Re: [HACKERS] TODO item

> Thinking about a little bit more, I have come across yet another
> possible solution. It is actually *very* simple. Details as follows.
> 
> In xact.c:RecordTransactionCommit() there are two FlushBufferPool
> calls. One is for relation files and the other is for pg_log. I add
> sync() right after these FlushBufferPool. It will force any pending
> kernel buffers physically be written onto disk, thus should guarantee
> the ACID of the transaction (see attached code fragment).

Interesting idea.  I had proposed this solution long ago.  My idea was
to buffer pg_log writes every 30 seconds.  Every 30 seconds, do a sync,
then write/sync pg_log.  Seemed like a good solution at the time, but
Vadim didn't like it.  I think he prefered to do logging, but honestly,
it was over a year ago, and we could have been benefiting from it all
this time.

Second, I had another idea.  What if we fsync()'ed a file descriptor
only when we were writing the _last_ dirty buffer for that file.  Seems
in many cases this would be a win.  I just don't know how hard that is
to figure out.  Seems there is no need to fsync() if we still have dirty
buffers around.

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