select * from v$database_block_corruption;

FILE#              BLOCK#             BLOCKS                           CORRUPTION_CHANGE#             CORRUPTIO       CON_ID
-------------------------------------- -------------------------------------- --------------------------------------------------- 
84                    	49422       	1                               	0                            ALL ZERO  	0
84	                49203  	        1                                	0                            ALL ZERO  	0
87	                1012613	        7                               	0                            ALL ZERO  	0
87	                1012726	        1                               	0                            ALL ZERO  	0
87	                1012669	        1                               	0                            ALL ZERO  	0
84	                49196  	        1                                	0                            FRACTURED	0
84	                49198  	        1                                 	0                            ALL ZERO  	0
84	                49200  	        2                                 	0                            ALL ZERO  	0
84	                49420  	        1                                	0                            FRACTURED	0

1. list failure;
2. advise failure;
3. blockrecover datafile ... block ...

select * from v$database_block_corruption;

set lines 200 pages 10000
col segment_name format a30

SELECT e.owner, e.segment_type, e.segment_name, e.partition_name, c.file#
, greatest(e.block_id, c.block#) corr_start_block#
, least(e.block_id+e.blocks-1, c.block#+c.blocks-1) corr_end_block#
, least(e.block_id+e.blocks-1, c.block#+c.blocks-1)
- greatest(e.block_id, c.block#) + 1 blocks_corrupted
, null description
FROM dba_extents e, v$database_block_corruption c
WHERE e.file_id = c.file#
AND e.block_id <= c.block# + c.blocks - 1
AND e.block_id + e.blocks - 1 >= c.block#
UNION
SELECT s.owner, s.segment_type, s.segment_name, s.partition_name, c.file#
, header_block corr_start_block#
, header_block corr_end_block#
, 1 blocks_corrupted
, 'Segment Header' description
FROM dba_segments s, v$database_block_corruption c
WHERE s.header_file = c.file#
AND s.header_block between c.block# and c.block# + c.blocks - 1
UNION
SELECT null owner, null segment_type, null segment_name, null partition_name, c.file#
, greatest(f.block_id, c.block#) corr_start_block#
, least(f.block_id+f.blocks-1, c.block#+c.blocks-1) corr_end_block#
, least(f.block_id+f.blocks-1, c.block#+c.blocks-1)
- greatest(f.block_id, c.block#) + 1 blocks_corrupted
, 'Free Block' description
FROM dba_free_space f, v$database_block_corruption c
WHERE f.file_id = c.file#
AND f.block_id <= c.block# + c.blocks - 1
AND f.block_id + f.blocks - 1 >= c.block#
ORDER BY file#, corr_start_block#;

SELECT * 
          FROM dba_lobs 
         WHERE owner='IBS'
           AND segment_name='SYS_LOB0000225532C00005$$';

set serverout on
		exec dbms_output.enable(100000);
		declare
		 error_1578 exception;
		 pragma exception_init(error_1578,-1578);
		 n number;
		 cnt number:=0;
		 badcnt number:=0;
		begin
		  for cursor_lob in
		        (select rowid r, [color=red]MY_COLUMN [/color]L from [color=red]MY_TABLE[/color])
		  loop
		    begin
		      n:=dbms_lob.instr(cursor_lob.L,hextoraw('AA25889911'),1,999999) ;
		    exception
		     when error_1578 then
		       dbms_output.put_line('Got ORA-1578 reading LOB at '||cursor_lob.R);
		       badcnt:=badcnt+1;
		    end;
		    cnt:=cnt+1;

		  end loop;
		  dbms_output.put_line('Scanned '||cnt||' rows - saw '||badcnt||' errors');
		end;
		/

dbms_lob.instr(cursor_lob.L,hextoraw('AA25889911'),1,999999) ;