desc dba_views does not exist in database open stage

While you issued this dba_*  dictionary views on database mount

SQL> alter database mount;

Database altered.

SQL> desc dba_views;
ERROR:
ORA-04043: object dba_views does not exist

After database opened

SQL> alter database open;

Database altered.

SQL> desc dba_views;
ERROR:
ORA-04043: object dba_views does not exist

Don’t issue this command on database mount stage

Restart the database normal

or

SQL> alter system flush shared_pool;

System altered.

SQL> desc dba_views;
Name Null? Type
—————————————– ——– —————————-

OWNER NOT NULL VARCHAR2(30)
VIEW_NAME NOT NULL VARCHAR2(30)
TEXT_LENGTH NUMBER
TEXT LONG
TYPE_TEXT_LENGTH NUMBER
TYPE_TEXT VARCHAR2(4000)
OID_TEXT_LENGTH NUMBER
OID_TEXT VARCHAR2(4000)
VIEW_TYPE_OWNER VARCHAR2(30)
VIEW_TYPE VARCHAR2(30)
SUPERVIEW_NAME VARCHAR2(30)
EDITIONING_VIEW VARCHAR2(1)
READ_ONLY VARCHAR2(1)