Re: Compatibility GUC for serializable

On 1/10/11 10:47 AM, Kevin Grittner wrote:
> If they're not using SERIALIZABLE, this patch will have no impact on
> them at all.  If they are using SELECT FOR UPDATE *with*
> SERIALIZABLE, everything will function exactly as it is except that
> there may be some serialization failures which they weren't getting
> before, either from the inevitable (but hopefully minimal) false
> positives inherent in the technique or because they missed covering
> something.

Right, that's what I'm worried about.  That's the sort of thing which is
very hard for a user to hunt down and troubleshoot, and could become a
blocker to upgrading.  Especially if they user has a vendor application
where they *can't* fix the code.  The only reason I'm ambivalent about
this is I'm unsure that there are more than a handful of people using
SERIALIZABLE in production applications, precisely because it's been so
unintuitive in the past.

Lemme start a survey on whether people use SERIALIZABLE.

--                                  -- Josh Berkus                                    PostgreSQL Experts Inc.
                        http://www.pgexperts.com