijs