CREATE TABLE Y_FIRST ( ID NUMBER NOT NULL PRIMARY KEY, TEXT VARCHAR2(10 BYTE), ID_FOREIGN NUMBER NOT NULL );
CREATE TABLE Y_SECOND ( ID NUMBER NOT NULL PRIMARY KEY, TEXT2 VARCHAR2(10 BYTE));

Insert into Y_FIRST (ID, TEXT, ID_FOREIGN) Values (1, 'erst1', 1);
Insert into Y_FIRST (ID, TEXT, ID_FOREIGN) Values (2, 'erst2', 1);
Insert into Y_FIRST (ID,  TEXT, ID_FOREIGN) Values (3, 'erst3', 2);
Insert into Y_FIRST  (ID,  TEXT, ID_FOREIGN) Values (4, 'erst4', 2);
COMMIT;

Insert into Y_SECOND (ID, TEXT2) Values (1, 'yes');
Insert into Y_SECOND (ID, TEXT2) Values (2, 'no');
COMMIT;

CREATE MATERIALIZED VIEW MV (RON,ID1,NAME1,ID2,NAME2) REFRESH COMPLETE ON DEMAND WITH PRIMARY KEY AS
SELECT ROWNUM AS RON, ab.ID AS ID1, ab.text AS NAME1,b.ID AS ID2, b.text2 AS NAME2 FROM y_first ab, y_second b WHERE ab.id_foreign = b.id;
COMMIT;

EXEC DBMS_MVIEW.REFRESH('mv','?');    

EXEC DBMS_MVIEW.REFRESH('mv','F');

ORA-12008: error in materialized view refresh path
ORA-01732: data manipulation operation not legal on this view materialized view
ORA-06512: in "SYS.DBMS_SNAPSHOT", line 2802
ORA-06512: in "SYS.DBMS_SNAPSHOT", line 3039
ORA-06512: in "SYS.DBMS_SNAPSHOT", line 2998
ORA-06512: in line 1

CREATE MATERIALIZED VIEW LOG ON Y_FIRST with primary key, rowid, sequence including new values;
CREATE MATERIALIZED VIEW LOG ON Y_SECOND with primary key, rowid, sequence including new values;

SCOTT@sol12 > select banner from v$version
  2  /

BANNER
--------------------------------------------------------------------------------
Oracle Database 12c Enterprise Edition Release 12.1.0.1.0 - 64bit Production
PL/SQL Release 12.1.0.1.0 - Production
CORE    12.1.0.1.0      Production
TNS for 64-bit Windows: Version 12.1.0.1.0 - Production
NLSRTL Version 12.1.0.1.0 - Production

SCOTT@sol12 > EXEC DBMS_MVIEW.REFRESH('mv','C');

PL/SQL procedure successfully completed.

SCOTT@sol12 > EXEC DBMS_MVIEW.REFRESH('mv','F');
BEGIN DBMS_MVIEW.REFRESH('mv','F'); END;

*
ERROR at line 1:
ORA-12004: REFRESH FAST cannot be used for materialized view "SCOTT"."MV"
ORA-06512: at "SYS.DBMS_SNAPSHOT", line 2802
ORA-06512: at "SYS.DBMS_SNAPSHOT", line 3039
ORA-06512: at "SYS.DBMS_SNAPSHOT", line 2998
ORA-06512: at line 1


SCOTT@sol12 > EXEC DBMS_MVIEW.REFRESH('mv','?');

PL/SQL procedure successfully completed.

SCOTT@sol12 > 

select banner from v$version;

Oracle Database 12c Enterprise Edition Release 12.1.0.1.0 - 64bit Production
PL/SQL Release 12.1.0.1.0 - Production
CORE	12.1.0.1.0	Production
TNS for 64-bit Windows: Version 12.1.0.1.0 - Production
NLSRTL Version 12.1.0.1.0 - Production

select * from v$parameter where name like 'noncdb%';

NUM,NAME,TYPE,VALUE,DISPLAY_VALUE,ISDEFAULT,ISSES_MODIFIABLE,ISSYS_MODIFIABLE,ISPDB_MODIFIABLE,ISINSTANCE_MODIFIABLE,ISMODIFIED,ISADJUSTED,ISDEPRECATED,ISBASIC,DESCRIPTION,UPDATE_COMMENT,HASH,CON_ID
3317,noncdb_compatible,1,FALSE,FALSE,TRUE,FALSE,FALSE,FALSE,FALSE,FALSE,FALSE,FALSE,FALSE,Non-CDB Compatible,null,2594626030,0

select NAME, DISPLAY_VALUE,ISDEFAULT, ISSES_MODIFIABLE, ISMODIFIED, ISADJUSTED,ISBASIC, DESCRIPTION from v$parameter where name like 'noncdb%'

NAME,DISPLAY_VALUE,ISDEFAULT,ISSES_MODIFIABLE,ISMODIFIED,ISADJUSTED,ISBASIC,DESCRIPTION
noncdb_compatible,FALSE,TRUE,FALSE,FALSE,FALSE,FALSE,Non-CDB Compatible

select cdb from v$database;

CDB
NO

CREATE TABLE Y_TEST2 (
    ID NUMBER NOT NULL PRIMARY KEY,
    TEXT VARCHAR2(255)
 );
 
 insert into y_test2 values(1,'yep');
 insert into y_test2 values(2,'no');
 
CREATE MATERIALIZED VIEW RATSCHINGS.MV_Y_TEST2 (ID,TEXT) REFRESH COMPLETE ON DEMAND WITH PRIMARY KEY AS 
SELECT ID, text FROM Y_TEST2;

exec dbms_mview.refresh('mv_y_test2', 'C');

ORA-12008: error in materialized view refresh path
ORA-01732: data manipulation operation not legal on this view materialized view
ORA-06512: in "SYS.DBMS_SNAPSHOT", line 2802
ORA-06512: in "SYS.DBMS_SNAPSHOT", line 3039
ORA-06512: in "SYS.DBMS_SNAPSHOT", line 2998
ORA-06512: in line 1