Re: Maximum transaction rate

On Wed, 18 Mar 2009, Martijn van Oosterhout wrote:

> Generally PG uses O_SYNC on open

Only if you change wal_sync_method=open_sync.  That's the very last option
PostgreSQL will try--only if none of the other are available will it use
that.

Last time I checked the defaults value for that parameter broke down like
this by platform:

open_datasync (O_DSYNC):  Solaris, Windows (I think there's a PG wrapper
involved for Win32)

fdatasync:  Linux (even though the OS just provides a fake wrapper around
fsync for that call)

fsync_writethrough:  Mac OS X

fsync:  FreeBSD

That makes the only UNIX{-ish} OS where the default is a genuine sync
write Solaris.

--
* Greg Smith gsmith@gregsmith.com http://www.gregsmith.com Baltimore, MD