Embedded Database Mixes On-Disk, All-In-Memory Techniques

Combining the strengths of the on-disk and all-in-memory approaches to data management into one solution, eXtremeDB Fusion embedded database from McObject offers developers the flexibility to optimize applications to their specific needs.

Traditional on-disk databases cache frequently requested data in memory, but write all database updates, insertions, and deletes through the cache to be stored on disk. In contrast, in-memory database systems (IMDSs) eliminate disk access and store data in main memory, sending data to the hard disk only when specified by the application. So IMDSs are very fast, and their streamlined design reduces RAM and CPU demands. However, on-disk database systems also have advantages. Some developers prefer the guaranteed persistence of automatic disk storage, and byte-for-byte, disk storage can be cheaper than memory. Disk storage can also take less physical space.

McObject’s eXtremeDB Fusion provides the best of both worlds. The result is a hybrid database for resource-constrained and high-performance systems. Specifying one set of data as transient (managed in memory), while choosing on-disk storage for other record types, requires a simple database schema declaration. The system’s on-disk features are uniquely configuarable—including three levels of transaction logging—to meet the target system’s footprint, performance, and durability needs. Developers can specify the maximum database size, which is especially important when the “disk” is actually a flash memory file system. Also, users can save and re-use database cache across session, so they can resume some activity when a device is switched back on, for example.

eXtremeDB Fusion will be sold alongside eXtremeDB and will be offered in High Availability, SQL, and 64-bit editions. Like eXtremeDB, eXtremeDB Fusion is available for many operating systems and with source code for porting to additional platforms.