Re: Possible causes for database corruption and solutions

Greg Smith <greg@xxxxxxxxxxxxxxx> · Wed, 16 Dec 2009 14:05:44 -0500

Michael Clark wrote:

  On Wed, Dec 16, 2009 at 11:25 AM, Greg Smith
  <greg@xxxxxxxxxxxxxxx>
wrote:

    Florian Weimer wrote:

I hope that Mac OS X turns off write caches on low battery.

I've never heard of such a thing.  The best you can do is try to push
the system into hibernation instead of going down hard.  That *should*
clear any disk caches as part of the graceful shutdown.  But you're
relying on a relatively fragile system now, once the battery is quite
low who knows if that will even execute in the window of time you have
left.

  And at this point it is not unreasonable to expect the user to
perform some sort of action. Shutdown before the power completely dies,
or plug in the power.

Sure, but the point is that if your database will get corrupted if that
doesn't happen, that's a mistake because sooner or later every such
portable system is going to end up there and not get plugged in on time.

-- 
Greg Smith    2ndQuadrant   Baltimore, MD
PostgreSQL Training, Services and Support
greg@xxxxxxxxxxxxxxx  www.2ndQuadrant.com