Ask about review indexes !

Hi all,

  My db is 9.2.0.4 64 bit on Unix.

  I used bellow script to view some detail informations of indexes:

select * from dba_indexeswhere owner='ACEVNPRD2'....

  From results returned, I can see two columns: NUM_ROWS and DISTINCT_KEYS and I want ask that, I can use them to review indexes on some columns are good or not.

  If ratio = DISTINCT_KEYS / NUM_ROWS =1 (or near equal 1) ==> Index is good , am I right ?

  Ex:  NUM_ROWS and DISTINCT_KEYS have value is 13737004 ==> ratio = 1 , so this index is good.

   NUM_ROWS=13737004 and DISTINCT_KEYS=10000==> ratio =0.00073  , so this index is bad.