Re: Major features for 9.1

From: Kevin Grittner
Subject: Re: Major features for 9.1
Date: ,
Msg-id: 4D9C845E020000250003C467@gw.wicourts.gov
(view: Whole thread, Raw)
In response to: Re: Major features for 9.1  (Peter Eisentraut)
List: pgsql-advocacy

Tree view

Major features for 9.1  (Josh Berkus, )
 Re: Major features for 9.1  (Thom Brown, )
 Re: Major features for 9.1  ("Joshua D. Drake", )
 Re: Major features for 9.1  (Pavel Stehule, )
 Re: Major features for 9.1  (Guillaume Lelarge, )
  Re: Major features for 9.1  (phb07, )
 Re: Major features for 9.1  ("Kevin Grittner", )
  Re: Major features for 9.1  (Florian Weimer, )
 Re: Major features for 9.1  (Robert Bernier, )
  Re: Major features for 9.1  (David Fetter, )
 Re: Major features for 9.1  (Simon Riggs, )
  Re: Major features for 9.1  (Josh Berkus, )
   Re: Major features for 9.1  (Simon Riggs, )
    Re: Major features for 9.1  (Gilberto Castillo Martínez<>, )
    Re: Major features for 9.1  (David Fetter, )
   Re: Major features for 9.1  (Peter Eisentraut, )
    Re: Major features for 9.1  (David Fetter, )
     Re: Major features for 9.1  (Peter Eisentraut, )
   Re: Major features for 9.1  (Peter Eisentraut, )
    Re: Major features for 9.1  (Joshua Berkus, )
     Re: Major features for 9.1  (Andrew Lardinois, )
     Re: Major features for 9.1  ("Kevin Grittner", )
     Re: Major features for 9.1  (David Fetter, )
     Re: Major features for 9.1  (Greg Smith, )
      Re: Major features for 9.1  (Joshua Berkus, )
      Re: Major features for 9.1  (Bruce Momjian, )
    Re: Major features for 9.1  (Gilberto Castillo Martínez<>, )
   Re: Major features for 9.1  (Joshua Berkus, )
    Re: Major features for 9.1  (Peter Eisentraut, )
    Re: Major features for 9.1  (Oleg Bartunov, )
 Re: Major features for 9.1  (Emanuel Calvo, )
 Re: Major features for 9.1  ("Kevin Grittner", )
 Re: Major features for 9.1  ("Kevin Grittner", )
  Re: Major features for 9.1  (Jeff Davis, )
   Re: Major features for 9.1  ("Kevin Grittner", )
    Re: Major features for 9.1  (Oleg Bartunov, )
     Re: Major features for 9.1  (Gilberto Castillo Martínez<>, )
    Re: Major features for 9.1  (Jeff Davis, )
     Re: Major features for 9.1  ("Kevin Grittner", )
 Re: Major features for 9.1  ("Kevin Grittner", )
  Re: Major features for 9.1  (Gilberto Castillo Martínez<>, )
   Re: Major features for 9.1  ("Kevin Grittner", )
    Re: Major features for 9.1  (Andrew Lardinois, )
     Re: Major features for 9.1  ("Kevin Grittner", )
      Re: Major features for 9.1  ("Kevin Grittner", )
       Re: Major features for 9.1  (Andrew Lardinois, )
        Re: Major features for 9.1  ("Kevin Grittner", )
         Re: Major features for 9.1  (Andrew Lardinois, )
     Re: Major features for 9.1  (Simon Riggs, )
 Re: Major features for 9.1  (Aidan Van Dyk, )
 Re: Major features for 9.1  ("Kevin Grittner", )
  Re: Major features for 9.1  (Nikolas Everett, )
  Re: Major features for 9.1  (Josh Berkus, )
   Re: Major features for 9.1  ("Kevin Grittner", )
  Re: Major features for 9.1  (Roy Hann, )
   Re: Major features for 9.1  (Jeff Davis, )
    Re: Major features for 9.1  (Peter Eisentraut, )
     Re: Major features for 9.1  ("Kevin Grittner", )
  Re: Major features for 9.1  (Roy Hann, )
   Re: Major features for 9.1  ("Kevin Grittner", )
    Re: Major features for 9.1  (Jeff Davis, )
     Re: Major features for 9.1  ("Kevin Grittner", )
 Re: Major features for 9.1  ("Kevin Grittner", )
 Re: Major features for 9.1  (Peter Eisentraut, )
  Re: Major features for 9.1  (Magnus Hagander, )
   Re: Major features for 9.1  (Peter Eisentraut, )
 Re: Major features for 9.1  ("Kevin Grittner", )
  Re: Major features for 9.1  ("Joshua D. Drake", )
  Re: Major features for 9.1  (Greg Smith, )
   Re: Major features for 9.1  ("Kevin Grittner", )
    Re: Major features for 9.1  (Greg Smith, )
     Re: Major features for 9.1  ("Kevin Grittner", )
 Re: Major features for 9.1  (Simon Riggs, )
  Re: Major features for 9.1  (Joshua Tolley, )
   Re: Major features for 9.1  (Gilberto Castillo Martínez<>, )
   Re: Major features for 9.1  (Thomas Kellerer, )

Peter Eisentraut <> wrote:
> On ons, 2011-04-06 at 11:01 -0700, Jeff Davis wrote:

>> One of the use cases of SSI is to enforce constraints, which are
>> certainly of interest to DBAs.
>
> Well, but users can freely change the isolation level, so it would
> not really be an effective constraint mechanism.

In our shop we plan to have a trigger check to ensure the isolation
level is serializable for all production tables.  In the long run,
it sure would be convenient to have a GUC setting to prohibit
explicitly setting the isolation level to something less strict than
the default, but it didn't seem wise to try to do that in the
initial release with the feature. People are probably going to want
a little wiggle room until the technique has some miles on it.

So, sure -- in our shop a user can change the isolation level, but
if they try to modify production data they will get an error with
such a setting, and if they view data from a read only transaction
in a state where a transient anomaly is visible to them, I guess
that's on them.

-Kevin


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