One of the most important properties of a database is durability. Durability means that after a transaction commits, you can be confident that, absent catastrophic hardware failure, the changes made by the commit won't be lost. This should remain true even if the operating system crashes or the system loses power soon after the commit. On Linux, and most other Unix operating systems, durability is ensured by calling the fsync system call at the right time. Durability comes at a performance co...