Elasticsearch 6.4.0 introduces a host of new features and improvements, emphasizing enhanced security, text processing, and client capabilities. Key security enhancements include support for Kerberos authentication, FIPS 140-2 compliance, and automatic plugin signature verification, which streamline operations in regulated environments and improve plugin integrity checks. Text processing sees advancements with the introduction of a super-fast Korean analyzer called "Nori" and the new index_phrases option for efficient phrase searches. Additionally, Elasticsearch SQL functionality is enhanced with new text manipulation functions and improved JDBC driver capabilities. The Java high-level REST client continues to expand, offering more APIs, and Painless scripting now includes better context documentation. Moreover, the X-Opaque-Id header feature is extended to audit logs, improving task tracking and cancellation. The release also improves the rollup feature, addressing bugs and expanding query capabilities, encouraging users to explore the updates and provide feedback.