Re: fsync alternatives (was: Re: [HACKERS] TODO item)

> Yes, the way I understand it is that one backend doing the fsync
> will sync the entire file perhaps forcing a sync in the middle of
> a somewhat critical update being done by another instance of the
> backend.

We don't mind that.  Until the transaction is marked as complete, they
can fsync anything we want.  We just want all stuff modified by a 
transaction fsynced before a transaction is marked as completed.

> I'm aware of the performance implications sync writes cause, but
> using fsync after every write seems to cause massive amounts of
> unessesary disk IO that could be avoided with using explicit
> sync descriptors with little increase in complexity considering
> what I understand of the current implementation.

Yes.


--  Bruce Momjian                        |  http://www.op.net/~candle pgman@candle.pha.pa.us               |  (610) 853-3000 +  If your life is a hard drive,     |  830 Blythe Avenue +  Christ can be your backup.        |  Drexel Hill, Pennsylvania 19026