Objects defined with the features compatible with oracle databases are defined in the oracle schema. Therefore, when using this function, it is necessary to add "oracle" to the "search_path" parameter in postgresql.conf.
search_path = '"$user", public, oracle'
Information
The search_path parameter specifies the order in which schemas are searched.
Refer to "Statement Behavior" in "Client Connection Defaults" in "Server Administration" in the PostgreSQL Documentation for information on search_path.
