Re: Major features for 9.1

From: Kevin Grittner
Subject: Re: Major features for 9.1
Date: ,
Msg-id: 4D99F855020000250003C262@gw.wicourts.gov
(view: Whole thread, Raw)
In response to: Re: Major features for 9.1  (Jeff Davis)
Responses: Re: Major features for 9.1  (Oleg Bartunov)
Re: Major features for 9.1  (Jeff Davis)
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, )

Jeff Davis <> wrote:
> On Mon, 2011-04-04 at 07:20 -0500, Kevin Grittner wrote:
>>> a) a two-line explanation of what the feature is and why it's
>>> valuable (for the release notes, etc.)
>>> b) a wiki page with a more detailed explaination and examples
>>> oriented towards the beginning-to-intermediate PostgreSQL user.
>>>
>>> Volunteers?
>>
>> I volunteer for SSI.
>
> The way I think about SSI is that it automatically detects live
> race conditions in your SQL transactions at runtime; and protects
> you by safely rolling some of them back (which can be retried
> safely).
>
> Maybe something along those lines?

That is very accessible to an IT manager who's not a database
expert, and conceptually very clean.  It doesn't directly address
what's innovative about it, though, nor does it directly address why
it's valuable -- although one could infer both through a close
reading.

To extend that such that the innovative nature and benefits are more
explicitly stated, perhaps:

SSI allows you to enforce arbitrarily complex user-defined business
rules within the database without blocking, by automatically
detecting live race conditions in your SQL transactions at runtime.
It protects you by safely rolling some of them back (which can be
retried safely).

It's more than two lines, but I'm not immediately able to see what
to cut.

By the way, I did some google searches to try to find a prior
production quality implementation, and have so far not found any.  I
have discovered that SSI is a very popular TLA, including its use
for something called Server Side Includes (SSI.php) which is a
popular enough technology with databases for people to be listing
years of experience with it on their LinkedIn pages.  I don't know
how much of a problem that might be.  I guess at a minimum we should
add Serializable Snapshot Isolation to the Wikipedia SSI page:

http://en.wikipedia.org/wiki/SSI

Maybe we shouldn't use SSI without spelling out Serializable
Snapshot Isolation, to avoid confusion.

-Kevin


pgsql-advocacy by date:

From: "Kevin Grittner"
Date:
Subject: Re: Major features for 9.1
From: Aidan Van Dyk
Date:
Subject: Re: Major features for 9.1