Doradus is an open source storage and query engine that runs on top of the Cassandra NoSQL database. It provides a high-level data model, Lucene-based query language, and sophisticated aggregate queries with multi-level grouping. You can embed Doradus in an application or execute it standalone with the bundled Jetty server or another web server to provide a REST API. Multiple storage services are available that organize data using techniques designed to benefit specific application types:

• The OLAP service borrows techniques from Online Analytical Processing, columnar storage, compression, and sharding to yield extremely compact databases. Doradus OLAP requires applications to organize data into time-based shards, and it prefers batch updates of semi-mutable data. For applications that can meet these constraints, databases are extremely compact, and analytic queries can search millions of objects per second.
• The Logging service is optimized to manage immutable, time-series data such as log records and events.
• The Spider service is suitable for data that is highly mutable, semi-structured to unstructured, and/or requires fine-grained updates. Updates are instantly reflected in searches, and objects can be updated simultaneously by different applications. Spider is ideal for applications emphasizing full text searches on irregular data.

All three services OLAP, Logging and Spider support the Doradus Query Language (DQL) for object and aggregate queries. For a more detailed overview of Doradus click here. See the Topics below for links to tutorials, examples, detailed documentation, and a simple 1-2-3 getting started process.