pgsql@mohawksoft.com writes:
> Does it make sense, then, to say that WAL O_SYNC should be O_SYNC? If
> there are no reasons not too, doesn't it make sense to make this the
> default. It will give a boost for any 2.4 Linux machines and won't seem to
> hurt anyone else.
You have got the terms of debate backwards here. These decisions were
already made once, on the basis of more testing than you have done
(okay, it wasn't months worth of work, but we at least exercised a
number of scenarios on a number of platforms). The question is not "why
shouldn't we make this the default" but "why should we make this the
default, and what are we likely to break if we do so?" Showing that one
release series of one platform wins in one particular set of tests is
not sufficient grounds for changing the default.
In particular, you need to offer some evidence for that completely
undocumented assertion that "it won't hurt anyone else".
regards, tom lane