What are the differences between Kylin and traditional OLAP databases?

Kylin is an open-source distributed analytics engine specially designed for processing OLAP queries on extremely large datasets. Unlike traditional OLAP databases, Kylin has the following unique features:

1. Processing large-scale data: Kylin is capable of handling data at the PB level, whereas traditional OLAP databases typically only handle data at the TB level.
2. Real-time querying: Kylin supports real-time querying, able to return query results within milliseconds, while traditional OLAP databases may take several minutes or even longer to execute the same queries.
3. Distributed architecture: Kylin utilizes a distributed architecture that can scale horizontally across multiple nodes, providing improved performance and fault tolerance.
4. Prediction: Kylin utilizes pre-calculation technology to accelerate queries, reduce the pressure of real-time computing, while traditional OLAP databases usually require calculation during query time.
5. Kylin supports multi-dimensional data models, making it easy to handle queries and analysis across multiple dimensions, whereas traditional OLAP databases may require complex data models to achieve the same functionality.

In general, Kylin offers better scalability, performance, and real-time querying capabilities compared to traditional OLAP databases, making it suitable for handling large-scale data scenarios.