Re: RE: xlog checkpoint depends on sync() ... seems uns afe

"Mikheev, Vadim" <vmikheev@SECTORBASE.COM> writes:
>> The idea is, that by the time the last sync has run, the 
>> first sync will be done flushing the buffers to disk. - this is what
>> we were told by the IBM engineers when I worked tier-2/3 AIX support
>> at IBM.

> I was told the same a long ago about FreeBSD. How much can we count on
> this undocumented sync() feature?

Sounds quite unreliable to me.  Unless there's some interlock ... like,
say, the second sync not being able to advance past a buffer page that's
as yet unwritten by the first sync.  But would all Unixen share such a
strange detail of implementation?
        regards, tom lane