On Thu, Dec 24, 2009 at 4:36 PM, Kian Wright
<kian.wright@senioreducators.com> wrote:
> I'm trying to create an index on the month and year of a date field (in
> 8.3), and I'm getting the "functions in index expression must be marked
> IMMUTABLE" error message.
If applied to a timestamp, it is immutable. If it's a timestamp with
timezone it's not, because the timezone can change, which would change
the index.