...and a question (SHA1 UUIDs)

[Bron Gondwana]

On Thu, 06 Sep 2007 09:53:27 -0400, "Ken Murchison" <murch at andrew.cmu.edu> said:
> Bron Gondwana wrote:
> > I guess there's still some value in having a "turn UUIDs off" config
> > option to allow people who don't want the CPU overhead of calculating
> > sha1 values to avoid it.  Unless we're planning to simplify the
> > replication system as well by absolutely demanding that UUIDs are
> > calculated on all messages.  I can see arguments for both sides, so
> > I guess it's down to an executive decision!
> 
> Right.  It comes down to whether we want/need to allow replication 
> without UUIDs.  We can trigger whether we calculate the SHA1 UUIDs on 
> the master by checking to see if 'sync_host' is set.

There's some value anyway for integrity checks.

> If we go with a 'uuid_mode' option, my inclination is default it to 
> 'none' or 'off', so standalone servers aren't wasting CPU by doing SHA1 
> (or else we couple check for 'sync_host' && 'uuid_mode' before doing
> SHA1).

I'd be inclined to make them two separate choices, because sha1 in the
index is still very valuable for integrity checks and potentially
duplicate finding (post dated "single instance store" even!)

Bron.
-- 
  Bron Gondwana
  brong at fastmail.fm