Re: BUG #5781: unaccent() function should be marked IMMUTABLE

Greg Stark <gsstark(at)mit(dot)edu> writes:
> On Fri, Dec 3, 2010 at 4:50 AM, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
>> Even if you're willing to
>> assume that the dictionary being used is the one defined by this
>> module, that dictionary depends on external configuration files
>> which are easily changeable.

> Don't we have precedent for this in assuming that things like tsearch
> dictionaries and parsers and system locales don't change underneath
> us?

The precedent is to assume such things are stable, not immutable.

Even if you want to assume that, the implementation of unaccent(text) is
such that its results depend on search_path, which is *definitely* not
acceptable for an immutable function. It would need a better way of
tying the function to the dictionary.

regards, tom lane