Re: BUG #5629: ALTER SEQUENCE foo START execute a RESTART - Mailing list pgsql-bugs

From Bruce Momjian
Subject Re: BUG #5629: ALTER SEQUENCE foo START execute a RESTART
Date
Msg-id 201009081723.o88HNBH24654@momjian.us
Whole thread Raw
Responses Re: BUG #5629: ALTER SEQUENCE foo START execute a RESTART  (Alexsander Rosa <alexsander.rosa@gmail.com>)
List pgsql-bugs
Alexsander Rosa wrote:
> Well, if it's not going to be fixed, then at least the docs should be
> revised to warn all 8.4+ users to avoid this command and, if it's really
> needed, always check the server version before using the ALTER SEQUENCE ...
> START command, once it has a potentially hazardous bug that interprets it as
> a RESTART in 8.3 version and below.

The proper place for such notification is the 8.4 release notes, which
states:

       Sequences now contain an additional 'start_value'
       column (Zoltan Boszormenyi)

       This supports <command>ALTER SEQUENCE ... RESTART.

Which means basically 8.3 didn't have a start field at all.

This is the first complaint I have heard about it. Do you have new
wording to suggest?  Perhaps:

    In previous releases, START behaved as RESTART.

---------------------------------------------------------------------------

>
> 2010/9/7 Bruce Momjian <bruce@momjian.us>
>
> > Alexsander Rosa wrote:
> > > What about the risk of using ALTER SEQUENCE ... START N in a mixed
> > > environment? In the 8.4.x servers it will work as designed but in the
> > 8.3.x
> > > (and below) servers, instead of issuing an error it will CORRUPT the
> > > sequence value without notice. I understand the point of keeping a
> > > (mis)feature when it's harmless or at least not amibiguous, but this is
> > not
> > > the case here. While the 8.4 behavior -- the correct one -- is a mere
> > > configuration of little consequence, the 8.3 (and below) behavior is an
> > > unexpected RESET. I think it's safer to require the people that was using
> > > old versions with the wrong spell to fix their code than put lots of
> > users
> > > of the current version in risk of using a potentially disastrous command
> > --
> > > when executed in previous versions. Should all 8.4.x (and beyond) users
> > be
> > > forced to check server version before issuing this command?
> >
> > Should all 8.3 users be required to retest their applications after a
> > minor upgrade?  No.
> >
> > --
> >  Bruce Momjian  <bruce@momjian.us>        http://momjian.us
> >  EnterpriseDB                             http://enterprisedb.com
> >
> >  + It's impossible for everything to be true. +
> >
>
>
>
> --
> Atenciosamente,
> Alexsander da Rosa
> Linux User #113925
>
> "Extremismo na defesa da liberdade n?o ? defeito.
> Modera??o na busca por justi?a n?o ? virtude."
> -- Barry Goldwater

--
  Bruce Momjian  <bruce@momjian.us>        http://momjian.us
  EnterpriseDB                             http://enterprisedb.com

  + It's impossible for everything to be true. +

pgsql-bugs by date:

Previous
From: Tom Lane
Date:
Subject: Re: BUG #5644: Selecting ROW() in variable with 9.0 not compatible with 8.4
Next
From: "Maxim Boguk"
Date:
Subject: BUG #5649: strange (probably bugged) explain analyze output