Обсуждение: BUG #15530: unable restore index on function from earthdistancecontrib

The following bug has been logged on the website:

Bug reference:      15530
Logged by:          Sergei Kornilov
Email address:      sk@zsrv.org
PostgreSQL version: 11.1
Operating system:   Linux Debian
Description:

Hello

We have some immutable language SQL functions in earthdistance contrib
module. So we can build indexes on this functions. But it is unable to
restore such indexes from dump due search_path restrictions in pg_dump.

Simple reproducer is:

SELECT pg_catalog.set_config('search_path', '', false);

CREATE EXTENSION IF NOT EXISTS cube WITH SCHEMA public;
CREATE EXTENSION IF NOT EXISTS earthdistance WITH SCHEMA public;

CREATE TABLE public.points (
    id integer NOT NULL,
    name character varying(255) NOT NULL,
    lng double precision NOT NULL,
    lat double precision NOT NULL
);

CREATE INDEX points_coordinates ON public.points USING gist
(public.ll_to_earth(lat, lng));

With error on last line:
> ERROR:  type "earth" does not exist
> LINE 1: ...ians($1))*sin(radians($2))),earth()*sin(radians($1)))::earth
>                                                                  ^
> QUERY:  SELECT

cube(cube(cube(earth()*cos(radians($1))*cos(radians($2))),earth()*cos(radians($1))*sin(radians($2))),earth()*sin(radians($1)))::earth
> CONTEXT:  SQL function "ll_to_earth" during inlining

Seems to be broken in all supported versions. I checked on fresh HEAD, 11.1
and 10.6.
How can we fix this? Extension is marked as relocatable

regards, Sergei

Hello

I think we can fix this issue by marking SQL language functions "set 
search_path from current". Both "alter extension" and "create extension" 
provided correct search_path and we can save it by native "set from 
current" feature. Please see attached patch.

regards, Sergei

>>>>> "Sergei" == Sergei Kornilov <sk@zsrv.org> writes:

 Sergei> Hello
 Sergei> I think we can fix this issue by marking SQL language functions
 Sergei> "set search_path from current".

Unfortunately using SET on sql-language functions prevents inlining.

-- 
Andrew (irc:RhodiumToad)

Andrew Gierth <andrew@tao11.riddles.org.uk> writes:
> "Sergei" == Sergei Kornilov <sk@zsrv.org> writes:
>  Sergei> I think we can fix this issue by marking SQL language functions
>  Sergei> "set search_path from current".

> Unfortunately using SET on sql-language functions prevents inlining.

Yeah.  Another problem is that SET FROM CURRENT will freeze the
search_path at the current setting, which means it'll likely
fail again if either extension in question gets relocated.

Even if this were a perfect solution, it only fixes things for
earthdistance, whereas the same problem exists for any extension
containing SQL or PL functions.  So I wish we had a more general
answer ... not that I know what that should look like.

            regards, tom lane