aboutdb_lost_write_protect

SQL> create table lost_write(t1 int) tablespace users; 
Table created.
SQL> 
SQL> insert into lost_write values(1);
1 row created.
SQL> commit;
Commit complete.
SQL> alter system checkpoint;
System altered.
select dbms_rowid.rowid_block_number(rowid),dbms_rowid.rowid_relative_fno(rowid) from lost_write;
DBMS_ROWID.ROWID_BLOCK_NUMBER(ROWID) DBMS_ROWID.ROWID_RELATIVE_FNO(ROWID)
------------------------------------ ------------------------------------
 222 6
	alter system set db_lost_write_protect=typical;
SQL> select name from v$datafile where file#=6;
NAME
--------------------------------------------------------------------------------
/s01/oradata/PDPROD/datafile/o1_mf_users_b2wgb20l_.dbf
update lost_write set t1=9999;
alter system flush buffer_cache;
dd if=/s01/oradata/PDPROD/datafile/o1_mf_users_b2wgb20l_.dbf skip=222 bs=8192 count=1 of=222_block
dd if=222_block of=/s01/oradata/PDPROD/datafile/o1_mf_users_b2wgb20l_.dbf seek=222 bs=8192 count=1 conv=notrunc