int yaz_retrieval_request(yaz_retrieval_t p,
const char *schema, Odr_oid *syntax,
const char **match_schema, Odr_oid **match_syntax,
int yaz_retrieval_request(yaz_retrieval_t p,
const char *schema, Odr_oid *syntax,
const char **match_schema, Odr_oid **match_syntax,