Evgeny Rodichev <er@sai.msu.su> writes:
>> Any claimed TPS rate exceeding your disk drive's rotation rate is a
>> red flag.
> Write cache is enabled under Linux by default all the time I make deal
> with it (since 1993).
You're playing with fire.
> fsync() really works fine as I switch off my notebook everyday 2-3 times,
> and never had any data loss :)
Given that it's a notebook, it's possible that the hardware is smart
enough not to power down the disk until the disk is done writing
everything it's cached. Do you care to try some experiments with
pulling out the battery while Postgres is busy making updates?
regards, tom lane