Aerospike Database 6.4 introduces several new features, including secondary index on flash, which allows for persistent storage of secondary indexes without consuming RAM, enabling warm restarts and improved performance in mixed workloads. The new feature also comes with a trade-off in terms of device IO cost. Additionally, Aerospike now supports integrating with secrets management services through the Secret Agent, which can fetch secrets from external services like AWS Secrets Manager. The release also includes improvements to Cross-Datacenter Replication (XDR) throughput and support for newer operating system distributions such as Amazon Linux 2023 and Debian 12. Furthermore, Aerospike has removed support for single-bin namespaces, a feature that provided savings in storage space, but is no longer necessary due to advancements in flash storage technology.