Dumping Oracle data block

Getting Absolute File number and Block number of a rowid

select rowid,

       dbms_rowid.rowid_to_absolute_fno(rowid, 'MURTY', 'T1') "File no" ,

       dbms_rowid.rowid_block_number(rowid) "Block no"

from t1;

ROWID              File no      Block no

------------------ ---------- ----------

AAADaGAAEAAAACEAAA          4        132

Getting header block of a segment

select header_file, header_block

from   dba_segments

where  owner='MURTY'

and    segment_name = 'T1';

HEADER_FILE HEADER_BLOCK

----------- ------------

          4          130

Dumping a single block

alter system dump datafile 4 block 132;

Finding an extent start and end

select file_id, block_id, blocks

from   dba_extents

where  owner = 'MURTY'

and    segment_name = 'T1';

   FILE_ID   BLOCK_ID     BLOCKS

---------- ---------- ----------

         4        128          8

Dumping more than one block

alter system dump datafile 4 block min 128 block max 135;