Database Storage Made Predictable
Modern embedded systems depend on flash memory for high-density data storage. Purpose-built for hard real-time workloads, eXtremeDB/rt supports both unmanaged raw flash and managed flash devices—giving developers the freedom to balance transaction latencies with design complexity. The Transactional Map File accelerates managed flash integration, while the Transactional Flash Translation Layer (TFTL™) delivers deterministic, low-overhead performance directly on raw flash for mission-critical applications.
Transactional File Mapping
The xFile module allows eXtremeDB/rt to store databases on top of an OS file system or FTL-enabled block device. It leverages the operating system’s file I/O services, enabling straightforward integration with general-purpose and RTOS environments. This approach benefits from existing storage infrastructure, making it ideal for rapid deployment and testing. While not as deterministic as raw flash access, it provides a balance between ease of use and acceptable latency for many embedded applications.
Transactional Flash Translation Layer
The xFlash module provides eXtremeDB/rt with direct, low-level access to raw NAND or NOR flash devices. It includes a transactional FTL that manages wear leveling, bad block handling, and recovery under the database kernel’s control. This design eliminates file system overhead, enabling highly deterministic real-time transaction performance. The xFlash approach is ideal for safety-critical and time-sensitive systems such as aerospace, automotive, medical, and critical infrastructure.
Feature |
Transactional File Mapping (xFile module) |
TFTL (xFlash module) |
|---|---|---|
| Underlying Medium | Any storage visible as a file or block device (SSD, eMMC, or raw device wrapped by an OS file system/FTL) | Directly on raw NAND/NOR flash chips |
| Access Path | Through OS file system/FTL and driver layers | Direct low-level flash access via eXtremeDB/rt transactional FTL |
| Latency | Higher, depends on OS file system/FTL overhead | Lower, bypasses file system/FTL and OS buffering |
| Determinism (real-time transactions) | Less predictable — subject to file system and flash memory management delays | Highly deterministic — under eXtremeDB/rt kernel control, no file system/FTL interference |
| Wear Leveling & Bad Block Management | Handled by SSD/eMMC controller or OS file system/FTL | Handled internally by eXtremeDB/rt transactional Flash Translation Layer (TFTL) |
| Configuration Complexity | Simple — specify a file path or block device | More complex — requires flash geometry, block/sector sizes, and device manufacturer driver integration |
| Best Use Cases | Quick integration on standard storage, development/testing, general embedded apps | Hard real-time systems, safety-critical apps in aerospace, automotive, medical, critical infrastructure |
| OS Dependencies | General-purpose and RTOS with file system/FTL or block I/O services | Minimal — only basic I/O and timing primitives, bare-metal possible |
RTOS Partners
