The document summarizes Apache Phoenix and its past, present, and future as a SQL interface for HBase. It describes Phoenix's architecture and key features like secondary indexes, joins, aggregations, and transactions. Recent releases added functional indexes, the Phoenix Query Server, and initial transaction support. Future plans include improvements to local indexes, integration with Calcite and Hive, and adding JSON and other SQL features. The document aims to provide an overview of Phoenix's capabilities and roadmap for building a full-featured SQL layer over HBase.