Horton

Re: SSI non-serializable UPDATE performance

Dan Ports <drkp@csail.mit.edu>

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From: Dan Ports <drkp@csail.mit.edu>
To: Robert Haas <robertmhaas@gmail.com>
Cc: Kevin Grittner <Kevin.Grittner@wicourts.gov>, Simon Riggs <simon@2ndQuadrant.com>, pgsql-hackers <pgsql-hackers@postgresql.org>
Date: 2011-04-29T07:23:56Z
Lists: pgsql-hackers

Commits

Same data as JSON: GET /api/v1/messages/:b64id/commits the thread's linked commits as JSON, with link sources. API reference →

  1. Add fast paths for cases when no serializable transactions are running.

Attachments

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.

Dan

-- 
Dan R. K. Ports              MIT CSAIL                http://drkp.net/