Re: date is not immutable ?

"Gaetano Mendola" <mendola@bigfoot.com> writes:
> I'm trying to create an index on a timestamptz field just extracting the
> date:
> # create index idx_user_logs_login_time_date on user_logs (
> date(login_time) );
> ERROR:  DefineIndex: index function must be marked IMMUTABLE

> why date is not marked immutable ?

Because the conversion depends on your timezone setting.

            regards, tom lane