To enable a high level of performance and determinism, the latest version of eXtremeDB Kernel Mode in-memory embedded database system deploys in the operating system kernel. This approach leverages the high priority, zero-latency responsiveness central to kernel tasks to meet the data sorting, access, and retrieval needs of applications that place key functions there. In the latest version, applications perform faster than with the standard user-mode, all-in-memory edition. These applications simulate an access-control system with its policy engine running in kernel mode. System requirements include checking a rules database to determine whether a process has permission to open specific files in a certain mode and at a certain time and date. When the database resides in the kernel along with the policy engine, performance accelerates by eliminating context switches or jumps between kernel and user space.