Re: We really ought to do something about O_DIRECT and data=journalled on ext4

On 11/30/2010 10:09 PM, Tom Lane wrote:
> Josh Berkus<josh@agliodbs.com>  writes:
>> Apparently, testing for O_DIRECT at compile time isn't adequate.  Ideas?
> We should wait for the outcome of the discussion about whether to change
> the default wal_sync_method before worrying about this.
>
>             

Tom,

we've just had a significant PGX customer encounter this with the latest 
Postgres on Redhat's freshly released flagship product. Presumably the 
default wal_sync_method will only change prospectively. But this will 
feel to every user out there who encounters it like a bug in our code, 
and it needs attention. It was darn difficult to diagnose, and many 
people will just give up in disgust if they encounter it.

cheers

andrew