Thread: Hot standby, freezing

While reading through the patch for what must be the 100th time by now,
it occurred to me that this comment in heap_xlog_freeze:

+       /*
+        * Freezing tuples does not require conflict processing
+        */

is plain wrong. In the master, we can freeze the xmin of a tuple that's
not yet visible to all read-only transactions in the standby. We do need
conflict processing there.

--  Heikki Linnakangas EnterpriseDB   http://www.enterprisedb.com

On Wed, 2009-11-11 at 12:35 +0200, Heikki Linnakangas wrote:
> While reading through the patch for what must be the 100th time by now,

:-)

> it occurred to me that this comment in heap_xlog_freeze:
> 
> +       /*
> +        * Freezing tuples does not require conflict processing
> +        */
> 
> is plain wrong. In the master, we can freeze the xmin of a tuple that's
> not yet visible to all read-only transactions in the standby. We do need
> conflict processing there.

I agree. Hmph, I wonder why I thought otherwise?

-- Simon Riggs           www.2ndQuadrant.com