Re: Snapshot synchronization, again...

Joachim Wieland <joe@mcknight.de>

From: Joachim Wieland <joe@mcknight.de>
To: Alvaro Herrera <alvherre@commandprompt.com>
Cc: pgsql-hackers <pgsql-hackers@postgresql.org>
Date: 2010-12-31T14:38:51Z
Lists: pgsql-hackers
On Fri, Dec 31, 2010 at 8:28 AM, Alvaro Herrera
<alvherre@commandprompt.com> wrote:
> A backend can have any number of snapshots registered, and those don't
> allow GlobalXmin to advance.  Consider an open cursor, for example.
> Even if the rest of the transaction is read committed, the snapshot
> registered by the open cursor still holds back GlobalXmin.  My
> (handwavy) idea is that whenever the transaction calls
> pg_publish_snapshot(), said snapshot is registered, which makes it safe
> to use even if the transaction continues to operate and obtain newer
> snapshots.

Cool, even better that this is taken care of already :-)

Thanks,
Joachim