Re: [HACKERS] index refuses to build

On Sun, Aug 26, 2012 at 09:47:01AM -0400, Bruce Momjian wrote:
> On Thu, Dec 29, 2011 at 10:40:19PM -0500, Tom Lane wrote:
> > Merlin Moncure <mmoncure@gmail.com> writes:
> > > On Thu, Dec 29, 2011 at 5:10 PM, Jean-Yves F. Barbier <12ukwn@gmail.com> wrote:
> > >> CREATE INDEX tst1m_name_lu_ix ON tst1m(unaccent(name));
> > >> ERROR:  functions in index expression must be marked IMMUTABLE
> >
> > > your problem is the unaccent function.  it's defined stable because
> > > the rules function it depends on can change after the index is built
> > > -- that would effectively introduce index corruption.  it's possible
> > > to bypass that restriction, but are you sure that's what you want to
> > > do?
> >
> > Hmm ... it's clear why unaccent(text) is only stable, because it depends
> > on the current search_path to find the "unaccent" dictionary.  But I
> > wonder whether it was an oversight that unaccent(regdictionary, text)
> > is stable and not immutable.  We don't normally mark functions as stable
> > just because you could in principle change their behavior by altering
> > some outside-the-database configuration files.
>
> Should we change the function signature for unaccent(regdictionary,
> text)?

Did we decide not to do this?

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

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