Re: Potential Large Performance Gain in WAL synching

"Curtis Faith" <curtis@galtair.com> writes:
> So, why don't we use files opened with O_DSYNC | O_APPEND for the WAL log
> and then use aio_write for all log writes?

We already offer an O_DSYNC option.  It's not obvious to me what
aio_write brings to the table (aside from loss of portability).
You still have to wait for the final write to complete, no?

> 2) Allow transactions to complete and do work while other threads are
> waiting on the completion of the log write.

I'm missing something.  There is no useful work that a transaction can
do between writing its commit record and reporting completion, is there?
It has to wait for that record to hit disk.
        regards, tom lane