LevelDB

oren.github.com/posts/leveldb.md at master · oren/oren.github.com · GitHub: "LevelDB is a very fast and lightweight embedded database. It was created by two Google engineers and is inpired by BigTable, Google's proprietary file system. You are probably using it without knowing it since it's part of the Chrome browser (exposed as IndexedDB).

Other databases in the embedded category are BerkelyDB and SQLite (it's important to point out the LevelDB is faster). By embedded it means you don't run it in a separate process as you would normally do with many of the popular databases such as MySQL, MongoDB or Redis. LevelDB is contained within your application process and can't be accessed from other process. It is literally just a file based store of key value pairs that does some fancy caching and compression.

If we compare it to Redis, it's even lighter, have more reliable writes and unlike Redis, you don't store your entire data in memory but in the file system. Another difference is Redis have more data structures (sets, lists etc) that LevelDB is lacking. The similarity is that both store key-value pairs and both can save json."

https://github.com/oren/oren.github.com/blob/master/posts/leveldb.md