Re: SSI non-serializable UPDATE performance - Mailing list pgsql-hackers

From Robert Haas
Subject Re: SSI non-serializable UPDATE performance
Date
Msg-id BANLkTimTNxYRtNJiERJPm+xoddHqRsGO1A@mail.gmail.com
Whole thread Raw
In response to Re: SSI non-serializable UPDATE performance  (Dan Ports <drkp@csail.mit.edu>)
List pgsql-hackers
On Fri, Apr 29, 2011 at 3:23 AM, Dan Ports <drkp@csail.mit.edu> wrote:
> On Thu, Apr 28, 2011 at 06:45:54PM +0200, Robert Haas wrote:
>> Yeah, I think Dan's notes about memory ordering would be good to include.
>
> I left it out initially because I didn't want to make things more
> confusing. As far as memory ordering is concerned, this is the same
> story as anything else that uses lwlocks: the spinlock memory barrier
> prevents memory accesses from being reordered before the lock is
> acquired. The only unusual thing here is that the lock in question
> isn't the one that protects the variable we're reading.
>
> But I'm OK with adding a comment if you think it helps. Patch attached.

Looks good.  Committed.

-- 
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company


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