Anybody know what hardware those benchmarks were on? Is it actually durable? They mention problems with writeback caching, but are they at least durable from the OS perspective? How well does it scale?
struct WriteOptions {
// If true, the write will be flushed from the operating system
// buffer cache (by calling WritableFile::Sync()) before the write
// is considered complete. If this flag is true, writes will be
// slower.
//
// If this flag is false, and the machine crashes, some recent
// writes may be lost. Note that if it is just the process that
// crashes (i.e., the machine does not reboot), no writes will be
// lost even if sync==false.
//
// In other words, a DB write with sync==false has similar
// crash semantics as the "write()" system call. A DB write
// with sync==true has similar crash semantics to a "write()"
// system call followed by "fsync()".
//
// Default: false
bool sync;
The benchmark numbers on the linked page were from a small million entry database that easily fits in the OS buffer cache.
(For those that aren't familiar, his bio is here: http://research.google.com/people/sanjay/index.html)
Safe to assume the data fit into memory..whatever amount there was.