Re: ERROR: functions in index expression must be marked IMMUTABLE

On 1 March 2017 at 13:36, Sven R. Kunze <srkunze(at)mail(dot)de> wrote:

> On 28.02.2017 17:50, David G. Johnston wrote:
>
> Supposedly one could provide a version of to_date that accepts a locale in
> which to interpret names in the input data - or extend the format string
> with some kind of "{locale=en_US}" syntax to avoid changing the function
> signature.
>
> if this is acceptable, I would be willing to contribute a patch to enable
> exactly this.
>

​I don't see how that would help. You can't set a function to be immutable
for "some" inputs (ie where locale is specified in the format string).

The only way to do it would be to add to_date(string, string, string) where
the third string specifies the locale, at which point I don't really see
why you would gain anything over creating your own UDF.

Geoff​