Apache Phoenix is a coating of traditional SQL-like syntactic sugar applied to Hadoop’s HBase NoSQL database. It was created as an internal project at Salesforce, later open-sourced on GitHub, and became a top-level Apache project in a very short period of time. HBase, the Hadoop database, is a highly-scalable NoSQL database. You can query HBase data using Phoenix with a syntax similar to SQL as used for relational databases. Apache Phoenix provides a JDBC driver and works as an SQL driver to HBase. Phoenix queries are optimized primarily for HBase and use many Hbase-related techniques, such as skip scan, to improve performance. We will cover skip scan and other advanced Phoenix topics in further chapters.