/*
 * I have found how identify index fragmentation, you have to call 
 *  ANALYZE INDEX VALIDATE STRUCTURE sql-statement, after that look in INDEX_STATS view 
 *  where is last analyze cmd report
 *   
 * Fragmentation is ratio del_lf_rows/lf_rows (in attachment)
 * http://dbataj.blogspot.com/2007/11/index-fragmentation-rebuild.html
 * http://download.oracle.com/docs/cd/B19306_01/server.102/b14237/statviews_4216.htm#sthref2013|
*/

set linesize 400
set pages 999
set heading off
set linesize 120
set feedback off

col owner for a20
col name for a40

spool analyze.sql
SELECT 
' ANALYZE INDEX '|| owner || '.' || index_name || ' VALIDATE STRUCTURE;' ||chr(10)||
' SELECT '''||owner||''' owner, name, ' || CHR(10) ||
' TRUNC(100*(del_lf_rows/(CASE WHEN lf_rows=0 THEN -1 ELSE lf_rows END)),2) fragment_pct ' || CHR(10) ||
' from index_stats;'
from dba_indexes
where owner IN ('MY_SCHEMA')
order by owner, index_name;