Re: Spread checkpoint sync

Cédric Villemain wrote:
> Is it worth a new thread with the different IO improvements done so
> far or on-going and how we may add new GUC(if required !!!) with
> intelligence between those patches ? ( For instance, hint bit IO limit
> needs probably a tunable to define something similar to
> hint_write_completion_target and/or IO_throttling strategy, ...items
> which are still in gestation...)
>   

Maybe, but I wouldn't bring all that up right now.  Trying to wrap up 
the CommitFest, too distracting, etc.

As a larger statement on this topic, I'm never very excited about 
redesigning here starting from any point other than "saw a bottleneck 
doing <x> on a production system".  There's a long list of such things 
already around waiting to be addressed, and I've never seen any good 
evidence of work related to hint bits being on it.  Please correct me if 
you know of some--I suspect you do from the way you're brining this up.  
If we were to consider kicking off some larger work here, I would drive 
that by asking where the data supporting that work being necessary is at 
first.  It's hard enough to fix a bottleneck that's staring right at 
you, trying to address one that's just theorized is impossible.

-- 
Greg Smith   2ndQuadrant US    greg@2ndQuadrant.com   Baltimore, MD
PostgreSQL Training, Services, and 24x7 Support  www.2ndQuadrant.us
"PostgreSQL 9.0 High Performance": http://www.2ndQuadrant.com/books