Thanks for the feedback folks. I had not seen the IMMUTABLE argument to CREATE FUNCTION and realize this change is too
expensive.
This probably will not be the last you hear on this since pureness and immutability are all the rage in development
circles.
> On Nov 7, 2019, at 12:38 PM, Tom Lane <tgl@sss.pgh.pa.us> wrote:
>
> Bruce Momjian <bruce@momjian.us> writes:
>> On Thu, Nov 7, 2019 at 02:17:58PM +0000, PG Doc comments form wrote:
>>> The adjective "immutable" describing the functions and operators used in an
>>> index (see two occurrences in doc snippet below) is incorrect and should be
>>> replaced with "pure".
>
>> I think the best we can do is to mention that IMMUTABLE functions mean
>> pure, but I am not sure there is even enough demand for that, vs.
>> confusing people.
>
> Yeah. I don't think this terminology is nearly as universal
> as the OP believes, so I don't feel a need to change anything.
>
> If we adopt Corey's proposal to create a glossary [1], there'd be
> room for a parenthetical comment like "(In some circles, "pure" is the
> preferred term for this function property.)" in the glossary entry for
> "immutable". I suspect it won't be the only entry that needs
> cross-references to other terminology.
>
> regards, tom lane
>
> [1] https://commitfest.postgresql.org/25/2305/