ORA-01578

ORA-01578: ORACLE data block corrupted (file # 8, block # 2020) ORA-01110

First find out database object is in that corrupt block. Use the following query:

SELECT owner,segment_name,segment_type 
FROM dba_extents
WHERE file_id=6 and 1856 BETWEEN block_id AND block_id+blocks;

There are two methods that you can use to recover !

   You define block is corrupted belong to which object by script:

        select 

        a.owner, 

        a.segment_name, 

        a.segment_type, 

        b.tablespace_name

     from 

        dba_extents a, 

        dba_data_files b

     where 

        a.file_id = b. file_id

        and b.relative_fno = 8     

        and 

        2020 between a.block_id AND a.block_id + a.blocks - 1;

   1. You have a backup of database ? 

    You use bellow commands to view errors and suggestion that oracle provide:

    RMAN> LIST FAILURE;         ---> Show all of errors

    RMAN> ADVISE FAILURE;   ---> Show advices that Oracle gave.

    RMAN> REPAIR FAILURE PREVIEW;   ---> View content of script that Oracle gave to recover block is corrupted.

    RMAN> REPAIR FAILURE NOPROMPT;   ---> Run script that Oracle gave.

   You can run script:

   run{

          allocate channel rman_bk_ch01 type disk format '...';     --> Location that contains your backups

          blockrecover corruption list;

   };

   or

   run{

          allocate channel rman_bk_ch01 type disk format '...';          

          blockrecover datafile 8 block 2020;

          release channel rman_bk_ch01;

   };

   2. You can use DBMS_REPAIR to repair block that correupted.