Date: August 8, 2014
The emergence of non-volatile dual in-line memory modules, or NVDIMMs, adds a new tool for in-memory database durability. In normal operation, this technology provides the capabilities of high speed DRAM. In the event of power loss, the ultracapacitor provides a burst of electricity that is used to write main memory contents to the NAND flash chip, where it can be held virtually indefinitely. Upon recovery, the NVDIMM restores data from NAND flash to DRAM. For in-memory databases, NVDIMMs’ promise is similar to that of battery-backed RAM, but without the battery and its shortcomings.