Re: [GENERAL] Bug with sequence - Mailing list pgsql-hackers

Oliver Elphick wrote:
> 
> On Wed, 2002-11-20 at 21:35, Robert Treat wrote:
> > On Wed, 2002-11-20 at 03:53, Oliver Elphick wrote:
> > > On Mon, 2002-11-18 at 15:45, Thomas Aichinger wrote:
> > > > Hi,
> > > >
> > > > I recently installed pg 7.2.3 on my linux box and discovered that
> > > > there are some problems with datatype serial and sequence.
> > > >
> > > > 1.) If you create a table with a datatype serial, the corrsponding
> > > > sequence will be created, but if you drop the table the sequence is
> > > > not dropped.
> > >
> > > This is fixed in 7.3
> > >
> >
> > out of curiosity, do you know the logic that implements this fix? I have
> > a couple of tables that use the same sequence; I'm wondering if dropping
> > one of the tables removes the sequence or if I have to drop all tables
> > before the sequence is removed
> 
> I just tried it.
> 
> I created a sequence using SERIAL when I created a table.  I used the
> same sequence for another table by setting a column default to
> nextval(sequence).
> 
> I deleted the first table.  The sequence was deleted too, leaving the
> default of the second table referring to a non-existent sequence.

This sounds like a serious bug in our behaviour, and not something we'd
like to release.

Specifically in relation to people's existing scripts, and also to
people who are doing dump/restore of specific tables (it'll kill the
sequences that other tables depend on too!)

No real issue with the nicety for newbies, but am very concerned about
the lack of a dependancy check here.

:-/

Regards and best wishes,

Justin Clift


> Could this be a TODO item in 7.4, to add a dependency check when a
> sequence is set as the default without being created at the same time?
> 
> --
> Oliver Elphick                                Oliver.Elphick@lfix.co.uk
> Isle of Wight, UK
> http://www.lfix.co.uk/oliver
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