Re: Compatibility GUC for serializable - Mailing list pgsql-hackers

From Ron Mayer
Subject Re: Compatibility GUC for serializable
Date
Msg-id 4D2DC046.3030608@cheapcomplexdevices.com
Whole thread Raw
In response to Re: Compatibility GUC for serializable  (Josh Berkus <josh@agliodbs.com>)
Responses Re: Compatibility GUC for serializable  ("Kevin Grittner" <Kevin.Grittner@wicourts.gov>)
List pgsql-hackers
Josh Berkus wrote:
>> Mainly, that it's not clear we need it.  Nobody's pointed to a concrete
>> failure mechanism that makes it necessary for an existing app to run
>> under fake-SERIALIZABLE mode.
> 
> I think it's quite possible that you're right, and nobody depends on
> current SERIALIZABLE behavior because it's undependable.  However, we
> don't *know* that -- most of our users aren't on the mailing lists,
> especially those who use packaged vendor software.
> 
> That being said, the case for a backwards-compatiblity GUC is weak, and
> I'd be ok with not having one barring someone complaining during beta,
> or survey data showing that there's more SERIALIZABLE users than we think.
> 
> Oh, survey:
> http://www.postgresql.org/community/
> 

That Survey's missing one important distinction for that discussion.

Do you take the the current survey answer
  "Yes, we depend on it for production code"

to imply
  "Yes, we depend on actual real SERIALIZABLE transactions in   production and will panic if you tell us we're not
gettingthat"
 

or
  "Yes, we depend on the legacy not-quite SERIALIZABLE transactions   in production and don't want real serializable
transactions"


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