SQL> select * from v$version;

BANNER                                                                          
--------------------------------------------------------------------------------
Oracle9i Enterprise Edition Release 9.2.0.8.0 - Production                      
PL/SQL Release 9.2.0.8.0 - Production                                           
CORE	9.2.0.8.0	Production                                                       
TNS for 32-bit Windows: Version 9.2.0.8.0 - Production                          
NLSRTL Version 9.2.0.8.0 - Production                                           

SQL> 
SQL> CREATE TABLE test_default
  2  AS
  3  SELECT COUNT(*) AS n, object_type AS name
  4  FROM all_objects WHERE ROWNUM < 100
  5  GROUP BY object_type;

Table created.

SQL> 
SQL> SELECT * FROM test_default;

         N NAME                                                                 
---------- ------------------------------                                       
        97 JAVA CLASS                                                           
         2 JAVA RESOURCE                                                        

SQL> 
SQL> ALTER TABLE test_default
  2  	ADD is_zero VARCHAR2(9 CHAR) DEFAULT 'Zero';

Table altered.

SQL> 
SQL> SELECT * FROM test_default;

         N NAME                           IS_ZERO                               
---------- ------------------------------ ----------                            
        97 JAVA CLASS                     Zero                                  
         2 JAVA RESOURCE                  Zero                                  

SQL> 
SQL> INSERT INTO test_default(n, name) VALUES(2022, 'New Year');

1 row created.

SQL> 
SQL> SELECT * FROM test_default;

         N NAME                           IS_ZERO                               
---------- ------------------------------ ----------                            
        97 JAVA CLASS                     Zero                                  
         2 JAVA RESOURCE                  Zero                                  
      2022 New Year                       Zero                                  

SQL> 
SQL> ALTER TABLE test_default
  2  	ADD millenium_first_day DATE DEFAULT DATE '2001-01-01';

Table altered.

SQL> 
SQL> SELECT * FROM test_default;

         N NAME                           IS_ZERO    MILLENIUM_FIRST_DA         
---------- ------------------------------ ---------- ------------------         
        97 JAVA CLASS                     Zero       01-JAN-01                  
         2 JAVA RESOURCE                  Zero       01-JAN-01                  
      2022 New Year                       Zero       01-JAN-01                  

PARSING IN CURSOR #1 len=71 dep=0 uid=66 oct=15 lid=66 tim=128234272 hv=1557695795 ad='69e0705c'
ALTER TABLE test_default
   ADD is_zero VARCHAR2(9 CHAR) DEFAULT 'Zero'
END OF STMT
PARSE #1:c=0,e=181,p=0,cr=0,cu=0,mis=1,r=0,dep=0,og=4,tim=128234267
BINDS #1:
...
=====================
PARSING IN CURSOR #6 len=42 dep=1 uid=66 oct=6 lid=66 tim=128263701 hv=146661771 ad='69e050c0'
update "TEST_DEFAULT" set "IS_ZERO"='Zero'
END OF STMT
PARSE #6:c=0,e=3191,p=0,cr=1,cu=0,mis=1,r=0,dep=1,og=4,tim=128263696
BINDS #6:
EXEC #6:c=0,e=75,p=0,cr=3,cu=4,mis=0,r=2,dep=1,og=4,tim=128263814
STAT #6 id=1 cnt=0 pid=0 pos=1 obj=0 op='UPDATE  '
STAT #6 id=2 cnt=2 pid=1 pos=1 obj=33217 op='TABLE ACCESS FULL TEST_DEFAULT '