How to find candidate indexes to rebuild?

set linesize 300
set serveroutput on size 100000
set feedback off
set timing on
set term off
set head off

spool rebuild.log

begin
dbms_output.enable('9999999');
for rIndex in (select s.owner,s.segment_name,sum(s.bytes/1024/1024)
from dba_segments s , dba_indexes i
where s.segment_type = 'INDEX'
and s.segment_name = i.index_name
and s.owner = i.owner
and i.index_type = 'NORMAL'
and s.owner not in ('SYS','SYSTEM','SYSMAN','SYSAUX','APPLSYS')
group by s.owner,s.segment_name
having sum(bytes/1024/1024) > 100) loop
execute immediate 'analyze index '||rIndex.owner||'.'||rIndex.segment_name||' validate structure';
end loop;
dbms_output.put_line('--- Reorganizando os indices ---');
for rRebuild in(SELECT name, height, lf_rows, owner
FROM INDEX_STATS st, dba_indexes di
where st.name = di.index_name) loop
execute immediate 'alter index '||rRebuild.owner||'.'||rRebuild.name||' rebuild online';
end loop;
end;
/
spool off