On Mon, 2005-05-30 at 02:52 -0400, Tom Lane wrote: > Some googling suggests so, eg > http://www.die.net/doc/linux/man/man2/open.2.html
Well, that claims that "data is guaranteed to have been transferred", but transferred to *where* is the question :) Transferring data to the disk's buffers and then not asking for the buffer to be flushed is not sufficient, for example. IMHO the fact that InnoDB uses both O_DIRECT and fsync() is more convincing. I'm still looking for a definitive answer, though. The other question is whether these semantics are identical among the various O_DIRECT implementations (e.g. Linux, FreeBSD, AIX, IRIX, and others). -Neil ---------------------------(end of broadcast)--------------------------- TIP 6: Have you searched our list archives? http://archives.postgresql.org