Subject Why write async is bad ?
Author Vander Clock Stephane

when i setup write async to true, it's mean the the database will store
in memory the write
and after several update (5 by default?) all the write will be flush to
the disk.

The main drawback, is that all the write are flush to the disk using the
current connection thread :(

it's mean that if i m the unlucky guy to commit the 5th update then my
commit will be more slower because
it's will also commit all the previous update.

i was thinking that it's a separate thread that was responsible to flush
to disk :( or i m wrong?