pg_restore “CREATE CAST” not executed if using public or pg_catalog schemas

Question

While moving database to another instance I'm using pg_dump and pg_restore with intermediate file.

Dump file was created like this:

pg_dump --host $SRC_DB_HOST --port 5432 "dbname=$SRC_DB user=$SRC_DB_USER sslrootcert=rds-combined-ca-bundle.pem sslmode=verify-full" --no-owner --verbose -Fc --file db.bak 

I definitely see that there are casts in the dump

$strings db.bak | grep "CREATE \(TYPE\|CAST\)"
CREATE TYPE public.score_group_name AS ENUM (
CREATE TYPE public.score_group_type AS ENUM (
CREATE CAST (character varying AS public.score_group_name) WITH INOUT AS IMPLICIT;
CREATE CAST (character varying AS public.score_group_type) WITH INOUT AS IMPLICIT;

But when I restore database running pg_restore with params:

pg_restore --verbose -Fc --no-acl --no-owner -n public --single-transaction db.bak > migration.log

there are no queries produced for creating it:

$ grep -e "\(CREATE\|DROP\) \(TYPE\|CAST\)" migration.log
CREATE TYPE public.score_group_name AS ENUM (
CREATE TYPE public.score_group_type AS ENUM (

Source PostgreSQL version:

PostgreSQL 9.6.11 on x86_64-pc-linux-gnu, compiled by gcc (GCC) 4.8.3 20140911 (Red Hat 4.8.3-9), 64-bit

Target PostgreSQL version:

PostgreSQL 9.6.10 on x86_64-pc-linux-gnu, compiled by gcc (Ubuntu 4.8.4-2ubuntu1~14.04.3) 4.8.4, 64-bit

PostgreSQL Utils versions:

$ pg_dump --version
pg_dump (PostgreSQL) 9.6.14
$ pg_restore --version
pg_restore (PostgreSQL) 9.6.14

UPDATE It seems that the root of the problem is -n public parameter, without schema filtering -- CREATE CAST statement is produced, but which schema should I add to the restore? Because -n public and -n pg_catalog filter out such statements.

Answer 1

The reason is that type casts do not live in a schema.

If you specify -n public, you will only get objects from that schema, and that does not include the type cast.