pg_temp schema created while using DB Link

Hello Everyone,

We have an issue with DB_Link from Oracle to PostgreSQL. When we try to access tables from Oracle database via DB_link, temp schemas(pg_temp,pg_toast) are automatically created in the database while using the query below.

create table as select * from table@oralink  


Even if we reload the database, the temp schemas are still there. 

Do you know the reason why the temp schemas are being created with DB_link?Does anyone has a solution for this problem?

Thank you

Regards,
Jill