Free and open-source software portal Lightning Memory-Mapped Database (LMDB) is an embedded transactional database in the form of a key-value store. LMDB
regions of the file can be mapped into the address space, and unmapped if another region needs to be mapped in. A few computers have a main memory larger than
single-level memory model in which there is no differentiation between process memory and file system consists of only a list of segments (files) mapped into