Apache Calcite
Apache Calcite is a full-stack category tool used for managing dynamic data. It’s an open-source database and data management framework. It comes with a SQL parser, an API for creating relational algebra expressions, and a query planning engine. Although it includes many of the components that make up a standard database management system, it still lacks several crucial features, such as data storage, data processing methods, and a metadata repository. Calcite has chosen to stay out of the data storage and processing business. This makes it a great candidate for bridging the gap between applications and one or more data storage and processing engines. It’s also a great starting point for creating a database: all you have to do is add data. Pros of using Calcite include query parser, validator, optimizer, aid for reading models in JSON format, numerous standard functions, aggregate functions, JDBC queries for Linq4j, JDBC back-ends, Linq4j front-end and SQL features.
To contribute to this project, hop onto: https://github.com/apache/calcite