> Now, with ext4 moving to full barrier/fsync support, we could get to the
> point where WAL in the main data FS can mimic the state where WAL is
> seperate, namely that WAL writes can "jump the queue" and be written
> without waiting for the data pages to be flushed down to disk, but also
> that you'll get the big backlog of data pages to flush when
> the first fsyncs on big data files start coming from checkpoints...
Does postgres write something to the logfile whenever a fsync() takes a
suspiciously long amount of time ?
