On Wed, 2009-05-27 at 19:51 -0500, Kevin Grittner wrote:
> Jeff Davis <pgsql@j-davis.com> wrote:
>
> > 1. implementation of the paper's technique sans predicate locking,
> > that would avoid more serialization anomalies but not all?
>
> I saw that as a step along the way to support for fully serializable
> transactions. If covered by a "migration path" GUC which defaulted to
> current behavior, it would allow testing of all of the code except the
> predicate lock tracking (before the predicate locking code was
> created), in order to give proof of concept, check performance impact
> of that part of the code, etc. I wasn't thinking that it would be a
> useful long-term option without the addition of the predicate locks.
>
OK, if that behavior is not ultimately useful, then I retract my
question.
We still need to know whether to use a GUC at all -- it won't actually
break applications to offer true serializability, it will only impact
performance.
Regards,Jeff Davis