As it's explained in the documentation, the table name - as needed by pdm_load/pdm_extract - , it's not always the same as the one in the SQL, that's why there is a mapping between them in the document. The pdm_ utilities don't connect directly to the SQL tables, but go through an intermediary layer (Data Element Dictionary), just as the names at the Objects and Attributes layer are different (i.e. grpmem).