pg_restore & search_path, COPY failed for table "mytable": ERROR: function myinnerfunction(integer) does not exist

Hi,

The following steps reproduce an error with pg_restore:

DROP TABLE IF EXISTS myTable;
DROP FUNCTION IF EXISTS myInnerFunction(INTEGER);
DROP FUNCTION IF EXISTS myOuterFunction(INTEGER);
DROP SCHEMA IF EXISTS myOtherSchema;

CREATE SCHEMA myOtherSchema;

SET search_path = myPrimarySchema, myOtherSchema, public;

CREATE OR REPLACE FUNCTION myOtherSchema.myInnerFunction(INTEGER) RETURNS
boolean
LANGUAGE sql IMMUTABLE STRICT
AS $$
SELECT TRUE;
$$;

CREATE OR REPLACE FUNCTION myOuterFunction(INTEGER) RETURNS boolean
LANGUAGE sql IMMUTABLE STRICT
AS $$
SELECT myInnerFunction($1);
$$;

CREATE TABLE myTable(
mycol INTEGER,
CONSTRAINT MyConstraint CHECK (myOuterFunction(mycol))
);

INSERT INTO myTable VALUES (1);

Do a pg_dump of myTable.

Doing a pg_restore, throws:
COPY failed for table "mytable": ERROR: function myinnerfunction(integer)
does not exist
LINE 2: SELECT myInnerFunction($1);
^
HINT: No function matches the given name and argument types. You might
need to add explicit type casts.
QUERY:
SELECT myInnerFunction($1);
CONTEXT: SQL function "myouterfunction" during inlining

Using pg_dump plain on myTable shows that search_path is set to
myPrimarySchema, pg_catalog, so is missing myOtherSchema.

I'm puzzled as to how search_path should be used,.
Should all references be schema qualified inside functions body ?
Or is search_path safe except in the body of functions used in index or
constraints ?

That's with version 9.5.3 & 9.6 beta 3.

Thanks,
Jean-Pierre Pelletier

On Thu, Jul 21, 2016 at 1:57 PM, Jean-Pierre Pelletier <
jppelletier(at)e-djuster(dot)com> wrote:

>
> I'm puzzled as to how search_path should be used,.
> Should all references be schema qualified inside functions body ?
>

​Pretty much...you can also do:

CREATE FUNCTION funcname()
SET search_path TO 'other_schemas_needed_by_this_function'
AS $$
[...]
$$​

​You don't have to specify the schema the function is going to reside
in...but there is exposure if you don't.​

Or is search_path safe except in the body of functions used in index or
> constraints ?
>

​pg_dump/pg_restore tends to be very conservative in setting search_path.
I'd say you are safe if you can successfully dump/restore and unsafe if you
cannot.

​Cross-schema dependencies can be problematic and if you are not willing to
test that your omissions are immaterial I'd say you should take the
paranoid route an schema-prefix everything - either explicitly or by taking
advantage of attribute setting options for functions.

Views, materialized and otherwise, are other areas commonly affected by lax
schema specifications.

David J.